1
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Xue S, Fernández A, Carrasco M. Featural Representation and Internal Noise Underlie the Eccentricity Effect in Contrast Sensitivity. J Neurosci 2024; 44:e0743232023. [PMID: 38050093 PMCID: PMC10860475 DOI: 10.1523/jneurosci.0743-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 12/06/2023] Open
Abstract
Human visual performance for basic visual dimensions (e.g., contrast sensitivity and acuity) peaks at the fovea and decreases with eccentricity. The eccentricity effect is related to the larger visual cortical surface area corresponding to the fovea, but it is unknown if differential feature tuning contributes to this eccentricity effect. Here, we investigated two system-level computations underlying the eccentricity effect: featural representation (tuning) and internal noise. Observers (both sexes) detected a Gabor embedded in filtered white noise which appeared at the fovea or one of four perifoveal locations. We used psychophysical reverse correlation to estimate the weights assigned by the visual system to a range of orientations and spatial frequencies (SFs) in noisy stimuli, which are conventionally interpreted as perceptual sensitivity to the corresponding features. We found higher sensitivity to task-relevant orientations and SFs at the fovea than that at the perifovea, and no difference in selectivity for either orientation or SF. Concurrently, we measured response consistency using a double-pass method, which allowed us to infer the level of internal noise by implementing a noisy observer model. We found lower internal noise at the fovea than that at the perifovea. Finally, individual variability in contrast sensitivity correlated with sensitivity to and selectivity for task-relevant features as well as with internal noise. Moreover, the behavioral eccentricity effect mainly reflects the foveal advantage in orientation sensitivity compared with other computations. These findings suggest that the eccentricity effect stems from a better representation of task-relevant features and lower internal noise at the fovea than that at the perifovea.
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Affiliation(s)
- Shutian Xue
- Department of Psychology, NewYork University, New York, New York 10003
| | - Antonio Fernández
- Department of Psychology, NewYork University, New York, New York 10003
| | - Marisa Carrasco
- Department of Psychology, NewYork University, New York, New York 10003
- Center for Neural Science, NewYork University, New York, New York 10003
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2
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Xue S, Fernández A, Carrasco M. Featural representation and internal noise underlie the eccentricity effect in contrast sensitivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.04.535413. [PMID: 37293084 PMCID: PMC10245727 DOI: 10.1101/2023.04.04.535413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Human visual performance for basic visual dimensions (e.g., contrast sensitivity and acuity) peaks at the fovea and decreases with eccentricity. The eccentricity effect is related to the larger surface area of the visual cortex corresponding to the fovea, but it is unknown if differential feature tuning contributes to this eccentricity effect. Here, we investigated two system-level computations underlying the eccentricity effect: featural representation (tuning) and internal noise. Observers (both sexes) detected a Gabor embedded in filtered white noise which appeared at the fovea or one of four perifoveal locations. We used psychophysical reverse correlation to estimate the weights assigned by the visual system to a range of orientations and spatial frequencies (SFs) in noisy stimuli, which are conventionally interpreted as perceptual sensitivity to the corresponding features. We found higher sensitivity to task-relevant orientations and SFs at the fovea than the perifovea, and no difference in selectivity for either orientation or SF. Concurrently, we measured response consistency using a double-pass method, which allowed us to infer the level of internal noise by implementing a noisy observer model. We found lower internal noise at the fovea than perifovea. Finally, individual variability in contrast sensitivity correlated with sensitivity to and selectivity for task-relevant features as well as with internal noise. Moreover, the behavioral eccentricity effect mainly reflects the foveal advantage in orientation sensitivity compared to other computations. These findings suggest that the eccentricity effect stems from a better representation of task-relevant features and lower internal noise at the fovea than at the perifovea.
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Affiliation(s)
- Shutian Xue
- Department of Psychology, New York University, New York, United States
| | - Antonio Fernández
- Department of Psychology, New York University, New York, United States
| | - Marisa Carrasco
- Department of Psychology, New York University, New York, United States
- Center for Neural Science, New York University, New York, United States
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3
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Investigation the role of contrast on habituation and sensitisation effects in peripheral areas of graphical user interfaces. Sci Rep 2022; 12:15281. [PMID: 36088380 PMCID: PMC9464255 DOI: 10.1038/s41598-022-16284-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 07/07/2022] [Indexed: 11/14/2022] Open
Abstract
Graphical user interfaces are designed so that the most important elements are usually located in the central part of the screen, where they catch the user’s attention. However, there are situations where it is necessary to attract the user’s attention to make him/her notice, e.g., a critical alert, which is customarily displayed in the peripheral area so as not to interact with the main content. Therefore, our focus is to deliver an increased visibility of content in the peripheral area of the display in a non-intrusive way. Thus, the main purpose of this work is to analyze the visibility of the stimulus (in the form of colored discs), displayed in the peripheral area of a screen, which distracts users from the central part of the interface. The habituation and sensitization effects were considered to study which parameters catch and hold the user’s attention, despite the length of their interaction with the system. The experiments performed indicated how the parameters should be set to reduce the habituation effect without the need to use content with the highest visual intensity. The results showed that a high visual intensity is not necessarily needed for the best impact. A medium contrast level, a horizontal or vertical display localization, and a flashing frequency of 2 Hz are sufficient to obtain the best visibility in the peripheral area. In the case of critical alerts and the need for short-term intensive stimuli, it is worth highlighting these with high contrast. This configuration should be the most effective if it is not a continuous operation. However, they can cause unnecessary irritation or even cognitive load for more extended usage.
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4
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Bozorgian A, Pedersen M, Thomas JB. Modification and evaluation of the peripheral contrast sensitivity function models. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2022; 39:1650-1658. [PMID: 36215633 DOI: 10.1364/josaa.445234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 07/27/2022] [Indexed: 06/16/2023]
Abstract
We propose a series of modifications to the Barten contrast sensitivity function model for peripheral vision based on anatomical and psychophysical studies. These modifications result in a luminance pattern detection model that could quantitatively describe the extent of veridical pattern resolution and the aliasing zone. We evaluated our model against psychophysical measurements in peripheral vision. Our numerical assessment shows that the modified Barten leads to lower estimate errors than its original version.
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5
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van Heusden E, Donk M, Olivers CNL. The dynamics of saliency-driven and goal-driven visual selection as a function of eccentricity. J Vis 2021; 21:2. [PMID: 33651878 PMCID: PMC7937996 DOI: 10.1167/jov.21.3.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 01/08/2021] [Indexed: 11/24/2022] Open
Abstract
Both saliency and goal information are important factors in driving visual selection. Saliency-driven selection occurs primarily in early responses, whereas goal-driven selection happens predominantly in later responses. Here, we investigated how eccentricity affects the time courses of saliency-driven and goal-driven visual selection. In three experiments, we asked people to make a speeded eye movement toward a predefined target singleton which was simultaneously presented with a non-target singleton in a background of multiple homogeneously oriented other items. The target singleton could be either more or less salient than the non-target singleton. Both singletons were presented at one of three eccentricities (i.e., near, middle, or far). The results showed that, even though eccentricity had only little effect on overall selection performance, the underlying time courses of saliency-driven and goal-driven selection altered such that saliency effects became protracted and relevance effects became delayed for far eccentricity conditions. The protracted saliency effect was shown to be modulated by expectations as induced by the preceding trial. The results demonstrate the importance of incorporating both time and eccentricity as factors in models of visual selection.
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Affiliation(s)
- Elle van Heusden
- Department of Experimental and Applied Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Mieke Donk
- Department of Experimental and Applied Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Christian N L Olivers
- Department of Experimental and Applied Psychology, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
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6
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Jigo M, Carrasco M. Differential impact of exogenous and endogenous attention on the contrast sensitivity function across eccentricity. J Vis 2020; 20:11. [PMID: 32543651 PMCID: PMC7416906 DOI: 10.1167/jov.20.6.11] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Both exogenous and endogenous covert spatial attention enhance contrast sensitivity, a fundamental measure of visual function that depends substantially on the spatial frequency and eccentricity of a stimulus. Whether and how each type of attention systematically improves contrast sensitivity across spatial frequency and eccentricity are fundamental to our understanding of visual perception. Previous studies have assessed the effects of spatial attention at individual spatial frequencies and, separately, at different eccentricities, but this is the first study to do so parametrically with the same task and observers. Using an orientation discrimination task, we investigated the effect of attention on contrast sensitivity over a wide range of spatial frequencies and eccentricities. Targets were presented alone or among distractors to assess signal enhancement and distractor suppression mechanisms of spatial attention. At each eccentricity, we found that exogenous attention preferentially enhanced spatial frequencies higher than the peak frequency in the baseline condition. In contrast, endogenous attention similarly enhanced a broad range of lower and higher spatial frequencies. The presence or absence of distractors did not alter the pattern of enhancement by each type of attention. Our findings reveal how the two types of covert spatial attention differentially shape how we perceive basic visual dimensions across the visual field.
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7
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Flexible parafoveal encoding of character order supports word predictability effects in Chinese reading: Evidence from eye movements. Atten Percept Psychophys 2020; 82:2793-2801. [PMID: 32406003 DOI: 10.3758/s13414-020-02050-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Several eye-movement studies have revealed flexibility in the parafoveal processing of character-order information in Chinese reading. In particular, studies show that processing a two-character word in a sentence benefits more from parafoveal preview of a nonword created by transposing rather than replacing its two characters. One issue that has not been investigated is whether the contextual predictability of the target word influences this processing of character order information. However, such a finding would provide novel evidence for an early influence of context on lexical processing in Chinese reading. Accordingly, we investigated this issue in an eye-movement experiment using the boundary paradigm and sentences containing two-character target words with high or low contextual predictability. Prior to the reader's gaze crossing an invisible boundary, each target word was shown normally (i.e. a valid preview) or with its two characters either transposed or replaced by unrelated characters to create invalid nonword previews. These invalid previews reverted to the target word once the reader's gaze crossed the invisible boundary. The results showed larger preview benefits (i.e. a decrease in fixation times) for target words following transposed-character than substituted-character previews, revealing a transposed-character effect similar to that in previous research. In addition, a word predictability effect (shorter fixation times for words with high than low predictability) was observed following both valid and transposed-character previews, but not substituted-character previews. The findings therefore reveal that context can influence an early stage of lexical processing in Chinese reading during which character order is processed flexibly.
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8
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Himmelberg MM, Winawer J, Carrasco M. Stimulus-dependent contrast sensitivity asymmetries around the visual field. J Vis 2020; 20:18. [PMID: 32986805 PMCID: PMC7533736 DOI: 10.1167/jov.20.9.18] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022] Open
Abstract
Asymmetries in visual performance at isoeccentric locations are well-documented and functionally important. At a fixed eccentricity, visual performance is best along the horizontal, intermediate along the lower vertical, and poorest along the upper vertical meridian. These performance fields are pervasive across a range of visual tasks, including those mediated by contrast sensitivity. However, contrast performance fields have not been characterized with a systematic manipulation of stimulus spatial frequency, eccentricity, and size; three parameters that constrain contrast sensitivity. Further, individual differences in performance fields measurements have not been assessed. Here, we use an orientation discrimination task to characterize the pattern of contrast sensitivity across four isoeccentric locations along the cardinal meridians, and to examine whether and how this asymmetry pattern changes with systematic manipulation of stimulus spatial frequency (4 cpd to 8 cpd), eccentricity (4.5 degrees to 9 degrees), and size (3 degrees visual angle to 6 degrees visual angle). Our data demonstrate that contrast sensitivity is highest along the horizontal, intermediate along the lower vertical, and poorest along the upper vertical meridian. This pattern is consistent across stimulus parameter manipulations, even though they cause profound shifts in contrast sensitivity. Eccentricity-dependent decreases in contrast sensitivity can be compensated for by scaling stimulus size alone. Moreover, we find that individual variability in the strength of performance field asymmetries is consistent across conditions. This study is the first to systematically and jointly manipulate, and compare, contrast performance fields across spatial frequency, eccentricity, and size, and to address individual variability in performance fields.
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Affiliation(s)
| | - Jonathan Winawer
- Department of Psychology, New York University, New York, NY, USA
- Center for Neural Science, New York University, New York, NY, USA
| | - Marisa Carrasco
- Department of Psychology, New York University, New York, NY, USA
- Center for Neural Science, New York University, New York, NY, USA
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9
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Feng Y, Wu Q, Yang J, Takahashi S, Ejima Y, Wu J, Zhang M. Eccentricity Effect of Deformation Detection for Radial Frequency Patterns With Their Centers at Fixation Point. Perception 2020; 49:858-881. [DOI: 10.1177/0301006620936473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We measured the eccentricity effect of deformation thresholds of circular contours for two types of the radial frequency (RF) patterns with their centers at the fixation point: constant circular contour frequency (CCF) RF patterns and constant RF magnified (retino-cortical scaling) RF patterns. We varied the eccentricity by changing the mean radius of the RF patterns while keeping the centers of the RF patterns at the fixation point. Our peripheral stimulus presentation was distinguished from previous studies which have simply translated RF patterns at different locations in the visual field. Sensitivity for such shape discrimination fell off as the moderate and high CCF patterns were presented on more eccentric sites but did not as the low CCF patterns. However, sensitivity held constant as the magnified RF patterns were presented on more eccentric sites, indicating that the eccentricity effects observed for the high and moderate CCF patterns were neutralized by retinocortical mapping. Notably, sensitivity for the magnified RF patterns with large radii (4°–16°) presented in the peripheral field revealed a similar RF dependence observed for RF patterns with small radii (0.25°–1.0°) presented at the fovea in previous studies.
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Affiliation(s)
- Yang Feng
- Biomedical Engineering Laboratory, Graduate School of Natural Science and Technology, Okayama University, Japan
| | - Qiong Wu
- Department of Psychology, Suzhou University of Science and Technology, China; Cognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan
| | | | | | - Yoshimichi Ejima
- Cognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan
| | - Jinglong Wu
- Key Laboratory of Biomimetic Robots and System, Ministry of Education, State Key Laboratory of Intelligent Control and Decision of Complex Systems, Beijing Institute of Technology, China; Cognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan
| | - Ming Zhang
- Department of Psychology, Suzhou University of Science and Technology, China; Cognitive Neuroscience Laboratory, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan; Department of Psychology, Soochow University, China
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10
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Cajar A, Engbert R, Laubrock J. How spatial frequencies and color drive object search in real-world scenes: A new eye-movement corpus. J Vis 2020; 20:8. [PMID: 38755794 PMCID: PMC7424126 DOI: 10.1167/jov.20.7.8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 03/29/2020] [Indexed: 11/24/2022] Open
Abstract
When studying how people search for objects in scenes, the inhomogeneity of the visual field is often ignored. Due to physiological limitations, peripheral vision is blurred and mainly uses coarse-grained information (i.e., low spatial frequencies) for selecting saccade targets, whereas high-acuity central vision uses fine-grained information (i.e., high spatial frequencies) for analysis of details. Here we investigated how spatial frequencies and color affect object search in real-world scenes. Using gaze-contingent filters, we attenuated high or low frequencies in central or peripheral vision while viewers searched color or grayscale scenes. Results showed that peripheral filters and central high-pass filters hardly affected search accuracy, whereas accuracy dropped drastically with central low-pass filters. Peripheral filtering increased the time to localize the target by decreasing saccade amplitudes and increasing number and duration of fixations. The use of coarse-grained information in the periphery was limited to color scenes. Central filtering increased the time to verify target identity instead, especially with low-pass filters. We conclude that peripheral vision is critical for object localization and central vision is critical for object identification. Visual guidance during peripheral object localization is dominated by low-frequency color information, whereas high-frequency information, relatively independent of color, is most important for object identification in central vision.
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Affiliation(s)
| | | | - Jochen Laubrock
- University of Potsdam, Potsdam, Germany
- Medizinische Hochschule Brandenburg Theodor Fontane, Neuruppin, Germany
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11
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Wolf C, Wagner I, Schütz AC. Competition between salience and informational value for saccade adaptation. J Vis 2020; 19:26. [PMID: 31880782 DOI: 10.1167/19.14.26] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
What we see is influenced by where we look. When confronted with multiple relevant targets, inaccurate saccade target selection can impair perceptual performance. Here we ask whether endpoint selection can be optimized by the mechanism maintaining saccade accuracy: saccade adaptation. Therefore, we introduce a double-target adaptation task, where a presaccadic peripheral stimulus (plaid) splits vertically into its two components (Gabor patches) during horizontal saccades. While both targets were task-relevant, one of them provided more information for the perceptual task, because it could only be identified after the saccade with near-foveal vision. The other target was highly salient and could also be identified in the presaccadic plaid using peripheral vision. This double-target paradigm induced saccade adaptation: Without a perceptual task, participants adapted to the salient target. When both targets were judged sequentially, participants mostly adapted to the target they had to judge first. When targets were judged simultaneously, endpoints were biased toward the informative target but showed no gradual learning and fell short of optimality. We observed gradual adaptation when targets shifted randomly such that a strategic adjustment of endpoints was not possible. Overall, these findings show that when multiple targets compete, our oculomotor system can learn to adjust endpoints in order to maximize information for perception. Yet individual variability and other factors affecting target priority play a crucial role.
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Affiliation(s)
- Christian Wolf
- AG Allgemeine und Biologische Psychologie, Philipps-Universität Marburg, Marburg, Germany.,Allgemeine Psychologie, Westfälische Wilhelms-Universität, Münster, Germany
| | - Ilja Wagner
- AG Allgemeine und Biologische Psychologie, Philipps-Universität Marburg, Marburg, Germany
| | - Alexander C Schütz
- AG Allgemeine und Biologische Psychologie, Philipps-Universität Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior, Marburg, Germany
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12
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Pamir Z, Canoluk MU, Jung JH, Peli E. Poor resolution at the back of the tongue is the bottleneck for spatial pattern recognition. Sci Rep 2020; 10:2435. [PMID: 32051455 PMCID: PMC7015888 DOI: 10.1038/s41598-020-59102-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 01/24/2020] [Indexed: 11/09/2022] Open
Abstract
Spatial patterns presented on the tongue using electro-tactile sensory substitution devices (SSDs) have been suggested to be recognized better by tracing the pattern with the tip of the tongue. We examined if the functional benefit of tracing is overcoming the poor sensitivity or low spatial resolution at the back of the tongue or alternatively compensating for limited information processing capacity by fixating on a segment of the spatial pattern at a time. Using a commercially available SSD, the BrainPort, we compared letter recognition performance in three presentation modes; tracing, static, and drawing. Stimulation intensity was either constant or increased from the tip to the back of the tongue to partially compensate for the decreasing sensitivity. Recognition was significantly better for tracing, compared to static and drawing conditions. Confusion analyses showed that letters were confused based on their characteristics presented near the tip in static and drawing conditions. The results suggest that recognition performance is limited by the poor spatial resolution at the back of the tongue, and tracing seems to be an effective strategy to overcome this. Compensating for limited information processing capacity or poor sensitivity by drawing or increasing intensity at the back, respectively, does not improve the performance.
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Affiliation(s)
- Zahide Pamir
- The Schepens Eye Research Institute of Mass. Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
| | - M Umut Canoluk
- The Schepens Eye Research Institute of Mass. Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Jae-Hyun Jung
- The Schepens Eye Research Institute of Mass. Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Eli Peli
- The Schepens Eye Research Institute of Mass. Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
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13
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Xie F, McGowan VA, Chang M, Li L, White SJ, Paterson KB, Wang J, Warrington KL. Revealing similarities in the perceptual span of young and older Chinese readers. Q J Exp Psychol (Hove) 2020; 73:1189-1205. [PMID: 31931668 DOI: 10.1177/1747021819899826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Older readers (aged 65+ years) of both alphabetic languages and character-based languages like Chinese read more slowly than their younger counterparts (aged 18-30 years). A possible explanation for this slowdown is that, due to age-related visual and cognitive declines, older readers have a smaller perceptual span and so acquire less information on each fixational pause. However, although aging effects on the perceptual span have been investigated for alphabetic languages, no such studies have been reported to date for character-based languages like Chinese. Accordingly, we investigated this issue in three experiments that used different gaze-contingent moving window paradigms to assess the perceptual span of young and older Chinese readers. In these experiments, text was shown either entirely as normal or normal only within a narrow region (window) comprising either the fixated word, the fixated word, and one word to its left, or the fixated word and either one or two words to its right. Characters outside these windows were replaced using a pattern mask (Experiment 1) or a visually similar character (Experiment 2), or blurred to render them unidentifiable (Experiment 3). Sentence reading times were overall longer for the older compared with the younger adults and differed systematically across display conditions. Crucially, however, the effects of display condition were essentially the same across the two age groups, indicating that the perceptual span for Chinese does not differ substantially for the older and young adults. We discuss these findings in relation to other evidence suggesting the perceptual span is preserved in older adulthood.
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Affiliation(s)
- Fang Xie
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Victoria A McGowan
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Min Chang
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Lin Li
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Sarah J White
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Kevin B Paterson
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
| | - Jingxin Wang
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Kayleigh L Warrington
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester, UK
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14
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Paterson KB, McGowan VA, Warrington KL, Li L, Li S, Xie F, Chang M, Zhao S, Pagán A, White SJ, Wang J. Effects of Normative Aging on Eye Movements during Reading. Vision (Basel) 2020; 4:vision4010007. [PMID: 31947552 PMCID: PMC7157620 DOI: 10.3390/vision4010007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 11/16/2022] Open
Abstract
Substantial progress has been made in understanding the mostly detrimental effects of normative aging on eye movements during reading. This article provides a review of research on aging effects on eye movements during reading for different writing systems (i.e., alphabetic systems like English compared to non-alphabetic systems like Chinese), focused on appraising the importance of visual and cognitive factors, considering key methodological issues, and identifying vital questions that need to be addressed and topics for further investigation.
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Affiliation(s)
- Kevin B. Paterson
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK; (V.A.M.); (K.L.W.); (A.P.); (S.J.W.)
- Correspondence:
| | - Victoria A. McGowan
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK; (V.A.M.); (K.L.W.); (A.P.); (S.J.W.)
| | - Kayleigh L. Warrington
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK; (V.A.M.); (K.L.W.); (A.P.); (S.J.W.)
| | - Lin Li
- Faculty of Psychology, Tianjin Normal University, Tianjin 300387, China; (L.L.); (F.X.); (M.C.); (S.Z.); (J.W.)
| | - Sha Li
- School of Psychology, Fujian Normal University, Fuzhou 350117, China;
| | - Fang Xie
- Faculty of Psychology, Tianjin Normal University, Tianjin 300387, China; (L.L.); (F.X.); (M.C.); (S.Z.); (J.W.)
| | - Min Chang
- Faculty of Psychology, Tianjin Normal University, Tianjin 300387, China; (L.L.); (F.X.); (M.C.); (S.Z.); (J.W.)
| | - Sainan Zhao
- Faculty of Psychology, Tianjin Normal University, Tianjin 300387, China; (L.L.); (F.X.); (M.C.); (S.Z.); (J.W.)
| | - Ascensión Pagán
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK; (V.A.M.); (K.L.W.); (A.P.); (S.J.W.)
| | - Sarah J. White
- Department of Neuroscience, Psychology and Behaviour, University of Leicester, Leicester LE1 7RH, UK; (V.A.M.); (K.L.W.); (A.P.); (S.J.W.)
| | - Jingxin Wang
- Faculty of Psychology, Tianjin Normal University, Tianjin 300387, China; (L.L.); (F.X.); (M.C.); (S.Z.); (J.W.)
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15
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Abstract
Readers can acquire useful information from only a narrow region of text around each fixation (the perceptual span), which extends asymmetrically in the direction of reading. Studies with bilingual readers have additionally shown that this asymmetry reverses with changes in horizontal reading direction. However, little is known about the perceptual span’s flexibility following orthogonal (vertical vs. horizontal) changes in reading direction, because of the scarcity of vertical writing systems and because changes in reading direction often are confounded with text orientation. Accordingly, we assessed effects in a language (Mongolian) that avoids this confound, in which text is conventionally read vertically but can also be read horizontally. Sentences were presented normally or in a gaze-contingent paradigm in which a restricted region of text was displayed normally around each fixation and other text was degraded. The perceptual span effects on reading rates were similar in both reading directions. These findings therefore provide a unique (nonconfounded) demonstration of perceptual span flexibility.
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16
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Warrington KL, Xie F, Wang J, Paterson KB. Aging Effects on the Visual Span for Alphabetic Stimuli. Exp Aging Res 2019; 45:387-399. [PMID: 31518213 DOI: 10.1080/0361073x.2019.1664465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background: The visual span (i.e., an estimate of the number of letters that can be recognized reliably on a single glance) is widely considered to impose an important sensory limitation on reading speed. With the present research, we investigated adult age differences in the visual span for alphabetic stimuli (i.e., Latin alphabetic letters), as aging effects on span size may make an important contribution to slower reading speeds in older adulthood. Method: A trigram task, in which sets of three letters were displayed randomly at specified locations to the right and left of a central fixation point, was used to estimate the size of the visual span for young (18-30 years) and older (65+years) adults while an eye tracker was used to ensure accurate central fixation during stimulus presentation. Participants also completed tests of visual acuity and visual crowding. Results: There were clear age differences in the size of the visual span. The older adults produced visual spans which were on average 1.2 letters smaller than the spans of young adults. However, both young and older adults produced spans smaller than those previously reported. In addition, span size correlated with measures of both visual acuity and measures of visual crowding. Conclusion: The findings show that the size of the visual span is smaller for older compared to young adults. The age-related reduction in span size is relatively small but may make a significant contribution to reduced parafoveal processing during natural reading so may play a role in the greater difficulty experienced by older adult readers. Moreover, these results highlight the importance of carefully controlling fixation location in visual span experiments.
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Affiliation(s)
- Kayleigh L Warrington
- Department of Neuroscience, Psychology and Behaviour, University of Leicester , Leicester UK
| | - Fang Xie
- Academy of Psychology and Behavior, Tianjin Normal University , Tianjin , China
| | - Jingxin Wang
- Academy of Psychology and Behavior, Tianjin Normal University , Tianjin , China
| | - Kevin B Paterson
- Department of Neuroscience, Psychology and Behaviour, University of Leicester , Leicester UK
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17
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Plouffe-Demers MP, Fiset D, Saumure C, Duncan J, Blais C. Strategy Shift Toward Lower Spatial Frequencies in the Recognition of Dynamic Facial Expressions of Basic Emotions: When It Moves It Is Different. Front Psychol 2019; 10:1563. [PMID: 31379648 PMCID: PMC6650765 DOI: 10.3389/fpsyg.2019.01563] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 06/20/2019] [Indexed: 11/15/2022] Open
Abstract
Facial expressions of emotion play a key role in social interactions. While in everyday life, their dynamic and transient nature calls for a fast processing of the visual information they contain, a majority of studies investigating the visual processes underlying their recognition have focused on their static display. The present study aimed to gain a better understanding of these processes while using more ecological dynamic facial expressions. In two experiments, we directly compared the spatial frequency (SF) tuning during the recognition of static and dynamic facial expressions. Experiment 1 revealed a shift toward lower SFs for dynamic expressions in comparison to static ones. Experiment 2 was designed to verify if changes in SF tuning curves were specific to the presence of emotional information in motion by comparing the SF tuning profiles for static, dynamic, and shuffled dynamic expressions. Results showed a similar shift toward lower SFs for shuffled expressions, suggesting that the difference found between dynamic and static expressions might not be linked to informative motion per se but to the presence of motion regardless its nature.
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Affiliation(s)
- Marie-Pier Plouffe-Demers
- Département de Psychologie, Universtité du Québec en Outaouais, Gatineau, QC, Canada.,Département de Psychologie, Université du Québec à Montréal, Montreal, QC, Canada
| | - Daniel Fiset
- Département de Psychologie, Universtité du Québec en Outaouais, Gatineau, QC, Canada
| | - Camille Saumure
- Département de Psychologie, Universtité du Québec en Outaouais, Gatineau, QC, Canada
| | - Justin Duncan
- Département de Psychologie, Universtité du Québec en Outaouais, Gatineau, QC, Canada.,Département de Psychologie, Université du Québec à Montréal, Montreal, QC, Canada
| | - Caroline Blais
- Département de Psychologie, Universtité du Québec en Outaouais, Gatineau, QC, Canada
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18
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Valsecchi M, Koenderink J, van Doorn A, Gegenfurtner KR. Prediction shapes peripheral appearance. J Vis 2019; 18:21. [PMID: 30593064 DOI: 10.1167/18.13.21] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Peripheral perception is limited in terms of visual acuity, contrast sensitivity, and positional uncertainty. In the present study we used an image-manipulation algorithm (the Eidolon Factory) based on a formal description of the visual field as a tool to investigate how peripheral stimuli appear in the presence of such limitations. Observers were asked to match central and peripheral stimuli, both configurations of superimposed geometric shapes and patches of natural images, in terms of the parameters controlling the amplitude of the perturbation (reach) and the cross-scale similarity of the perturbation (coherence). We found that observers systematically tended to report the peripheral stimuli as having shorter reach and higher coherence. This means that their matches both were less distorted and had sharper edges relative to the actual stimulus. Overall, the results indicate that the way we see objects in our peripheral visual field is complemented by our assumptions about the way the same objects would appear if they were viewed foveally.
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Affiliation(s)
- Matteo Valsecchi
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Jan Koenderink
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany.,Experimental Psychology, KU Leuven, Leuven, Belgium.,Experimental Psychology, Utrecht University, Utrecht, the Netherlands
| | - Andrea van Doorn
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany.,Experimental Psychology, KU Leuven, Leuven, Belgium.,Experimental Psychology, Utrecht University, Utrecht, the Netherlands
| | - Karl R Gegenfurtner
- Abteilung Allgemeine Psychologie, Justus-Liebig-Universität Giessen, Giessen, Germany
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19
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Alberti CF, Bex PJ. Binocular contrast summation and inhibition depends on spatial frequency, eccentricity and binocular disparity. Ophthalmic Physiol Opt 2018; 38:525-537. [PMID: 30221370 PMCID: PMC6202146 DOI: 10.1111/opo.12581] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/10/2018] [Indexed: 11/30/2022]
Abstract
PURPOSE When central vision is compromised, visually-guided behaviour becomes dependent on peripheral retina, often at a preferred retinal locus (PRL). Previous studies have examined adaptation to central vision loss with monocular 2D paradigms, whereas in real tasks, patients make binocular eye movements to targets of various sizes and depth in 3D environments. METHODS We therefore examined monocular and binocular contrast sensitivity functions with a 26-AFC (alternate forced choice) band-pass filtered letter identification task at 2° or 6° eccentricity in observers with simulated central vision loss. Binocular stimuli were presented in corresponding or non-corresponding stereoscopic retinal locations. Gaze-contingent scotomas (0.5° radius disks of pink noise) were simulated independently in each eye with a 1000 Hz eye tracker and 120 Hz dichoptic shutter glasses. RESULTS Contrast sensitivity was higher for binocular than monocular conditions, but only exceeded probability summation at low-mid spatial frequencies in corresponding retinal locations. At high spatial frequencies or non-corresponding retinal locations, binocular contrast sensitivity showed evidence of interocular suppression. CONCLUSIONS These results suggest that binocular vision deficits may be underestimated by monocular vision tests and identify a method that can be used to select a PRL based on binocular contrast summation.
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Affiliation(s)
| | - Peter J Bex
- Department of Psychology, Northeastern University, Boston, USA
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20
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The impact of mobile phone use on where we look and how we walk when negotiating floor based obstacles. PLoS One 2017; 12:e0179802. [PMID: 28665942 PMCID: PMC5493336 DOI: 10.1371/journal.pone.0179802] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/05/2017] [Indexed: 11/20/2022] Open
Abstract
Pedestrians regularly engage with their mobile phone whilst walking. The current study investigated how mobile phone use affects where people look (visual search behaviour) and how they negotiate a floor based hazard placed along the walking path. Whilst wearing a mobile eye tracker and motion analysis sensors, participants walked up to and negotiated a surface height change whilst writing a text, reading a text, talking on the phone, or without a phone. Differences in gait and visual search behaviour were found when using a mobile phone compared to when not using a phone. Using a phone resulted in looking less frequently and for less time at the surface height change, which led to adaptations in gait by negotiating it in a manner consistent with adopting an increasingly cautious stepping strategy. When using a mobile phone, writing a text whilst walking resulted in the greatest adaptions in gait and visual search behaviour compared to reading a text and talking on a mobile phone. Findings indicate that mobile phone users were able to adapt their visual search behaviour and gait to incorporate mobile phone use in a safe manner when negotiating floor based obstacles.
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21
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Li L, Li S, Wang J, McGowan VA, Liu P, Jordan TR, Paterson KB. Aging and the optimal viewing position effect in visual word recognition: Evidence from English. Psychol Aging 2017; 32:367-376. [PMID: 28406653 PMCID: PMC5459221 DOI: 10.1037/pag0000163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Words are recognized most efficiently by young adults when fixated at an optimal viewing position (OVP), which for English is between a word’s beginning and middle letters. How this OVP effect changes with age is unknown but may differ for older adults due to visual declines in later life. Accordingly, a lexical decision experiment was conducted in which short (5-letter) and long (9-letter) words were fixated at various letter positions. The older adults produced slower responses. But, crucially, effects of fixation location for each word-length did not differ substantially across age groups, indicating that OVP effects are preserved in older age.
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Affiliation(s)
- Lin Li
- Academy of Psychology and Behavior, Tianjin Normal University
| | - Sha Li
- Academy of Psychology and Behavior, Tianjin Normal University
| | - Jingxin Wang
- Academy of Psychology and Behavior, Tianjin Normal University
| | - Victoria A McGowan
- Department of Neuroscience, Psychology and Behaviour, University of Leicester
| | - Pingping Liu
- Centre on Aging Psychology, Institute of Psychology, Chinese Academy of Sciences
| | - Timothy R Jordan
- Cognition and Neuroscience Research Laboratory, Department of Psychology, Zayed University Dubai
| | - Kevin B Paterson
- Department of Neuroscience, Psychology and Behaviour, University of Leicester
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22
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Quaia C, Optican LM, Cumming BG. Combining 1-D components to extract pattern information: It is about more than component similarity. J Vis 2017; 17:21. [PMID: 28355633 PMCID: PMC5373814 DOI: 10.1167/17.3.21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
At least under some conditions, plaid stimuli are processed by combining information first extracted in orientation and scale-selective channels. The rules that govern this combination across channels are only partially understood. Although the available data suggests that only components having similar spatial frequency and contrast are combined, the extent to which this holds has not been firmly established. To address this question, we measured, in human subjects, the short-latency reflexive vergence eye movements induced by stereo plaids in which spatial frequency and contrast of the components are independently varied. We found that, although similarity in component spatial frequency and contrast matter, they interact in a nonseparable way. One way in which this relationship might arise is if the internal estimate of contrast is not a faithful representation of stimulus contrast but is instead spatial frequency–dependent (with higher spatial frequencies being boosted). We propose that such weighting might have been put in place by a mechanism that, in an effort of achieve contrast constancy and/or coding efficiency, regulates the gain of detectors in early visual cortex to equalize their long-term average response to natural images.
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Affiliation(s)
- Christian Quaia
- Laboratory of Sensorimotor Research, National Eye Institute, NIH, DHHS, Bethesda, MD,
| | - Lance M Optican
- Laboratory of Sensorimotor Research, National Eye Institute, NIH, DHHS, Bethesda, MD,
| | - Bruce G Cumming
- Laboratory of Sensorimotor Research, National Eye Institute, NIH, DHHS, Bethesda, MD,
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23
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Rovamo J, Leinonen L, Laurinen P, Virsu V. Temporal Integration and Contrast Sensitivity in Foveal and Peripheral Vision. Perception 2016; 13:665-74. [PMID: 6543946 DOI: 10.1068/p130665] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Spatial contrast sensitivity functions and temporal integration functions for gratings with dark surrounds were measured at various eccentricities in photopic vision. Contrast sensitivity decreased with increasing eccentricity at all exposure durations and spatial frequencies tested. The decrease was faster at high than at low spatial frequencies, but similar at different exposure durations. When cortically similar stimulus conditions were produced at different eccentricities by M-scaling, contrast sensitivity became independent of visual field location at all exposure durations tested. The results support the view that in photopic vision spatiotemporal information processing is qualitatively similar across the visual field, and that quantitative differences result from retinotopical differences in ganglion cell sampling. For gratings of constant retinal area temporal integration (improvement of contrast sensitivity with increasing exposure duration) was more extensive at high than at low retinal spatial frequencies but independent of cortical spatial frequency and eccentricity. For M-scaled gratings temporal integration was more extensive at high than at low cortical spatial frequencies but independent of retinal spatial frequency and eccentricity. The results suggest that the primary determinant of temporal integration is not spatial frequency but grating value that is calculated as AF2 square cycles (cycle2), where A is grating area and F spatial frequency.
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24
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Abstract
The finding that word length plays a fundamental role in determining where and for how long readers fixate within a line of text has been central to the development of sophisticated models of eye movement control. However, research in this area is dominated by the use of Latinate languages (e.g., English, French, German), and little is known about eye movement control for alphabetic languages with very different visual characteristics. To address this issue, the present experiment undertook a novel investigation of the influence of word length on eye movement behavior when reading Arabic. Arabic is an alphabetic language that not only is read from right to left but has visual characteristics fundamentally different from Latinate languages, and so is ideally suited to testing the generality of mechanisms of eye movement control. The findings reveal that readers were more likely to fixate and refixate longer words, and also that longer words tended to be fixated for longer. In addition, word length influenced the landing positions of initial fixations on words, with the effect that readers fixated the center of short words and fixated closer to the beginning letters for longer words, and the location of landing positions affected both the duration of the first fixation and probability of refixating the word. The indication now, therefore, is that effects of word length are a widespread and fundamental component of reading and play a central role in guiding eye-movement behavior across a range of very different alphabetic systems.
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25
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Maiello G, Chessa M, Solari F, Bex PJ. Simulated disparity and peripheral blur interact during binocular fusion. J Vis 2014; 14:13. [PMID: 25034260 DOI: 10.1167/14.8.13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
We have developed a low-cost, practical gaze-contingent display in which natural images are presented to the observer with dioptric blur and stereoscopic disparity that are dependent on the three-dimensional structure of natural scenes. Our system simulates a distribution of retinal blur and depth similar to that experienced in real-world viewing conditions by emmetropic observers. We implemented the system using light-field photographs taken with a plenoptic camera which supports digital refocusing anywhere in the images. We coupled this capability with an eye-tracking system and stereoscopic rendering. With this display, we examine how the time course of binocular fusion depends on depth cues from blur and stereoscopic disparity in naturalistic images. Our results show that disparity and peripheral blur interact to modify eye-movement behavior and facilitate binocular fusion, and the greatest benefit was gained by observers who struggled most to achieve fusion. Even though plenoptic images do not replicate an individual’s aberrations, the results demonstrate that a naturalistic distribution of depth-dependent blur may improve 3-D virtual reality, and that interruptions of this pattern (e.g., with intraocular lenses) which flatten the distribution of retinal blur may adversely affect binocular fusion.
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Affiliation(s)
- Guido Maiello
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USADepartment of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, ItalyUCL Institute of Ophthalmology, University College London, London, UK
| | - Manuela Chessa
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, Italy
| | - Fabio Solari
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genoa, Genoa, Italy
| | - Peter J Bex
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
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26
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Wallis TSA, Taylor CP, Wallis J, Jackson ML, Bex PJ. Characterization of field loss based on microperimetry is predictive of face recognition difficulties. Invest Ophthalmol Vis Sci 2014; 55:142-53. [PMID: 24302589 DOI: 10.1167/iovs.13-12420] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine how visual field loss as assessed by microperimetry is correlated with deficits in face recognition. METHODS Twelve patients (age range, 26-70 years) with impaired visual sensitivity in the central visual field caused by a variety of pathologies and 12 normally sighted controls (control subject [CS] group; age range, 20-68 years) performed a face recognition task for blurred and unblurred faces. For patients, we assessed central visual field loss using microperimetry, fixation stability, Pelli-Robson contrast sensitivity, and letter acuity. RESULTS Patients were divided into two groups by microperimetry: a low vision (LV) group (n = 8) had impaired sensitivity at the anatomical fovea and/or poor fixation stability, whereas a low vision that excluded the fovea (LV:F) group (n = 4) was characterized by at least some residual foveal sensitivity but insensitivity in other retinal regions. The LV group performed worse than the other groups at all blur levels, whereas the performance of the LV:F group was not credibly different from that of the CS group. The performance of the CS and LV:F groups deteriorated as blur increased, whereas the LV group showed consistently poor performance regardless of blur. Visual acuity and fixation stability were correlated with face recognition performance. CONCLUSIONS Persons diagnosed as having disease affecting the central visual field can recognize faces as well as persons with no visual disease provided that they have residual sensitivity in the anatomical fovea and show stable fixation patterns. Performance in this task is limited by the upper resolution of nonfoveal vision or image blur, whichever is worse.
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Affiliation(s)
- Thomas S A Wallis
- Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts
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27
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28
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Dorr M, Lesmes LA, Lu ZL, Bex PJ. Rapid and reliable assessment of the contrast sensitivity function on an iPad. Invest Ophthalmol Vis Sci 2013; 54:7266-73. [PMID: 24114545 PMCID: PMC4589140 DOI: 10.1167/iovs.13-11743] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 09/17/2013] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Letter acuity, the predominant clinical assessment of vision, is relatively insensitive to slow vision loss caused by eye disease. While the contrast sensitivity function (CSF) has demonstrated the potential to monitor the slow progress of blinding eye diseases, current tests of CSF lack the reliability or ease-of-use to capture changes in vision timely. To improve the current state of home testing for vision, we have developed and validated a computerized adaptive test on a commercial tablet device (iPad) that provides an efficient and easy-to-use assessment of the CSF. METHODS We evaluated the reliability, accuracy, and flexibility of tablet-based CSF assessment. Repeated tablet-based assessments of the spatial CSF, obtained from four normally-sighted observers, which each took 3 to 5 minutes, were compared to measures obtained on CRT-based laboratory equipment; additional tablet-based measures were obtained from six subjects under three different luminance conditions. RESULTS A Bland-Altman analysis demonstrated that tablet-based assessment was reliable for estimating sensitivities at specific spatial frequencies (coefficient of repeatability 0.14-0.40 log units). The CRT- and tablet-based results demonstrated excellent agreement with absolute mean sensitivity differences <0.05 log units. The tablet-based test also reliably identified changes in contrast sensitivity due to different luminance conditions. CONCLUSIONS We demonstrate that CSF assessment on a mobile device is indistinguishable from that obtained with specialized laboratory equipment. We also demonstrate better reliability than tests used currently for clinical trials of ophthalmic therapies, drugs, and devices.
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Affiliation(s)
- Michael Dorr
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Adaptive Sensory Technology, Boston, Massachusetts
| | - Luis A. Lesmes
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Adaptive Sensory Technology, Boston, Massachusetts
| | - Zhong-Lin Lu
- Center for Cognitive and Behavioral Brain Imaging, Arts & Sciences, Department of Psychology, The Ohio State University, Columbus, Ohio
| | - Peter J. Bex
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
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29
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Clatworthy PL, Warburton EA, Tolhurst DJ, Baron JC. Visual contrast sensitivity deficits in 'normal' visual field of patients with homonymous visual field defects due to stroke: a pilot study. Cerebrovasc Dis 2013; 36:329-35. [PMID: 24193224 DOI: 10.1159/000354810] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/05/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Homonymous visual field defects (VFD) are common following stroke, and often recover, partially or fully, by unknown mechanisms. In clinical practice, visual field recovered on perimetry is often considered perceptually normal. However, studies have shown contrast sensitivity (CS) deficits in patients with stroke and homonymous VFD. This study investigated the origin of visual CS loss in patients with VFD due to stroke. We hypothesised that CS deficits would be found in visual field areas appearing normal on perimetry, in patients with ischaemic stroke affecting the retrochiasmal visual system, and that the spatiotemporal properties of this CS loss would be consistent with those of 'blindsight', perhaps suggesting similar underlying mechanisms. METHODS CS measurements were made in 20 healthy participants, and in 7 patients with stroke causing homonymous VFD sparing foveal vision, measured using Humphrey static perimetry (SITA-Fast 24-2 procedure). Importantly, patients with concomitant visuospatial neglect were excluded. CS measurements were made using a modification of the method of increasing contrast, corrected for reaction time. Three spatial stimuli were used, at several spatial frequencies: (1) large sinusoidal gratings; (2) foveal Gabor patches; and (3) Gabor patches presenting in the putatively recovered visual field, near VFD. Stimuli with different temporal profiles were used to selectively stimulate transient and sustained visual channels, to provide insight into mechanisms of visual loss and/or recovery. Analysis of variance (ANOVA) was used in the analysis of the measurements, allowing for correction for age and stimulus eccentricity. RESULTS ANOVA for sustained grating stimuli showed orientation-selective (horizontal) CS loss (p = 0.025); no such loss was apparent in the central visual field (foveal Gabor stimuli). Localised CS close to VFD was reduced in stroke-affected hemifields compared with unaffected hemifields (p ≤ 0.005), though these areas appeared normal on perimetry. In these areas, CS was relatively preserved for transient compared with sustained stimuli (Wilcoxon signed rank tests). CONCLUSIONS The finding of specific CS deficits in the normal-appearing visual field of patients with homonymous VFD due to stroke suggests that static perimetry provides an inadequate assessment of visual function in these patients, with clear implications for testing of vision in clinical practice. The results are consistent with relative sparing of the transient/magnocellular visual channel. These findings demand further investigation. If confirmed in larger, longitudinal studies, this will have important implications for the mechanisms of recovery, and may provide a target for visual rehabilitation - for example, using repeated detection practice ('perceptual learning').
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Affiliation(s)
- Philip L Clatworthy
- Stroke Research Group, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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30
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Tremblay EJ, Stamenov I, Beer RD, Arianpour A, Ford JE. Switchable telescopic contact lens. OPTICS EXPRESS 2013; 21:15980-15986. [PMID: 23842384 DOI: 10.1364/oe.21.015980] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We present design and first demonstration of optics for a telescopic contact lens with independent optical paths for switching between normal and magnified vision. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8 x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision. We present an experimental demonstration of the contact lens mounted on a life-sized optomechanical model eye and, using a pair of modified commercial 3D television glasses, demonstrate electrically operated polarization switching between normal and magnified vision.
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Affiliation(s)
- Eric J Tremblay
- Department of Electrical & Computer Engineering, UCSD, La Jolla, CA 92093, USA.
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31
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Boucart M, Moroni C, Thibaut M, Szaffarczyk S, Greene M. Scene categorization at large visual eccentricities. Vision Res 2013; 86:35-42. [PMID: 23597581 DOI: 10.1016/j.visres.2013.04.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 03/13/2013] [Accepted: 04/04/2013] [Indexed: 11/28/2022]
Abstract
Studies of scene perception have shown that the visual system is particularly sensitive to global properties such as the overall layout of a scene. Such global properties cannot be computed locally, but rather require relational analysis over multiple regions. To what extent is observers' perception of scenes impaired in the far periphery? We examined the perception of global scene properties (Experiment 1) and basic-level categories (Experiment 2) presented in the periphery from 10° to 70°. Pairs of scene photographs were simultaneously presented left and right of fixation for 80ms on a panoramic screen (5m diameter) covering the whole visual field while central fixation was controlled. Observers were instructed to press a key corresponding to the spatial location left/right of a pre-defined target property or category. The results show that classification of global scene properties (e.g., naturalness, openness) as well as basic-level categorization (e.g., forests, highways), while better near the center, were accomplished with a performance highly above chance (around 70% correct) in the far periphery even at 70° eccentricity. The perception of some global properties (e.g., naturalness) was more robust in peripheral vision than others (e.g., indoor/outdoor) that required a more local analysis. The results are consistent with studies suggesting that scene gist recognition can be accomplished by the low resolution of peripheral vision.
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Affiliation(s)
- Muriel Boucart
- Lab. Neurosciences Fonctionnelles & Pathologies, Université Lille-Nord de France, CHU Lille, CNRS, France.
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32
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Traschütz A, Zinke W, Wegener D. Speed change detection in foveal and peripheral vision. Vision Res 2012; 72:1-13. [DOI: 10.1016/j.visres.2012.08.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 08/06/2012] [Accepted: 08/31/2012] [Indexed: 10/27/2022]
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Jordan TR, Patching GR, Thomas SM. Assessing the Role of Hemispheric Specialisation, Serial-Position Processing, and Retinal Eccentricity in Lateralised Word RecognitioN. Cogn Neuropsychol 2012; 20:49-71. [PMID: 20957564 DOI: 10.1080/02643290244000185] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The advantage for words in the right visual hemifield (RVF) has been assigned parallel orthographic processing by the left hemisphere and sequential by the right. However, an examination of previous studies of serial position performance suggests that orthographic processing in each hemifield is modulated by retinal eccentricity. To investigate this issue, we presented words at eccentricities of 1, 2, 3, and 4 degrees. Serial position performance was measured using the Reicher-Wheeler task to suppress influences of guesswork and an eye-tracker controlled fixation location. Greater eccentricities produced lower overall levels of performance in each hemifield although RVF advantages for words obtained at each eccentricity (Experiments 1 and 2). However, performance in both hemifields revealed similar U-shaped serial position performance at all eccentricities. Moreover, this performance was not influenced by lexical constraint (high, low; Experiment 2) or status (word, nonword; Experiment 3), although only words (not nonwords) produced an RVF advantage. These findings suggest that although each RVF advantage was produced by left-hemisphere function, the same pattern of orthographic analysis was used by each hemisphere at each eccentricity.
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Relationship between BOLD amplitude and pattern classification of orientation-selective activity in the human visual cortex. Neuroimage 2012; 63:1212-22. [PMID: 22917989 DOI: 10.1016/j.neuroimage.2012.08.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 07/27/2012] [Accepted: 08/05/2012] [Indexed: 11/23/2022] Open
Abstract
Orientation-selective responses can be decoded from fMRI activity patterns in the human visual cortex, using multivariate pattern analysis (MVPA). To what extent do these feature-selective activity patterns depend on the strength and quality of the sensory input, and might the reliability of these activity patterns be predicted by the gross amplitude of the stimulus-driven BOLD response? Observers viewed oriented gratings that varied in luminance contrast (4, 20 or 100%) or spatial frequency (0.25, 1.0 or 4.0 cpd). As predicted, activity patterns in early visual areas led to better discrimination of orientations presented at high than low contrast, with greater effects of contrast found in area V1 than in V3. A second experiment revealed generally better decoding of orientations at low or moderate as compared to high spatial frequencies. Interestingly however, V1 exhibited a relative advantage at discriminating high spatial frequency orientations, consistent with the finer scale of representation in the primary visual cortex. In both experiments, the reliability of these orientation-selective activity patterns was well predicted by the average BOLD amplitude in each region of interest, as indicated by correlation analyses, as well as decoding applied to a simple model of voxel responses to simulated orientation columns. Moreover, individual differences in decoding accuracy could be predicted by the signal-to-noise ratio of an individual's BOLD response. Our results indicate that decoding accuracy can be well predicted by incorporating the amplitude of the BOLD response into simple simulation models of cortical selectivity; such models could prove useful in future applications of fMRI pattern classification.
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Poggel DA, Treutwein B, Calmanti C, Strasburger H. The Tölz Temporal Topography Study: mapping the visual field across the life span. Part I: the topography of light detection and temporal-information processing. Atten Percept Psychophys 2012; 74:1114-32. [PMID: 22484795 PMCID: PMC5486645 DOI: 10.3758/s13414-012-0278-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Temporal performance parameters vary across the visual field. Their topographical distributions relative to each other and relative to basic visual performance measures and their relative change over the life span are unknown. Our goal was to characterize the topography and age-related change of temporal performance. We acquired visual field maps in 95 healthy participants (age: 10-90 years): perimetric thresholds, double-pulse resolution (DPR), reaction times (RTs), and letter contrast thresholds. DPR and perimetric thresholds increased with eccentricity and age; the periphery showed a more pronounced age-related increase than the center. RT increased only slightly and uniformly with eccentricity. It remained almost constant up to the age of 60, a marked change occurring only above 80. Overall, age was a poor predictor of functionality. Performance decline could be explained only in part by the aging of the retina and optic media. In Part II, we therefore examine higher visual and cognitive functions.
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Affiliation(s)
- Dorothe A. Poggel
- Generation Research Program (GRP), Ludwig-Maximilian University Munich, Human Science Center, Bad Tölz, Germany
- Department of Medical Psychology and Medical Sociology, Georg-August University Göttingen, Göttingen, Germany
- Hanse-Wissenschaftskolleg Institute of Advanced Study, Lehmkuhlenbusch 4, 27753 Delmenhorst, Germany
| | | | - Claudia Calmanti
- Generation Research Program (GRP), Ludwig-Maximilian University Munich, Human Science Center, Bad Tölz, Germany
| | - Hans Strasburger
- Generation Research Program (GRP), Ludwig-Maximilian University Munich, Human Science Center, Bad Tölz, Germany
- Department of Medical Psychology and Medical Sociology, Georg-August University Göttingen, Göttingen, Germany
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Chanceaux M, Vitu F, Bendahman L, Thorpe S, Grainger J. Word processing speed in peripheral vision measured with a saccadic choice task. Vision Res 2012; 56:10-9. [DOI: 10.1016/j.visres.2012.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 01/17/2012] [Accepted: 01/20/2012] [Indexed: 11/17/2022]
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Megna N, Rocchi F, Baldassi S. Spatio-temporal templates of transient attention revealed by classification images. Vision Res 2011; 54:39-48. [PMID: 22186227 DOI: 10.1016/j.visres.2011.11.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 11/15/2011] [Accepted: 11/16/2011] [Indexed: 11/17/2022]
Abstract
Visual attention is captured by transient signals in the periphery of the visual field, allowing enhanced perceptual representations in spatial tasks. However, it has been reported that the same cues impair performance in temporal tasks (e.g., Yeshurun, 2004; Yeshurun & Levy, 2003). This findings suggest that transient attention enhances the activity of slow, high-resolution channels, like parvocellular neurons, and/or shuts off faster channels better sensitive to low spatial frequencies, such as the ones of the magnocellular system. To test this idea, we have measured the spatio-temporal perceptive fields for transiently cued signals at various eccentricities using the classification images (CI) technique. At near eccentricities transient attention caused the perceptual templates to be sharper in space and characterized by much stronger high spatial frequency components. At the same time, they show a consistently larger temporal integration window. These effects of attention on perceptual filters are strongly reduced at far eccentricities and disappear when using longer target-cue lags. These data provide evidence in support of the parvocellular model of transient, exogenous attention, showing that in the presence of a well timed spatial cue observers rely on noisy evidence lasting longer and with finer spatial configurations.
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Affiliation(s)
- Nicola Megna
- Department of Physics and Astronomy, University of Florence, Via Sansone 1, 50019 Sesto Fiorentino, Florence, Italy
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Strasburger H, Rentschler I, Jüttner M. Peripheral vision and pattern recognition: a review. J Vis 2011; 11:13. [PMID: 22207654 PMCID: PMC11073400 DOI: 10.1167/11.5.13] [Citation(s) in RCA: 425] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 09/06/2011] [Indexed: 11/24/2022] Open
Abstract
We summarize the various strands of research on peripheral vision and relate them to theories of form perception. After a historical overview, we describe quantifications of the cortical magnification hypothesis, including an extension of Schwartz's cortical mapping function. The merits of this concept are considered across a wide range of psychophysical tasks, followed by a discussion of its limitations and the need for non-spatial scaling. We also review the eccentricity dependence of other low-level functions including reaction time, temporal resolution, and spatial summation, as well as perimetric methods. A central topic is then the recognition of characters in peripheral vision, both at low and high levels of contrast, and the impact of surrounding contours known as crowding. We demonstrate how Bouma's law, specifying the critical distance for the onset of crowding, can be stated in terms of the retinocortical mapping. The recognition of more complex stimuli, like textures, faces, and scenes, reveals a substantial impact of mid-level vision and cognitive factors. We further consider eccentricity-dependent limitations of learning, both at the level of perceptual learning and pattern category learning. Generic limitations of extrafoveal vision are observed for the latter in categorization tasks involving multiple stimulus classes. Finally, models of peripheral form vision are discussed. We report that peripheral vision is limited with regard to pattern categorization by a distinctly lower representational complexity and processing speed. Taken together, the limitations of cognitive processing in peripheral vision appear to be as significant as those imposed on low-level functions and by way of crowding.
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Affiliation(s)
- Hans Strasburger
- Institut für Medizinische Psychologie, Ludwig-Maximilians-Universität, München, Germany
| | - Ingo Rentschler
- Institut für Medizinische Psychologie, Ludwig-Maximilians-Universität, München, Germany
| | - Martin Jüttner
- Department of Psychology, School of Life & Health Sciences, Aston University, Birmingham, UK
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39
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Discrimination of natural scenes in central and peripheral vision. Vision Res 2011; 51:1686-98. [DOI: 10.1016/j.visres.2011.05.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 05/12/2011] [Accepted: 05/20/2011] [Indexed: 11/20/2022]
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Clark CL, Hardy JL, Volbrecht VJ, Werner JS. Scotopic spatiotemporal sensitivity differences between young and old adults. Ophthalmic Physiol Opt 2011; 30:339-50. [PMID: 20629957 DOI: 10.1111/j.1475-1313.2010.00740.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Our lab has previously demonstrated losses in contrast sensitivity to low spatial frequencies under scotopic conditions with older adults. It is not clear, however, whether the temporal frequency of a stimulus alters the relation between age and the spatial contrast sensitivity function (sCSF) under scotopic conditions. METHODS A maximum-likelihood, two-alternative, temporal forced-choice QUEST procedure was used to measure threshold to spatially and temporally modulated stimuli in both young (mean = 26 years) and old (mean = 75 years) adults. RESULTS In general, the shapes of the spatial and temporal CSFs were low-pass for both young and old observers; contrast sensitivity decreased at approximately the same rate with increasing spatial frequency and temporal frequency for both age groups, although the overall sensitivity of the old group was lower than that of the young group. The high-frequency resolution limit was lower for the old group compared to the young group. CONCLUSIONS The differences in contrast sensitivity between the young and old groups suggest a uniform loss in sensitivity of the channels mediating spatial and temporal vision. Because of this loss, the spatial and temporal window of visibility for the older adults is compromised relative to the younger adults.
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Affiliation(s)
- Cynthia L Clark
- School of Psychological Sciences, University of Northern Colorado, Campus Box 94, Greeley, CO, USA
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41
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Effects of increased letter spacing on word identification and eye guidance during reading. Mem Cognit 2010; 38:502-12. [PMID: 20516230 DOI: 10.3758/mc.38.4.502] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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42
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Jordan TR, Paterson KB. Re-evaluating split-fovea processing in word recognition: A critical assessment of recent research. Neuropsychologia 2009; 47:2341-53. [PMID: 18723038 DOI: 10.1016/j.neuropsychologia.2008.07.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 07/08/2008] [Accepted: 07/20/2008] [Indexed: 10/21/2022]
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Drasdo N, Millican CL, Katholi CR, Curcio CA. The length of Henle fibers in the human retina and a model of ganglion receptive field density in the visual field. Vision Res 2007; 47:2901-11. [PMID: 17320143 PMCID: PMC2077907 DOI: 10.1016/j.visres.2007.01.007] [Citation(s) in RCA: 198] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 12/29/2006] [Accepted: 01/04/2007] [Indexed: 11/21/2022]
Abstract
An experimental study of lateral displacement of ganglion cells (GCs) from foveal cones in six human retinas is reported. At 406-675 microm in length, as measured in radially oriented cross-sections, Henle fibers are substantially longer than previously reported. However, a new theoretical model indicates that the discrepancies in these reports are mainly due to meridional differences. The model takes into account the effects of optical degradation and peripheral ON/OFF asymmetry and predicts a central GC:cone ratio of 2.24:1. It provides estimates of cumulative counts and GC receptive field density at 0 degrees -30 degrees along the principal meridians of the visual field.
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Affiliation(s)
- Neville Drasdo
- School of Optometry and Vision Sciences, Cardiff University CF10 3NB, UK
| | - C. Leigh Millican
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham AL, USA
| | - Charles R. Katholi
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham AL, USA
| | - Christine A. Curcio
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham AL, USA
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44
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Carrasco M, Giordano AM, McElree B. Attention speeds processing across eccentricity: feature and conjunction searches. Vision Res 2006; 46:2028-40. [PMID: 16481020 PMCID: PMC2871539 DOI: 10.1016/j.visres.2005.12.015] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2005] [Revised: 12/15/2005] [Accepted: 12/16/2005] [Indexed: 11/22/2022]
Abstract
We investigated whether the effect of covert attention on information accrual varies with eccentricity (4 degrees vs 9 degrees) and the complexity of the visual search task (feature vs conjunction). We used speed-accuracy tradeoff procedures to derive conjoint measures of the speed of information processing and accuracy in each search task. Information processing was slower with more complex conjunction searches than with simpler feature searches, and overall it was faster at peripheral (9 degrees) than parafoveal (4 degrees) locations in both search types. Covert attention increased discriminability and accelerated information accrual at both eccentricities, and the magnitude of this attentional effect was the same for both feature (simple) and conjunction (complex) searches. Interestingly, in contrast to the compensatory effect of covert attention on information processing at iso-eccentric locations (temporal performance fields), covert attention did not eliminate speed differences across eccentricity.
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Affiliation(s)
- Marisa Carrasco
- Department of Psychology, New York University, New York, NY 10003, USA.
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45
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Poirier FJAM, Gurnsey R. Non-monotonic changes in performance with eccentricity modeled by multiple eccentricity-dependent limitations. Vision Res 2005; 45:2436-48. [PMID: 15979465 DOI: 10.1016/j.visres.2005.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2004] [Revised: 03/10/2005] [Accepted: 03/15/2005] [Indexed: 11/25/2022]
Abstract
Eccentricity-dependent resolution losses are sometimes compensated for in psychophysical experiments by magnifying (scaling) stimuli at each eccentricity. The use of either pre-selected scaling factors or unscaled stimuli sometimes leads to non-monotonic changes in performance as a function of eccentricity. We argue that such non-monotonic changes arise when performance is limited by more than one type of constraint at each eccentricity. Building on current methods developed to investigate peripheral perception [e.g., Watson, A. B. (1987). Estimation of local spatial scale. Journal of the Optical Society of America A, 4 (8), 1579-1582; Poirier, F. J. A. M., & Gurnsey, R. (2002). Two eccentricity dependent limitations on subjective contour discrimination. Vision Research, 42, 227-238; Strasburger, H., Rentschler, I., & Harvey Jr., L. O. (1994). Cortical magnification theory fails to predict visual recognition. European Journal of Neuroscience, 6, 1583-1588], we show how measured scaling can deviate from a linear function of eccentricity in a grating acuity task [Thibos, L. N., Still, D. L., & Bradley, A. (1996). Characterization of spatial aliasing and contrast sensitivity in peripheral vision. Vision Research, 36(2), 249-258]. This framework can also explain the central performance drop [Kehrer, L. (1989). Central performance drop on perceptual segregation tasks. Spatial Vision, 4, 45-62] and a case of "reverse scaling" of the integration window in symmetry [Tyler, C. W. (1999). Human symmetry detection exhibits reverse eccentricity scaling. Visual Neuroscience, 16, 919-922]. These cases of non-monotonic performance are shown to be consistent with multiple sources of resolution loss, each of which increases linearly with eccentricity. We conclude that most eccentricity research, including "oddities", can be explained by multiple-scaling theory as extended here, where the receptive field properties of all underlying mechanisms in a task increase in size with eccentricity, but not necessarily at the same rate.
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Affiliation(s)
- Frédéric J A M Poirier
- Neurodynamics and Vision Lab--Centre for Vision Research, York University, Computer Sciences and Engineering Building, Room B0002E, 4700 Keele Street, Toronto, Ontario, Canada M3J 1P3.
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Jordan TR, Patching GR. Assessing effects of stimulus orientation on perception of lateralized words and nonwords. Neuropsychologia 2003; 41:1693-702. [PMID: 12887993 DOI: 10.1016/s0028-3932(02)00326-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Numerous studies of the processes of visual word recognition in the left and right cerebral hemispheres have attempted to control for confounding differences in the retinal placement (and hence visual acuity) of the beginnings of words by re-orientating normally-horizontal words vertically. However, despite the popularity of this approach, little is known about the precise effects that vertically orientating normally-horizontal words exert on hemispheric processes of word recognition. In this study, we investigated perception of horizontal and vertical English words and nonwords in the left visual field (LVF) and right visual field (RVF). An eye-tracking device ensured central fixation and a 2AFC paradigm (Reicher-Wheeler task) suppressed influences of non-perceptual bias. Horizontal stimuli produced a strong right visual field advantage for words but not for nonwords, whereas, vertical stimuli produced no hemifield differences at all. Moreover, vertical stimuli produced an advantage for words over nonwords in both visual fields whereas horizontal stimuli produced this effect only in the right visual field. Implications of these findings for the sensitivity of processes of word perception to stimulus orientation in the two cerebral hemispheres are discussed.
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Affiliation(s)
- Timothy R Jordan
- School of Psychology, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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47
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Jordan TR, Redwood M, Patching GR. Effects of form familiarity on perception of words, pseudowords, and nonwords in the two cerebral hemispheres. J Cogn Neurosci 2003; 15:537-48. [PMID: 12803965 DOI: 10.1162/089892903321662921] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Previous investigations of hemispheric processes of word perception provide a mixed picture of the sensitivity of each hemisphere to the familiarity of the visual form of lateralized displays. We investigated this issue by presenting words, pseudowords, and nonwords briefly to either the left (LH) or right (RH) hemisphere in lowercase, uppercase, and a matched, unfamiliar mixed-case form, and used an eye tracker to ensure central fixation and the Reicher-Wheeler task to suppress influences of stimulus asymmetry. Familiarity of form exerted a substantial effect on perception. In particular, perception of LH and RH displays of words, pseudowords, and nonwords was least accurate for mixed case, intermediate for upper case, and most accurate for lowercase. However, form had no effect on the LH advantage observed for words, pseudowords, and nonwords, indicating that form affected processing in both hemispheres to a similar extent. Moreover, LH and RH displays both showed that mixed case disrupted performance most for words, and more for pseudowords than for nonwords, indicating the sensitivity to form shown by each hemisphere reflected more than a general perceptual process. Implications for the role of form familiarity in hemispheric processing of words are discussed.
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Affiliation(s)
- Timothy R Jordan
- School of psychology, University of Nottingham, Nottingham, England, UK.
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48
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Jordan TR, Patching GR, Thomas SM. Asymmetries and Eccentricities in Studies of Lateralised Word Recognition: A Response to Nazir. Cogn Neuropsychol 2003; 20:81-9. [DOI: 10.1080/02643290244000202] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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49
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Anderson RS, Zlatkova MB, Beirne RO. The contrast sensitivity function for detection and resolution of blue-on-yellow gratings in foveal and peripheral vision. Ophthalmic Physiol Opt 2002; 22:420-6. [PMID: 12358313 DOI: 10.1046/j.1475-1313.2002.00068.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previous studies using polychromatic gratings have shown that the peripheral grating contrast sensitivity function is significantly different when the task is resolution rather than detection. Specifically, in the middle frequency range, while resolution acuity drops suddenly to zero, detection performance continues up to much higher frequencies, accompanied by observations of aliasing. We wanted to determine if the same holds true for blue-cone isolating gratings in either foveal or peripheral vision. Contrast sensitivity function (CSFs) were measured at the fovea and 20 degrees eccentricity in the temporal retina under conditions of short-wavelength-sensitive (SWS)-cone pathway isolation using a two-alternative forced choice paradigm. The detection and resolution CSF were identical at the low frequency end but at higher frequencies resolution sensitivity falls abruptly while contrast detection remained possible till higher frequencies [cut-off frequencies: fovea detection 6.0 cycles (degree)(-1), resolution 4.6 cycles (degree)(-1); periphery detection 1.6 cycles (degree)(-1), resolution 1.05 cycles (degree)(-1)]. Aliasing was observable when spatial frequency exceeded the resolution limit. Medium/high contrast blue-cone-mediated resolution acuity is sampling limited in both the fovea and periphery. Previous studies of blue-cone contrast sensitivity which employed a detection task do not reflect the true resolution limit.
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Affiliation(s)
- R S Anderson
- Vision Science Research Group, School of Biomedical Sciences, University of Ulster at Coleraine, UK
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50
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Abstract
We investigated the effect that spatially coincident luminance increments (luminance pedestals) have on flicker thresholds at several eccentricities and target sizes. Luminance pedestals elevated flicker amplitude-thresholds more when stimuli were presented eccentrically, both at low (4 Hz) and high (20 Hz) temporal frequencies. Altering the size of the eccentric stimulus failed to equate central and eccentric thresholds at all pedestal amplitudes. Comparisons with flicker thresholds at various background luminances suggests that the increase in luminance-pedestal flicker thresholds peripherally is due to increased suppressive rod-cone interactions, increased effectiveness of luminous contrast on edge-sensitive flicker mechanisms, as well as increased gain in the light adaptation response.
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Affiliation(s)
- Andrew John Anderson
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Vic. 3010, Australia
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