1
|
Schmid D, Hesse C, Schenk T. The redundant target paradigm and its use as a blindsight-test: A meta-analytic study. Cortex 2023; 169:326-352. [PMID: 37981442 DOI: 10.1016/j.cortex.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/04/2023] [Accepted: 08/30/2023] [Indexed: 11/21/2023]
Abstract
The redundant target effect (RTE) is the well-known effect whereby a single target is detected faster when a second, redundant target is presented simultaneously. The RTE was shown in different experimental designs and applied in various clinical contexts. However, there are also studies showing non-effects or effects in the opposite direction. Our meta-analysis aims to investigate the replicability of the RTE. Herein, we focused on the clinical context within which the RTE has been applied most often and for which it gained particular prominence: The research on blindsight and other forms of residual vision in patients with damage to the neuronal visual system. The application of the RTE in clinical contexts assumes that whenever vision is present, an RTE will be found. Put differently, the RTE as a tool to uncover residual vision presumes that the RTE is a consistent feature of vision in the healthy population. We found a significant summary effect size of the RTE in healthy participants. The effect size depended on certain experimental features: task type, target configuration in the redundant condition, and how reaction times were computed in the single condition. A specific feature combination is typically used in blindsight research. Analyzing studies with this feature combination revealed a significant summary effect size in healthy participants predicting positive RTEs for future studies. A power-analysis revealed a required sample size of 14 participants to obtain an RTE with high reliability. However, the required sample size is rarely reached in blindsight research. Rather, blindsight research is mostly based on single-case studies. In summary, the RTE is a robust effect on group level but does not occur in every single individual. This means failure to obtain an RTE in a single patient should not be interpreted as evidence for the absence of residual vision in this patient.
Collapse
Affiliation(s)
- Doris Schmid
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
| | - Constanze Hesse
- School of Psychology, University of Aberdeen, King's College, Aberdeen, United Kingdom.
| | - Thomas Schenk
- Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
| |
Collapse
|
2
|
Willis HE, Ip IB, Watt A, Campbell J, Jbabdi S, Clarke WT, Cavanaugh MR, Huxlin KR, Watkins KE, Tamietto M, Bridge H. GABA and Glutamate in hMT+ Link to Individual Differences in Residual Visual Function After Occipital Stroke. Stroke 2023; 54:2286-2295. [PMID: 37477008 PMCID: PMC10453332 DOI: 10.1161/strokeaha.123.043269] [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: 12/23/2022] [Revised: 05/09/2023] [Accepted: 05/31/2023] [Indexed: 07/22/2023]
Abstract
BACKGROUND Damage to the primary visual cortex following an occipital stroke causes loss of conscious vision in the contralateral hemifield. Yet, some patients retain the ability to detect moving visual stimuli within their blind field. The present study asked whether such individual differences in blind field perception following loss of primary visual cortex could be explained by the concentration of neurotransmitters γ-aminobutyric acid (GABA) and glutamate or activity of the visual motion processing, human middle temporal complex (hMT+). METHODS We used magnetic resonance imaging in 19 patients with chronic occipital stroke to measure the concentration of neurotransmitters GABA and glutamate (proton magnetic resonance spectroscopy) and functional activity in hMT+ (functional magnetic resonance imaging). We also tested each participant on a 2-interval forced choice detection task using high-contrast, moving Gabor patches. We then measured and assessed the strength of relationships between participants' residual vision in their blind field and in vivo neurotransmitter concentrations, as well as visually evoked functional magnetic resonance imaging activity in their hMT+. Levels of GABA and glutamate were also measured in a sensorimotor region, which served as a control. RESULTS Magnetic resonance spectroscopy-derived GABA and glutamate concentrations in hMT+ (but not sensorimotor cortex) strongly predicted blind-field visual detection abilities. Performance was inversely related to levels of both inhibitory and excitatory neurotransmitters in hMT+ but, surprisingly, did not correlate with visually evoked blood oxygenation level-dependent signal change in this motion-sensitive region. CONCLUSIONS Levels of GABA and glutamate in hMT+ appear to provide superior information about motion detection capabilities inside perimetrically defined blind fields compared to blood oxygenation level-dependent signal changes-in essence, serving as biomarkers for the quality of residual visual processing in the blind-field. Whether they also reflect a potential for successful rehabilitation of visual function remains to be determined.
Collapse
Affiliation(s)
- Hanna E. Willis
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| | - I. Betina Ip
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| | - Archie Watt
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| | - Jon Campbell
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| | - Saad Jbabdi
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| | - William T. Clarke
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| | - Matthew R. Cavanaugh
- Flaum Eye Institute and Center for Visual Science, University of Rochester, NY (M.R.C., K.R.H.)
| | - Krystel R. Huxlin
- Flaum Eye Institute and Center for Visual Science, University of Rochester, NY (M.R.C., K.R.H.)
| | - Kate E. Watkins
- Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology (K.E.W.), University of Oxford, United Kingdom
| | - Marco Tamietto
- Department of Psychology, University of Torino, Italy (M.T.)
- Department of Medical and Clinical Psychology, and CoRPS—Center of Research on Psychology in Somatic Diseases—Tilburg University, the Netherlands (M.T.)
| | - Holly Bridge
- Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neurosciences (H.E.W., I.B.I., A.W., J.C., S.J., W.T.C., H.B.), University of Oxford, United Kingdom
| |
Collapse
|
3
|
Leitner MC, Ladek AM, Hutzler F, Reitsamer H, Hawelka S. Placebo effect after visual restitution training: no eye-tracking controlled perimetric improvement after visual border stimulation in late subacute and chronic visual field defects after stroke. Front Neurol 2023; 14:1114718. [PMID: 37456634 PMCID: PMC10339290 DOI: 10.3389/fneur.2023.1114718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction A significant number of Restitution Training (RT) paradigms claim to ameliorate visual field loss after stroke by re-activating neuronal connections in the residual visual cortex due to repeated bright light-stimulation at the border of the blind and intact fields. However, the effectiveness of RT has been considered controversial both in science and clinical practice for years. The main points of the controversy are (1) the reliability of perimetric results which may be affected by compensatory eye movements and (2) heterogeneous samples consisting of patients with visual field defects and/or visuospatial neglect. Methods By means of our newly developed and validated Virtual Reality goggles Salzburg Visual Field Trainer (SVFT) 16 stroke patients performed RT on a regular basis for 5 months. By means of our newly developed and validated Eye Tracking Based Visual Field Analysis (EFA), we conducted a first-time full eye-movement-controlled perimetric pre-post intervention study. Additionally, patients subjectively rated the size of their intact visual field. Results Analysis showed that patients' mean self-assessment of their subjective visual field size indicated statistically significant improvement while, in contrast, objective eye tracking controlled perimetric results revealed no statistically significant effect. Discussion Bright-light detection RT at the blind-field border solely induced a placebo effect and did not lead to training-induced neuroplasticity in the visual cortex of the type needed to ameliorate the visual field size of stroke patients.
Collapse
Affiliation(s)
- Michael Christian Leitner
- Salzburg University of Applied Sciences, Salzburg, Austria
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria
- Department of Psychology, University of Salzburg, Salzburg, Austria
| | - Anja-Maria Ladek
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Salzburg, Austria
- Department of Ophthalmology and Optometry, SALK, University Hospital of the Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Florian Hutzler
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria
- Department of Psychology, University of Salzburg, Salzburg, Austria
| | - Herbert Reitsamer
- Research Program for Experimental Ophthalmology and Glaucoma Research, Department of Ophthalmology and Optometry, University Hospital of the Paracelsus Medical University Salzburg, Salzburg, Austria
- Department of Ophthalmology and Optometry, SALK, University Hospital of the Paracelsus Medical University Salzburg, Salzburg, Austria
| | - Stefan Hawelka
- Centre for Cognitive Neuroscience (CCNS), University of Salzburg, Salzburg, Austria
- Department of Psychology, University of Salzburg, Salzburg, Austria
| |
Collapse
|
4
|
Rowland BA, Bushnell CD, Duncan PW, Stein BE. Ameliorating Hemianopia with Multisensory Training. J Neurosci 2023; 43:1018-1026. [PMID: 36604169 PMCID: PMC9908311 DOI: 10.1523/jneurosci.0962-22.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
Hemianopia (unilateral blindness), a common consequence of stroke and trauma to visual cortex, is a debilitating disorder for which there are few treatments. Research in an animal model has suggested that visual-auditory stimulation therapy, which exploits the multisensory architecture of the brain, may be effective in restoring visual sensitivity in hemianopia. It was tested in two male human patients who were hemianopic for at least 8 months following a stroke. The patients were repeatedly exposed to congruent visual-auditory stimuli within their blinded hemifield during 2 h sessions over several weeks. The results were dramatic. Both recovered the ability to detect and describe visual stimuli throughout their formerly blind field within a few weeks. They could also localize these stimuli, identify some of their features, and perceive multiple visual stimuli simultaneously in both fields. These results indicate that the multisensory therapy is a rapid and effective method for restoring visual function in hemianopia.SIGNIFICANCE STATEMENT Hemianopia (blindness on one side of space) is widely considered to be a permanent disorder. Here, we show that a simple multisensory training paradigm can ameliorate this disorder in human patients.
Collapse
Affiliation(s)
| | - Cheryl D Bushnell
- Neurology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | - Pamela W Duncan
- Neurology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157
| | | |
Collapse
|
5
|
Méndez CA, Celeghin A, Diano M, Orsenigo D, Ocak B, Tamietto M. A deep neural network model of the primate superior colliculus for emotion recognition. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210512. [PMID: 36126660 PMCID: PMC9489290 DOI: 10.1098/rstb.2021.0512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Although sensory processing is pivotal to nearly every theory of emotion, the evaluation of the visual input as ‘emotional’ (e.g. a smile as signalling happiness) has been traditionally assumed to take place in supramodal ‘limbic’ brain regions. Accordingly, subcortical structures of ancient evolutionary origin that receive direct input from the retina, such as the superior colliculus (SC), are traditionally conceptualized as passive relay centres. However, mounting evidence suggests that the SC is endowed with the necessary infrastructure and computational capabilities for the innate recognition and initial categorization of emotionally salient features from retinal information. Here, we built a neurobiologically inspired convolutional deep neural network (DNN) model that approximates physiological, anatomical and connectional properties of the retino-collicular circuit. This enabled us to characterize and isolate the initial computations and discriminations that the DNN model of the SC can perform on facial expressions, based uniquely on the information it directly receives from the virtual retina. Trained to discriminate facial expressions of basic emotions, our model matches human error patterns and above chance, yet suboptimal, classification accuracy analogous to that reported in patients with V1 damage, who rely on retino-collicular pathways for non-conscious vision of emotional attributes. When presented with gratings of different spatial frequencies and orientations never ‘seen’ before, the SC model exhibits spontaneous tuning to low spatial frequencies and reduced orientation discrimination, as can be expected from the prevalence of the magnocellular (M) over parvocellular (P) projections. Likewise, face manipulation that biases processing towards the M or P pathway affects expression recognition in the SC model accordingly, an effect that dovetails with variations of activity in the human SC purposely measured with ultra-high field functional magnetic resonance imaging. Lastly, the DNN generates saliency maps and extracts visual features, demonstrating that certain face parts, like the mouth or the eyes, provide higher discriminative information than other parts as a function of emotional expressions like happiness and sadness. The present findings support the contention that the SC possesses the necessary infrastructure to analyse the visual features that define facial emotional stimuli also without additional processing stages in the visual cortex or in ‘limbic’ areas. This article is part of the theme issue ‘Cracking the laugh code: laughter through the lens of biology, psychology and neuroscience’.
Collapse
Affiliation(s)
- Carlos Andrés Méndez
- Department of Psychology, University of Torino, Via Verdi 10, Torino 10124, Italy
| | - Alessia Celeghin
- Department of Psychology, University of Torino, Via Verdi 10, Torino 10124, Italy
| | - Matteo Diano
- Department of Psychology, University of Torino, Via Verdi 10, Torino 10124, Italy
| | - Davide Orsenigo
- Department of Psychology, University of Torino, Via Verdi 10, Torino 10124, Italy
| | - Brian Ocak
- Department of Psychology, University of Torino, Via Verdi 10, Torino 10124, Italy.,Section of Cognitive Neurophysiology and Imaging, National Institute of Mental Health, 49 Convent Drive, Bethesda, MD 20892, USA
| | - Marco Tamietto
- Department of Psychology, University of Torino, Via Verdi 10, Torino 10124, Italy.,Department of Medical and Clinical Psychology, and CoRPS - Center of Research on Psychology in Somatic diseases, Tilburg University, PO Box 90153, 5000 LE Tilburg, The Netherlands
| |
Collapse
|
6
|
He Q, Yang XY, Zhao D, Fang F. Enhancement of visual perception by combining transcranial electrical stimulation and visual perceptual training. MEDICAL REVIEW (BERLIN, GERMANY) 2022; 2:271-284. [PMID: 37724187 PMCID: PMC10388778 DOI: 10.1515/mr-2022-0010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/16/2022] [Indexed: 09/20/2023]
Abstract
The visual system remains highly malleable even after its maturity or impairment. Our visual function can be enhanced through many ways, such as transcranial electrical stimulation (tES) and visual perceptual learning (VPL). TES can change visual function rapidly, but its modulation effect is short-lived and unstable. By contrast, VPL can lead to a substantial and long-lasting improvement in visual function, but extensive training is typically required. Theoretically, visual function could be further improved in a shorter time frame by combining tES and VPL than by solely using tES or VPL. Vision enhancement by combining these two methods concurrently is both theoretically and practically significant. In this review, we firstly introduced the basic concept and possible mechanisms of VPL and tES; then we reviewed the current research progress of visual enhancement using the combination of two methods in both general and clinical population; finally, we discussed the limitations and future directions in this field. Our review provides a guide for future research and application of vision enhancement and restoration by combining VPL and tES.
Collapse
Affiliation(s)
- Qing He
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Xin-Yue Yang
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Daiqing Zhao
- Department of Psychology, The Pennsylvania State University, University Park, State College, PA, USA
| | - Fang Fang
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Key Laboratory of Machine Perception, Ministry of Education, Peking University, Beijing, China
- IDG/McGovern Institute for Brain Research, Peking University, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| |
Collapse
|
7
|
He Q, Gan S. Neural Mechanisms of Visual Field Recovery after Perceptual Training in Cortical Blindness. J Neurosci 2022; 42:1886-1887. [PMID: 35264430 PMCID: PMC8916751 DOI: 10.1523/jneurosci.1953-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 01/08/2022] [Accepted: 01/12/2022] [Indexed: 11/21/2022] Open
Affiliation(s)
- Qing He
- School of Psychological and Cognitive Sciences, Peking University, Beijing, 100871, China
| | - Shuoqiu Gan
- Department of Medical Imaging, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| |
Collapse
|
8
|
Hurme M, Railo H. Promise and challenges for discovering transcranial magnetic stimulation induced "numbsense"-Commentary on Ro & Koenig (2021). Conscious Cogn 2021; 98:103265. [PMID: 34971969 DOI: 10.1016/j.concog.2021.103265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/18/2021] [Accepted: 12/20/2021] [Indexed: 11/19/2022]
Abstract
The notion that behavioral responses to stimuli can be mediated by separate unconscious and conscious sensory pathways remains popular, but also hotly debated. Recently, Ro and Koenig (2021) reported that when activity in somatosensory cortex was interfered with transcranial magnetic stimulation (TMS), participants could discriminate tactile stimuli they reported not consciously feeling. The study launches an interesting new area of research, helping to uncover mechanisms of unconscious perception that possibly generalize across different sensory modalities. However, we argue here that the study by Ro and Koenig also has several significant shortcomings, and it fails to provide evidence that pathways bypassing primary somatosensory cortex enable unconscious tactile discrimination. By referring to numerous studies investigating TMS-induced blindsight, we outline challenges in demonstrating unconscious sensory pathways using TMS. By facing to these challenges, research investigating TMS-induced numbsense has potential to stimulate progress in stubborn debates and reveal modality-general mechanisms of unconscious perception.
Collapse
Affiliation(s)
- Mikko Hurme
- Turku Brain and Mind Center, University of Turku, Turku, Finland.
| | - Henry Railo
- Turku Brain and Mind Center, University of Turku, Turku, Finland; Department of Psychology and Speech-Language Pathology, University of Turku, Turku 20014, Finland
| |
Collapse
|
9
|
Spared perilesional V1 activity underlies training-induced recovery of luminance detection sensitivity in cortically-blind patients. Nat Commun 2021; 12:6102. [PMID: 34671032 PMCID: PMC8528839 DOI: 10.1038/s41467-021-26345-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 09/29/2021] [Indexed: 11/19/2022] Open
Abstract
Damage to the primary visual cortex (V1) causes homonymous visual-field loss long considered intractable. Multiple studies now show that perceptual training can restore visual functions in chronic cortically-induced blindness (CB). A popular hypothesis is that training can harness residual visual functions by recruiting intact extrageniculostriate pathways. Training may also induce plastic changes within spared regions of the damaged V1. Here, we link changes in luminance detection sensitivity with retinotopic fMRI activity before and after visual discrimination training in eleven patients with chronic, stroke-induced CB. We show that spared V1 activity representing perimetrically-blind locations prior to training predicts the amount of training-induced recovery of luminance detection sensitivity. Additionally, training results in an enlargement of population receptive fields in perilesional V1, which increases blind-field coverage and may support further recovery with subsequent training. These findings uncover fundamental changes in perilesional V1 cortex underlying training-induced restoration of conscious luminance detection sensitivity in CB. In humans, stroke damage to V1 causes large visual field defects. Spared V1 activity prior to training predicts the amount of training-induced recovery in luminance detection sensitivity. Moreover, visual training changes population receptive field properties within residual V1 circuits.
Collapse
|