Inhibition of return at different eccentricities in the visual field share the same temporal window

Diurnal rhythm of temporal reproduction in the visual field

The perception of short-term temporal intervals has been suggested to be modulated by the circadian clock, yet systematic studies investigating this relationship are scarce. In this study, we examined the diurnal variations in temporal reproduction around 2-3 seconds with different stimulus eccentricities. Eighteen female participants completed a visual temporal reproduction task at nine time points throughout the day. The results showed significant interactions between clock time and duration, implying diurnal rhythmic variations in temporal reproduction. The reproduction of shorter duration (1500 ms) was overestimated with its highest accuracy in the morning, while the reproduction of longer duration (4500 ms) was underestimated with an approximate 3-hour advancement in acrophase than the shorter duration (1500 ms). No significant eccentricity effects were observed, suggesting homogenous temporal processing across visual fields. The results suggest the presence of diurnal rhythms in the perception of short-term temporal durations, confirming a two-process model of time perception operating within a 2-3 second time window.

Three-phase temporal dynamics in random number generation

"Inhibition of return" (IOR) was originally described in the field of spatial attention, but it has also been observed in random number generation tasks. Subjects showed a tendency of "repetition avoidance," which can be considered as equivalent to IOR in another cognitive domain. As temporal factors have been suspected to play an important role in random number generation, we aimed to examine how such factors might influence regularities such as repetition avoidance in random number generation tasks. Participants were instructed to verbally generate a sequence of numbers at a certain pace, that is, with either 0.5, 1.5, 3 or 4 s between each response. Each number in the sequence should have the same probability of appearance and should be independent from the others. However, it was observed that the human-generated sequences differed drastically from computer-simulated pseudo-random sequences. The distribution of the repetition gap, which indicates how many different numbers are reported between two identical numbers in the generated sequences, showed a "three-phase" characteristic: a phase of avoidance of the same number, an oscillatory component for coming back to the same number, and finally an exponential decay of number selection frequencies. This three-phase characteristic was independent of the time interval between responses. These observations indicate an item-based process in random number generation, making a time-based control in this task rather unlikely as has been hypothetically assumed.

Temporal twilight zone and beyond: Timing mechanisms in consciously delayed actions

Precise timing is essential for many kinds of human behavior. When a fastest response is not required, movements are initiated at the appropriate time requiring an anticipatory temporal component. Temporal mechanisms for movements with such an anticipatory component are not yet sufficiently understood; in particular, it is not known whether on the operational level for delayed movements distinct time windows are used or whether anticipatory control is characterized by continuous temporal processing. With a modified reaction-time paradigm, we asked participants to act with predefined time delays between 400 and 5000 ms; after each individual trial, a numerical feedback was provided which allowed correction of the response time for each next trial. Visual stimuli (Experiment 1) and auditory stimuli (Experiment 2) were used. In the statistical analyses, piecewise linear models and exponential decay models for the response variability of different delay times were compared. These analyses favored piecewise linear models; a decreasing variability with increasing delay of voluntary controlled actions was observed up to ~1 s, followed by close to constant variability beyond this delay. We suggest that precise temporal control of voluntary delayed movements is reached only after a "temporal twilight zone" of ~1 s, which apparently marks a temporal border between two different timing mechanisms.

The three second time window in poems and language processing in general: Complementarity of discrete timing and temporal continuity

The existence of discrete time windows has triggered the search for permanence and continuity for artists (including poets) in multiple cultures throughout history. In this article, we argue that there exists a 3-s window in the temporal structure of poems as well as in the aesthetic appreciation of poetry by reviewing previous literature on the temporal aspects of poems. This 3-s window can also be considered to be a general temporal machinery underlying human behavior, including language production and perception in general. The reafference principle has provided us a unique frame for understanding cognitive processes. However, "time" was absent in the original two-stage reafference principle. Therefore, we propose a three-stage cycling model of language perception, taking into account time and time windows. We also inspect the possible neural implementations of the three stages: the generation, maintenance, and comparison of predictions (as well as the integration of predictions into the representational context). These three stages are embedded in a temporal window of ~3 s and are repeated in a cycling mode, resulting in the representational context being continuously updated. Thus, it is possible that "semantics" could be carried forward across different time windows, being a "glue" linking the discrete time windows and thus achieving the subjective feeling of temporal continuity. Candidates of such "semantic glue" could include semantic and syntactic structures as well as identity and emotion.

Exogeneous Spatial Cueing beyond the Near Periphery: Cueing Effects in a Discrimination Paradigm at Large Eccentricities

Although visual attention is one of the most thoroughly investigated topics in experimental psychology and vision science, most of this research tends to be restricted to the near periphery. Eccentricities used in attention studies usually do not exceed 20° to 30°, but most studies even make use of considerably smaller maximum eccentricities. Thus, empirical knowledge about attention beyond this range is sparse, probably due to a previous lack of suitable experimental devices to investigate attention in the far periphery. This is currently changing due to the development of temporal high-resolution projectors and head-mounted displays (HMDs) that allow displaying experimental stimuli at far eccentricities. In the present study, visual attention was investigated beyond the near periphery (15°, 30°, 56° Exp. 1) and (15°, 35°, 56° Exp. 2) in a peripheral Posner cueing paradigm using a discrimination task with placeholders. Interestingly, cueing effects were revealed for the whole range of eccentricities although the inhomogeneity of the visual field and its functional subdivisions might lead one to suspect otherwise.

Covert attention beyond the range of eye-movements: Evidence for a dissociation between exogenous and endogenous orienting

The relationship between covert shift of attention and the oculomotor system has been the subject of numerous studies. A widely held view, known as Premotor Theory, is that covert attention depends upon activation of the oculomotor system. However, recent work has argued that Premotor Theory is only true for covert, exogenous orienting of attention and that covert endogenous orienting is largely independent of the oculomotor system. To address this issue we examined how endogenous and exogenous covert orienting of attention was affected when stimuli were presented at a location outside the range of saccadic eye movements. Results from Experiment 1 showed that exogenous covert orienting was abolished when stimuli were presented beyond the range of saccadic eye movements, but preserved when stimuli were presented within this range. In contrast, in Experiment 2 endogenous covert orienting was preserved when stimuli appeared beyond the saccadic range. Finally, Experiment 3 confirmed the observations of Exp.1 and 2. Our results demonstrate that exogenous, covert orienting is limited to the range of overt saccadic eye movements, whereas covert endogenous orienting is not. These results are consistent with a weak, exogenous-only version of Premotor Theory.

Does cue processing modulate inhibition of return in a detection task?

While the abrupt onset of a peripheral visual cue usually leads to speeded responses to following targets at the cued relative to other positions, responses are slowed if targets lag behind the cue by more than ~200 ms. This response delay is termed inhibition of return (IOR) and has been considered as a mechanism to orient behavior toward novel areas. IOR has been found in both detection and discrimination tasks with later onset in discrimination tasks, probably due to a higher processing demand. Here we examined whether the processing demand of cues can modulate IOR in the detection task. The task to the peripheral cues, either color or gap cues, was passive viewing in one session (single task) and discrimination in another session (dual task). The results showed that the time course of IOR was resistant to the cue processing, while the magnitude of IOR was increased when the processing load became larger in the dual task relative to the single task. These results indicate that IOR in target detection is both reflexive in that its temporal dynamics remain invariant, and flexible in that its magnitude is modulated by task requirement.

Attentional modulation of speed-change perception in the perifoveal and near-peripheral visual field

The ability to perceive changes in motion, such as rapid changes of speed, has important ecological significance. We show that exogenous and endogenous attention have different effects on speed-change perception and operate differently in different regions of the visual field. Using a spatial-cueing paradigm, with either exogenous or endogenous cues followed by drifting Gabor patches of changing speed that appear at the cued or uncued location, we measured participants’ thresholds for localizing both acceleration and deceleration of the Gabor patches in different regions (5° and 10°) of the visual field. The results revealed a larger exogenous cueing effect, indexed by a lower threshold for the cued relative to the uncued conditions, at 5° for perceiving acceleration and at 10° for perceiving deceleration. Endogenous attention, in contrast, improved performance equally at both eccentricities. We conclude that exogenous and endogenous spatial orienting constitute two independent attentional systems, with distinct modulation patterns on speed change perception in the visual field. While exogenous attentional modulation is eccentricity-dependent, endogenous attention acts homogeneously in perifoveal and near-peripheral regions of the visual field.

East of West, West of East: a matter of global and local identity

Research is a very personal matter. On the basis of experiences in different countries with researchers from different cultures over many years, some observations will be described. The conceptual frame of this attempt is to look for anthropological universals and cultural specifics. Much can be learned from spatial representations in the arts. Whereas in the West since Renaissance time the central perspective has become dominant in visual art, in Eastern landscape paintings the "floating view" is typical. The claim that the central perspective corresponds to geometric laws and matches how we see the world is misleading for at least two reasons: It violates mechanisms of size constancy, and the visual world is spatially reduced in pictures to the perifoveal region only. Research on spatial attention has disclosed two different attentional systems being responsible either for near-fovea vision or for the far periphery. This fundamental principle as a global characteristic of visual processing is neglected in Western art. In Eastern art with a floating view geometric laws are violated, and different potential perspectives are integrated within a holistic pattern. The semantics of what shall be expressed becomes important irrespective of physical parameters. The latter may also create the unique phenomenon of becoming subjectively part of the picture confirming personal identity. Cultural specifics like in the arts (what one might expect) can surprisingly also be observed in theoretical considerations about visual processing. Whereas in the tradition of Western science visual percepts are built up with local elements like feature detectors, in an important Chinese theory global topological features are analyzed first. An important task of the brain is to create the identity of a percept on the basis of spatially and temporally distributed neural activities. It is, thus, an important theoretical question how to deal with the challenge to create and maintain the identity of a percept for some time. It is suggested that one should leave behind a monocausal reasoning for such explanations but adopt for analytical strategies the concept of complementarity as a generative principle.

Complementarity As Generative Principle: A Thought Pattern for Aesthetic Appreciations and Cognitive Appraisals in General

In experimental aesthetics the relationship between the arts and cognitive neuroscience has gained particular interest in recent years. But has cognitive neuroscience indeed something to offer when studying the arts? Here we present a theoretical frame within which the concept of complementarity as a generative or creative principle is proposed; neurocognitive processes are characterized by the duality of complementary activities like bottom-up and top-down control, or logistical functions like temporal control and content functions like perceptions in the neural machinery. On that basis a thought pattern is suggested for aesthetic appreciations and cognitive appraisals in general. This thought pattern is deeply rooted in the history of philosophy and art theory since antiquity; and complementarity also characterizes neural operations as basis for cognitive processes. We then discuss some challenges one is confronted with in experimental aesthetics; in our opinion, one serious problem is the lack of a taxonomy of functions in psychology and neuroscience which is generally accepted. This deficit makes it next to impossible to develop acceptable models which are similar to what has to be modeled. Another problem is the severe language bias in this field of research as knowledge gained in many languages over the ages remains inaccessible to most scientists. Thus, an inspection of research results or theoretical concepts is necessarily too narrow. In spite of these limitations we provide a selective summary of some results and viewpoints with a focus on visual art and its appreciation. It is described how questions of art and aesthetic appreciations using behavioral methods and in particular brain-imaging techniques are analyzed and evaluated focusing on such issues like the representation of artwork or affective experiences. Finally, we emphasize complementarity as a generative principle on a practical level when artists and scientists work directly together which can lead to new insights and broader perspectives on both sides.

Scanning the world in three seconds: Mismatch negativity as an indicator of temporal segmentation

It has been shown recently that a temporal window of approximately 3 s has a modulatory effect on mismatch negativity (MMN). This special temporal window has been interpreted as representing the "subjective present," and reflecting a temporal segmentation in behavioral and cognitive functions. A more detailed look into the temporal structure of the MMN appeared to be reasonable as group data might shadow the underlying mechanisms because of too-high response variance. In this study, we tested one subject on 11 successive days at the same circadian phase using a passive auditory oddball paradigm with interstimulus intervals (ISIs) ranging from 1 s to 6 s. We observed a U-shape function of MMN showing the largest amplitudes to the oddball stimuli with an ISI of 2 s and 3 s being flanked by smaller response amplitudes for shorter and longer ISIs. This result pattern can be explained with an oscillatory neural mechanism underlying the temporal modulation of MMN. Besides confirming and substantiating temporal segmentation in sensory processing, the present study also demonstrates that a single case study can be a useful and complementary tool in cognitive research.

Effect of Exogenous Cues on Covert Spatial Orienting in Deaf and Normal Hearing Individuals

Deaf individuals have been known to process visual stimuli better at the periphery compared to the normal hearing population. However, very few studies have examined attention orienting in the oculomotor domain in the deaf, particularly when targets appear at variable eccentricity. In this study, we examined if the visual perceptual processing advantage reported in the deaf people also modulates spatial attentional orienting with eye movement responses. We used a spatial cueing task with cued and uncued targets that appeared at two different eccentricities and explored attentional facilitation and inhibition. We elicited both a saccadic and a manual response. The deaf showed a higher cueing effect for the ocular responses than the normal hearing participants. However, there was no group difference for the manual responses. There was also higher facilitation at the periphery for both saccadic and manual responses, irrespective of groups. These results suggest that, owing to their superior visual processing ability, the deaf may orient attention faster to targets. We discuss the results in terms of previous studies on cueing and attentional orienting in deaf.

In the jungle of time: the concept of identity as a way out

What could be a unifying principle for the manifold of temporal experiences: the simultaneity or temporal order of events, the subjective present, the duration of experiences, or the impression of a continuity of time? Furthermore, we time travel to the past visiting in imagination previous experiences in episodic memory, and we also time travel to the future anticipating actions or plans. For such time traveling we divide time into three domains: past, present, and future. What could be an escape out of this “jungle of time” characterized by many different perceptual and conceptual phenomena? The key concept we want to propose is “identity” which is derived from homeostasis as a fundamental biological principle. Within this conceptual frame two modes of identity are distinguished: individual or self-identity required because of homeostatic demands, and object-related identity necessary for the reliability and efficiency of neuro-cognitive processing. With this concept of self- and object-identity, the different temporal experiences can be conceptualized within a common frame. Thus, we propose a fundamental biological principle to conceptually unify temporal phenomena on the psychological level.

Inhibition of return in the visual field: the eccentricity effect is independent of cortical magnification

Inhibition of return (IOR) as an indicator of attentional control is characterized by an eccentricity effect, that is, the more peripheral visual field shows a stronger IOR magnitude relative to the perifoveal visual field. However, it could be argued that this eccentricity effect may not be an attention effect, but due to cortical magnification. To test this possibility, we examined this eccentricity effect in two conditions: the same-size condition in which identical stimuli were used at different eccentricities, and the size-scaling condition in which stimuli were scaled according to the cortical magnification factor (M-scaling), thus stimuli being larger at the more peripheral locations. The results showed that the magnitude of IOR was significantly stronger in the peripheral relative to the perifoveal visual field, and this eccentricity effect was independent of the manipulation of stimulus size (same-size or size-scaling). These results suggest a robust eccentricity effect of IOR which cannot be eliminated by M-scaling. Underlying neural mechanisms of the eccentricity effect of IOR are discussed with respect to both cortical and subcortical structures mediating attentional control in the perifoveal and peripheral visual field.