Multiple Visual Latency

1998 ◽  
Vol 9 (2) ◽  
pp. 135-138 ◽  
Author(s):  
Jüri Allik ◽  
Kairi Kreegipuu
Keyword(s):  
Visual Stimulus ◽  
Temporal Order ◽  
Visual Awareness ◽  
Common Belief ◽  
Evoked Responses ◽  
Visual Events ◽  
Visual Latency ◽  
Direction Of Movement ◽  
Perceptual Latency ◽  
Visual Delay

It has long been known that a dark visual stimulus is seen later than a bright one, with a delay up to several 10s of milliseconds. Systematic studies of various phenomena demonstrating this delay have revealed that the perceptual latency decreases monotonically as the stimulus intensity increases. Because latencies measured by psychological methods and cortical evoked responses are very similar to electroretinogram latencies, it has become a common belief that there is little in the intensity-dependent latency function that cannot be explained by retinal processes. In this study, we report evidence that there is no one absolute visual delay common to the whole visual system, but rather that the delay varies considerably in different perceptual subsystems. The relative visual latency was found to be considerably shorter in the task involving detecting the direction of movement than in other perceptual tasks that presume visual awareness of the beginning or temporal order of visual events.

Multiple Visual Latency

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 69-69 ◽  
Author(s):  
J Allik ◽  
K Kreegipuu
Keyword(s):  
Discrimination Task ◽  
Temporal Order ◽  
Visual Awareness ◽  
Common Belief ◽  
Visual Events ◽  
Visual Latency ◽  
Relative Delay ◽  
Perceptual Latency ◽  
Visual Delay ◽  
Movement Discrimination

It has long been known that the time taken to detect a dim visual stimulus is longer than that to detect a bright one, with a relative delay of up to several tens of milliseconds. Systematic studies of various phenomena demonstrating this delay have revealed that the perceptual latency decreases monotonically as the stimulus intensity increases. Because latencies measured by psychological methods and cortical evoked responses are very similar to electroretinogram latencies, it has become a common belief that there is little in the intensity-dependent latency function that cannot be explained by retinal processes. We report evidence that there is not one absolute visual delay common to the whole visual system, but that the delay varies considerably in different perceptual subsystems. The relative visual latency was found to be considerably shorter in a movement-discrimination task than in other perceptual tasks which presume visual awareness of the onset of visual events, or of their temporal order.

Audiovisual Simultaneity Judgements in Synaesthesia

2021 ◽  
pp. 1-12
Author(s):  
Anna Borgolte ◽  
Ahmad Bransi ◽  
Johanna Seifert ◽  
Sermin Toto ◽  
Gregor R. Szycik ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Temporal Order ◽  
Multisensory Processing ◽  
Sensory Modality ◽  
Stimulus Onset ◽  
Control Subjects ◽  
Visual Events

Abstract Synaesthesia is a multimodal phenomenon in which the activation of one sensory modality leads to an involuntary additional experience in another sensory modality. To date, normal multisensory processing has hardly been investigated in synaesthetes. In the present study we examine processes of audiovisual separation in synaesthesia by using a simultaneity judgement task. Subjects were asked to indicate whether an acoustic and a visual stimulus occurred simultaneously or not. Stimulus onset asynchronies (SOA) as well as the temporal order of the stimuli were systematically varied. Our results demonstrate that synaesthetes are better in separating auditory and visual events than control subjects, but only when vision leads.

scholarly journals Direct Cortical Recordings Suggest Temporal Order of Task-Evoked Responses in Human Dorsal Attention and Default Networks

2018 ◽  
Vol 38 (48) ◽  
pp. 10305-10313 ◽  
Author(s):  
Omri Raccah ◽  
Amy L. Daitch ◽  
Aaron Kucyi ◽  
Josef Parvizi
Keyword(s):  
Temporal Order ◽  
Evoked Responses

scholarly journals Visual delay affects force scaling and weight perception during object lifting in virtual reality

2019 ◽  
Vol 121 (4) ◽  
pp. 1398-1409 ◽  
Author(s):  
Vonne van Polanen ◽  
Robert Tibold ◽  
Atsuo Nuruki ◽  
Marco Davare
Keyword(s):  
Virtual Reality ◽  
Multisensory Integration ◽  
Force Feedback ◽  
Haptic Feedback ◽  
Visual Signals ◽  
Visual Events ◽  
Object Lifting ◽  
Relative Weighting ◽  
The Brain ◽  
Visual Delay

Lifting an object requires precise scaling of fingertip forces based on a prediction of object weight. At object contact, a series of tactile and visual events arise that need to be rapidly processed online to fine-tune the planned motor commands for lifting the object. The brain mechanisms underlying multisensory integration serially at transient sensorimotor events, a general feature of actions requiring hand-object interactions, are not yet understood. In this study we tested the relative weighting between haptic and visual signals when they are integrated online into the motor command. We used a new virtual reality setup to desynchronize visual feedback from haptics, which allowed us to probe the relative contribution of haptics and vision in driving participants’ movements when they grasped virtual objects simulated by two force-feedback robots. We found that visual delay changed the profile of fingertip force generation and led participants to perceive objects as heavier than when lifts were performed without visual delay. We further modeled the effect of vision on motor output by manipulating the extent to which delayed visual events could bias the force profile, which allowed us to determine the specific weighting the brain assigns to haptics and vision. Our results show for the first time how visuo-haptic integration is processed at discrete sensorimotor events for controlling object-lifting dynamics and further highlight the organization of multisensory signals online for controlling action and perception. NEW & NOTEWORTHY Dexterous hand movements require rapid integration of information from different senses, in particular touch and vision, at different key time points as movement unfolds. The relative weighting between vision and haptics for object manipulation is unknown. We used object lifting in virtual reality to desynchronize visual and haptic feedback and find out their relative weightings. Our findings shed light on how rapid multisensory integration is processed over a series of discrete sensorimotor control points.

Temporal-Order Discrimination for Selected Auditory and Visual Stimulus Dimensions

1998 ◽  
Vol 41 (2) ◽  
pp. 300-314 ◽  
Author(s):  
Dennis J. McFarland ◽  
Anthony T. Cacace ◽  
Gavin Setzen
Keyword(s):  
Visual Stimulus ◽  
Test Performance ◽  
Temporal Order ◽  
Sensory Modality ◽  
Stimulus Dimension ◽  
Psychophysical Method ◽  
Adaptive Procedure ◽  
Color Test ◽  
Correct Point ◽  
Adult Volunteers

Thresholds for the discrimination of temporal order were determined for selected auditory and visual stimulus dimensions in 10 normal-adult volunteers. Auditory stimuli consisted of binary pure tones varying in frequency or sound pressure level, and visual stimuli consisted of binary geometric forms varying in size, orientation, or color. We determined the effect of psychophysical method and the reliability of performance across stimulus dimensions. Using a single-track adaptive procedure, Experiment 1 showed that temporal-order thresholds (TOTs) varied with stimulus dimension, being lowest for auditory frequency, intermediate for size, orientation, and auditory level, and longest for color. Test performance improved over sessions and the profile of thresholds across stimulus dimensions had a modest reliability. Experiment 2 used a double-interleaved adaptive procedure and TOTs were similarly ordered as in Experiment 1. However, TOT swere significantly lower for initially ascending versus descending tracks. With this method, the reliability of the profile across stimulus dimensions and tracks was relatively low. In Experiment 3, psychometric functions were obtained for each of the stimulus dimensions and thresholds were defined as the interpolated 70.7% correct point. The relative ordering of TOTs was similar to those obtained in the first two experiments. Non-monotonicities were found in some of the psychometric functions, with the most prominent being for the color dimension. A crossexperiment comparison of results demonstrates that TOTs and their reliability are significantly influenced by the psychophysical method. Taken together, these results support the notion that the temporal resolution of ordered stimuli involves perceptual mechanisms specific to a given sensory modality or submodality.

Intermodal Perception of Temporal Order and Motor Skills: Effects of Age

1968 ◽  
Vol 26 (3) ◽  
pp. 987-1000 ◽  
Author(s):  
Albert J. Dinnerstein ◽  
Phyllis Zlotogura
Keyword(s):  
Motor Skills ◽  
Temporal Order ◽  
Short Term Memory ◽  
Motor Task ◽  
Reaction Times ◽  
Short Term ◽  
Tactile Stimuli ◽  
Serial Reaction ◽  
Intermodal Perception ◽  
Perceptual Latency

Employing visual, auditory, and tactile stimuli, intermodal differences in perceptual latency were inferred by means of perception of temporal order (PTO) and by varieties of serial reaction times (RT) to the same stimuli. Skill at reading, peg board, tapping, and tracking was also determined for the same Ss. Mean intermodal differences in latency inferred from PTO were significantly different from those obtained from mean RTs. A correlation matrix showed that individual differences in visual, auditory and tactile latencies inferred from PTO were relatively independent of latencies inferred from RT. Consonant with previous studies, PTO scores correlated with reading rate and also with peg board speed. Taking age of Ss into account, the latter correlations were seen to be due exclusively to the presence of older Ss, who did show a correlation between PTO and RT. It was hypothesized that aged Ss show a decrease in perceptual “channel capacity” and a resulting overloading of short-term memory when faced with a complex perceptual and motor task.

Unconscious inference and conscious representation: Why primary visual cortex (V1) is directly involved in visual awareness

2008 ◽  
Vol 31 (2) ◽  
pp. 209-210 ◽  
Author(s):  
Zhicheng Lin
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Vision System ◽  
Visual Awareness ◽  
Moving Object ◽  
Delay Compensation ◽  
Visual Hierarchy ◽  
Target Article ◽  
Visual Delay

AbstractThe extent to which visual processing can proceed in the visual hierarchy without awareness determines the magnitude of perceptual delay. Increasing data demonstrate that primary visual cortex (V1) is involved in consciousness, constraining the magnitude of visual delay. This makes it possible that visual delay is actually within the optimal lengths to allow sufficient computation; thus it might be unnecessary to compensate for visual delay.The time delay problem – that perception lives slightly in the past as a result of neural conduction – has recently attracted a considerate amount of attention in the context of the flash-lag effect. The effect refers to a visual illusion wherein a brief flash of light and a continuously moving object that physically align in space and time are perceived to be displaced from one another – the flashed stimulus appears to lag behind the moving object (Krekelberg & Lappe 2001). In the target article, Nijhawan compellingly argues that delay compensation could be undertaken by a predictive process in the feedforward pathways in the vision system. Before jumping into the quest for the mechanism of delay compensation, however, I would like to argue that the magnitude of delay has been overestimated, and that it might even be unnecessary to compensate for such a delay.

scholarly journals Stuck on a Plateau? A Model-Based Approach to Fundamental Issues in Visual Temporal-Order Judgments

2018 ◽  
Author(s):  
Jan Tünnermann ◽  
Ingrid Scharlau
Keyword(s):  
Model Comparison ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Visual Cognition ◽  
Judgment Task ◽  
Accurate Data ◽  
Model Based ◽  
Visual Events ◽  
Temporal Order Judgments ◽  
Model Based Analysis

Humans are incapable of judging the temporal order of visual events at brief temporal separations with perfect accuracy. Their performance---which is of much interest in visual cognition and attention research---can be measured with the temporal-order judgment task, which typically produces S-shaped psychometric functions. Occasionally, researchers reported plateaus within these functions, and some theories predict such deviation from the basic S shape. However, the centers of the psychometric functions result from the weakest performance at the most difficult presentations and therefore fluctuate strongly, leaving existence and exact shapes of plateaus unclear. This study set out to investigate whether plateaus disappear if the data accuracy is enhanced, or if we are ``stuck on a plateau'', or rather with it. For this purpose, highly accurate data were assessed by model-based analysis. The existence of plateaus is confidently confirmed and two plausible mechanisms derived from very different models are presented. Neither model, however, performs well in the presence of a strong attention manipulation, and model comparison remains unclear on the question which of the models describes the data best. Nevertheless, the present study includes the highest accuracy in visual TOJ data and the most explicit models of plateaus in TOJ studied so far.

scholarly journals Stuck on a Plateau? A Model-Based Approach to Fundamental Issues in Visual Temporal-Order Judgments

2018 ◽  
Author(s):  
Jan Tünnermann ◽  
Ingrid Scharlau
Keyword(s):  
Model Comparison ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Visual Cognition ◽  
Judgment Task ◽  
Accurate Data ◽  
Model Based ◽  
Visual Events ◽  
Temporal Order Judgments ◽  
Model Based Analysis

Humans are incapable of judging the temporal order of visual events at brief temporal separations with perfect accuracy. Their performance---which is of much interest in visual cognition and attention research---can be measured with the temporal-order judgment task, which typically produces S-shaped psychometric functions. Occasionally, researchers reported plateaus within these functions, and some theories predict such deviation from the basic S shape. However, the centers of the psychometric functions result from the weakest performance at the most difficult presentations and therefore fluctuate strongly, leaving existence and exact shapes of plateaus unclear. This study set out to investigate whether plateaus disappear if the data accuracy is enhanced, or if we are ``stuck on a plateau'', or rather with it. For this purpose, highly accurate data were assessed by model-based analysis. The existence of plateaus is confidently confirmed and two plausible mechanisms derived from very different models are presented. Neither model, however, performs well in the presence of a strong attention manipulation, and model comparison remains unclear on the question which of the models describes the data best. Nevertheless, the present study includes the highest accuracy in visual TOJ data and the most explicit models of plateaus in TOJ studied so far.

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