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Investigative Ophthalmology & Visual... Jan 2022We developed a stereo task that is based on a motion direction discrimination to examine the role that depth can play in disambiguating motion direction.
PURPOSE
We developed a stereo task that is based on a motion direction discrimination to examine the role that depth can play in disambiguating motion direction.
METHODS
In this study, we quantified normal adults' static and dynamic (i.e., laterally moving) stereoscopic performance using a psychophysical task, where we dichoptically presented randomly arranged, limited lifetime Gabor elements at two depth planes (one plane was at the fixation plane and the other at an uncrossed disparity relative to the fixation plane). Each plane contained half of the elements. For the dynamic condition, all elements were vertically oriented and moved to the left in one plane and to the right in another plane; for the static condition, the elements were horizontally oriented in one plane and vertically oriented in another plane.
RESULTS
For the range of motion speed that we measured (from 0.17°/s to 5.33°/s), we observed clear speed tuning of the stereo sensitivity (P = 3.0 × 10-5). The shape of this tuning did not significantly change with different spatial frequencies. We also found a significant difference in stereo sensitivity between stereopsis with static and laterally moving stimuli (speed = 0.67°/s; P = 0.004). Such difference was not evident when we matched the task between the static and moving stimuli.
CONCLUSIONS
We report that lateral motion modulates human global depth perception. This motion/stereo constraint is related to motion velocity not stimulus temporal frequency. We speculate that the processing of motion-based stereopsis of the kind reported here occurs in dorsal extrastriate cortex.
Topics: Adult; Depth Perception; Female; Humans; Male; Motion Perception; Psychophysics; Reference Values; Vision Disparity; Vision, Binocular; Visual Cortex; Young Adult
PubMed: 35077551
DOI: 10.1167/iovs.63.1.32 -
Journal of Vision Dec 2011This is a survey of psychophysical studies of motion perception carried out mainly in the last 10 years. It covers a wide range of topics, including the detection and... (Review)
Review
This is a survey of psychophysical studies of motion perception carried out mainly in the last 10 years. It covers a wide range of topics, including the detection and interactions of local motion signals, motion integration across various dimensions for vector computation and global motion perception, second-order motion and feature tracking, motion aftereffects, motion-induced mislocalizations, timing of motion processing, cross-attribute interactions for object motion, motion-induced blindness, and biological motion. While traditional motion research has benefited from the notion of the independent "motion processing module," recent research efforts have been also directed to aspects of motion processing in which interactions with other visual attributes play critical roles. This review tries to highlight the richness and diversity of this large research field and to clarify what has been done and what questions have been left unanswered.
Topics: Humans; Motion Perception; Photic Stimulation; Psychophysics
PubMed: 22144564
DOI: 10.1167/11.5.11 -
Perception 1999
Topics: Computer Graphics; Humans; Psychophysics; Research Design
PubMed: 10664762
DOI: 10.1068/p2806ed -
Vision Research Jul 2011This review focuses on covert attention and how it alters early vision. I explain why attention is considered a selective process, the constructs of covert attention,... (Review)
Review
This review focuses on covert attention and how it alters early vision. I explain why attention is considered a selective process, the constructs of covert attention, spatial endogenous and exogenous attention, and feature-based attention. I explain how in the last 25 years research on attention has characterized the effects of covert attention on spatial filters and how attention influences the selection of stimuli of interest. This review includes the effects of spatial attention on discriminability and appearance in tasks mediated by contrast sensitivity and spatial resolution; the effects of feature-based attention on basic visual processes, and a comparison of the effects of spatial and feature-based attention. The emphasis of this review is on psychophysical studies, but relevant electrophysiological and neuroimaging studies and models regarding how and where neuronal responses are modulated are also discussed.
Topics: Attention; Contrast Sensitivity; History, 20th Century; History, 21st Century; Humans; Photic Stimulation; Psychophysics; Visual Cortex; Visual Fields; Visual Perception
PubMed: 21549742
DOI: 10.1016/j.visres.2011.04.012 -
Current Protocols in Neuroscience Jun 2020We describe a set of protocols for doing visual psychophysical experiments in head-fixed mice. The goal of this approach was to conduct in mice the same type of precise...
We describe a set of protocols for doing visual psychophysical experiments in head-fixed mice. The goal of this approach was to conduct in mice the same type of precise and well-controlled tests of visual perception and decision making as is commonly done in primates. For example, these experimental protocols were the basis for our demonstration that mice are capable of visual selective attention in paradigms adapted from classic attention cueing paradigms in primates. Basic Protocol 1 describes how to construct the experimental apparatus, including the removable wheel assembly on which the mice run during the visual tasks, the lick spout used to deliver rewards and detect licks, and the behavioral box that places these components together with the visual displays. We also describe the functions of the computerized control system and the design of the customized head fixture. Basic Protocol 2 describes the preparation of mice for the experiments, including the detailed surgical steps. Basic Protocol 3 describes the transition to a food schedule for the mice and how to operate the experimental apparatus. Basic Protocol 4 outlines the logic of the task design and the steps necessary for training the mice. Finally, Basic Protocol 5 describes how to obtain and analyze the psychometric data. Our methods include several distinctive features, including a custom quick-release method for holding the head and specific strategies for training mice over multiple weeks. Published 2020. U.S. Government. Basic Protocol 1: Experimental apparatus Basic Protocol 2: Head fixture surgery Basic Protocol 3: General operation of the experimental apparatus Basic Protocol 4: Behavioral task design and training Basic Protocol 5: Psychometric data collection and analysis.
Topics: Animals; Attention; Behavior, Animal; Cues; Mice; Neurosciences; Psychophysics; Reward
PubMed: 32216169
DOI: 10.1002/cpns.95 -
Psychological Research Sep 2018The displacement of the final position of a moving object in the direction of the observed motion path, i.e. an overestimation, is known as representational momentum. It...
The displacement of the final position of a moving object in the direction of the observed motion path, i.e. an overestimation, is known as representational momentum. It has been described both in the visual and the auditory domain, and is suggested to be modality-independent. Here, we tested whether a representational momentum can also be demonstrated in the somatosensory domain. While the cognitive literature on representational momentum suggests that it can, previous work on the psychophysics of tactile motion perception would rather predict an underestimation of the perceived endpoint of a tactile stimulus. Tactile motion stimuli were applied on the left and the right dorsal forearms of 32 healthy participants, who were asked to indicate the subjectively perceived endpoint of the stimulation. Velocity, length and direction of the trajectory were varied. Contrary to the prediction based on the representational momentum literature, participants in our experiment significantly displaced the endpoint against the direction of movement (underestimation). The results are thus compatible with previous psychophysical findings on the perception of tactile motion. Further studies combining paradigms from classical psychophysics and cognitive psychology will be needed to resolve the apparently paradoxical predictions by the two literatures.
Topics: Female; Humans; Male; Middle Aged; Motion Perception; Psychophysics; Touch Perception
PubMed: 28597136
DOI: 10.1007/s00426-017-0879-1 -
Vision Research Aug 2006This brief review article brings together a series of related experiments in psychophysics and physiology that show striking similarities between measurements in human... (Review)
Review
This brief review article brings together a series of related experiments in psychophysics and physiology that show striking similarities between measurements in human observers and in single neurons. We consider seven pairs of primary research articles, each pair consisting of one paper in physiology and one in psychophysics, and we highlight common features between receptive and perceptive fields obtained using reverse correlation. We conclude by discussing how to assess the validity of perceptive fields as predictors of human responses, and by deriving a novel expression for the maximum trial-by-trial predictability attainable by any model for any psychophysical task.
Topics: Humans; Models, Neurological; Models, Psychological; Neurons; Psychophysics; Visual Perception
PubMed: 16542700
DOI: 10.1016/j.visres.2006.02.002 -
PLoS Computational Biology Jan 2021The connection between stimulus perception and time perception remains unknown. The present study combines human and rat psychophysics with sensory cortical neuronal...
The connection between stimulus perception and time perception remains unknown. The present study combines human and rat psychophysics with sensory cortical neuronal firing to construct a computational model for the percept of elapsed time embedded within sense of touch. When subjects judged the duration of a vibration applied to the fingertip (human) or whiskers (rat), increasing stimulus intensity led to increasing perceived duration. Symmetrically, increasing vibration duration led to increasing perceived intensity. We modeled real spike trains recorded from vibrissal somatosensory cortex as input to dual leaky integrators-an intensity integrator with short time constant and a duration integrator with long time constant-generating neurometric functions that replicated the actual psychophysical functions of rats. Returning to human psychophysics, we then confirmed specific predictions of the dual leaky integrator model. This study offers a framework, based on sensory coding and subsequent accumulation of sensory drive, to account for how a feeling of the passage of time accompanies the tactile sensory experience.
Topics: Action Potentials; Adult; Animals; Computational Biology; Humans; Male; Models, Neurological; Psychophysics; Rats; Rats, Wistar; Somatosensory Cortex; Task Performance and Analysis; Time Perception; Vibration; Vibrissae; Young Adult
PubMed: 33513135
DOI: 10.1371/journal.pcbi.1008668 -
Scandinavian Journal of Work,... 1999Psychophysics is a very old branch of psychology that is concerned with the relationship between physical stimuli that occur in the "outside world", and the sensations... (Review)
Review
Psychophysics is a very old branch of psychology that is concerned with the relationship between physical stimuli that occur in the "outside world", and the sensations they produce in the body's "inside world". According to modern psychophysical theory, the strength of a sensation is directly related to the intensity of its physical stimulus by means of a power function. The history and development of psychophysics is briefly reviewed, and the application of psychophysics to manual handling tasks and repetitive hand and wrist motion is described. The advantages and disadvantages of psychophysics are discussed. The following 4 directions for future research are suggested: further validation of the data, expansion into other areas of concern (eg, other body parts, jobs, and postures), broadening of the subject base by including symptomatic subjects, and greater inclusion of psychophysical measures (eg, pain, fatigue, and discomfort) in studies of musculoskeletal disorders.
Topics: Ergonomics; Forecasting; Humans; Lifting; Musculoskeletal Diseases; Occupational Diseases; Occupational Health; Psychophysics; Reproducibility of Results; Research; Risk Factors
PubMed: 10628435
DOI: No ID Found -
Ophthalmic & Physiological Optics : the... Mar 2014(1) To devise a model-based method for estimating the probabilities of binocular fusion, interocular suppression and diplopia from psychophysical judgements, (2) To map... (Review)
Review
PURPOSE
(1) To devise a model-based method for estimating the probabilities of binocular fusion, interocular suppression and diplopia from psychophysical judgements, (2) To map out the way fusion, suppression and diplopia vary with binocular disparity and blur of single edges shown to each eye, (3) To compare the binocular interactions found for edges of the same vs opposite contrast polarity.
METHODS
Test images were single, horizontal, Gaussian-blurred edges, with blur B = 1-32 min arc, and vertical disparity 0-8.B, shown for 200 ms. In the main experiment, observers reported whether they saw one central edge, one offset edge, or two edges. We argue that the relation between these three response categories and the three perceptual states (fusion, suppression, diplopia) is indirect and likely to be distorted by positional noise and criterion effects, and so we developed a descriptive, probabilistic model to estimate both the perceptual states and the noise/criterion parameters from the data.
RESULTS
(1) Using simulated data, we validated the model-based method by showing that it recovered fairly accurately the disparity ranges for fusion and suppression, (2) The disparity range for fusion (Panum's limit) increased greatly with blur, in line with previous studies. The disparity range for suppression was similar to the fusion limit at large blurs, but two or three times the fusion limit at small blurs. This meant that diplopia was much more prevalent at larger blurs, (3) Diplopia was much more frequent when the two edges had opposite contrast polarity. A formal comparison of models indicated that fusion occurs for same, but not opposite, polarities. Probability of suppression was greater for unequal contrasts, and it was always the lower-contrast edge that was suppressed.
CONCLUSIONS
Our model-based data analysis offers a useful tool for probing binocular fusion and suppression psychophysically. The disparity range for fusion increased with edge blur but fell short of complete scale-invariance. The disparity range for suppression also increased with blur but was not close to scale-invariance. Single vision occurs through fusion, but also beyond the fusion range, through suppression. Thus suppression can serve as a mechanism for extending single vision to larger disparities, but mainly for sharper edges where the fusion range is small (5-10 min arc). For large blurs the fusion range is so much larger that no such extension may be needed.
Topics: Diplopia; Humans; Psychophysics; Vision Disparity; Vision, Binocular
PubMed: 24476421
DOI: 10.1111/opo.12108