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Journal of Experimental Psychology.... Jun 2023We investigated temporal properties of visual perception as a function of eccentricity, that is, spatial position relative to the fovea. Our experiments were motivated...
We investigated temporal properties of visual perception as a function of eccentricity, that is, spatial position relative to the fovea. Our experiments were motivated by well-characterized non-uniformities in neuron distribution in the human eye and early visual pathways. These non-uniformities have been extensively studied in the context of spatial perception, while largely neglected in relation to temporal perception. In Experiment 1, participants fixated the rapid serial visual presentation letter stream and were instructed to report the letter which appeared simultaneously with a brief cue presented at different locations along the horizontal meridian. Participants exhibited a tendency to report earlier letters with more peripheral as compared to central cues, indicating that they misperceived differently located stimuli as simultaneous even though they were never presented together. Experiment 2 conceptually replicated the findings of Experiment 1. Experiment 3 further demonstrated that the effect is specifically due to eccentricity, and not the relative distance between the stimuli. We argue that such location-based misperceptions of simultaneity arise because transient stimuli at more eccentric locations advance to perception faster than stimuli at or near the fovea. Collectively, these experiments show, for the first time, how processing speed differences across the visual field translate into differences in perceived simultaneity. They also demonstrate, for the first time, location-based misperceptions of simultaneity for stimuli never presented together. Finally, Experiment 4 showed that greater eccentricity also increased the perceived duration of a stimulus compared to fovea. These results reveal the breadth of perceptual effects driven by temporal processing differences across the visual field. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Topics: Humans; Visual Perception; Vision, Ocular; Visual Fields; Space Perception; Time Perception
PubMed: 36701526
DOI: 10.1037/xge0001352 -
Annual Review of Neuroscience Jul 2023Despite increasing evidence of its involvement in several key functions of the cerebral cortex, the vestibular sense rarely enters our consciousness. Indeed, the extent... (Review)
Review
Despite increasing evidence of its involvement in several key functions of the cerebral cortex, the vestibular sense rarely enters our consciousness. Indeed, the extent to which these internal signals are incorporated within cortical sensory representation and how they might be relied upon for sensory-driven decision-making, during, for example, spatial navigation, is yet to be understood. Recent novel experimental approaches in rodents have probed both the physiological and behavioral significance of vestibular signals and indicate that their widespread integration with vision improves both the cortical representation and perceptual accuracy of self-motion and orientation. Here, we summarize these recent findings with a focus on cortical circuits involved in visual perception and spatial navigation and highlight the major remaining knowledge gaps. We suggest that vestibulo-visual integration reflects a process of constant updating regarding the status of self-motion, and access to such information by the cortex is used for sensory perception and predictions that may be implemented for rapid, navigation-related decision-making.
Topics: Motion Perception; Cues; Visual Perception; Vestibule, Labyrinth; Cerebral Cortex
PubMed: 37428601
DOI: 10.1146/annurev-neuro-120722-100503 -
Nature Human Behaviour Sep 2021Human visual perception carves a scene at its physical joints, decomposing the world into objects, which are selectively attended, tracked and predicted as we engage our... (Review)
Review
Human visual perception carves a scene at its physical joints, decomposing the world into objects, which are selectively attended, tracked and predicted as we engage our surroundings. Object representations emancipate perception from the sensory input, enabling us to keep in mind that which is out of sight and to use perceptual content as a basis for action and symbolic cognition. Human behavioural studies have documented how object representations emerge through grouping, amodal completion, proto-objects and object files. By contrast, deep neural network models of visual object recognition remain largely tethered to sensory input, despite achieving human-level performance at labelling objects. Here, we review related work in both fields and examine how these fields can help each other. The cognitive literature provides a starting point for the development of new experimental tasks that reveal mechanisms of human object perception and serve as benchmarks driving the development of deep neural network models that will put the object into object recognition.
Topics: Humans; Neural Networks, Computer; Pattern Recognition, Visual; Recognition, Psychology; Visual Pathways; Visual Perception
PubMed: 34545237
DOI: 10.1038/s41562-021-01194-6 -
Vision Research Mar 2023Optic flow is an important visual cue for human perception and locomotion and naturally triggers eye movements. Here we investigate whether the perception of optic flow...
Optic flow is an important visual cue for human perception and locomotion and naturally triggers eye movements. Here we investigate whether the perception of optic flow direction is limited or enhanced by eye movements. In Exp. 1, 23 human observers localized the focus of expansion (FOE) of an optic flow pattern; in Exp. 2, 18 observers had to detect brief visual changes at the FOE. Both tasks were completed during free viewing and fixation conditions while eye movements were recorded. Task difficulty was varied by manipulating the coherence of radial motion from the FOE (4 %-90 %). During free viewing, observers tracked the optic flow pattern with a combination of saccades and smooth eye movements. During fixation, observers nevertheless made small-scale eye movements. Despite differences in spatial scale, eye movements during free viewing and fixation were similarly directed toward the FOE (saccades) and away from the FOE (smooth tracking). Whereas FOE localization sensitivity was not affected by eye movement instructions (Exp. 1), observers' sensitivity to detect brief changes at the FOE was 27 % higher (p <.001) during free-viewing compared to fixation (Exp. 2). This performance benefit was linked to reduced saccade endpoint errors, indicating the direct beneficial impact of foveating eye movements on performance in a fine-grain perceptual task, but not during coarse perceptual localization.
Topics: Humans; Eye Movements; Optic Flow; Saccades; Motion; Photic Stimulation; Fixation, Ocular; Visual Perception; Motion Perception
PubMed: 36566560
DOI: 10.1016/j.visres.2022.108164 -
Journal of Vision Aug 2016Static visual stimuli are smeared across the retina during saccades, but in normal conditions this smear is not perceived. Instead, we perceive the visual scene as... (Review)
Review
Static visual stimuli are smeared across the retina during saccades, but in normal conditions this smear is not perceived. Instead, we perceive the visual scene as static and sharp. However, retinal smear is perceived if stimuli are shown only intrasaccadically, but not if the stimulus is additionally shown before a saccade begins, or after the saccade ends (Campbell & Wurtz, 1978). This inhibition has been compared to forward and backward metacontrast masking, but with spatial relations between stimulus and mask that are different from ordinary metacontrast during fixation. Previous studies of smear masking have used subjective measures of smear perception. Here we develop a new, objective technique for measuring smear masking, based on the spatial localization of a gap in the smear created by very quickly blanking the stimulus at various points during the saccade. We apply this technique to show that smear masking survives dichoptic presentation (suggesting that it is therefore cortical in origin), as well as separations of as much as 6° between smear and mask.
Topics: Humans; Perceptual Masking; Retina; Saccades; Visual Perception
PubMed: 27479918
DOI: 10.1167/16.10.1 -
Cortex; a Journal Devoted To the Study... Jul 2021Memory research has identified many strategies to enhance memory. However, natural foundations of enhanced memory are vastly underexplored. Interestingly, numerous...
Memory research has identified many strategies to enhance memory. However, natural foundations of enhanced memory are vastly underexplored. Interestingly, numerous studies show that synesthesia is associated with enhanced memory performance. Although it has been hypothesized for years that wider changes in visual perception are closely linked with enhanced memory functions in synesthesia, the hypothesis has never been directly put to the test. Here, we investigated whether visual perceptual abilities in synesthesia are linked with higher memory performance by comparing synesthetes who experience colors for letters with non-synesthetic color experts and non-synesthetic individuals from the more general population. Our results showed that synesthesia and expertise share a common profile of enhanced visual perceptual ability and memory in contrast to non-synesthetic individuals from the more general population. Overall, our findings suggest that visual perception and visual memory are more closely connected than previously thought.
Topics: Color Perception; Humans; Memory, Short-Term; Pattern Recognition, Visual; Perceptual Disorders; Photic Stimulation; Synesthesia; Visual Perception
PubMed: 33905967
DOI: 10.1016/j.cortex.2021.01.024 -
Nagoya Journal of Medical Science Aug 2018Several studies have investigated perceptual processes in patients with schizophrenia. Research confirms that visual impairments are one of the most important features... (Review)
Review
Several studies have investigated perceptual processes in patients with schizophrenia. Research confirms that visual impairments are one of the most important features of schizophrenia. Many studies, using behavioral and psychological experiments, confirm that visual impairments can be used to determine illness severity, state, and best treatments. Herein, we review recent research pertaining to visual function in patients with schizophrenia and highlight the relationship between laboratory findings and subjective, real-life reports from patients themselves. The purpose of this review is to 1) describe visual impairments that manifest in patients with schizophrenia, 2) examine the relationship between visual dysfunction, assessed by laboratory tests, and the experiences of patients themselves, and 3) describe real-life experiences related to visual function in this population. In this review, the impairments of motion and color perception, perceptual organization, and scan paths are summarized, along with the relationship between laboratory findings and patients' real-world subjective experiences related to visual function.
Topics: Color Perception; Humans; Schizophrenia; Vision Disorders; Visual Perception
PubMed: 30214081
DOI: 10.18999/nagjms.80.3.317 -
Journal of Vision Apr 2024We obtain large amounts of external information through our eyes, a process often considered analogous to picture mapping onto a camera lens. However, our eyes are never...
We obtain large amounts of external information through our eyes, a process often considered analogous to picture mapping onto a camera lens. However, our eyes are never as still as a camera lens, with saccades occurring between fixations and microsaccades occurring within a fixation. Although saccades are agreed to be functional for information sampling in visual perception, it remains unknown if microsaccades have a similar function when eye movement is restricted. Here, we demonstrated that saccades and microsaccades share common spatiotemporal structures in viewing visual objects. Twenty-seven adults viewed faces and houses in free-viewing and fixation-controlled conditions. Both saccades and microsaccades showed distinctive spatiotemporal patterns between face and house viewing that could be discriminated by pattern classifications. The classifications based on saccades and microsaccades could also be mutually generalized. Importantly, individuals who showed more distinctive saccadic patterns between faces and houses also showed more distinctive microsaccadic patterns. Moreover, saccades and microsaccades showed a higher structure similarity for face viewing than house viewing and a common orienting preference for the eye region over the mouth region. These findings suggested a common oculomotor program that is used to optimize information sampling during visual object perception.
Topics: Humans; Saccades; Male; Female; Adult; Fixation, Ocular; Young Adult; Visual Perception; Photic Stimulation; Pattern Recognition, Visual
PubMed: 38656530
DOI: 10.1167/jov.24.4.20 -
Trends in Cognitive Sciences Oct 2016The cortical visual system is almost universally thought to be segregated into two anatomically and functionally distinct pathways: a ventral occipitotemporal pathway... (Review)
Review
The cortical visual system is almost universally thought to be segregated into two anatomically and functionally distinct pathways: a ventral occipitotemporal pathway that subserves object perception, and a dorsal occipitoparietal pathway that subserves object localization and visually guided action. Accumulating evidence from both human and non-human primate studies, however, challenges this binary distinction and suggests that regions in the dorsal pathway contain object representations that are independent of those in ventral cortex and that play a functional role in object perception. We review here the evidence implicating dorsal object representations, and we propose an account of the anatomical organization, functional contributions, and origins of these representations in the service of perception.
Topics: Animals; Humans; Pattern Recognition, Visual; Perception; Visual Pathways; Visual Perception
PubMed: 27615805
DOI: 10.1016/j.tics.2016.08.003 -
Neural Networks : the Official Journal... Aug 2023Motion perception is an essential ability for animals and artificially intelligent systems interacting effectively, safely with surrounding objects and environments.... (Review)
Review
Motion perception is an essential ability for animals and artificially intelligent systems interacting effectively, safely with surrounding objects and environments. Biological visual systems, that have naturally evolved over hundreds-million years, are quite efficient and robust for motion perception, whereas artificial vision systems are far from such capability. This paper argues that the gap can be significantly reduced by formulation of ON/OFF channels in motion perception models encoding luminance increment (ON) and decrement (OFF) responses within receptive field, separately. Such signal-bifurcating structure has been found in neural systems of many animal species articulating early motion is split and processed in segregated pathways. However, the corresponding biological substrates, and the necessity for artificial vision systems have never been elucidated together, leaving concerns on uniqueness and advantages of ON/OFF channels upon building dynamic vision systems to address real world challenges. This paper highlights the importance of ON/OFF channels in motion perception through surveying current progress covering both neuroscience and computationally modelling works with applications. Compared to related literature, this paper for the first time provides insights into implementation of different selectivity to directional motion of looming, translating, and small-sized target movement based on ON/OFF channels in keeping with soundness and robustness of biological principles. Existing challenges and future trends of such bio-plausible computational structure for visual perception in connection with hotspots of machine learning, advanced vision sensors like event-driven camera finally are discussed.
Topics: Animals; Motion Perception; Visual Perception; Vision, Ocular; Visual Pathways; Motion
PubMed: 37263088
DOI: 10.1016/j.neunet.2023.05.031