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Journal of Vision Sep 2022Saccades let the visual scene sweep with high speed across the retina, thus producing a massive motion stimulus. Yet, in natural vision, we never perceive motion that is...
Saccades let the visual scene sweep with high speed across the retina, thus producing a massive motion stimulus. Yet, in natural vision, we never perceive motion that is produced by saccades. The absence of perisaccadic motion perception might be caused by a transient reduction of visual sensitivity at the time of saccade initiation, so-called saccadic suppression. Saccade suppression occurs for contrast, displacement, and motion stimuli. Saccade suppression of displacements has been shown to be context sensitive. After performing saccades in sessions without perisaccadic stimulation, saccade suppression magnitude is drastically decreased (Zimmermann, 2020). Here, we aimed to test whether saccade suppression of contrast is similarly modulated by context. To this end, we projected stimuli on a homogeneously white wall such that we could establish a ganzfeld-like environment that, depending on the experimental session, did or did not contain any visible contrast stimuli. We first successfully replicated the context sensitivity of saccade suppression of displacements. Then, we tested context sensitivity of contrast suppression by asking subjects to perform several saccades either across the uniform white wall or across a background consisting of a sinusoidal grating. In contrast to perisaccadic context sensitivity for displacement suppression, we did not find context sensitivity for suppression of contrast.
Topics: Humans; Motion Perception; Photic Stimulation; Retina; Saccades; Vision, Ocular; Visual Perception
PubMed: 36083219
DOI: 10.1167/jov.22.10.10 -
Journal of Vision Jan 2014Even though the dynamicity of our environment is a given, much of what we know on fixation selection comes from studies of static scene viewing. We performed a direct...
Even though the dynamicity of our environment is a given, much of what we know on fixation selection comes from studies of static scene viewing. We performed a direct comparison of fixation selection on static and dynamic visual stimuli and investigated how far identical mechanisms drive these. We recorded eye movements while participants viewed movie clips of natural scenery and static frames taken from the same movies. Both were presented in the same high spatial resolution (1080 × 1920 pixels). The static condition allowed us to check whether local movement features computed from movies are salient even when presented as single frames. We observed that during the first second of viewing, movement and static features are equally salient in both conditions. Furthermore, predictability of fixations based on movement features decreased faster when viewing static frames as compared with viewing movie clips. Yet even during the later portion of static-frame viewing, the predictive value of movement features was still high above chance. Moreover, we demonstrated that, whereas the sets of movement and static features were statistically dependent within these sets, respectively, no dependence was observed between the two sets. Based on these results, we argue that implied motion is predictive of fixation similarly to real movement and that the onset of motion in natural stimuli is more salient than ongoing movement is. The present results allow us to address to what extent and when static image viewing is similar to the perception of a dynamic environment.
Topics: Adult; Attention; Eye Movements; Female; Fixation, Ocular; Humans; Male; Motion Perception; Young Adult
PubMed: 24396045
DOI: 10.1167/14.1.2 -
Vision Research Oct 1999This paper reviews literature on the motion processing of dynamic change in binocular disparity, called stereoscopic (cyclopean) motion. Studies investigating the visual... (Review)
Review
This paper reviews literature on the motion processing of dynamic change in binocular disparity, called stereoscopic (cyclopean) motion. Studies investigating the visual processing of stereoscopic motion in the Z-axis, stereoscopic motion in the X/Y plane, and cyclopean motion are discussed. It is concluded that stereoscopic motion is processed by a motion-sensing system composed of special-purpose mechanisms that function like low-level motion sensors. For animals with binocular vision, low-level motion processing may involve, at least in part, stereoscopic processing.
Topics: Animals; Motion Perception; Neurophysiology; Perceptual Distortion; Psychological Tests; Psychophysics; Vision Disparity; Visual Pathways
PubMed: 10615499
DOI: 10.1016/s0042-6989(99)00047-4 -
Journal of Vision 2015Visual motion serves as a cue for high-level percepts. The present study reports novel modulation of animacy perception through synchronous motion. A target dot moving...
Visual motion serves as a cue for high-level percepts. The present study reports novel modulation of animacy perception through synchronous motion. A target dot moving along a random trajectory was presented. The trajectory was generated based on a variant of 1/f noise; hence, the dot could be perceived as animate. Participants were asked to rate the strength of perceived animacy and perceived intention from the target dot. Several task-irrelevant dots surrounding the target were also presented. Results indicated that perceived animacy and intention were drastically weakened when surrounding dots created synchronous motion with the target dot as compared to when surrounding dots did not create synchronous motion. A series of follow-up experiments replicated these results and revealed specific characteristics of this modulation. The present findings suggest synchronous visual motion serves as a strong modulator of animacy perception.
Topics: Cues; Humans; Motion Perception; Optical Illusions; Pattern Recognition, Visual
PubMed: 26114680
DOI: 10.1167/15.8.17 -
Developmental Cognitive Neuroscience Apr 2018The ability to perceive others' actions and goals from human motion (i.e., biological motion perception) is a critical component of social perception and may be linked...
The ability to perceive others' actions and goals from human motion (i.e., biological motion perception) is a critical component of social perception and may be linked to the development of real-world social relationships. Adult research demonstrates two key nodes of the brain's biological motion perception system-amygdala and posterior superior temporal sulcus (pSTS)-are linked to variability in social network properties. The relation between social perception and social network properties, however, has not yet been investigated in middle childhood-a time when individual differences in social experiences and social perception are growing. The aims of this study were to (1) replicate past work showing amygdala and pSTS sensitivity to biological motion in middle childhood; (2) examine age-related changes in the neural sensitivity for biological motion, and (3) determine whether neural sensitivity for biological motion relates to social network characteristics in children. Consistent with past work, we demonstrate a significant relation between social network size and neural sensitivity for biological motion in left pSTS, but do not find age-related change in biological motion perception. This finding offers evidence for the interplay between real-world social experiences and functional brain development and has important implications for understanding disorders of atypical social experience.
Topics: Adolescent; Brain; Child; Female; Humans; Magnetic Resonance Imaging; Male; Motion Perception; Social Networking
PubMed: 29529533
DOI: 10.1016/j.dcn.2018.02.012 -
Vision Research May 2019Discrimination performance is better for cardinal motion directions than for oblique ones, a phenomenon known as the oblique effect. In a first experiment of this paper,...
Discrimination performance is better for cardinal motion directions than for oblique ones, a phenomenon known as the oblique effect. In a first experiment of this paper, we tested the oblique effect for coarse motion direction discrimination and compared performance for the two cardinal and two diagonal motion directions. Our results provide evidence for the oblique effect for coarse motion direction discrimination. Interestingly, the oblique effect was larger between horizontal and diagonal than between vertical and diagonal motion directions. In a second experiment, we assessed fine motion direction discrimination for horizontal and vertical motion. It has been suggested that differences in performance strongly depend on motion coherence. Therefore, we tested performance at predetermined motion coherences of 30%, 40%, 50%, 60% and 70%. Unsurprisingly, performance overall increased with increasing motion coherence and angular deviations between control and test stimulus. More importantly, however, we found an advantage for horizontal over vertical fine motion direction discrimination. Noteworthy is the large variability in performance across experimental conditions in both experiments, which highlights the importance of considering individual difference when assessing perceptual phenomena within large groups of naïve participants.
Topics: Adolescent; Adult; Discrimination, Psychological; Female; Humans; Male; Motion Perception; Orientation; Psychophysics; Sensory Thresholds; Young Adult
PubMed: 30878277
DOI: 10.1016/j.visres.2019.03.005 -
Journal of Vision Jan 2017Motion parallax, the perception of depth resulting from an observer's self-movement, has almost always been studied with random dot textures in simplified orthographic...
Motion parallax, the perception of depth resulting from an observer's self-movement, has almost always been studied with random dot textures in simplified orthographic rendering. Here we examine depth from motion parallax in more naturalistic conditions using textures with an overall 1/f spectrum and dynamic perspective rendering. We compared depth perception for orthographic and perspective rendering, using textures composed of two types of elements: random dots and Gabor micropatterns. Relative texture motion (shearing) with square wave corrugation patterns was synchronized to horizontal head movement. Four observers performed a two-alternative forced choice depth ordering task with monocular viewing, in which they reported which part of the texture appeared in front of the other. For both textures, depth perception was better with dynamic perspective than with orthographic rendering, particularly at larger depths. Depth ordering performance with naturalistic 1/f textures was slightly lower than with the random dots; however, with depth-related size scaling of the micropatterns, performance was comparable to that with random dots. We also examined the effects of removing each of the three cues that distinguish dynamic perspective from orthographic rendering: (a) small vertical displacements, (b) lateral gradients of speed across the corrugations, and (c) speed differences in rendered near versus far surfaces. Removal of any of the three cues impaired performance. In conclusion, depth ordering performance is enhanced by all of the dynamic perspective cues but not by using more naturalistic 1/f textures.
Topics: Cues; Depth Perception; Head Movements; Humans; Motion; Motion Perception
PubMed: 28114478
DOI: 10.1167/17.1.10 -
PloS One 2012Vision in Autism Spectrum Conditions (ASC) is characterized by enhanced perception of local elements, but impaired perception of global percepts. Deficits in coherent...
Vision in Autism Spectrum Conditions (ASC) is characterized by enhanced perception of local elements, but impaired perception of global percepts. Deficits in coherent motion perception seem to support this characterization, but the roots and robustness of such deficits remain unclear. We aimed to investigate the dynamics of the perceptual decision-making network known to support coherent motion perception. In a series of forced-choice coherent motion perception tests, we parametrically varied a single stimulus dimension, viewing duration, to test whether the rate at which evidence is accumulated towards a global decision is atypical in ASC. 40 adult participants (20 ASC) performed a classic motion discrimination task, manually indicating the global direction of motion in a random-dot kinematogram across a range of coherence levels (2-75%) and stimulus-viewing durations (200-1500 ms). We report a deficit in global motion perception at short viewing durations in ASC. Critically, however, we found that increasing the amount of time over which motion signals could be integrated reduced the magnitude of the deficit, such that at the longest duration there was no difference between the ASC and control groups. Further, the deficit in motion integration at the shortest duration was significantly associated with the severity of autistic symptoms in our clinical population, and was independent from measures of intelligence. These results point to atypical integration of motion signals during the construction of a global percept in ASC. Based on the neural correlates of decision-making in global motion perception our findings suggest the global motion deficit observed in ASC could reflect a slower or more variable response from the primary motion area of the brain or longer accumulation of evidence towards a decision-bound in parietal areas.
Topics: Adult; Child; Child Development Disorders, Pervasive; Humans; Intelligence Tests; Motion Perception; Vision, Ocular; Young Adult
PubMed: 23185249
DOI: 10.1371/journal.pone.0048173 -
The Journal of Neuroscience : the... Jul 2013Abnormal smooth pursuit eye movements in patients with schizophrenia are often considered a consequence of impaired motion perception. Here we used a novel motion...
Abnormal smooth pursuit eye movements in patients with schizophrenia are often considered a consequence of impaired motion perception. Here we used a novel motion prediction task to assess the effects of abnormal pursuit on perception in human patients. Schizophrenia patients (n = 15) and healthy controls (n = 16) judged whether a briefly presented moving target ("ball") would hit/miss a stationary vertical line segment ("goal"). To relate prediction performance and pursuit directly, we manipulated eye movements: in half of the trials, observers smoothly tracked the ball; in the other half, they fixated on the goal. Strict quality criteria ensured that pursuit was initiated and that fixation was maintained. Controls were significantly better in trajectory prediction during pursuit than during fixation, their performance increased with presentation duration, and their pursuit gain and perceptual judgments were correlated. Such perceptual benefits during pursuit may be due to the use of extraretinal motion information estimated from an efference copy signal. With an overall lower performance in pursuit and perception, patients showed no such pursuit advantage and no correlation between pursuit gain and perception. Although patients' pursuit showed normal improvement with longer duration, their prediction performance failed to benefit from duration increases. This dissociation indicates relatively intact early visual motion processing, but a failure to use efference copy information. Impaired efference function in the sensory system may represent a general deficit in schizophrenia and thus contribute to symptoms and functional outcome impairments associated with the disorder.
Topics: Adult; Female; Humans; Male; Middle Aged; Motion; Motion Perception; Photic Stimulation; Pursuit, Smooth; Schizophrenia
PubMed: 23864667
DOI: 10.1523/JNEUROSCI.0578-13.2013 -
Multiple-stage ambiguity in motion perception reveals global computation of local motion directions.Journal of Vision Dec 2016The motion of a 1D image feature, such as a line, seen through a small aperture, or the small receptive field of a neural motion sensor, is underconstrained, and it is...
The motion of a 1D image feature, such as a line, seen through a small aperture, or the small receptive field of a neural motion sensor, is underconstrained, and it is not possible to derive the true motion direction from a single local measurement. This is referred to as the aperture problem. How the visual system solves the aperture problem is a fundamental question in visual motion research. In the estimation of motion vectors through integration of ambiguous local motion measurements at different positions, conventional theories assume that the object motion is a rigid translation, with motion signals sharing a common motion vector within the spatial region over which the aperture problem is solved. However, this strategy fails for global rotation. Here we show that the human visual system can estimate global rotation directly through spatial pooling of locally ambiguous measurements, without an intervening step that computes local motion vectors. We designed a novel ambiguous global flow stimulus, which is globally as well as locally ambiguous. The global ambiguity implies that the stimulus is simultaneously consistent with both a global rigid translation and an infinite number of global rigid rotations. By the standard view, the motion should always be seen as a global translation, but it appears to shift from translation to rotation as observers shift fixation. This finding indicates that the visual system can estimate local vectors using a global rotation constraint, and suggests that local motion ambiguity may not be resolved until consistencies with multiple global motion patterns are assessed.
Topics: Adaptation, Physiological; Humans; Motion Perception; Orientation; Photic Stimulation; Rotation
PubMed: 27936271
DOI: 10.1167/16.15.7