Backward position shift in apparent motion

Li, Hsin-Hung; Shim, Won Mok; Cavanagh, Patrick

doi:10.1167/14.1.16

Cited by 20 publications

(2 citation statements)

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“…Perceived motion is a powerful cue, as it also conveys direction (which is all that is needed in a direction-discrimination task). Further, numerous illusions attest the influence of motion or apparent motion on position estimates [39][40][41]. In the control conditions, those signals are clearly seen and can reinforce the perception of a displacement.…”

Section: A General Bias Revealed Under Conditions Of Impoverished Visionmentioning

confidence: 93%

Saccadic Suppression of Displacement Does Not Reflect a Saccade-Specific Bias to Assume Stability

Born

2019

Vision

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Across saccades, small displacements of a visual target are harder to detect and their directions more difficult to discriminate than during steady fixation. Prominent theories of this effect, known as saccadic suppression of displacement, propose that it is due to a bias to assume object stability across saccades. Recent studies comparing the saccadic effect to masking effects suggest that suppression of displacement is not saccade-specific. Further evidence for this account is presented from two experiments where participants judged the size of displacements on a continuous scale in saccade and mask conditions, with and without blanking. Saccades and masks both reduced the proportion of correctly perceived displacements and increased the proportion of missed displacements. Blanking improved performance in both conditions by reducing the proportion of missed displacements. Thus, if suppression of displacement reflects a bias for stability, it is not a saccade-specific bias, but a more general stability assumption revealed under conditions of impoverished vision. Specifically, I discuss the potentially decisive role of motion or other transient signals for displacement perception. Without transients or motion, the quality of relative position signals is poor, and saccadic and mask-induced suppression of displacement reflects performance when the decision has to be made on these signals alone. Blanking may improve those position signals by providing a transient onset or a longer time to encode the pre-saccadic target position.

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Section: A General Bias Revealed Under Conditions Of Impoverished Visionmentioning

confidence: 93%

Saccadic Suppression of Displacement Does Not Reflect a Saccade-Specific Bias to Assume Stability

Born

2019

Vision

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“…Motion-induced position shifts (MIPS) are a class of visual illusion that have long intrigued scientists (e.g., Matin et al, 1976 ; Freyd and Finke, 1984 ; Ramachandran and Inada, 1985 ; Bülthoff et al, 1989 ; Fröhlich, 1923 ; De Valois and De Valois, 1991 ; Nijhawan, 1994 ; Müsseler and Aschersleben, 1998 ; Whitney and Cavanagh, 2000 , 2002 ; Thornton, 2002 ; Müsseler and Kerzel, 2004 ; see Whitney, 2002 ; Burr and Thompson, 2011 for reviews). Today, such effects continue to promote important insights into how motion and position interact during object localization, particularly with respect to the level(s) of processing at which such interactions arise (e.g., Arnold et al, 2007 ; Eagleman and Sejnowski, 2007 ; Mather and Pavan, 2009 ; Shapiro et al, 2010 ; Tse et al, 2011 ; Kosovicheva et al, 2012 ; Maus et al, 2013a , b ; Li et al, 2014 ). The current paper is concerned with one specific visual illusion where local motion within an object causes a shift in its perceived global position (Ramachandran and Anstis, 1990 ; De Valois and De Valois, 1991 ).…”

Section: Introductionmentioning

confidence: 99%

Action can amplify motion-induced illusory displacement

Caniard

Bülthoff

Thornton

2015

Front. Hum. Neurosci.

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Local motion is known to produce strong illusory displacement in the perceived position of globally static objects. For example, if a dot-cloud or grating drifts to the left within a stationary aperture, the perceived position of the whole aperture will also be shifted to the left. Previously, we used a simple tracking task to demonstrate that active control over the global position of an object did not eliminate this form of illusion. Here, we used a new iPad task to directly compare the magnitude of illusory displacement under active and passive conditions. In the active condition, participants guided a drifting Gabor patch along a virtual slalom course by using the tilt control of an iPad. The task was to position the patch so that it entered each gate at the direct center, and we used the left/right deviations from that point as our dependent measure. In the passive condition, participants watched playback of standardized trajectories along the same course. We systematically varied deviation from midpoint at gate entry, and participants made 2AFC left/right judgments. We fitted cumulative normal functions to individual distributions and extracted the point of subjective equality (PSE) as our dependent measure. To our surprise, the magnitude of displacement was consistently larger under active than under passive conditions. Importantly, control conditions ruled out the possibility that such amplification results from lack of motor control or differences in global trajectories as performance estimates were equivalent in the two conditions in the absence of local motion. Our results suggest that the illusion penetrates multiple levels of the perception-action cycle, indicating that one important direction for the future of perceptual illusions may be to more fully explore their influence during active vision.

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Changes in perceptual sensitivity related to spatial cues depends on subcortical activity

Lovejoy

Krauzlis

2017

Proc. Natl. Acad. Sci. U.S.A.

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Spatial cues allow animals to selectively attend to relevant visual stimuli while ignoring distracters. This process depends on a distributed neuronal network, and an important current challenge is to understand the functional contributions made by individual brain regions within this network and how these contributions interact. Recent findings point to a possible anatomical segregation, with cortical and subcortical brain regions contributing to different functional components of selective attention. Cortical areas, especially visual cortex, may be responsible for implementing changes in perceptual sensitivity by changing the signal-tonoise ratio, whereas other regions, such as the superior colliculus, may be involved in processes that influence selection between competing stimuli without regulating perceptual sensitivity. Such a segregation of function would predict that when activity in the superior colliculus is suppressed by reversible inactivation, animals should still show changes in perceptual sensitivity mediated by the intact cortical circuits. Contrary to this prediction, here we report that inactivation of the primate superior colliculus eliminates the changes in perceptual sensitivity made possible by spatial cues. These findings demonstrate changes in perceptual sensitivity depend not only on neuronal activity in cortex but also require interaction with signals from the superior colliculus.attention | perception | sensitivity | superior colliculus | cortex S patial cues are known to improve perceptual sensitivity on visual discrimination and detection tasks, and these behavioral effects seem to originate from changes in neural activity across several brain regions (1). In monkey visual cortex, spatial cues change the statistics of neuronal activity, and these changes are thought to reflect an increase in signal-to-noise synonymous with the spatially restricted changes in perceptual sensitivity characteristic of selective attention (2-4). The frontal and parietal cortex are also strongly implicated in the control of spatial attention (2, 3). Electrical microstimulation of neurons in frontal cortex of monkeys leads to shifts in selective attention mimicking the effects of visual cues (5); conversely, suppression of neural activity in frontal or parietal cortex leads to deficits in performance on attention-demanding tasks (6-8).These and similar observations have led to an explanatory framework in which the fidelity of sensory processing in visual cortex is regulated by a network of frontal and parietal cortical areas (9-12). This framework predicts that suppression of activity in one or more of these areas should impair the ability of an animal to use cues to improve its perceptual sensitivity. This prediction has not been directly tested in animals, although clinical cases (13) and experiments in humans using transcranial magnetic stimulation (14, 15) corroborate the idea that these cortical areas are important for the orienting of attention and the use of spatial cues.In addition to this network o...

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Backward position shift in apparent motion

Cited by 20 publications

References 35 publications

Saccadic Suppression of Displacement Does Not Reflect a Saccade-Specific Bias to Assume Stability

Saccadic Suppression of Displacement Does Not Reflect a Saccade-Specific Bias to Assume Stability

Action can amplify motion-induced illusory displacement

Changes in perceptual sensitivity related to spatial cues depends on subcortical activity

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