Temporal Integration of Movement: The Time-Course of Motion Streaks Revealed by Masking

Alais, David; Apthorp, Deborah; Karmann, Anna; Cass, John

doi:10.1371/journal.pone.0028675

Cited by 17 publications

(14 citation statements)

References 52 publications

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“…Thus, rapid retinal motion produces responses both in motion-selective cells tuned to that direction, and in orientation-selective cells tuned to an orientation aligned with the axis of the motion—the motion-streak. Psychophysical evidence from orientation detection and after-effects, as well as recent neuroimaging data, is consistent with the view that motion-streaks excite orientation-tuned cells in the human visual system (Alais et al, 2011; Apthorp et al, 2011, 2013). Geisler (1999) proposed that the outputs of motion- and orientation-selective cells are combined in visual cortex to create a “spatial motion-direction” (SMD) sensor tuned to both streak orientation and motion direction.…”

Section: Motion-streakssupporting

confidence: 81%

Interactions between motion and form processing in the human visual system

Mather¹,

Pavan²,

Marotti³

et al. 2013

Front. Comput. Neurosci.

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The predominant view of motion and form processing in the human visual system assumes that these two attributes are handled by separate and independent modules. Motion processing involves filtering by direction-selective sensors, followed by integration to solve the aperture problem. Form processing involves filtering by orientation-selective and size-selective receptive fields, followed by integration to encode object shape. It has long been known that motion signals can influence form processing in the well-known Gestalt principle of common fate; texture elements which share a common motion property are grouped into a single contour or texture region. However, recent research in psychophysics and neuroscience indicates that the influence of form signals on motion processing is more extensive than previously thought. First, the salience and apparent direction of moving lines depends on how the local orientation and direction of motion combine to match the receptive field properties of motion-selective neurons. Second, orientation signals generated by “motion-streaks” influence motion processing; motion sensitivity, apparent direction and adaptation are affected by simultaneously present orientation signals. Third, form signals generated by human body shape influence biological motion processing, as revealed by studies using point-light motion stimuli. Thus, form-motion integration seems to occur at several different levels of cortical processing, from V1 to STS.

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Section: Motion-streakssupporting

confidence: 81%

Interactions between motion and form processing in the human visual system

Mather¹,

Pavan²,

Marotti³

et al. 2013

Front. Comput. Neurosci.

View full text Add to dashboard Cite

show abstract

“…On the other hand, Cesaro and Agostini examined motionpath distortion for speeds of 0.78, 1.55, and 38/s with a single dot of a diameter of 0.0228. While the speeds adopted by Cesaro and Agostini are sufficient to generate a motion streak, it can be questioned whether a motion streak is perceptible given the very small size of the stimulus, and the fact that motion streaks are likely to be low contrast given the fact that they arise from temporal integration (Alais, Apthorp, Karmann, & Cass, 2011;Apthorp, Cass, & Alais, 2010;Kelly, 1961). The fact that increasing speed produces a reduction in the ''slalom'' effect is consistent with a reduction in the visibility of the object at faster speeds.…”

Section: Introductionmentioning

confidence: 92%

The role of motion streaks in the perception of the kinetic Zollner illusion

Khuu

2012

Journal of Vision

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In classic geometric illusions such as the Zollner illusion, vertical lines superimposed on oriented background lines appear tilted in the direction opposite to the background. In kinetic forms of this illusion, an object moving over oriented background lines appears to follow a titled path, again in the direction opposite to the background. Existing literature does not proffer a complete explanation of the effect. Here, it is suggested that motion streaks underpin the illusion; that the effect is a consequence of interactions between detectors tuned to the orientation of background lines and those sensing the motion streaks that arise from fast object motion. This account was examined in the present study by measuring motion-tilt induction under different conditions in which the strength or salience of motion streaks was attenuated: by varying object speed (Experiment 1), contrast (Experiment 2), and trajectory/length by changing the element life-time within the stimulus (Experiment 3). It was predicted that, as motion streaks become less available, background lines would less affect the perceived direction of motion. Consistent with this prediction, the results indicated that, with a reduction in object speed below that required to generate motion streaks (< 1.12°/s), Weber contrast (< 0.125) and motion streak length (two frames) reduced or extinguished the motion-tilt-induction effect. The findings of the present study are consistent with previous reports and computational models that directly combine form and motion information to provide an effective determinant of motion direction.

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“…The RDKs consisted of 100% peak contrast dots with a Laplacian of Gaussian (LoG) profile (Curran et al 2009) with ϭ 0.05°and a peak spatial frequency of 10.6 cycles/deg. The spatial profile of the isotropic LoG dots minimized the artifactual orientation signals known as "motion streaks" resulting from the temporal integration of dot trajectories (Alais et al 2011;Geisler 1999), which may have arisen with nonfiltered dot stimuli. The RDKs had a dot density of 5.9 dots/deg 2 and moved at an average speed of 1.78°/s.…”

Section: Visual Stimulimentioning

confidence: 99%

Human cortical and behavioral sensitivity to patterns of complex motion at eccentricity

Maloney

Watson

Clifford

2013

Journal of Neurophysiology

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Complex patterns of image motion (contracting, expanding, rotating, and spiraling fields) are important in the coordination of visually guided behaviors. Whereas specialized detectors in monkey visual cortex show selectivity for particular patterns of complex motion, their representation in human visual cortex remains unclear. In the present study, functional magnetic resonance imaging (fMRI) was used to investigate the sensitivity of functionally defined regions of human visual cortex to parametrically modulated complex motion trajectories, coupled with complementary psychophysical testing. A unique stimulus design made it possible to disambiguate the neural responses and psychophysical sensitivity to complex motions per se from the distribution of local motions relative to the fovea, which are known to enhance cortical activity when presented radial to fixation. This involved presenting several small, separate motion fields in the periphery in a manner that distinguished them from global optic flow patterns. The patterns were morphed through complex motion space in a systematic time-locked fashion when presented in the scanner. Anisotropies were observed in the fMRI signal, marked by an enhanced response to expanding vs. contracting fields, even in early visual cortex. Anisotropies in the psychophysical sensitivity measures followed a similar pattern that was correlated with activity in areas hV4, V5/MT, and MST. This represents the first systematic examination of complex motion perception at both a behavioral and neural level in human observers. The characteristic processing anisotropy revealed in both data sets can inform models of complex motion processing, particularly with respect to computations performed in early visual cortex.

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Temporal Integration of Movement: The Time-Course of Motion Streaks Revealed by Masking

Cited by 17 publications

References 52 publications

Interactions between motion and form processing in the human visual system

Interactions between motion and form processing in the human visual system

The role of motion streaks in the perception of the kinetic Zollner illusion

Human cortical and behavioral sensitivity to patterns of complex motion at eccentricity

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