Motion and position coding

Arnold, Derek H.; Thompson, Michael; Johnston, Alan

doi:10.1016/j.visres.2007.04.025

Cited by 48 publications

(80 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present context, such modulations could be driven by scaling processes driven by higher-level visual brain structures (Taira et al, 2000;Tsutsui et al, 2002;Sterzer and Rees, 2006). The present data cannot distinguish between these two possibilities [but see Arnold et al (2007) for data concerning illusory motion-induced position shifts]. Additional work will therefore be required to discover the neurophysiological mechanism/s underlying the interactions between spatial coding and apparent viewing distance that have been identified here.…”

Section: Discussionmentioning

confidence: 77%

“…We suggest an alternative. Apparent position shifts could instead be driven by intercortical and intracortical brain region interactions that modulate a cortical cell's response, without changing the locus on the retinal surface/s from which input is derived (Liu et al, 2006;Arnold et al, 2007;Viswanathan and Freeman, 2007). In the present context, such modulations could be driven by scaling processes driven by higher-level visual brain structures (Taira et al, 2000;Tsutsui et al, 2002;Sterzer and Rees, 2006).…”

Section: Discussionmentioning

confidence: 90%

See 1 more Smart Citation

Perceived Size and Spatial Coding

Arnold

Birt²,

Wallis³

2008

Journal of Neuroscience

View full text Add to dashboard Cite

Images of the same physical dimensions on the retina can appear to represent different-sized objects. One reason for this is that the human visual system can take viewing distance into account when judging apparent size. Sequentially presented images can also prompt spatial coding interactions. Here we show, using a spatial coding phenomenon (the tilt aftereffect) in tandem with viewing distance cues, that the tuning of such interactions is not simply determined by the physical dimensions of retinal input. Rather, we find that they are contingent on apparent size. Our data therefore reveal that spatial coding interactions in human vision are modulated by processes involved in the determination of apparent size.

show abstract

Section: Discussionmentioning

confidence: 77%

Section: Discussionmentioning

confidence: 90%

Perceived Size and Spatial Coding

Arnold

Birt²,

Wallis³

2008

Journal of Neuroscience

View full text Add to dashboard Cite

show abstract

“…For example, motion can be perceived in stimuli with no directional motion signal by tracking position changes along a specific direction (10). These phenomena, however, are currently regarded as arising from independent mechanisms (11)(12)(13)(14).…”

mentioning

confidence: 99%

Unifying account of visual motion and position perception

Kwon

Tadin

Knill

2015

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

115

151

View full text Add to dashboard Cite

Despite growing evidence for perceptual interactions between motion and position, no unifying framework exists to account for these two key features of our visual experience. We show that percepts of both object position and motion derive from a common object-tracking system-a system that optimally integrates sensory signals with a realistic model of motion dynamics, effectively inferring their generative causes. The object-tracking model provides an excellent fit to both position and motion judgments in simple stimuli. With no changes in model parameters, the same model also accounts for subjects' novel illusory percepts in more complex moving stimuli. The resulting framework is characterized by a strong bidirectional coupling between position and motion estimates and provides a rational, unifying account of a number of motion and position phenomena that are currently thought to arise from independent mechanisms. This includes motion-induced shifts in perceived position, perceptual slow-speed biases, slowing of motions shown in visual periphery, and the well-known curveball illusion. These results reveal that motion perception cannot be isolated from position signals. Even in the simplest displays with no changes in object position, our perception is driven by the output of an objecttracking system that rationally infers different generative causes of motion signals. Taken together, we show that object tracking plays a fundamental role in perception of visual motion and position.visual motion perception | Kalman filter | object tracking | causal inference | motion-induced position shift R esearch into the basic mechanisms of visual motion processing has largely focused on simple cases in which motion signals are fixed in space and constant over time (e.g., moving patterns presented in static windows) (1). Although this approach has resulted in considerable advances in our understanding of low-level motion mechanisms, it leaves open the question of how the brain integrates changing motion and position signals; when objects move in the world, motion generally co-occurs with changes in object position. The process of generating coherent estimates of object motion and position is known in the engineering and computer vision literature as "tracking" (e.g., as used by the Global Positioning System) (2). Conceptualizing motion and position perception in the broader context of object tracking suggests an alternative conceptual framework-one that we show provides a unifying account for a number of perceptual phenomena.An optimal tracking system would integrate incoming position and motion signals with predictive information from the recent past to continuously update perceptual estimates of both an object's position and its motion. Were such a system to underlie perception, position and motion should be perceptually coupled in predictable ways. Signatures of such a coupling appear in a number of known phenomena. On one hand, local motion signals can predictively bias position percepts (3-8). On the other hand, we can pe...

show abstract

“…In the visual studies, the induced displacement in RF spatial representation occurs in a direction opposite to that of the motion signals inducing it. At first glance this seems surprising since it is in exactly the opposite direction to behavioural measurements of motion-induced positional shifts in human subjects, where the perceived location of a stationary object is displaced in the direction of motion (Ramachandran and Anstis 1990;De Valois and De Valois 1991;Arnold et al 2007). However, as retinotopic location is derived from a population response (e.g.…”

Section: Discussionmentioning

confidence: 93%

“…The band-pass tuning of our behavioural effects are obviously inconsistent with such a role. Moreover, auditory RF shifts are mediated by a displacement of both edges of the receptive field (Witten et al 2006), whilst motion-induced spatial misperceptions measured psychophysically, in the visual domain at least, are brought about by changes in apparent contrast at only one edge of the stimulus (Arnold et al 2007;Tsui et al 2007). Clearly, the physiological processes that mediate motion-induced positional shifts remain uncertain.…”

Section: Discussionmentioning

confidence: 99%

Distortions of perceived auditory and visual space following adaptation to motion

2008

View full text Add to dashboard Cite

Adaptation to visual motion can induce marked distortions of the perceived spatial location of subsequently viewed stationary objects. These positional shifts are direction specific and exhibit tuning for the speed of the adapting stimulus. In this study, we sought to establish whether comparable motion-induced distortions of space can be induced in the auditory domain. Using individually measured head related transfer functions (HRTFs) we created auditory stimuli that moved either leftward or rightward in the horizontal plane. Participants adapted to unidirectional auditory motion presented at a range of speeds and then judged the spatial location of a brief stationary test stimulus. All participants displayed direction-dependent and speed-tuned shifts in perceived auditory position relative to a 'no adaptation' baseline measure. To permit direct comparison between effects in different sensory domains, measurements of visual motion-induced distortions of perceived position were also made using stimuli equated in positional sensitivity for each participant. Both the overall magnitude of the observed positional shifts, and the nature of their tuning with respect to adaptor speed were similar in each case. A third experiment was carried out where participants adapted to visual motion prior to making auditory position judgements. Similar to the previous experiments, shifts in the direction opposite to that of the adapting motion were observed. These results add to a growing body of evidence suggesting that the neural mechanisms that encode visual and auditory motion are more similar than previously thought.

show abstract

Motion and position coding

Cited by 48 publications

References 29 publications

Perceived Size and Spatial Coding

Perceived Size and Spatial Coding

Unifying account of visual motion and position perception

Distortions of perceived auditory and visual space following adaptation to motion

Contact Info

Product

Resources

About