102 research outputs found
Optimal encoding of interval timing in expert percussionists
We measured temporal reproduction in expert drummers, string-musicians and non-musical subjects. While duration reproduction of the controls showed a characteristic regression to the mean, drummers responded veridically. This behavior is well explained by a model that combines optimally the sensory estimate for duration (more precise in drummers) with a prior, given by the average of the past few trials. These results highlight the efficiency and adaptability of sensori-motor mechanisms estimating temporal duration
Adaptation-Induced Compression of Event Time Occurs Only for Translational Motion
Adaptation to fast motion reduces the perceived duration of stimuli displayed at the same location as the adapting stimuli. Here we show that the adaptation-induced compression of time is specific for translational motion. Adaptation to complex motion, either circular or radial, did not affect perceived duration of subsequently viewed stimuli. Adaptation with multiple patches of translating motion caused compression of duration only when the motion of all patches was in the same direction. These results show that adaptation-induced compression of event-time occurs only for uni-directional translational motion, ruling out the possibility that the neural mechanisms of the adaptation occur at early levels of visual processing
Blood Oxygen Level-Dependent Activation of the Primary Visual Cortex Predicts Size Adaptation Illusion
In natural scenes, objects rarely occur in isolation but appear within a spatiotemporal context. Here, we show that the perceived size of a stimulus is significantly affected by the context of the scene: brief previous presentation of larger or smaller adapting stimuli at the same region of space changes the perceived size of a test stimulus, with larger adapting stimuli causing the test to appear smaller than veridical and vice versa. In ahumanfMRI study, we measured the blood oxygen level-dependent activation (BOLD) responses of the primary visual cortex (V1) to the contours of large-diameter stimuli and found that activation closely matched the perceptual rather than the retinal stimulus size: the activated area of V1 increased or decreased, depending on the size of the preceding stimulus. A model based on local inhibitory V1 mechanisms simulated the inward or outward shifts of the stimulus contours and hence the perceptual effects. Our findings suggest that area V1 is actively involved in reshaping our perception to match the short-term statistics of the visual scene
Adaptation to the Speed of Biological Motion in Autism
See the readme.doc file in the zipped folde
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