Rapid Motion Adaptation Reveals the Temporal Dynamics of Spatiotemporal Correlation between ON and OFF Pathways.

Can Oluk,Andrea Pavan,Hulusi Kafaligonul

doi:10.1038/srep34073

Can Oluk, Andrea Pavan + Show 1 more

Open Access

https://doi.org/10.1038/srep34073

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Journal: Scientific Reports	Publication Date: Sep 26, 2016
Citations: 9	License type: CC BY 4.0

Affiliation: Bilkent University, University of Lincoln

Abstract

At the early stages of visual processing, information is processed by two major thalamic pathways encoding brightness increments (ON) and decrements (OFF). Accumulating evidence suggests that these pathways interact and merge as early as in primary visual cortex. Using regular and reverse-phi motion in a rapid adaptation paradigm, we investigated the temporal dynamics of within and across pathway mechanisms for motion processing. When the adaptation duration was short (188 ms), reverse-phi and regular motion led to similar adaptation effects, suggesting that the information from the two pathways are combined efficiently at early-stages of motion processing. However, as the adaption duration was increased to 752 ms, reverse-phi and regular motion showed distinct adaptation effects depending on the test pattern used, either engaging spatiotemporal correlation between the same or opposite contrast polarities. Overall, these findings indicate that spatiotemporal correlation within and across ON-OFF pathways for motion processing can be selectively adapted, and support those models that integrate within and across pathway mechanisms for motion processing.

Highlights

At the early stages of visual analysis, two major categories of retinal ganglion cells have been identified based on their contrast polarity preferences: ON- and OFF-center ganglion cells
Bonferroni corrected pairwise comparisons showed that direction reports in the expected direction for regular motion were significantly higher than reverse-phi for all stimulus durations (188 ms, p = 0.003; 376 ms, p = 0.019; 752 ms, p = 0.049)
Several studies emphasized the segregation of the two pathways at early stages of visual motion processing, suggesting that the information carried by the two pathways remains segregated and feeds separate motion detectors[19,35]

Summary

Introduction

At the early stages of visual analysis, two major categories of retinal ganglion cells have been identified based on their contrast polarity preferences: ON- and OFF-center ganglion cells. There is physiological evidence in cats and macaque monkeys that reverse-phi motion activates directional selective neurons in primary visual cortex (V1) and MT tuned to the direction opposite to the physical displacement[14,15]. Though these studies describe the neural correlates of reverse-phi motion at early stages of motion processing, it is still unclear how spatiotemporal correlation between opposite contrast polarities is achieved for directional selectivity[13,16]. These distinctive effects of rapid motion adaptation are considered to be perceptual manifestations of neural plasticity at different levels of motion processing[21,23,24,27,28]

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