The Study On Early Visual Cortex Mechanisms Of Visual Attention Modulation On Visual Cognition Of Based On Population Receptive Field

Objective:Attention allows us to selectively process the vast amount of information that we confront.Previous studies have shown that visual attention had modulations on the visual cognition in visual cortex.However,many patients with clinical psychology and neurological diseases suffer from attention deficit.Therefore,understanding the brain mechanisms of the visual attention may lay a foundation for diagnosis in early and clarifying the mechanism of related diseases Methods:Studies on population receptive field(pRF)in the aspect of the functional unit of visual processing will contribute to explaining the brain mechanisms of visual cognition In this project,two kinds of attention tasks will be designed based on the visual stimulus of pRF experiment.Using functional magnetic resonance image(fMRI)and population receptive field(pRF)analysis,then draw the outline of early visual cortex(V1-V3)of the subjects,we will investigate the change of pRF size on visual cortexs between the two attention conditions by using paired t-test.Results:(1)The pRF approach measures more accurate visual field maps than the phaseencoded approaches;(2)In all the subjects,The pRF size increases with eccentricity with in each map and the pRF size from the V1 to V3 also increased gradually,which is consistent with the previous studies;(3)based on the eccentricity,the view field is divided into a central field of view(eccentricity of 0-5°)and peripheral vision(eccentricity of 5-10°),results show thatcompared with under attending full field task,the pRF size of the peripheral view of V3 is significantly smaller than under attending center task(t(9)= 4.7133,P= 0.003).Conclusion:(1)Visual attention can modulate human visual cognition by reducing the pRF size of the peripheral visual field in V3 in early visual cortex.(2)The attention regulation of visual cortex is hierarchical.