摘要：SummaryTo explore the relative contributions of higher-order and primary visual cortex (V1) to visual perception, we compared cats' behavioral and V1 neuronal contrast sensitivity functions (CSF) and threshold versus external noise contrast (TvC) functions before and after top-down influence of area 7 (A7) was modulated with transcranial direct current stimulation (tDCS). We found that suppressing top-down influence of A7 with cathode-tDCS, but not sham-tDCS, reduced behavioral and neuronal contrast sensitivity in the same range of spatial frequencies and increased behavioral and neuronal contrast thresholds in the same range of external noise levels. The neuronal CSF and TvC functions were highly correlated with their behavioral counterparts both before and after the top-down suppression. Analysis of TvC functions using the Perceptual Template Model (PTM) indicated that top-down influence of A7 increased both behavioral and V1 neuronal contrast sensitivity by reducing internal additive noise and the impact of external noise.Graphical abstractDisplay OmittedHighlights•Top-down suppression lowers both behavioral and V1 neuronal CSF functions•Top-down suppression raises both behavioral and V1 neuronal TvC functions•The neuronal CSFs and TvCs are highly correlated with their behavioral counterparts•Top-down influence lowers internal additive noise and impact of external noise in V1Biological science, Behavioral neuroscience, Sensory neuroscience, Visual neuroscience
