Search Papers | Poster Sessions | All Posters
Poster B116 in Poster Session B - Thursday, August 8, 2024, 1:30 – 3:30 pm, Johnson Ice Rink
Neural Computations Underlying Polar Angle Asymmetries
Shutian Xue1 (), Marisa Carrasco1; 1New York University
Visual performance varies around polar angle and this variation has been related to quantitative factors (e.g., cone density, retinal ganglion cell density and cortical surface area). However, retinal or cortical factors only explains a small portion of polar angle asymmetries, indicating that qualitatively distinct neural computations may also contribute to asymmetries. Here, we investigated whether two computations –featural representation and internal noise– vary around polar angle and underlie polar angle asymmetries. Using a detection task and the psychophysical reverse correlation, we derived the representation of orientations and spatial frequencies, which differed around polar angle in distinct ways. Critically, the extent of asymmetries of orientation sensitivity correlated with the corresponding performance differences, indicating that the sensitivity to orientation (but not spatial frequency) underlie polar angle asymmetries. Concurrently, we estimated internal noise using double-pass method and a noisy observer model, revealing a similar level of internal noise around polar angle and no correlation between the extent of asymmetries. Thus, polar angle asymmetries stem from differential featural representation, but not internal noise.
Keywords: Polar angle asymmetries Reverse correlation Featural representation Internal noise