The Flip Tilt Illusion: Visible in Peripheral Vision as Predicted by the Central-Peripheral Dichotomy.

Li Zhaoping

doi:10.1177/2041669520938408

Abstract

Consider a gray field comprising pairs of vertically aligned dots; in each pair, one dot is white the other black. When viewed in a peripheral visual field, these pairs appear horizontally aligned. By the Central-Peripheral Dichotomy, this flip tilt illusion arises because top-down feedback from higher to lower visual cortical areas is too weak or absent in the periphery to veto confounded feedforward signals from the primary visual cortex (V1). The white and black dots in each pair activate, respectively, on and off subfields of V1 neural receptive fields. However, the sub-fields’ orientations, and the preferred orientations, of the most activated neurons are orthogonal to the dot alignment. Hence, V1 reports the flip tilt to higher visual areas. Top-down feedback vetoes such misleading reports, but only in the central visual field.

Highlights

Consider a gray field comprising pairs of vertically aligned dots; in each pair, one dot is white the other black
A vertical hetero-pair could excite a horizontally-tuned primary visual cortex (V1) neuron (Figure 2B), when each dot is in the contrast-corresponding subfield of its visual receptive field (RF), but is ineffective to excite a vertically-tuned V1 neuron (Figure 2C)
When needed to resolve the ambiguity caused by feedforward information loss, top-down feedback queries V1 for additional information, using a form of analysis-by-synthesis (Zhaoping, 2017) to see whether the would-be visual input for each alternative hypothesis matches the actual inputs in V1

Summary

Introduction

Consider a gray field comprising pairs of vertically aligned dots; in each pair, one dot is white the other black. Perception, neural mechanisms, top-down feedback, attention, peripheral vision, primary visual cortex (V1), feedforward-feedback-verify-(re)weight, central-peripheral dichotomy, analysisby-synthesis

Results

Conclusion