A tilt after-effect for images of buildings: evidence of selectivity for the orientation of everyday scenes.

Ahamed Miflah Hussain Ismail,Joshua A Solomon,Isabelle Mareschal,Miles Hansard

doi:10.1098/rsos.160551

Ahamed Miflah Hussain Ismail, Joshua A Solomon + Show 2 more

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https://doi.org/10.1098/rsos.160551

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Abstract

The tilt after-effect (TAE) is thought to be a manifestation of gain control in mechanisms selective for spatial orientation in visual stimuli. It has been demonstrated with luminance-defined stripes, contrast-defined stripes, orientation-defined stripes and even with natural images. Of course, all images can be decomposed into a sum of stripes, so it should not be surprising to find a TAE when adapting and test images contain stripes that differ by 15° or so. We show this latter condition is not necessary for the TAE with natural images: adaptation to slightly tilted and vertically filtered houses produced a ‘repulsive’ bias in the perceived orientation of horizontally filtered houses. These results suggest gain control in mechanisms selective for spatial orientation in natural images.

Highlights

Gibson & Radner [1] demonstrated that adapting to a line tilted between 2.5° and 45° from vertical makes a vertical ‘test’ stimulus, presented in the same retinal location, appear tilted in a direction opposite to that of the adaptor
In Experiment 2, the specific question we address is whether the tilt after-effect (TAE) for natural scenes arises because of interactions between mechanisms selective for natural scenes, or whether it is a by-product of suppression between more lower level mechanisms, selective for spatial orientation in general
Our results extend Dekel & Sagi’s [13] findings of TAEs with natural images as adaptors and sinusoidal gratings as tests, by showing that adaptation to global orientation can occur between adaptors and tests that are natural images

Summary

Introduction

Gibson & Radner [1] demonstrated that adapting to a line tilted between 2.5° and 45° from vertical makes a vertical ‘test’ stimulus, presented in the same retinal location, appear tilted in a direction opposite to that of the adaptor. This repulsive effect on perceived orientation is known as the tilt after-effect (TAE). The TAE is a natural consequence of orientation-selective suppression, which effectively skews neural 2 responses away from the adapting orientation. Using after-effects, psychophysicists have inferred the existence of neural selectivity for such complex attributes as shape, glossiness and facial expression [8]. Inferring neural mechanisms from perceptual after-effects is not always as straightforward as one might hope

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