TY - JOUR

T1 - Effects of stereoscopic disparity on early ERP components during classification of three-dimensional objects

AU - Pegna, Alan

AU - Darque, Alexandre

AU - Roberts, Mark

AU - Leek, Charles

N1 - The Quarterly Journal of Experimental Psychology was part of the Taylor & Francis group where this article appeared online early May 2017. In January 2018 this was taken up as part of Sage and this article appeared on their website as first published online 1.1.18. We have kept the online early date as it was when it appeared with Taylor and Francis as this is the first date the article appeared in the Public domain.

PY - 2018/6/1

Y1 - 2018/6/1

N2 - This study investigates the effects of stereo disparity on the perception of three-dimensional (3D) object shape. We tested the hypothesis that stereo input modulates the brain activity related to perceptual analyses of 3D shape configuration during image classification. High-density (256-channel) EEG was used to record the temporal dynamics of visual shape processing under conditions of two-dimensional (2D) and three-dimensional (3D) visual presentation. On each trial, observers made image classification judgements (‘Same’/’Different’) to two briefly presented, multi-part, novel objects. On different-object trials, stimuli could either share volumetric parts but not the global 3D shape configuration, have different parts but the same global 3D shape configuration, or differ on both aspects. Analyses using mass univariate contrasts showed that the earliest sensitivity to 2D versus 3D viewing appeared as a negative deflection over posterior locations on the N1 component between 160ms-220ms post stimulus onset. Subsequently, ERP modulations during the N2 time window between 240ms-370ms were linked to image classification. N2 activity reflected two distinct components – an early N2 (240ms-290ms) and a late N2 (290ms-370ms) that showed different patterns of responses to 2D and 3D input, and differential sensitivity to 3D object structure. The results revealed that stereo input modulates the neural correlates of 3D object shape. We suggest that this reflects differential perceptual processing of object shape under conditions of stereo or mono input. These findings challenge current theories that attribute no functional role for stereo input during 3D shape perception.

AB - This study investigates the effects of stereo disparity on the perception of three-dimensional (3D) object shape. We tested the hypothesis that stereo input modulates the brain activity related to perceptual analyses of 3D shape configuration during image classification. High-density (256-channel) EEG was used to record the temporal dynamics of visual shape processing under conditions of two-dimensional (2D) and three-dimensional (3D) visual presentation. On each trial, observers made image classification judgements (‘Same’/’Different’) to two briefly presented, multi-part, novel objects. On different-object trials, stimuli could either share volumetric parts but not the global 3D shape configuration, have different parts but the same global 3D shape configuration, or differ on both aspects. Analyses using mass univariate contrasts showed that the earliest sensitivity to 2D versus 3D viewing appeared as a negative deflection over posterior locations on the N1 component between 160ms-220ms post stimulus onset. Subsequently, ERP modulations during the N2 time window between 240ms-370ms were linked to image classification. N2 activity reflected two distinct components – an early N2 (240ms-290ms) and a late N2 (290ms-370ms) that showed different patterns of responses to 2D and 3D input, and differential sensitivity to 3D object structure. The results revealed that stereo input modulates the neural correlates of 3D object shape. We suggest that this reflects differential perceptual processing of object shape under conditions of stereo or mono input. These findings challenge current theories that attribute no functional role for stereo input during 3D shape perception.

KW - 3D SHAPE PERCEPTION, GLOBAL CONFIGURATION, LOCAL PART STRUCTURE, EVOKED POTENTIALS, ERP

U2 - 10.1080/17470218.2017.1333129

DO - 10.1080/17470218.2017.1333129

M3 - Article

VL - 71

SP - 1419

EP - 1430

JO - Quarterly Journal of Experimental Psychology

JF - Quarterly Journal of Experimental Psychology

SN - 1747-0218

IS - 6

ER -