Perceptual Discrimination of Basic Object Features Is Not Facilitated When Priming Stimuli Are Prevented From Reaching Awareness by Means of Visual Masking.

Hayden J Peel,Philippe A Chouinard,Irene Sperandio,Robin Laycock

doi:10.3389/fnint.2018.00013

Hayden J Peel, Philippe A Chouinard + Show 2 more

Open Access

https://doi.org/10.3389/fnint.2018.00013

Copy DOI

Abstract

Our understanding of how form, orientation and size are processed within and outside of awareness is limited and requires further investigation. Therefore, we investigated whether or not the visual discrimination of basic object features can be influenced by subliminal processing of stimuli presented beforehand. Visual masking was used to render stimuli perceptually invisible. Three experiments examined if visible and invisible primes could facilitate the subsequent feature discrimination of visible targets. The experiments differed in the kind of perceptual discrimination that participants had to make. Namely, participants were asked to discriminate visual stimuli on the basis of their form, orientation, or size. In all three experiments, we demonstrated reliable priming effects when the primes were visible but not when the primes were made invisible. Our findings underscore the importance of conscious awareness in facilitating the perceptual discrimination of basic object features.

Highlights

Many studies have demonstrated that the processing of visually presented faces (Kouider et al, 2009; Faivre et al, 2012), words (De Houwer et al, 2002; Klauer et al, 2007; Ortells et al, 2016) and numbers (Dehaene et al, 1998; Naccache and Dehaene, 2001) can occur outside of awareness
Electrophysiological studies in nonhuman primates and functional magnetic resonance imaging studies in humans have demonstrated that the primary visual cortex (V1) can process information about the size and orientation of stimuli
The masking technique used was successful in rendering stimuli perceptually invisible—with categorization accuracy being at chance-level when responding to the masked prime images in both recognition tasks

Summary

Introduction

Many studies have demonstrated that the processing of visually presented faces (Kouider et al, 2009; Faivre et al, 2012), words (De Houwer et al, 2002; Klauer et al, 2007; Ortells et al, 2016) and numbers (Dehaene et al, 1998; Naccache and Dehaene, 2001) can occur outside of awareness. Less research has considered how more basic features of objects might be processed outside of awareness. We aimed to determine if different types of basic stimulus features can be processed outside of awareness. We used a priming paradigm to determine if the subconscious processing of stimulus form, orientation and size could alter the subsequent conscious perception of another stimulus. Visual areas are known to be important in processing basic low-level stimulus features while later ones are more concerned with more complex features (Tanaka, 1993). Electrophysiological studies in nonhuman primates and functional magnetic resonance imaging (fMRI) studies in humans have demonstrated that the primary visual cortex (V1) can process information about the size and orientation of stimuli (for a review see Grill-Spector et al, 2001). As information is processed further along the ventral stream, neurons have larger receptive fields

Objectives

Results

Conclusion