Causal manipulation of feed-forward and recurrent processing differentially affects measures of consciousness

Allen, C, Viola, T, Irvine, E, Sedgmond, J, Castle, H, Gray, R and Chambers, C.D (2020) 'Causal manipulation of feed-forward and recurrent processing differentially affects measures of consciousness.' Neuroscience of Consciousness, 2020 (1). niaa015. ISSN 2057-2107

[img]
Preview
Text
13591.pdf - Published Version
CC BY 4.0.

Download (640kB) | Preview
Official URL: https://doi.org/10.1093/nc/niaa015

Abstract

It has been theorized that cortical feed-forward and recurrent neural activity support unconscious and conscious cognitive processes, respectively. Here we causally tested this proposition by applying event-related transcranial magnetic stimulation (TMS) at early and late times relative to visual stimuli, together with a pulse designed to suppress conscious detection. Consistent with pre-registered hypotheses, early TMS affected residual, reportedly ‘unseen’ capacity. However, conscious perception also appeared critically dependent upon feed-forward processing to a greater extent than the later recurrent phase. Additional exploratory analyses suggested that these early effects dissociated from top-down criterion measures, which were most affected by later TMS. These findings are inconsistent with a simple dichotomy where feed-forward and recurrent processes correspond to unconscious and conscious mechanisms. Instead, different components of awareness may correspond to different phases of cortical dynamics in which initial processing is broadly perceptual whereas later recurrent processing might relate to decision to report.

Item Type: Article
Keywords: transcranial magnetic stimulation, blindsight, conscious perception, unconscious processing, signal detection theory, feed-forward/recurrent
Divisions: School of Sciences
Identification Number: https://doi.org/10.1093/nc/niaa015
Related URLs:
Date Deposited: 28 Oct 2020 18:43
Last Modified: 28 Oct 2020 18:45
Request a change to this item or report an issue Request a change to this item or report an issue
Update item (repository staff only) Update item (repository staff only)