RT Journal Article
SR Electronic
T1 Human self-initiated action is preceded by a reliable process of noise reduction
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 120105
DO 10.1101/120105
A1 Nima Khalighinejad
A1 Aaron Schurger
A1 Andrea Desantis
A1 Leor Zmigrod
A1 Patrick Haggard
YR 2017
UL http://biorxiv.org/content/early/2017/03/24/120105.abstract
AB A gradual buildup of electrical potential over motor areas precedes self-initiated movements. These “readiness potentials” (RPs) could simply reflect stochastic fluctuations in neural activity. We operationalised self-initiated actions as endogenous ‘skip’ responses while waiting for target stimuli in a perceptual decision task. Across-trial variability of EEG decreased more markedly prior to self-initiated compared to externally-triggered skip actions. This convergence towards a fixed pattern suggests a consistent preparatory process prior to self-initiated action. A leaky stochastic accumulator model could reproduce these features of the data, given the additional assumption of a decrease in noise level at the input to the accumulator prior to self-initiated, but not externally-triggered actions. The assumed reduction in neural noise was supported by analyses of both within-trial EEG variability and of spectral power. We suggest that a process of noise reduction is consistently recruited prior to self-initiated action. This precursor event may underlie the emergence of RP.