title: Single-trial analysis of neuroimaging data: inferring neural networks underlying perceptual decision-making in the human brain.
abstract: Advances in neural signal and image acquisition as well as in multivariate signal processing and machine learning are enabling a richer and more rigorous understanding of the neural basis of human decision-making. Decision-making is essentially characterized behaviorally by the variability of the decision across individual trials--e.g., error and response time distributions. To infer the neural processes that govern decision-making requires identifying neural correlates of such trial-to-trial behavioral variability. In this paper, we review efforts that utilize signal processing and machine learning to enable single-trial analysis of neural signals acquired while subjects perform simple decision-making tasks. Our focus is on neuroimaging data collected noninvasively via electroencephalograpy (EEG) and functional magnetic resonance imaging (fMRI). We review the specific framework for extracting decision-relevant neural components from the neuroimaging data, the goal being to analyze the trial-to-trial variability of the neural signal along these component directions and to relate them to elements of the decision-making process. We review results for perceptual decision-making and discrimination tasks, including paradigms in which EEG variability is used to inform an fMRI analysis. We discuss how single-trial analysis reveals aspects of the underlying decision-making networks that are unobservable using traditional trial-averaging methods.
authors.affiliation: Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA. psajda@columbia.edu
authors.forename: Paul
authors.initials: P
authors.lastname: Sajda
authors.forename: Marios G
authors.initials: MG
authors.lastname: Philiastides
authors.forename: Lucas C
authors.initials: LC
authors.lastname: Parra
mesh_terms: D001185:Artificial Intelligence; D001921:Brain / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D004569:Electroencephalography / Q000379:methods; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009415:Nerve Net / Q000502:physiology*; D059906:Neuroimaging / Q000379:methods*; D011340:Problem Solving / Q000502:physiology; D011930:Reaction Time / Q000502:physiology