title: Human decision making based on variations in internal noise: an EEG study.
abstract: Perceptual decision making is prone to errors, especially near threshold. Physiological, behavioural and modeling studies suggest this is due to the intrinsic or 'internal' noise in neural systems, which derives from a mixture of bottom-up and top-down sources. We show here that internal noise can form the basis of perceptual decision making when the external signal lacks the required information for the decision. We recorded electroencephalographic (EEG) activity in listeners attempting to discriminate between identical tones. Since the acoustic signal was constant, bottom-up and top-down influences were under experimental control. We found that early cortical responses to the identical stimuli varied in global field power and topography according to the perceptual decision made, and activity preceding stimulus presentation could predict both later activity and behavioural decision. Our results suggest that activity variations induced by internal noise of both sensory and cognitive origin are sufficient to drive discrimination judgments.
authors.affiliation: Medical Research Council Institute of Hearing Research, Nottingham, United Kingdom. Sygal@ihr.mrc.ac.uk
authors.forename: Sygal
authors.initials: S
authors.lastname: Amitay
authors.forename: Jeanne
authors.initials: J
authors.lastname: Guiraud
authors.forename: Ediz
authors.initials: E
authors.lastname: Sohoglu
authors.forename: Oliver
authors.initials: O
authors.lastname: Zobay
authors.forename: Barrie A
authors.initials: BA
authors.lastname: Edmonds
authors.forename: Yu-Xuan
authors.initials: YX
authors.lastname: Zhang
authors.forename: David R
authors.initials: DR
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001921:Brain / Q000502:physiology*; D003657:Decision Making / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D009622:Noise; D055815:Young Adult