title: Single-trial magnetoencephalography signals encoded as an unfolding decision process.
abstract: The model of a stochastic decision process unfolding in motor and premotor regions of the brain was encoded in single-trial magnetoencephalographic (MEG) recordings while ten healthy subjects performed a sensorimotor Reaction Time (RT) task. The duration of single-trial MEG signals preceding the motor response, recorded over the motor cortex contralateral to the responding hand, co-varied with RT across trials according to the model's prediction. Furthermore, these signals displayed the same properties of a "rising-to-a-fixed-threshold" decision process as posited by the model and observed in the activity of single neurons in the primate cortex. The present findings demonstrate that non-averaged, single-trial MEG recordings can be used to test models of cognitive processes, like decision-making, in humans.
authors.affiliation: Cognition and Action Group, Neurology Department, National and Kapodistrian University of Athens, Medical School, Aeginition Hospital, 72 V Sofias Ave, Athens 11528, Greece. smyrnis@med.uoa.gr
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Smyrnis
authors.forename: Dimitris S
authors.initials: DS
authors.lastname: Mylonas
authors.forename: Roozbeh
authors.initials: R
authors.lastname: Rezaie
authors.forename: Constantinos I
authors.initials: CI
authors.lastname: Siettos
authors.forename: Errikos
authors.initials: E
authors.lastname: Ventouras
authors.forename: Periklis Y
authors.initials: PY
authors.lastname: Ktonas
authors.forename: Ioannis
authors.initials: I
authors.lastname: Evdokimidis
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Papanicolaou
mesh_terms: D000328:Adult; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D011930:Reaction Time / Q000502:physiology*; D055815:Young Adult