title: Human alpha rhythms during visual delayed choice reaction time tasks: a magnetoencephalography study.
abstract: Magnetoencephalography (MEG) includes fast and comfortable recording procedures very suitable for the neurophysiological study of cognitive functions in aged people. In this exploratory MEG study in normal young adults, we tested whether very simple short-term memory (STM) demands induce visible changes in amplitude and latency of surface alpha rhythms. Two delayed response tasks were used. In the STM condition, a simple cue stimulus (one bit) was memorized along a brief delay period (3.5-5.5 s). In the control (no short-term memory; NSTM) condition, the cue stimulus remained available along the delay period. To make extremely simple the tasks, the explicit demand was visuospatial but the retention could be also based on phonological and somatomotor coding. Compared to the control condition, the amplitude of the alpha 1 (6-8 Hz) ERD decreased in the left hemisphere, whereas the amplitude of the alpha 2 (8-10 Hz) and alpha 3 (10-12 Hz) event-related desynchronization (ERD) increased in right and left parietal areas, respectively. Furthermore, the latency of the alpha ERD peak was slightly but significantly (P < 0.05) later in STM compared to control condition. In conclusion, whole-head MEG technology and very simple STM demands revealed significant changes of human neuromagnetic alpha rhythms in normal young adults.
authors.affiliation: Dipartimento di Fisiologia Umana e Farmacologia, Università La Sapienza, Rome, Italy. claudio.babiloni@uniromal.it
authors.forename: Claudio
authors.initials: C
authors.lastname: Babiloni
authors.forename: Fabio
authors.initials: F
authors.lastname: Babiloni
authors.forename: Filippo
authors.initials: F
authors.lastname: Carducci
authors.forename: Febo
authors.initials: F
authors.lastname: Cincotti
authors.forename: Claudio
authors.initials: C
authors.lastname: Del Percio
authors.forename: Stefania
authors.initials: S
authors.lastname: Della Penna
authors.forename: Raffaella
authors.initials: R
authors.lastname: Franciotti
authors.forename: Sandro
authors.initials: S
authors.lastname: Pignotti
authors.forename: Vittorio
authors.initials: V
authors.lastname: Pizzella
authors.forename: Paolo Maria
authors.initials: PM
authors.lastname: Rossini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Sabatini
authors.forename: Kathya
authors.initials: K
authors.lastname: Torquati
authors.forename: Gian Luca
authors.initials: GL
authors.lastname: Romani
mesh_terms: D000328:Adult; D000513:Alpha Rhythm; D001931:Brain Mapping; D002755:Choice Behavior / Q000502:physiology*; D003344:Cortical Synchronization; D005074:Evoked Potentials, Visual / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008570:Memory, Short-Term / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*