Human alpha rhythms during visual delayed choice reaction time tasks: a magnetoencephalography study.
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.
Babiloni
Claudio
C
Dipartimento di Fisiologia Umana e Farmacologia, Università La Sapienza, Rome, Italy. claudio.babiloni@uniromal.it
Babiloni
Fabio
F
Carducci
Filippo
F
Cincotti
Febo
F
Del Percio
Claudio
C
Della Penna
Stefania
S
Franciotti
Raffaella
R
Pignotti
Sandro
S
Pizzella
Vittorio
V
Rossini
Paolo Maria
PM
Sabatini
Elisabetta
E
Torquati
Kathya
K
Romani
Gian Luca
GL
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*