TY - JOUR
TI - Frontal-parietal activation differences observed before the execution of
remembered saccades: an event-related potentials study
AU - Evdokimidis, I
AU - Smyrnis, N
AU - Constantinidis, TS
AU - Gourtzelidis, P
AU - and Papageorgiou, C
JO - Cognitive Brain Research
PY - 2001
VL - 12
TODO - 1
SP - 89-99
PB - ELSEVIER SCIENCE BV
SN - 0926-6410
TODO - 10.1016/S0926-6410(01)00037-4
TODO - event-related potential; working memory; saccade; eye-movement; frontal
cortex; parietal cortex
TODO - Healthy subjects performed saccadic eye movements in one memory (MEM)
and two (delay tasks delay, DEL and modified delay, M-DEL) while we
recorded scalp event-related potentials (ERPs) from 25 electrode sites.
In the MEM task the subjects were instructed to retain in memory the
location of a visual target for a delay of 1-6 s and then perform a
remembered saccade at the go signal. In the DEL task, the target
remained on until movement completion and in the M-DEL task the target,
that was visible during the delay period, disappeared synchronously with
the go signal. A reduction in response latency and an increase in the
percentage of dysmetric movements were observed fur the MEM task
compared to the two delay tasks. An increased ERP activity at the
central-frontal electrode sites compared to the parietal sites was
significant only for the MEM task early on during the delay period
(500-1000 ms). During the period preceding the onset of the saccade, a
parietal increase of activity was observed for all tasks. Furthermore
the activity was smaller for the frontal compared to the parietal areas
only for the memory task thus indicating a near reversal of the previous
pattern of activity observed during the early delay period. This
specific activation pattern of frontal and parietal areas, observed for
the MEM task only, requires further investigation focusing on the
temporal pattern of activation of large brain areas involved in working
memory processing. (C) 2001 Elsevier Science B.V. All rights reserved.
ER -