I. Evdokimidis et al., CHANGES OF PRESACCADIC CORTICAL ACTIVITY WHEN PERFORMING HORIZONTAL, VISUALLY GUIDED SACCADES, Electroencephalography and clinical neurophysiology, 102(3), 1997, pp. 256-260
When a visually guided saccade task is running, the presaccadic potent
ial obtained in the initial period of the task differs from those obta
ined later, while the subject's oculomotor performance remains unaffec
ted. These time-related changes of cortical activity consist both of a
n overall decreasing electrical activity as well as a selective one ov
er certain cortical areas. The generalised reduced activity already de
scribed in earlier studies is considered as an unspecified effect such
as fatigue or decreased motivation. On the contrary, the pronounced s
elective changes of cortical activity obtained over cortical areas suc
h as the centro-parietal and frontal cortices, should be related with
more specific, that is, visuomotor function. We assume that at the beg
inning of the task the performance of the saccade needs the activation
of several cortical areas but later on the same oculomotor plan runs
sufficiently under subcortical control. (C) 1997 Elsevier Science Irel
and Ltd.