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Titolo:
Event-related potentials and saccadic reaction times: effects of fixation point offset or change
Autore:
Spantekow, A; Krappmann, P; Everling, S; Flohr, H;
Indirizzi:
Univ Bremen, Inst Brain Res, D-28334 Bremen, Germany Univ Bremen Bremen Germany D-28334 st Brain Res, D-28334 Bremen, Germany Queens Univ, Dept Physiol, Kingston, ON K7L 3N6, Canada Queens Univ Kingston ON Canada K7L 3N6 siol, Kingston, ON K7L 3N6, Canada
Titolo Testata:
EXPERIMENTAL BRAIN RESEARCH
fascicolo: 3, volume: 127, anno: 1999,
pagine: 291 - 297
SICI:
0014-4819(199908)127:3<291:EPASRT>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
BILATERAL STIMULUS ARRAYS; INDEX FOCUSED ATTENTION; EXPRESS SACCADES; SUPERIOR COLLICULUS; WARNING SIGNALS; CORTICAL POTENTIALS; VISUAL-ATTENTION; EARLY SELECTION; GAP; DISENGAGEMENT;
Keywords:
eye movements; gap effect; event-related potentials; fixation; humans;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
30
Recensione:
Indirizzi per estratti:
Indirizzo: Spantekow, A Univ Bremen, Inst Brain Res, NW2-PF 67,POB 33 04 40, D-28334 Bremen, Germany Univ Bremen NW2-PF 67,POB 33 04 40 Bremen Germany D-28334 ny
Citazione:
A. Spantekow et al., "Event-related potentials and saccadic reaction times: effects of fixation point offset or change", EXP BRAIN R, 127(3), 1999, pp. 291-297

Abstract

Previous studies have shown that saccadic reaction times (SRTs) are reduced if the initial fixation point (FP) disappears 200 ms (gap period) before a peripheral target is presented. This gap saccade task is associated with a negative cortical potential at the end of the gap period. To determine whether the neural processes underlying this potential account for the reduction of SRTs during gap saccade tasks, we recorded event-related potentials (ERPs) in 19 subjects performing a gap saccade task (gap duration 200 ms), a warning saccade task (the color of the FP changed 200 ms prior to target appearance) and an overlap task (the FP remained visible during the trial). SRTs were shortest during the gap task, longest during the overlap task and intermediate during the warning task. The gap and warning tasks were accompanied by the same widespread negative cortical potential with a maximum at the time of stimulus presentation. These findings indicate that the warning effect mediated by the disappearance of the FP during gap saccade tasks is responsible for the gap negativity which was observed by several authors. Our findings of shorter SRTs during the gap task than the warning task, however, suggest that the gap has an additional effect that probably dependson subcortical mechanisms.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/07/20 alle ore 16:49:20