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Titolo:
Influence of previous visual stimulus or saccade on saccadic reaction times in monkey
Autore:
Dorris, MC; Taylor, TL; Klein, RM; Munoz, DP;
Indirizzi:
QueensLUniv, Dept Physiol, MRC, Grp Sensory Motor Neurosci, Kingston, ON K7 Queens Univ Kingston ON Canada K7L 3N6 ry Motor Neurosci, Kingston, ON K7 Dalhousie Univ, Dept Psychol, Halifax, NS B3H 4J1, Canada Dalhousie Univ Halifax NS Canada B3H 4J1 hol, Halifax, NS B3H 4J1, Canada
Titolo Testata:
JOURNAL OF NEUROPHYSIOLOGY
fascicolo: 5, volume: 81, anno: 1999,
pagine: 2429 - 2436
SICI:
0022-3077(199905)81:5<2429:IOPVSO>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
HUMAN EXPRESS SACCADES; SUPERIOR COLLICULUS; EYE-MOVEMENTS; RETINAL ECCENTRICITY; TARGET SELECTION; WARNING SIGNALS; NEURAL BASIS; ATTENTION; LATENCY; INHIBITION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
68
Recensione:
Indirizzi per estratti:
Indirizzo: Munoz, DP QueensLUniv, Dept Physiol, MRC, Grp Sensory Motor Neurosci, Kingston, ON K7 Queens Univ Kingston ON Canada K7L 3N6 eurosci, Kingston, ON K7
Citazione:
M.C. Dorris et al., "Influence of previous visual stimulus or saccade on saccadic reaction times in monkey", J NEUROPHYS, 81(5), 1999, pp. 2429-2436

Abstract

Saccadic reaction times (SRTs) to suddenly appearing targets are influenced by neural processes that occur before and after target presentation. The majority of previous studies have focused on how posttarget factors, such as target attributes or changes in task complexity, affect SRTs. Studies of pretarget factors have focused on how prior knowledge of the timing or location of the impending target, gathered through cueing or probabilistic information, affects SRTs. Our goal was to investigate additional pretarget factors to determine whether SRTs can also be influenced by the history of saccadic and visual activity even when these factors are spatially unpredictive as to the location of impending saccadic targets. Monkeys were trained ontwo paradigms. In the saccade-saccade paradigm, monkeys were required to follow a saccadic target that stepped from a central location, to an eccentric location, back to center, and finally to a second eccentric location. The stimulus-saccade paradigm was similar, except the central fixation targetremained illuminated during presentation of the first eccentric stimulus; the monkey was required to maintain central fixation and to make a saccade to the second eccentric stimulus only on disappearance of the fixation point. In both paradigms, the first eccentric stimulus was presented at the same, opposite, or orthogonal location with respect to the final target location in a given trial. We measured SRTs to the final target under conditions in which all parameters were identical except for the location of the firsteccentric stimulus. In the saccade-saccade paradigm, we found that the SRTto the final target was slowest when it was presented opposite to the initial saccadic target, whereas in the stimulus-saccade paradigm the SRT to the final target was slowest when it was presented at the same location as the initial stimulus. In both paradigms, these increases in SRTs were greatest during the shortest intervals between presentation of successive eccentric stimuli, yet these effects remained present for the longest intervals employed in this study. SRTs became faster as the direction and eccentricity of the two successive stimuli became increasingly misaligned from that whichproduced the maximal SRT slowing in each paradigm. The results of the stimulus-saccade paradigm are similar to the phenomenon of inhibition of return(IOR) in which human subjects are slower to respond to stimuli that are presented at previously cued locations. We interpret these findings in terms of overlapping representations of visuospatial and oculomotor activity in the same neural structures.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 12/08/20 alle ore 19:29:52