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Titolo:
Dependence of saccade-related activity in the primate superior colliculus on visual target presence
Autore:
Edelman, JA; Goldberg, ME;
Indirizzi:
NEI, Sensorimotor Res Lab, Bethesda, MD 20892 USA NEI Bethesda MD USA 20892 I, Sensorimotor Res Lab, Bethesda, MD 20892 USA
Titolo Testata:
JOURNAL OF NEUROPHYSIOLOGY
fascicolo: 2, volume: 86, anno: 2001,
pagine: 676 - 691
SICI:
0022-3077(200108)86:2<676:DOSAIT>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
LATERAL INTRAPARIETAL AREA; FRONTAL EYE FIELD; NEURONAL-ACTIVITY; SINGLE NEURONS; BEHAVIORAL-CHARACTERISTICS; FUNCTIONAL-PROPERTIES; COGNITIVE ACTIVATION; EXPRESS SACCADES; AUDITORY TARGETS; PARIETAL CORTEX;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
68
Recensione:
Indirizzi per estratti:
Indirizzo: Edelman, JA Harvard Univ, Dept Psychol, 33 Kirkland St,7th Floor, Cambridge, MA 02138 USA Harvard Univ 33 Kirkland St,7th Floor Cambridge MA USA 02138 A
Citazione:
J.A. Edelman e M.E. Goldberg, "Dependence of saccade-related activity in the primate superior colliculus on visual target presence", J NEUROPHYS, 86(2), 2001, pp. 676-691

Abstract

Neurons in the intermediate layers of the superior colliculus respond to visual targets and/or discharge immediately before and during saccades. These visual and motor responses have generally been considered independent, with the visual response dependent on the nature of the stimulus, and the saccade-related activity related to the attributes of the saccade, but not to how the saccade was elicited. In these experiments we asked whether saccade-related discharge in the superior colliculus depended on whether the saccade was directed to a visual target. We recorded extracellular activity of neurons in the intermediate layers of the superior colliculus of three rhesus monkeys during saccades in tasks in which we varied the presence or absence of a visual target and the temporal delays between the appearance and disappearance of a target and saccade initiation. Across our sample of neurons (n = 64), discharge was highest when a saccade was made to a still-present visual target, regardless of whether the target had recently appeared or had been present for several hundred milliseconds. Discharge was intermediate when the target had recently disappeared and lowest when the target had never appeared during that trial. These results are consistent with the hypothesis that saccade-related discharge decreases as the time between the target disappearance and saccade initiation increases. Saccade velocity was also higher for saccades to visual targets, and correlated on a trial-by-trial basis with perisaccadic discharge for many neurons. However, discharge of many neurons was dependent on task but independent of saccade velocity, and across our sample of neurons, saccade velocity was higher for saccades made immediately after target appearance than would be predicted by discharge level. A tighter relationship was found between saccade precision and perisaccadic discharge. These findings suggest that just as the purpose of thesaccadic system in primates is to drive the fovea to a visual target, presaccadic motor activity in the superior colliculus is most intense when sucha target is actually present. This enhanced activity may, itself, contribute to the enhanced performance of the saccade system when the saccade is made to a real visual target.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/04/20 alle ore 19:53:11