The emergence of temporal hyperacuity from widely tuned cell populations.
Network
; 15(3): 159-77, 2004 Aug.
Article
en En
| MEDLINE
| ID: mdl-15468733
ABSTRACT
Typically, individual neural cells operate on a millisecond time scale yet behaviorally animals reveal sub-microsecond acuity. Our model resolves this huge discrepancy by using populations of many widely tuned cells to attain sub-microsecond resolution in a temporal discrimination task. An echolocating bat uses its auditory system to locate objects and it demonstrates remarkable temporal precision in psychophysical tasks. Auditory cells were simulated using realistic parameters and connected in three ascending layers with descending projections from auditory cortex. Coincidence detection of firing collicular cells at thalamus and subsequent integration of multiple inputs at cortex, produce an estimate of time represented as the mean of the active cortical population. Multiple estimates allow the model bat to use memory to recognize predictable change in stimuli values. The best performance is produced using cortical feedback and a computation of target time based on combining the current and previous estimates. Temporal hyperacuity is attained through population coding of physiologically realistic cells but depends on the inherent properties of the psychophysical task.
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Bases de datos:
MEDLINE
Asunto principal:
Corteza Auditiva
/
Percepción Espacial
/
Percepción del Tiempo
/
Ecolocación
/
Modelos Neurológicos
/
Neuronas
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Network
Año:
2004
Tipo del documento:
Article
País de afiliación:
Estados Unidos