INVESTIGADORES
MINDLIN Bernardo Gabriel
artículos
Título:
Neurophysiological bases of exponential sensory decay and top-down memory retrieval: a model
Autor/es:
ARIEL ZYLBERBERG; STANISLAS DEHAENE; GABRIEL B. MINDLIN; MARIANO SIGMAN
Revista:
frontiers in computational neuroscience
Editorial:
Frontiers Research Foundation
Referencias:
Año: 2009 vol. 3 p. 1 - 16
ISSN:
1662-5188
Resumen:
                                       Behavioral observations suggest that multiple sensory elements can be maintained for a short time,                                       forming a perceptual buffer which fades after a few hundred milliseconds. Only a subset of thisof Medicine, USA                                       perceptual buffer can be accessed under top-down control and broadcasted to working memory                                       and consciousness. In turn, single-cell studies in awake-behaving monkeys have identified two                                       distinct waves of response to a sensory stimulus: a first transient response largely determined by                                       stimulus properties and a second wave dependent on behavioral relevance, context and learning.                                       Here we propose a simple biophysical scheme which bridges these observations and establishes                                       concrete predictions for neurophsyiological experiments in which the temporal interval between                                       stimulus presentation and top-down allocation is controlled experimentally. Inspired in single-cell                                       observations, the model involves a first transient response and a second stage of amplification and                                       retrieval, which are implemented biophysically by distinct operational modes of the same circuit,                                       regulated by external currents. We explicitly investigated the neuronal dynamics, the memory                                       trace of a presented stimulus and the probability of correct retrieval, when these two stages were                                       bracketed by a temporal gap. The model predicts correctly the dependence of performance with                                       response times in interference experiments suggesting that sensory buffering does not require a                                       specific dedicated mechanism and establishing a direct link between biophysical manipulations                                       and behavioral observations leading to concrete predictions.