Dissociable neural mechanisms for encoding predictable and unpredictable events.
J Cogn Neurosci
; 18(7): 1120-32, 2006 Jul.
Article
en En
| MEDLINE
| ID: mdl-16839286
ABSTRACT
Attention is a necessary condition for the formation of new episodic memories, yet little is known about how dissociable attentional mechanisms for "top-down" and "bottom-up" orienting contribute to encoding. Here, subjects performed an intentional encoding task in which to-be-learned items were interspersed with irrelevant stimuli such that subjects could anticipate the appearance of some study items but not others. Subjects were more likely to later remember stimuli whose appearance was predictable at encoding. Electroencephalographic data were acquired during the study phase of the experiment to assess how synchronous neural activity related to later memory for predictable stimuli (to which attention could be oriented in a top-down fashion) and unpredictable stimuli (which rely to a greater extent on bottom-up attentional orienting). Over left frontal regions, gamma-band activity (25-55 Hz) early (approximately 150 msec) in the epoch was a robust predictor of later memory for predictable items, consistent with an emerging view that links high-frequency neural synchrony to top-down attention. By contrast, later (approximately 400 msec) theta-band activity (4-8 Hz) over the left and midline frontal cortex predicted subsequent memory for unpredictable items, suggesting a role in bottom-up attentional orienting. These results reveal for the first time the contribution of dissociable attentional mechanisms to successful encoding and contribute to a growing literature dedicated to understanding the role of neural synchrony in cognition.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Atención
/
Electroencefalografía
/
Red Nerviosa
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Límite:
Adolescent
/
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
J Cogn Neurosci
Asunto de la revista:
NEUROLOGIA
Año:
2006
Tipo del documento:
Article
País de afiliación:
Estados Unidos