Article

Bases neurobiológicas del contraste negativo sucesivo

Revista latinoamericana de psicología (Impact Factor: 0.64). 01/2001; 33(3).
Source: DOAJ

ABSTRACT

El contraste negativo sucesivo (CNS) es unode los efectos paradójicos del reforzamiento que se produce ante una sorpresiva disminución en la calidad y/o cantidad de un reforzador esperado. En el presente trabajo se hace una revisión de la información existente sobre las bases neurobiológicas del CNS en procedimientos instrumentales y consumatorios. Se analizan los estudios del efecto de drogas, lesiones cerebrales, estimulación y registro electrofisiológico sobre este fenómeno. La mayoría de las investigaciones se han concentrado en evaluar el papel de los factores emocionales involucrados, habiendo pocos estudios sobre los factores cognitivos (representación interna del reforzador, memoria de refuerzos previos y expectativa de reforzamiento). Las investigaciones con drogas revelan que el CNS se atenúa o desaparece con la aplicación de drogas tranquilizantes y no se modifica por la administración de antidepresivos o neurolépticos. Además, el sistema gabaérgico de la amígdala y el sistema colinérgico participan en la modulación de la memoria para los cambios de reforzamiento. Los estudios con lesiones muestran que en el CNS instrumental estaráninvolucrados el septum, hipocampo y cíngulo, mientras que en el CNS consumatorio, lo estarían la amígdala y el núcleo parabraquial. Los estudios de registro electrofisiológico sugieren la participación de la corteza prefrontal en la expresión de estos fenómenos.

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