Papers by Ester Ruth Serinio
The initial learning and subsequent behavioral expression of fear are often viewed as independent... more The initial learning and subsequent behavioral expression of fear are often viewed as independent processes with potentially unique neural substrates. Laboratory animal studies of Pavlovian fear conditioning suggest that the amygdala is important for both forming stimulus associations and for subsequently expressing learned behavioral responses. In the present article, human amygdala activity was studied during the autonomic expression of conditional fear in two differential conditioning experiments with event-related functional magnetic resonance imaging and concurrent recording of skin conductance responses (SCRs). Trials were classified on the basis of individual participants' SCRs. Significant amygdala responding was detected only during trials on which a signal both predicted shock and elicited significant conditional SCR. Conditional stimulus presentation or autonomic activity alone was not sufficient. These results indicate that amygdala activity may specifically reflect the expression of learned fear responses and support the position that this region plays a central role in the expression of emotional reactions. In Pavlovian fear conditioning, a conditional stimulus (CS) is paired with an aversive unconditional stimulus (UCS) such as electric shock. As the CS and UCS are repeatedly and consistently paired, the CS alone begins to elicit behavioral responses in anticipation of a UCS presentation. Learning the predictive relationship between the CS and UCS and then expressing an appropriate response to the CS after learning has taken place are often viewed as two dissociable processes that may rely on distinct neural circuits. The brain circuits underlying Pavlovian fear conditioning support both the acquisition and expression of fear responses (Davis, 2000; LeDoux, 2000; Maren, 2001). The amygdala, a critical component within this circuit, is made up of several distinct nuclei that appear to be differentially involved in either learning stimulus associations or expressing fear responses
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Papers by Ester Ruth Serinio