Cognition, Behavior, and Memory
Author: Juan Ignacio Segura | Email: jisegura@mail.austral.edu.ar
Ana Paula Colombini1°2°, Thiago Casetta1°3°,Juan Ignacio Segura1°2°, Guillermina Alvarez1°2°, Martina López1°4°, Bautista Elizalde Acevedo1°2°, Lucía Alba-Ferrara1°2°
1° ENyS – Hospital el Cruce – CONICET – UNAJ, Argentina
2° Facultad de Ciencias Biomédicas, Universidad Austral.
3° Facultad de Humanidades, Universidad de Belgrano.
4° Facultad de Psicología, Universidad de Montevideo.
Objective:Identify the neurological basis of inhibitory control in response to hedonic stimuli in problem drinkers, which may act as a mechanism of behavioural change without formal treatment.
Methodology:24 participants underwent an fMRI scan during a dichotic listening task. Two stimuli were presented simultaneously on each ear; one alcohol-related and one unrelated. Participants were asked to focus their attention on one ear and respond whether the sound was alcohol related. We considered two trial types: Bottom-Up (BU) (alcohol-related stimulus in the attended ear) and Top-Down (TD) (alcohol-related stimulus in the ignored ear). We measured alcohol consumption with the AUDIT scale.
Results:BU trials activated the Right Angular Gyrus, Right Precentral Gyrus, Left Middle Frontal Gyrus and Right Superior Parietal Gyrus; while TD trials activated the Left Postcentral Gyrus, Right Parahippocampal Gyrus, Right Cerebellum, Dorsolateral Prefrontal Cortex (DLPFC), Right Superior and Left Inferior Temporal Gyrus, and Right Precentral Gyrus.
Discussion:TD trials possess higher cognitive demand, as they require the subject to ignore the distracting hedonic stimulus. This explains the activation of the DLPFC. The absence of this activation in BU trials suggests a decrease in cognitive demand and control, provoked by the involuntary capture of attention by the hedonic stimulus. The DLPFC may underlie a necessary control mechanism that inhibits behaviour directed to alcohol search.