The extinction of conditioned fear and its implications for cue exposure therapy [ 2007 - 2009 ]

Research Grant

Researchers: Prof Reginald Westbrook (Principal investigator) ,  Dr Justin Harris

Brief description This project studies extinction of Pavlovian conditioned fear reactions in rats. Extinction of these reactions is an animal model for exposure therapy used in the treatment of anxiety disorders in people. In exposure therapy, the patient, aided by the clinician, confronts trauma-related cues in the absence of any overt danger. The intention of this therapy is to reduce the ability of the trauma-related cues to provoke the fear reactions that are undermining the patient's quality of life. In Pavlovian conditioning, subjects (typically rats) are exposed to a signaling relation between an initially neutral stimulus (e.g., a noise) and a feared outcome (e.g., foot shock). When later repeatedly exposed to the initially neutral but now feared stimulus (the noise) in the absence of the feared outcome, the fear reactions it acquired progressively decline until eventually it fails to elicit any such reactions. The fear reactions are said to have been extinguished. There has been significant progress in understanding the psychological processes and neural mechanisms underlying the acquisition of fear reactions, but much less is known about the processes and mechanisms underlying the extinction of these reactions. The project has two general objectives. The first is to determine the conditions of extinction training that promote long-term loss of fear reactions. The second objective is to determine how the brain controls this extinction of learned fear. Achieving these aims will be significant for two reasons. First, it will contribute to understanding the mechanisms by which animals (including people) learn to adjust their behaviour to bring it into line with the current relations that exist between events in the world. Second, it will provide important information about how such adjustment is facilitated or impaired across extinction training and, thereby, contribute towards understanding both the successes and failures of cue exposure therapy for fear-related disorders.

Funding Amount $AUD 322,430.03

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant