The crippling homunculus: inefficient executive control and the persistence of intrusive memories

PhD ceremony: J.R.L. Verwoerd, 14.45 uur, Academiegebouw, Broerstraat 5, Groningen

Thesis: The crippling homunculus: inefficient executive control and the persistence of intrusive memories

Promotor(s): prof. P.J. de Jong

Faculty: Behavioural and Social Sciences

Research has shown that about two-third of the general population will be exposed to a traumatic event at least once in their lives. The emotional impact of a traumatic event (e.g., a major traffic accident) may largely disrupt normal memory functioning. In the aftermath of trauma, most people are confronted with unexpected and unwanted reliving experiences of parts of the event, commonly known as intrusive memories. These mainly visual images are accompanied with strong emotional responses (e.g., fear, shame), which could hinder normal daily life for weeks. After some time, the majority of the trauma survivors will be able to gain control over the stressful intrusive memories and refocus their attention on work and family life. However, a small number of the survivors would show a persistence of intrusive re-experiencing for months or even years. This group would eventually develop a posttraumatic stress disorder (PTSD). This raises the question of how this difference in control between people who show natural recovery and people with persistent intrusions and PTSD could be explained. The key question of this dissertation was whether an innate or early acquired flexibility/capacity to resist unwanted information from consciousness would contribute to regaining control over disruptive memory functioning and support natural recovery after trauma. In five analogue studies (using undergraduates as research participants), it was shown that flexible control over the contents of consciousness prior to experiencing a stressful event (e.g., a trauma-film) would provide people the tools to reduce the frequency of intrusive memories after trauma.