Cognitive control and regulation of mood
The neurotransmitter serotonin regulates cognitive processes (e.g. impulsivity), and mood. The interplay between cognition, mood and serotonin is the focus of this project. It has been shown in a series of experiments that manipulation of serotonin in the healthy brain leads to increased impulsivity in men, whereas women experience more depressive symptoms. It is previously documented that a common variant of a gene influencing the serotonin level in the brain is associated with vulnerability for the development of mood disorders (depression). Healthy women carrying this variant of the gene have more problems inhibiting the effects of negative stimuli compared to those carrying a more resistant variant of this gene. This research will give new insights into the cognitive mechanisms underlying the development and maintenance of mood disorders.
Impulsivity disorders. Neuropsychological perspectives
Although central in a number of clinical contexts, knowledge about impulsivity is lacking. Based on a neuroscience perspective we investigate patients with borderline personality disorder (BPD) and adolescents engaged in non-suicidal self harming. Both traditional neuropsychological test methods and new experimental paradigms are used. BPD patients seem to select inappropriate choices in an experimental situation, which might be a model for better understanding of the problems these patients often encounter in their daily life. Impulsivity in self-harming adolescents might be related to problems regulating affects.
Memory processes after exposure to severe trauma
People exposed to shocking, horrific events, experience long lasting negative effects. Some suffer a chronic combination of symptoms that is at the core of the debilitating condition called posttraumatic stress disorder (PTSD): re-experiencing, heightened physiological preparedness and avoidance behaviours. PTSD is unique among the anxiety disorders because instead of being preoccupied with a future threat, the mental life of sufferers is dominated by an event that has already taken place. For this reason, cognitive psychologists have argued that PTSD can be seen as a disorder of memory, and this research programme is attempting to shed some light on the cognitive patterns of impairment after trauma exposure. Exploring the similarities between the cognitive patterns after trauma and in depressed patients is also a feature of the research.
Publications
Brennen, T. (2010). Reflections on collaboration with Tuzla in the field of psychology and war: Past, present and future. Acta Medica Saliniana, 39, 43-45.
Brennen, T., Dybdahl, R., & Kapidžić, A. (2007). Trauma-related and neutral false memories in war-induced Posttraumatic Stress Disorder. Consciousness and Cognition, 16, 877-885.
Brennen, T., Hasanović, M., Zotović, M., Blix, I., Skar, A.M.S., Kravić Prelić, N., Mehmedović, I., Pajević, I., Popović, N., and Gavrilov-Jerković, V. (2010). Trauma exposure in childhood impairs the ability to recall specific autobiographical memories in late adolescence. Journal of Traumatic Stress, 23, 240-247.
Dehli, L. & Brennen, T. (2009). Does retrieval-induced forgetting occur for emotional stimuli? Cognition and Emotion, 23, 1056-1068.
Landrø, N.I., Jonassen, R., Lyche, P., Neumeister, A., Stiles, T.C. & Endestad, T. (2009). Male - female serotonin transporter polymorphisms and emotion processing. Frontiers in Neuroscience, 3, 244-245.
Lyche, P., Jonassen, R., Stiles, T.C., Ulleberg, P. & Landrø, N.I. (accepted pending revisions). Attentional functions in unipolar major depression with and without co-morbid anxiety. Archives of Clinical Neuropsychology.
Lyche, P., Jonassen, R., Stiles, T.C., Ulleberg, P. & Landrø, N.I. (accepted pending revisions). Verbal memory functions in unipolar major depression with and without co-morbid anxiety. The Clinical Neuropsychologist.
Fikke, L., Landrø, N.I. Melinder, A. (accepted pending revisions). Working memory and verbal learning are impaired in adolescents engaging in non-suicidal self-injury. Journal of the International Neuropsychological Society.
Fikke, L., Melinder, A. & Landrø, N.I. (2010). Executive functions are impaired in adolescents engaging in non-suicidal self harming. Psychological Medicine, In press.
Geraerts, E. & Brennen, T. (2006). Investigating cognitive abnormalities in Posttraumatic Stress Disorder. In M.J.Roy (Ed.), Novel approaches to the diagnosis and treatment of posttraumatic stress disorder (pp. 31-40). Amsterdam: IOS Press (NATO Science Series).
Haaland Øksendal, V., Esperaas, L. & Landrø, N.I. (2009). Selective deficit in executive functions among patients with borderline personality disorder. Psychological Medicine, 39,10, 1733-1743.
Haaland Øksendal, V. & Landrø, N.I. (2009). Pathological dissociation and neuropsychological functioning in borderline personality disorder. Acta Psychiatrica Scandinavica, 119, 333-416.
Haaland Øksendal V.& Landrø, N.I. (2007). Decision making as measured with the Iowa Gambling Task in patients with borderline personality disorder. Journal of the International Neuropsychological Society, 13, 699-703.
Walderhaug, E., Herman, A.I., Magnusson, A., Morgan, M.J. & Landrø, N.I. (2010). The short (s) allele of the serotonin transporter polymorphism and acute tryptophan depletion both increase impulsivity in men. Neuroscience Letters, 473, 208-211.
Walderhaug, E., Landrø, N.I., & Magnusson, A. (2008). A synergic effect between lowered serotonin and novel situations on impulsivity measured by CPT. Journal of Clinical and Experimental Neuropsychology, 30, 204-11.
Walderhaug, E., Magnusson, A., Neumeister, A., Lappalainen, J., Refsum, H., Lunde, H. & Landrø, N.I. (2007). Interactive effects of sex and 5-HTTLPR on mood and impulsivity during tryptophan depletion in healthy people. Biological Psychiatry, 62, 593-99.
Wang, C.E., Brennen, T. and Holte, A. (2006). Automatic and effortful processing of self-statements in depression. Cognitive Behaviour Therapy, 35, 117-124.
Wang, C.E., Brennen, T. and Holte, A. (2006). Decreased approach motivation in depression. Scandinavian Journal of Psychology, 47, 505-511.
