Retrieval induced forgetting in depression and schizophrenia: role of mood and the cholinergic system

Sterkaj, F. 2012. Retrieval induced forgetting in depression and schizophrenia: role of mood and the cholinergic system. PhD thesis University of Westminster School of Social Sciences, Humanities and Languages

TitleRetrieval induced forgetting in depression and schizophrenia: role of mood and the cholinergic system
TypePhD thesis
AuthorsSterkaj, F.
Abstract

Retrieval-induced forgetting (RIF) is a robust phenomenon, which holds that recalling information from long-term memory can suppress the accessibility of related

representations. Both inhibitory and interference processes have been identified as potential mechanisms that may underlie these automatic effects of retrieval.

Depression and schizophrenia are known to be associated with inhibitory deficits and there is evidence demonstrating a reduced RIF among these disorders. Very few

studies have however investigated RIF in these disorders and the mixed findings

reported in the literature are inconclusive.

This programme of research addressed methodological issues surrounding the RIF

procedure along with mediating factors contributing to the inhibitory processes that underlie this mechanism. These factors have been largely ignored thus far, however there is evidence that mediation of the cholinergic system with nicotine increases RIF whilst low mood reduces the RIF effect. In a series of studies, selected

neuropsychological measures, RIF, smoking status and mood were assessed in a

sample of individuals with clinical depression, individuals with schizophrenia, healthy control comparisons, a group of twin pairs diagnosed with schizophrenia and a group of healthy twin pairs.

Within depression and schizophrenia both groups demonstrated the standard pattern of RIF. However this effect was significantly reduced in the clinical groups in

comparison to the healthy controls, indicating an impaired RIF effect in individuals with depression and schizophrenia. A study investigating the different RIF

procedures revealed that RIF may be a stable measure over time. However it may

not be a heritable aspect of cognition as the study of twin pairs revealed no evidence of a genetic association. RIF was however, found to be associated with smoking

status and mood in both patients and controls with a reduction in RIF with low mood and an increase in RIF with smoking status.

These findings confirm that RIF is an important factor in depression and

schizophrenia with potential implications for clinical settings. The twin study suggests that RIF is most likely influenced by environmental factors. Indeed modulation of the cholinergic system and mood were found to play a part in mediating inhibitory

processes that underlie RIF. These findings have important implications for the

theoretical accounts of RIF and the neurochemical bases of inhibitory processes.

Year2012
FileFiorentina_STERKAJ.pdf
Publication dates
Completed2012

Related outputs

Retrieval-induced forgetting and clinical depression
Groome, D.H. and Sterkaj, F. 2010. Retrieval-induced forgetting and clinical depression. Cognition and Emotion. 24 (1), pp. 63-70.

Retrieval-induced forgetting in schizophrenia and depression
Groome, D.H. and Sterkaj, F. 2008. Retrieval-induced forgetting in schizophrenia and depression. in: Proceedings of the British Psychological Society Social Psychology Section Annual Conference, 2 - 4 April 2008, Royal Dublin Society BPS.

Permalink - https://westminsterresearch.westminster.ac.uk/item/8z941/retrieval-induced-forgetting-in-depression-and-schizophrenia-role-of-mood-and-the-cholinergic-system


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