The neurocognitive mechanisms underlying perseveration
| dc.contributor.author | Monti Ewing, Jocelyn Anne | |
| dc.contributor.supervisor | Costa, Louis | |
| dc.date.accessioned | 2025-06-16T23:01:33Z | |
| dc.date.available | 2025-06-16T23:01:33Z | |
| dc.date.issued | 1985 | |
| dc.degree.department | Department of Psychology | |
| dc.description.abstract | This dissertation was divided into three parts. The first part presented a critical review of the neuropsychological literature regarding perseveration and demonstrated the absence of a systematic theoretical model of the mechanisms underlying this phenomenon, particularly in patients with nonfrontal lesions. The second part presented such a model, based on both neuropsychological and cognitive data concerned with the voluntary regulation of attention (cerebral activation). Perseveration is viewed as one manifestation of the breakdown of such regulatory processes and the model provides a framework both for the integration of past findings and for future, more systematic investigation of the nature of perseverative phenomena. The third part presented several such investigations in order to provide both a preliminary empirical validation of the model and to demonstrate its heuristic potential for both neuropsychology and cognitive psychology. Three research questions were investigated using a multiple case study design. Each of eighteen non-frontal (six "deep," six "shallow, " six "combined"), seven frontal and eleven normal (non brain-damaged) subjects were tested and the quality and pattern of their results were examined in detail. Both individual performances and trends within and between groups were discussed. A voluntary attention deficit could account for 77. 8 percent of the perseverative errors made by the eighteen nonfrontal patients (reflective perseveration) and could not be accounted for by previous explanations of perseverative mechanisms. Furthermore, there was a strong positive association between reflective perseveration and other signs of a voluntary attention deficit. Similar errors, in terms of the quality, pattern and association with other signs of an attentional deficit, were seen in the frontal patients. The majority of patients with deep midline involvement demonstrated signs of an attentional deficit (six combined, four deep), whereas only one shallow patient did so, providing preliminary support for the model's neuroanatomical proposals. Finally, three classification systems for perseverative errors were investigated, both confirming and extending earlier typologies across a variety of patients and tasks. The implications of these results for modifications to the model, future investigations and for the potential of such an integrated approach to both neuropsychology and cognitive psychology were discussed. | |
| dc.description.scholarlevel | Graduate | |
| dc.identifier.uri | https://hdl.handle.net/1828/22389 | |
| dc.language.iso | en | |
| dc.rights | Available to the World Wide Web | |
| dc.title | The neurocognitive mechanisms underlying perseveration | |
| dc.type | Thesis |