[{"key":"dc.contributor.author","value":"Mumby, David Gerald","language":null},{"key":"dc.date.accessioned","value":"2008-12-23T22:31:02Z","language":null},{"key":"dc.date.available","value":"2008-12-23T22:31:02Z","language":null},{"key":"dc.date.issued","value":"1992","language":null},{"key":"dc.identifier.uri","value":"http:\/\/hdl.handle.net\/2429\/3293","language":null},{"key":"dc.description.abstract","value":"The nonrecurring-items delayed nonmatching-to-sample (DNMS) task is an integral part of\r\ncontemporary monkey models of brain-damage-produced amnesia. This thesis began the development\r\nof a comparable rat model of brain-damage-produced amnesia. First, a DNMS task for rats was\r\ndesigned by adapting key features of the monkey task. Then, the rat DNMS task was studied in three\r\nexperiments; each assessed the comparability of the rat DNMS task to the monkey DNMS task.\r\nExperiment 1 determined the rate at which the rat DNMS task is learned and the asymptotic level at\r\nwhich it is performed, Experiment 2 assessed the memory abilities that it taps, and Experiment 3\r\ninvestigated the brain structures that are involved i n its performance.\r\nIn Experiment 1, rats were trained on the DNMS task and their performance was assessed at\r\nretention delays of 4, 15, 60, 120, and 600 s. All of the rats learned the DNMS task, and their\r\nperformance was comparable to that commonly reported for monkeys in terms of both the rate at\r\nwhich they acquired the nonmatching rule at a brief retention delay and their asymptotic accuracy at\r\ndelays of up to 120 s. These results establish that rats can perform a DNMS task that closely resembles\r\nthe monkey DNMS task and that they can approximate the level of performance that is achieved by\r\nmonkeys.\r\nExperiment 2 examined the effects of distraction during the retention delay on the DNMS performance of rats. Rats were tested at retention delays of 60 s. On half of the trials, the rats\r\nperformed a distraction task during the retention delay; on the other half, they did not. Consistent with\r\nfindings from monkeys and humans, distraction during the retention delay disrupted the DNMS\r\nperformance of rats. This suggests that similar memory abilities are involved in the DNMS\r\nperformance of rats, monkeys, and humans. Experiment 3 investigated the effects of separate and combined bilateral lesions of the\r\nhippocampus and the amygdala on DNMS performance in pretrained rats. Rats were tested both\r\nbefore and after surgery at retention delays of 4, 15, 60, 120, and 600 s. Each experimental rat received\r\nbilateral lesions of the hippocampus, amygdala, or both. There were no significant differences among\r\nthe three experimental groups, and the rats in each of the three experimental groups were significantly\r\nimpaired, in comparison to no-surgery control rats, only at the 600-s delay. In contrast, rats that had\r\nsustained inadvertent entorhinal and perirhinal cortex damage during surgery displayed profound\r\nD N M S deficits. These results parallel the results of recent studies of the neural basis of DNMS in\r\nmonkeys. They suggest that, in contrast to one previously popular view, neither the hippocampus nor\r\nthe amygdala play a critical role in the DNMS of pretrained animals and that the entorhinal and\r\nperirhinal cortex are critically involved.\r\nOn the basis of these findings, it appears that the rat DNMS task may prove to be a useful\r\ncomponent of rat models of brain-damage-produced amnesia. This conclusion is supported by the\r\npreliminary results of several experiments that are currently employing the task.","language":"en"},{"key":"dc.format.extent","value":"4495793 bytes","language":null},{"key":"dc.format.mimetype","value":"application\/pdf","language":null},{"key":"dc.language.iso","value":"eng","language":"en"},{"key":"dc.publisher","value":"University of British Columbia","language":null},{"key":"dc.rights","value":"For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https:\/\/open.library.ubc.ca\/terms_of_use.","language":null},{"key":"dc.title","value":"The development of a rat model of brain-damage-produced amnesia","language":"en"},{"key":"dc.type","value":"Text","language":null},{"key":"dc.degree.name","value":"Doctor of Philosophy - PhD","language":"en"},{"key":"dc.degree.discipline","value":"Psychology","language":"en"},{"key":"dc.degree.grantor","value":"University of British Columbia","language":null},{"key":"dc.date.graduation","value":"1992-05","language":"en"},{"key":"dc.type.text","value":"Thesis\/Dissertation","language":"en"},{"key":"dc.description.affiliation","value":"Arts, Faculty of","language":null},{"key":"dc.description.affiliation","value":"Psychology, Department of","language":null},{"key":"dc.degree.campus","value":"UBCV","language":"en"},{"key":"dc.description.scholarlevel","value":"Graduate","language":"en"}]