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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Retention of brightness discrimination in Paramecia, P. caudatum /

Mingee, Catherine M. January 2009 (has links)
Thesis (M.A.)--University of Toledo, 2009. / Typescript. "Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Arts Degree in Psychology." "A thesis entitled"--at head of title. Bibliography: leaves 17-18.
2

The development of a rat model of brain-damage-produced amnesia

Mumby, David Gerald 05 1900 (has links)
The nonrecurring-items delayed nonmatching-to-sample (DNMS) task is an integral part of contemporary monkey models of brain-damage-produced amnesia. This thesis began the development of a comparable rat model of brain-damage-produced amnesia. First, a DNMS task for rats was designed by adapting key features of the monkey task. Then, the rat DNMS task was studied in three experiments; each assessed the comparability of the rat DNMS task to the monkey DNMS task. Experiment 1 determined the rate at which the rat DNMS task is learned and the asymptotic level at which it is performed, Experiment 2 assessed the memory abilities that it taps, and Experiment 3 investigated the brain structures that are involved i n its performance. In Experiment 1, rats were trained on the DNMS task and their performance was assessed at retention delays of 4, 15, 60, 120, and 600 s. All of the rats learned the DNMS task, and their performance was comparable to that commonly reported for monkeys in terms of both the rate at which they acquired the nonmatching rule at a brief retention delay and their asymptotic accuracy at delays of up to 120 s. These results establish that rats can perform a DNMS task that closely resembles the monkey DNMS task and that they can approximate the level of performance that is achieved by monkeys. Experiment 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 performed a distraction task during the retention delay; on the other half, they did not. Consistent with findings from monkeys and humans, distraction during the retention delay disrupted the DNMS performance of rats. This suggests that similar memory abilities are involved in the DNMS performance of rats, monkeys, and humans. Experiment 3 investigated the effects of separate and combined bilateral lesions of the hippocampus and the amygdala on DNMS performance in pretrained rats. Rats were tested both before and after surgery at retention delays of 4, 15, 60, 120, and 600 s. Each experimental rat received bilateral lesions of the hippocampus, amygdala, or both. There were no significant differences among the three experimental groups, and the rats in each of the three experimental groups were significantly impaired, in comparison to no-surgery control rats, only at the 600-s delay. In contrast, rats that had sustained inadvertent entorhinal and perirhinal cortex damage during surgery displayed profound D N M S deficits. These results parallel the results of recent studies of the neural basis of DNMS in monkeys. They suggest that, in contrast to one previously popular view, neither the hippocampus nor the amygdala play a critical role in the DNMS of pretrained animals and that the entorhinal and perirhinal cortex are critically involved. On the basis of these findings, it appears that the rat DNMS task may prove to be a useful component of rat models of brain-damage-produced amnesia. This conclusion is supported by the preliminary results of several experiments that are currently employing the task.
3

Medial and dorsal cortex function and foraging strategy in lizards /

Day, Elaine Baird, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 202-215). Available also in a digital version from Dissertation Abstracts.
4

A study of short-term remembering in the possum : using a delayed-matching-to-sample procedure /

Hardaker, Bethany Jane. January 2006 (has links)
Thesis (M.Soc.Sc. Psychology)--University of Waikato, 2006. / Includes bibliographical references (leaves 60-64)
5

The development of a rat model of brain-damage-produced amnesia

Mumby, David Gerald 05 1900 (has links)
The nonrecurring-items delayed nonmatching-to-sample (DNMS) task is an integral part of contemporary monkey models of brain-damage-produced amnesia. This thesis began the development of a comparable rat model of brain-damage-produced amnesia. First, a DNMS task for rats was designed by adapting key features of the monkey task. Then, the rat DNMS task was studied in three experiments; each assessed the comparability of the rat DNMS task to the monkey DNMS task. Experiment 1 determined the rate at which the rat DNMS task is learned and the asymptotic level at which it is performed, Experiment 2 assessed the memory abilities that it taps, and Experiment 3 investigated the brain structures that are involved i n its performance. In Experiment 1, rats were trained on the DNMS task and their performance was assessed at retention delays of 4, 15, 60, 120, and 600 s. All of the rats learned the DNMS task, and their performance was comparable to that commonly reported for monkeys in terms of both the rate at which they acquired the nonmatching rule at a brief retention delay and their asymptotic accuracy at delays of up to 120 s. These results establish that rats can perform a DNMS task that closely resembles the monkey DNMS task and that they can approximate the level of performance that is achieved by monkeys. Experiment 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 performed a distraction task during the retention delay; on the other half, they did not. Consistent with findings from monkeys and humans, distraction during the retention delay disrupted the DNMS performance of rats. This suggests that similar memory abilities are involved in the DNMS performance of rats, monkeys, and humans. Experiment 3 investigated the effects of separate and combined bilateral lesions of the hippocampus and the amygdala on DNMS performance in pretrained rats. Rats were tested both before and after surgery at retention delays of 4, 15, 60, 120, and 600 s. Each experimental rat received bilateral lesions of the hippocampus, amygdala, or both. There were no significant differences among the three experimental groups, and the rats in each of the three experimental groups were significantly impaired, in comparison to no-surgery control rats, only at the 600-s delay. In contrast, rats that had sustained inadvertent entorhinal and perirhinal cortex damage during surgery displayed profound D N M S deficits. These results parallel the results of recent studies of the neural basis of DNMS in monkeys. They suggest that, in contrast to one previously popular view, neither the hippocampus nor the amygdala play a critical role in the DNMS of pretrained animals and that the entorhinal and perirhinal cortex are critically involved. On the basis of these findings, it appears that the rat DNMS task may prove to be a useful component of rat models of brain-damage-produced amnesia. This conclusion is supported by the preliminary results of several experiments that are currently employing the task. / Arts, Faculty of / Psychology, Department of / Graduate
6

Evidence that pigeons are not lost in space : pigeons perform well at long retention intervals on a modified delayed matching of key location task

Willson, Robert James January 1988 (has links)
The present series of experiments examined pigeons' spatial working memory using two variants of the delayed matching of key location paradigm (Wilkie & Summer, 1982). Exposure to the sample location was extended to 15 min and pecks to this stimulus (S+) produced grain on a variable interval 30-s schedule (the 1 Cue group). For some subjects (the 2 Cues group) both the positive and negative (S-) stimuli were presented during the sample period. In a subsequent test phase subjects were exposed to both the S+ and S- for 1 min. If the subject made more responses to the S+ an additional 15 min of access to the S+ occurred, with grain available on the previous schedule. If more responses were made to the S- the trial terminated and the subject was immediately removed from the apparatus. In the first experiment all subjects performed well with retention intervals of up to 30 s, a level of performance better than previously demonstrated in the delayed matching of key location (Wilkie & Summers, 1982). However, subjects' performance was disrupted when they were removed from the apparatus during the retention interval. Subjects in the 1 Cue group were more severely disrupted than the subjects in the 2 Cues group. Performance improved dramatically when these subjects were subsequently trained and tested on the 2 cues condition. Experiment 2 examined the differences between the 1 cue and 2 cues tasks further. All subjects were run for 30 trials on each task and removed from the apparatus during the retention interval. Performance on the 2 cues task was significantly higher for all subjects. When subjects were switched to the 1 cue task, performance immediately dropped and remained at a low level for all blocks tested. The observed differences probably reflect the operation of transfer appropriate processing (cf. Morris, Bransford, & Franks, 1977), given the similarity between training and testing on the 2 cues task. Experiment 3 used the 2 cues task to examine the performance of pigeons when retention intervals longer than 30 s were imposed between training and testing. The retention interval was incremented in the following stages: 5 min, 15 min, 30 min, 1 hr, 2 hr, 4 hr, 8 hr, 12 hr and 24 hr. Subjects were run until their performance fell below a criterion (70% accuracy or better for a block of 10 trials). When a subject failed to attain criterion within 3 blocks, no further data were collected from that subject. Subjects' upper retention limit varied somewhat, ranging from a minimum of 30 min to a maximum of 24 hr, but the performance of most subjects began to deteriorate at about 4 hr, a level considerably above the upper limit previously demonstrated in other paradigms (30 min-Spetch & Honig, 1988). Experiment 4 was a systematic replication of Experiment 3, using a mixed, rather than an incremental, schedule of retention intervals. Performance was not quite as good. For most subjects performance began to deteriorate at about 2 hr, somewhat sooner than in Experiment 3, but nevertheless higher than the level of performance seen in other paradigms. The results of the present experiments are interpreted in terms of the ecological validity of the procedures employed. The implications of the present studies for the study of "adaptive specializations in cognition" (Sherry, 1984; Sherry & Schacter, 1987), are also discussed, as are the implications for the distinction between reference and working memory. / Arts, Faculty of / Psychology, Department of / Graduate
7

Effects of response bias on learning and memory tasks in squirrel monkeys

Scott, Anne G. (Anne Grete), 1949- January 1987 (has links)
Six squirrel monkeys were tested on short-term memory tasks assessing ability to suppress perseverative responses that had been previously reinforced. Each trial was divided into three parts: Initial Preference Assay (IPA), Bias-Conditioning (BC), and Reversal Conditioning (RC), and alternated between two conditions: experimental and control. Strength of response bias (based on choices of response during IPA) exceeded chance levels for each monkey. Eighty-four percent of responses to BC of the experimental trials were made to the response loci chosen in IPA even though that response was not rewarded. Monkeys made 38% correct responses during RC but shifted from making most errors during control trials in the beginning of the experiment to making most errors during experimental trials by the end of the experiment. Monkeys had developed a strategy of persevering from IPA to BC and then shifting to the other, not previously chosen window on RC, which led to correct responses in the experimental trials. (Abstract shortened with permission of author.)
8

Memória em beija-flores / Hummingbirds Memory

Matsuda, Sylvia Maria 20 March 2008 (has links)
Os beija-flores, por serem aves altamente especializadas na exploração de néctar e possuírem uma das maiores taxas metabólicas dentre os endotermos, são altamente dependentes de estratégias que otimizem a utilização dos recursos disponíveis no meio. Depreende-se, assim, que uma memória detalhada dos diferentes aspectos de seus recursos alimentares seja um importante componente do seu sucesso alimentar. Estudos recentes têm mostrado que alguns animais não humanos exibem a capacidade de lembrar \"onde\" e \"quando\" eventos específicos (\"o quê\") ocorreram. Considera-se que o conhecimento concomitante sobre \"o quê\", \"onde\" e \"quando\" caracteriza um tipo de memória denominada \"memória episódica\", considerada, até então, privativa de seres humanos. A proposta do presente trabalho foi avaliar (1) a preferência de beija-flores das espécies Amazilia lactea e Eupetomena macroura por duas concentrações de solução de sacarose (\"o quê\"); na espécie E. macroura (2) sua memória espacial (\"onde\") e sua memória sobre pistas intrínsecas associadas à fonte alimentar (\"o quê\"); e (3) sua capacidade de se recordar da hora do dia (\"quando\") associada à localização espacial (\"onde\") e à cor de alimentadores (\"o quê\"). Os resultados mostraram que os beija-flores são capazes de processar informações sobre \"o quê\", \"quando\" e \"onde\" de seus recursos alimentares e que utilizam essas informações flexivelmente quando confrontados com diferentes situações experimentais, exibindo, assim, conhecimento sobre os principais elementos que caracterizam uma memória do tipo-episódica. / Hummingbirds are highly specialized for nectar consumption as a main food source. Since these animals exhibit one of the highest metabolic rates among endoterms, they depend on strategies that optimize the use of the available food resources. Therefore, a detailed memory for the location, quality and time of food availability is likely to be an important component of their feeding strategies and success. Recent studies have shown that some non-human animals exhibit the capacity of remembering \"where\" and \"when\" specific events (\"what\") occurred. Simultaneous recalling of \"what\", \"where\" and \"when\" specific events occurred characterizes a kind of memory known as \"episodic-memory\", considered, until recently, exclusive to humans. This study aimed at evaluating (1) the preference for either 20 or 40% sucrose solutions (\"what\") by exemplars of Amazilia lactea and Eupetomena macroura hummingbirds, (2) the memory for spatial locations (\"where\") and for intrinsic cues (\"what\") associated with food resources by exemplars of E. macroura, and (3) the ability of exemplars of E. macroura to learn an association including the time of day (\"when\") spatial locations (\"where\") offered profitable colored feeders (\"what\"). The results showed that the hummingbirds are capable of memorizing information about \"what\", \"when\" and \"where\" food resources are available and of using this information flexibly. Therefore, these results clearly indicate that hummingbirds exhibit an episodic-like type of memory.
9

Conditioned place preference and spatial memory : contributions towards thalamus and memory : a thesis submitted in partial fulfillment of the requirements for the Degree of Master of Science in Psychology at the University of Canterbury /

Adams, Melissa Jean. January 2006 (has links)
Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 88-92). Also available via the World Wide Web.
10

Memória em beija-flores / Hummingbirds Memory

Sylvia Maria Matsuda 20 March 2008 (has links)
Os beija-flores, por serem aves altamente especializadas na exploração de néctar e possuírem uma das maiores taxas metabólicas dentre os endotermos, são altamente dependentes de estratégias que otimizem a utilização dos recursos disponíveis no meio. Depreende-se, assim, que uma memória detalhada dos diferentes aspectos de seus recursos alimentares seja um importante componente do seu sucesso alimentar. Estudos recentes têm mostrado que alguns animais não humanos exibem a capacidade de lembrar \"onde\" e \"quando\" eventos específicos (\"o quê\") ocorreram. Considera-se que o conhecimento concomitante sobre \"o quê\", \"onde\" e \"quando\" caracteriza um tipo de memória denominada \"memória episódica\", considerada, até então, privativa de seres humanos. A proposta do presente trabalho foi avaliar (1) a preferência de beija-flores das espécies Amazilia lactea e Eupetomena macroura por duas concentrações de solução de sacarose (\"o quê\"); na espécie E. macroura (2) sua memória espacial (\"onde\") e sua memória sobre pistas intrínsecas associadas à fonte alimentar (\"o quê\"); e (3) sua capacidade de se recordar da hora do dia (\"quando\") associada à localização espacial (\"onde\") e à cor de alimentadores (\"o quê\"). Os resultados mostraram que os beija-flores são capazes de processar informações sobre \"o quê\", \"quando\" e \"onde\" de seus recursos alimentares e que utilizam essas informações flexivelmente quando confrontados com diferentes situações experimentais, exibindo, assim, conhecimento sobre os principais elementos que caracterizam uma memória do tipo-episódica. / Hummingbirds are highly specialized for nectar consumption as a main food source. Since these animals exhibit one of the highest metabolic rates among endoterms, they depend on strategies that optimize the use of the available food resources. Therefore, a detailed memory for the location, quality and time of food availability is likely to be an important component of their feeding strategies and success. Recent studies have shown that some non-human animals exhibit the capacity of remembering \"where\" and \"when\" specific events (\"what\") occurred. Simultaneous recalling of \"what\", \"where\" and \"when\" specific events occurred characterizes a kind of memory known as \"episodic-memory\", considered, until recently, exclusive to humans. This study aimed at evaluating (1) the preference for either 20 or 40% sucrose solutions (\"what\") by exemplars of Amazilia lactea and Eupetomena macroura hummingbirds, (2) the memory for spatial locations (\"where\") and for intrinsic cues (\"what\") associated with food resources by exemplars of E. macroura, and (3) the ability of exemplars of E. macroura to learn an association including the time of day (\"when\") spatial locations (\"where\") offered profitable colored feeders (\"what\"). The results showed that the hummingbirds are capable of memorizing information about \"what\", \"when\" and \"where\" food resources are available and of using this information flexibly. Therefore, these results clearly indicate that hummingbirds exhibit an episodic-like type of memory.

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