<p>Cognitive psychologists have long known that there are limitations on human information processing abilities. As such we must constantly attend to relevant information in our environment, sometimes for further processing, at the expense of other information. Visual search tasks have been used extensively by researchers who seek to understand the consequences that this selective attention process has on memory. It has been argued that the priming effects observed in efficient visual search tasks reflect specialized, short-term memory representations that differ markedly from the memory representations believed to produce priming effects in other performance tasks. To the extent that this is true, researchers must adopt a necessary level of complexity in terms of the memory models used to explain the full range of human behavior. The empirical goal of this thesis was to provide a rigorous examination of priming effects in efficient visual search, in order to determine whether such effects can be explained by reference to general, well-studied memory mechanisms that have yielded significant explanatory power in other attention and performance tasks. The results of the experiments reported here suggest that general, well-studied memory principles may be a suitable candidate explanation for priming effects in efficient visual search.</p> / Doctor of Philosophy (PhD)

This project compared three techniques of assessing waking fantasy, or daydreaming. The Thematic Apperception Test (TAT), the Imaginal Processes Inventory (IPI), and time-sampled ongoing mentation reports (OMR) were the three measures employed. Seven qualities were compared, as measured by the three methods, using a multitrait-multimethod correlation matrix. Neither extensive convergent nor extensive discriminant validity was demonstrated among the three measures. This suggests that one should use caution in comparing research findings which utilize different measures of waking fantasy.

This study investigated the influence of age, processing speed, working memory,and associative processes on the acquisition of contingency information. Young and older adults completed positive (+.65) and negative (-.65) contingency tasks that measured their ability to discover the relationship between a symptom (e.g., FEVER) and a fictional disease (e.g., OLYALGIA). Both d' scores, i.e., contingency learning, and contingency estimates, i.e., contingency judgment, were examined. Participants were also asked to complete cognitive tasks that measure the constructs of processing speed, working memory resources, associative memory, and associative learning. Structural equation modeling was used to examine the direct and indirect relationships between processing speed, working memory resources, associative memory, associative learning, and positive and negative contingency learning and judgment for young and older adult groups. Young adults outperformed older adults on the cognitive tasks and on contingency learning and judgment tasks. However, age differences were smaller for the positive contingency than for negative contingency. A comparison of the structural equation models for young and older adults showed no relationship between any cognitive construct and negative contingency learning. However, young adults' judgment for the negative contingency was directly influenced by associative learning, while their learning and judgment for the positive contingency was directly influenced by associative memory. For older adults, working memory executive function directly influenced their judgment for the negative contingency and their learning and judgment for the positive contingency. Processing speed had an indirect effect on older adults' contingency learning and judgment that was mediated by working memory executive functioning. The differences in the young adults' models as well as the difference between the young and older adults' models for positive and negative contingencies suggest that while associative processing is important, it may not account for all of the variation in contingency learning and judgment. The young adults' models for the negative contingency task indicates that higher level processes, such as inductive reasoning, maybe involved in negative contingency judgment because the associative learning task required some level of hypothesis testing. In contrast, positive contingency learning and judgment could rely primarily on more basic associative processes. The present findings therefore suggest that an overall model of contingency learning must include both associative processes and inductive reasoning processes. Older adults' general contingency performance was most directly related to their working memory executive functioning, suggesting that the decline in their working memory has the strongest effect on their ability to acquire and use information about contingencies. In fact, the age related decline in working memory seems to affect older adults' ability to acquire both positive and negative contingencies. The similarities across the older adult models for positive and negative contingencies indicate that the underlying deficit in older adults' working memory executive functioning that affects their overall contingency learning and judgment performance. This basic working memory executive functioning deficit for older adults also explains why their models for positive and negative contingency did not exhibit direct relationships between associative tasks and contingency learning as observed for the young adult models.

Whereas previous research has demonstrated that trait ratings of faces at encoding leads to enhanced recognition accuracy as compared to feature ratings, this set of experiments examines whether ratings given after encoding and just prior to recognition influence face recognition accuracy. In Experiment 1 subjects who made feature ratings just prior to recognition were significantly less accurate than subjects who made no ratings or trait ratings. In Experiment 2 ratings were manipulated at both encoding and retrieval. The retrieval effect was smaller and nonsignificant, but a combined probability analysis showed that it was significant when results from both experiments are considered jointly. In a third experiment exposure duration at retrieval, a potentially confounding factor in Experiments 1 and 2, had a nonsignificant effect on recognition accuracy, suggesting that it probably does not explain the results from Experiments 1 and 2. These experiments demonstrate that face recognition accuracy can be influenced by processing instructions at retrieval.

A controlled presleep experience was used in an attempt to trace waking experience in dreams. Dream reports were collected in the laboratory from 12 dreamers (half men, half women; half recallers, half nonrecallers), using the electrophysiological method of Dement and Kleitman. Following a baseline night, each dreamer was awakened on three consecutive nights during every REM period (rapid eye movement and Stage 1-ascending EEG pattern). Immediately prior to sleep on Night 3, four of the dreamers viewed an emotionally arousing film, four others viewed a slide sequence having the same content as the stressful film, and four others viewed an emotionally "neutral" film. Two independent judges, using Hall and Van de Castle's dream content analysis method and a tally system designed specifically for this study, failed to differentiate dreamers in the three groups on the basis of their dream content. Analyses of variance of dream content scores also failed to provide any evidence for differences among groups, recallers and nonrecallers, or nights. Some differences in dreaming style (e.g., total REM time, recallability) were noted. Limitations of the study and methodological problems were discussed. Posthoc analyses of dream reports with experimental situation content, dreamers' associations to their own dreams, and some clinical interpretations were included.

Subliminal perception is defined as a process whereby a subject reports no awareness of a visual stimulus, and yet his/her verbal behavior, subjectively experienced as “guesses”, is influenced by the stimulation. Various studies have found evidence for and against subliminal perception using discrimination tasks and subjective judgments. Explanations of subliminal perception include the partial cue hypothesis, the theory of perception of structural differences, and the theory that responses to subliminal stimuli are of a semantic nature. This study was conducted to determine whether subliminal perception involves a discrimination of structural characteristics or a discrimination of the semantic quality of words prior to specific identification. It was also an attempt to find the relationship between the level of stimulus awareness and the type of response.

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This study investigated the possibility that the short-term memory factor may be one of the variables involved in the learning of motor skills. The subjects of the study were all of the seventh grade gym students at Logan Junior High School who were rated by their teachers as being in the upper or lower one-fourth of their class in respect to their abilities in sport skills, After a short-term memory (STM) test develop ed by the researcher was administered to this group, their scores were compared to determine whether there was a significant difference between the upper and lower one-fourth. An analysis of variance determined that among the boys and the girls taken separately and the group as a whole, means for the top group were higher on the STM test and that the difference was significant at the , 01 level. It was also found that the mean score of the entire group of girls was significantly higher than that of the boys at the .05 level. There was no significant difference in the way the STM test discriminated between the top and bottom boys and the top and bottom girls. Since the other variables were not controlled, this study was only able to distinguish between groups, and there were many individual exceptions. However, the test showed great variability in STM ability among normal individuals in the same age group, and suggests a relationship between this ability and the ability to acquire sport skills.

Thesis (M.Psych./Ph.D.)--University of Western Australia, 2007.