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The present study was designed to investigate the reliability of the Frostig Developmental Test of Visual Perception with retarded subjects. The Frostig test is divided into five subtests involving visuo-perceptual tasks and measurements. This study computed reliability coefficients on all the subtests as well as on the total scores. The Peabody Picture Vocabulary Test and the Frostig Developmental test of Visual Perception were also correlated in an attempt to assess an aspect of Frostig validity. The sixty retarded subjects used in this study were divided into groups on the basis of both chronological and mental age, and the test-retest method of reliability assessment was used. The results of this study indicate that the total test scores of the Frostig Developmental Test of Visual Perception are reliable when dealing with the perceptual performance of retarded subjects. The stability of the subtest shows greater variation than does that of the total scores. The subtests of Eye-Motor Coordination and Form Constancy yielded the most variable results and it is evident that with the population studied, these subtests cannot be considered stable enough to be individually, diagnostically, useful. The Peabody Picture Vocabulary correlation with the Frostig Developmental Test of Visual Perception of .537 was significant at the .01 level. / Arts, Faculty of / Psychology, Department of / Graduate

The problem in this thesis developed out of a consideration of the relationship between personality and perception, and particularly, a consideration of how an important autochthonous determinant of perception might be differentially affected when the perceptual system is serving the purposes of the organism generally. Perception has been considered as a functional process with its main experiential and autochthonous determinants and it has been suggested that both types of determinants are instrumental in bringing the perceptual process within the overall consistency of organismic function. The experiment undertaken in this thesis is an attempt to examine one part of this last-mentioned proposition, namely, that an autochthonous.determinant will differentially contribute to perceptual functioning as the "Anschauung" or 'personality style' of the organism varies. The personality attribute Security-Insecurity proposed by A.H. Maslow was chosen as one variable for this study. It was chosen because that author's theoretical approach to the problem of personality functioning seemed consistent with a view of 'the organism as a whole', as well as with a view of the perceptual and other processes acting in accord with the characteristic 'style of organismic functioning. Maslow has stated that an 'insecure' person will emote, think, perceive, and in every way function insecurely. In addition to the relevance of this theoretical approach, Maslow devised a questionnaire type Security-Insecurity Test which, he believes, serves to identify those individuals who are relatively 'secure' and 'insecure'. This test was consequently available to use as the instrument for measuring the personality variable in this experiment. The autochthonous perceptual determinant, 'visual perceptual closure', was chosen for this study as it was identified by L.L. Thurstone as being one of the most important of the perceptual determinants. Moreover, in his study where he identified closure and other variables, Thurstone suggested that the characteristics of the person as a whole might be inferred from the dynamics of one these functions. This is in accord with Maslow's above stated view. Bruner and Postman also postulate a relationship between personality functioning and the determinant 'closure'. When Thurstone identified 'closure' he did so on the basis of tests which measure that ability. Measuring instruments for the perceptual variable were consequently available. The Gottschaldt Figures Test was used here together with the Mooney Closure Test. Though this second test was not used by Thurstone, it is derived mainly from the Street Gestalt Completion Test which he did use. The Gottschaldt and the Mooney tests served as separate measures of the perceptual variable in this experiment. The experiment consisted of a test of the hypothesis that 'insecure' subjects would have impaired closure ability as compared with 'secure' subjects. Introductory psychology students at U.B.C. were tested and the relationships between their 'insecurity' and 'closure' scores were determined. This was done, firstly, by finding intercorrelations (Pearson Product-Moment 'r'), and secondly, by determining the differences between the means of closure test scores of matched 'secure' and 'insecure' groups. The hypothesis was not supported by the data obtained in either of these experimental designs. / Arts, Faculty of / Psychology, Department of / Graduate

This investigation studies the role of the middle ear muscles in the TTS reduction that occurs when phonation accompanies exposure to a high intensity low frequency pure tone. Changes in acoustic admittance (taken as a measure of middle ear muscle activity) were compared with changes in TTS, recorded under similar experimental conditions. The TTS paradigm consisted of measuring subjects' hearing thresholds before and after 5 minute exposure to a 500 Hz, 117.5 dB SPL tone, accompanied or not by phonation (humming). The paradigm was repeated with threshold measurement being replaced by otoadmittance measurement; in this case admittance changes were recorded before, during, and after the fatigue exposure. The results show that TTS from the exposure tone with phonation was significantly less than TTS from the exposure tone with no phonation. The effect of phonation on TTS was most significant at early post-exposure times. No significant TTS differences between males and females were found. Changes in the two admittance components at the beginning and at the end of exposure were significantly larger when phonation accompanied the exposure than when not. This finding suggests that more middle ear muscle activity occurs when phonation accompanies exposure than when no phonation is performed. Most admittance measurements did not correlate significantly with any of the TTS measurements. The only significant correlations indicated that the smaller the middle ear muscle activity resulting from the fatigue exposure alone, the larger the amount of protection provided by phonation, as measured by differences between TTS values at early postexposure times between the two conditions. This finding suggests that most individuals may have middle ear muscles that contract weakly in response to intense acoustic stimulation alone but that these muscles contract significantly when phonation accompanies the acoustic stimulation. Thus, phonation provides considerable protection of the ear from the 500 Hz fatigue tone, as shown by the reduced TTS when phonation accompanies exposure. The results also suggest that the middle ear muscles are a major factor in reduced TTS with phonation but other mechanisms such as inefficient stapes vibration and attentional factors may also be involved. More research is necessary to determine the exact role each mechanism plays in the reduction of TTS with phonation. / Medicine, Faculty of / Audiology and Speech Sciences, School of / Graduate

Perceptual learning was studied using luminous figures in a dark room. It was found that as a result of previous close temporal and spatial concurrence, discriminably different stimuli under reduced stimulation conditions disappear together more frequently than without such an association. This occurred despite a demonstrated link between identical stimuli prior to the learning experience. Moreover it was shown that the extent to which the stimuli subsequently "operated" together was a function of the frequency and duration of their previous joint occurrence. Temporal and spatial stimulus-stimulus relationships were manipulated and differences between sequential and simultaneous presentations and between different presentation rates were observed and discussed. The effect of auditory experience on subsequent disappearances of the same stimuli presented visually was also examined and the results supported the inter-modal perceptual learning hypothesis. The phenomena observed in all these experiments were interpreted in terms of Hebb's theory of perceptual association. / Arts, Faculty of / Psychology, Department of / Graduate

The question is addressed of whether the perception of a form is exclusively determined by a prior analysis of its elements, and two major paradigms are reviewed, viz., Gestalt and information processing. Three experiments were carried out. Experiment 1 employed a signal detection task to test the hypothesis that embedding a line segment feature in a unitary figural context would facilitate its detection. The contextual effect found falsified the theory of a one-way causation between analysis of figural elements and form perception. Experiment 2 showed that a necessary condition of this context effect on feature detection is the three-dimensionality of the unitary context. With bi-hemiretinal stimulus presentation Experiment 3 showed a significant context effect in the RVF, but not in the LVF. Some current paradigms are applied to these results; it is argued concurrently that the explanation of phenomena called "perceptual" entails the solution of two problems:, that of determining what constitutes such an explanation, and an adequate theory of the experiential aspect of perceptual phenomena. These are addressed in Appendices A and B. / Arts, Faculty of / Psychology, Department of / Graduate

During the time when a child learns the sound system of his language, there is much evidence that the child can perceive phonological distinctions and therefore detect phonetic differences before he can produce these distinctions. This evidence is often provided to disprove the hypothesis that the child could be using an "active" model of speech perception. One such model, the analysis by synthesis model of speech perception, supposes that decoding of the acoustic signal employs the articulatory representation that would be required to produce the hypothesized identity of the incoming signal. The model proposes that while the human auditory system is innately equipped to handle the segments contained in speech, that the correlations between the acoustic information and articulation are learned with experience and form the basis for the division of the continuous acoustic signal into discrete categories of speech sounds. This thesis reviews recent research into the speech perception process and revises the analysis by synthesis model. It reveals that the human auditory system is innately equipped to divide stimuli (both speech and non-speech) that vary along certain acoustic dimensions into discrete classes. The unique processing that results for speech stimuli, occurs when the stimuli is recognized as having a function in the system of language. Hence the requirements for phonetic processing involve the psychological realization that stimulus originated in the human vocal tract. This investigation then reviewed the available literature on the perception and production of children acquiring language to determine whether there is support for their use of the revised analysis by synthesis model. The results favoured that children do use such a model. When resolving the various acoustic cues that combine to form a stimulus complex, the child does refer to his articulatory abilities. Lacking full articulatory knowledge, the perceptual errors that typify children's language, occur. It was shown that the child need not have the precise adult articulatory configuration in order to utilize this model. The model is operative during the child's perception of both himself and the adult. In both instances the comparator performs the function of matching the child's articulatory representation with his perceived representation of a form. The results serve to improve his knowledge of acoustic-articulatory correlations. In this manner the processes of perception and production are closely integrated and as understanding of their fine interrelationship improves, production becomes more accurate and perception is simplified. / Medicine, Faculty of / Audiology and Speech Sciences, School of / Graduate

Previous research (Werker, Gilbert, Humphrey, & Tees, 1981) in which we compared English infants, English adults, and Hindi adults on their ability to discriminate two pairs of Hindi (non-English) speech contrasts indicated that infants without prior specific language experience can discriminate speech sounds according to phonetic categories, whereas adults may lose this ability as a function of either age and/or specific language experience. The present work was designed to answer several questions that emerged from that earlier research. First, experiments focussed on delineating the time course of the "decline" in non-native speech discrimination abilities across childhood. Second, experiments examined the generality of developmental change between infancy and adulthood by looking at cross-language speech perception of a new (Thompson, an Interior Salish Native Indian Language) non-English speech contrast. Third, speech perception performance was examined in relation to cognitive and linguistic development to try to determine why the decline occurred at one rather than another point in ontogeny. Finally, an attempt was made to clarify the nature and implications of the apparent loss of non-native speech perception abilities by varying both the discrimination procedure and the perceptual set conditions used in adult testing. The results of these experiments replicate our original findings (Werker, et. al., 1981) showing that infants can discriminate the universal set of phonetic contrasts, and that there is a decline in this ability as a result of specific linguistic experience. This decline occurs within the first year of life. The data tentatively support the notion that a certain level of memory development (enabling an early form of representational ability) may be necessary before specific experience can modify initial infant abilities. In addition, the results show a difference between phonetic and phonemic (meaning based) perception in adult subjects, with the phonemic being the most robust and the most easily demonstrated. It is suggested that phonemic perception may reflect the structuring of cognitive/perceptual categories. Speculation as to the form (prototypical) and the format (initially enactive, later symbolic) of the representation of these categories is offered. / Arts, Faculty of / Psychology, Department of / Graduate

Includes bibliographical references / M.S. Florida State College for Women 1933

Given the importance of correctly perceiving and remembering faces for successful social interaction, face processing is one of the most widely studied cognitive domain in behavioral, neurophysiological and neuroimaging research, particularly, based on a group-mean approach. However, above mean differences, inter- and intra-individual variability in face processing provide valuable information for investigating the underlying mechanisms and binding the behavioral and neural substrates for better understanding of face processing.. In my dissertation I investigated the biological mechanisms underlying face cognition from an inter- and intra-individual variability perspective at the genetic, neural, and behavioral levels. The neural activities related to face processing are measured by event-related potentials (ERPs) and their trial-by-trial latency variability are estimated using a novel and well-established method, Residue Iteration Decomposition (RIDE).. Study 1 demonstrates the reliability of RIDE in extracting single-trial parameters of the P3b component, which is used in the investigation of the neural basis of intra-subject variability (ISV) in face processing speed in Study 2. In the Study 2, individual differences in ISV of face processing speed, measured at both behavioral and neural levels during a face processing task, are studied in their genetic variation. The results suggest that individual differences in ISV are related not only to the COMT Val158Met polymorphism, but also to the type of cognitive processing (e.g., memory domain). Moreover, we showed that ISV in reaction time can be partially explained by ISV in the speed of central cognitive processes.. Furthermore, the individual differences approach in Study 3, provided valuable and novel information beyond the common group-mean approach applied in the N1/N170-related research. Based on this approach, not only we could replicate previous findings that the N170 predicts individual differences in face cognition abilities, but also we could decompose individual differences in the N170 into a domain-general and a face-specific part with different predictive powers. Moreover, we showed that top-down modulations on the N170 have separable and qualitatively different relationships to face cognition abilities.. In summary, the integrated results from different studies in my dissertation demonstrate the psychological importance of the information provided by inter- and intra-individual variability in face processing in the investigation of its underlying biological mechanisms.