Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

An empirical exploration of factors that facilitate priming in young children was undertaken utilizing sequentially degraded pictures (fragpix) developed by Snodgrass and her colleagues. The identification of fragmented pictures was studied by 288 children across four experiments. In the first two experiments abbreviated sets of fragpix were generated for use with young children. Experiments 3 and 4 manipulated five attributes of the priming stimulus to measure their effect on direct and indirect tests of memory. Experiment 3 was a scaling study that delineated age associated identification thresholds for fragpix. It also examined hypotheses regarding the impact of prior exposure and perceptual closure on indirect and direct tests of memory. During the exposure and test condition, 3-, 4-, 5- and 8-year olds were shown fragpix in descending degrees of fragmentation until they correctly named the picture. Snodgrass proposed perceptual closure as an explanatory mechanism for identification of incomplete pictures. To explore this hypothesis, following identification of each fragpic, half the children were shown the completed picture. This manipulation had no facilitative effect on identification or recall of fragmented pictures. Two measures of prior exposure, priming and transfer, were also computed. Age differences were found on picture identification, free recall, and picture recognition measures of discrimination and response bias. A linear trend was revealed on measures of priming for picture identification, and for picture recognition but not for recall. A similar method was used for each of the first three experiments: Fragpix were presented in their most degraded form with pictorial information systematically added until the picture was named. Snodgrass and Feenan (1990) suggested that priming might be equally effective if only single levels of fragmentation were presented. They reported that exposing adults to moderately fragmented pictures promoted closure and was more beneficial for later identification, than exposure to maximally-fragmented or nearly completed pictures. Experiment 4 tested this "optimal level" hypothesis with 5- and 8-year olds. Scores from Experiment 3 were used to select age-specific levels of fragmentation that made fragpix easy, moderately easy, or difficult to identify. Attributes of the priming stimulus were manipulated in Experiment 4 to examine the differential impact of varying exposure conditions on performance and on the magnitude of priming. Three manipulations occurred: One varied number of stimulus changes across levels of fragmentation, a second varied order of difficulty, and a third varied the nature of stimulus change (random or systematic). Manipulating the priming stimulus influenced fragpix identification and priming, but had little definitive impact on free recall. For both ages stimuli presented in a systematic rather than random order facilitated picture identification and the magnitude of priming. In addition, developmental differences emerged among systematic orders of presentation. Five-year-olds demonstrated optimal performance in picture identification and measures of picture recognition when there were multiple changes in temporal contrast, while order of difficulty (moderate to easy to hard) was more facilitative for 8-year-olds. A finding for a quadratic function for 8-year-olds on picture identification and magnitude of priming supported a moderately fragmented stimulus being an optimal prime, while for 5-year-olds, the relationship was monotonic. This pattern was not observed on the direct memory tests. It is argued that both perceptual and cognitive components of the task influence performance in an integrative manner on indirect and direct memory tests. A modified form of transfer appropriate processing is proposed as a reasonable explanation of the findings. / Graduate

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Call number: LD2668 .T4 1937 A31

In this dissertation an attempt was made to uncover the source of verbal associations. The investigation focused on establishing the locus of representation for associative relationships in the cognitive system and whether this locus is different from that for semantic relationships. A picture naming task and an object decision task were used within the standard priming paradigm, in which the target is preceded by a prime. A dual-level model was proposed in which associative relatedness is represented at a lemma level that connects the lexical form representation of a word to its semantic information. According to this model an interaction between associative and categorical relatedness should occur in picture naming, but not in object decision, when primes and targets share both relationships, and this is what was observed. To investigate the mechanisms of associative priming, asymmetrically associated prime-target pairs were used to create two situations. In the forward priming condition the target was an associate of the prime (e.g., brick-house), and in the backward priming condition the prime was an associate of the target (e.g., babyrattle). Unexpectedly, facilitation was observed for backward priming at the short SOA in picture naming. Because no effect was observed for this condition in the object decision task, and given that forward priming produced facilitation in both tasks spreading activation was upheld as the mechanism for associative priming. In order to investigate whether the source of the relationship between associates might be in their latent semantic content, the impact of instrument relationships (e.g., grinder-coffee), script relationships (e.g., zoo-tiger), and proximity in multidimensional semantic space were also investigated in the picture naming task. Items that were close in semantic space, but did not share any semantic relationships, produced the same priming pattern as category co-ordinates in picture naming (i.e., interference), while instrumental and script relationships did not produce a priming pattern that matched either that observed for associative or categorical relatedness. These results were taken to indicate that the source of associative relationships is in the co-occurrence of words in the language, which further supported the main claim of a dual-level model where information about verbal associations is stored outside semantic memory.

Thesis (M. Ed.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.