The main goal of this dissertation was to examine rhesus macaque and preschool child performance on invisible displacement tasks. In Study 1, rhesus monkeys were tested on a ramp task wherein an object rolled down a ramp behind four doors. An obstacle was placed along the ramp at one of four doors, and monkeys had to open the door nearest to the obstacle. Macaques were unable to locate the object until they were provided with cuing trials. In Study 2, macaques were tested on a vertical tube task. The tube had an occluding panel with three doors and an obstacle that was placed beneath one of the doors. Three of six monkeys were able to solve this task without any cuing. Subsequent studies manipulating the number of available doors identified the length of trajectory of the falling object as aiding performance. In Study 3, monkeys were tested on a trajectory task consisting of an apparatus with three tubes, each extending from the top of the apparatus into three widely spaced cups. The animals were shown a predetermined length of the object's trajectory (ranging from 15 cm to 35 cm) before it disappeared behind an occluding panel. Ten of eleven monkeys were able to solve the task. Young adults were initially affected by the trajectory length but were able to solve the task after minimal experience. In contrast, both elderly and juvenile macaques partially solved the task when given the maximum amount of information. Subsequent tests showed that performance of juvenile macaques was related to trajectory information whereas elderly macaques used a strategy of searching where the object was last seen. In the final four studies, we investigated the failure of preschool children to solve the ramp task. We conducted various manipulations to promote integration of the obstacle into the child's solution, none of which markedly improved performance. In conclusion, macaques appear to (1) have difficulty understanding the contact-mechanics between objects and obstacles and (2) use trajectory information to solve invisible displacement tasks. Children, however, appear unable to incorporate the obstacle into their solution even with the addition of cues.

Abstract not available

Language processing requires the organization of a complex physical pattern into a memory representation which captures the meaning relations intended in the utterance. Theories of language processing have focussed on the structure of syntax and semantics as the underlying organization of memory representations. Although research on prosodic information in spoken language has demonstrated that prosody can affect language processing, theories have usually treated prosodic information as a source of cues in developing a syntactic or semantic representation. This thesis proposes that prosody occupies a distinct level of representation in the language processing system. The organization of the prosodic representation determines the availability of information in memory as well as the processing units for higher levels of analysis. Two experiments are presented in support of this view. The first experiment compared listening comprehension time for sentences with good and poor prosodic information. The pattern of results was best explained by assuming an internal representation of the prosodic contours. The second experiment found similar effects for temporally organized sentences in reading. Two pilot experiments were conducted to test a specific representation model. These experiments served to evaluate some techniques for further research in auditory language processing.

The fundamental question to be answered in this dissertation is, What sort of structure controls the timing of an utterance during sentence production? Timing here refers to the ordering of elements (i.e., words) within an utterance, and the specification of the duration of each element and any pauses. The structure which controls timing is thus a plan or motor program for some segment of speech. The experimental paradigm used in this dissertation is a sentence repetition task in which subjects either read sentences aloud or repeat sentences temporarily held in a short-term memory buffer. Various measures such as word and pause duration as well as initiation time (time to begin saying an utterance) were examined. The first experiment demonstrates that a syntactic structure does not have the necessary properties to control utterance timing, contrary to claims made by Cooper and Paccia-Cooper (1980). Instead, it is necessary to posit a phonological level of representation constructed from the syntactic structure; it is a phonological structure which guides utterance timing. However, the first experiment also demonstrates that a phonological structure with the properties ascribed to it by Gee and Grosjean (1983) does not have the right properties to account for timing either. I present an alternative view of phonological structure, and a model of the way in which it is created from a syntactic structure. The most important characteristic of the model is that it separates planning-based acoustic effects from more rhythmically determined ones (timing-based effects). Creation of the phonological structure produces the planning effects; execution of the structure produces the rhythmic ones. The phonological structure has the characteristics of a metrical grid: Information concerning timing relations within an utterance are specified in a way that abstracts from the actual segmental content of the utterance.

Abstract not available

Despite assumptions about television addiction in the literature on television viewing, there have been no systematic attempts to document it. The present study was the first. A review of theories on addiction processes concluded that the theoretical consensus on addiction permits the possibility of the existence of this phenomenon in TV viewing. Also, the theories point to the effective domain as an area in which to expect differences between TV addicts and normal viewers. Both the scientific and popular conceptions of TV addiction were also reviewed. A content analysis of the popular literature provided specific guidelines for the operational definition of TV addiction used in this study. A television viewing questionnaire which included a self-rating scale of items derived from descriptions of addicts in the popular literature, as well as many other measures, was administered by mail to a random sample of residents of Springfield, Massachusetts, in the spring of 1982. The response rate was 65%. The results of confirmatory factor analyses failed to support the hypothesis that TV addiction exists as it is described in the popular literature. None of the respondents scored at or above the criterion for the existence of the addiction factor in their responses. An alternative two-factor model was better able to account for the item covariences. Descriptive statistics on the addiction scale items indicate that most respondents feel that TV-addictive behavior is completely uncharacteristic of them. Yet, 65% agreed that "Television is addictive" and eleven respondents called themselves addicts. It was observed that the average number of hours reported in viewing time for this group was over double that of the entire sample. Future analyses of this data will test alternative conceptions of television addiction. An attempt was made to account for the popularity of the notion of television as a "plug-in drug" in terms of (1) our sparse scientific knowledge about the nature of the viewing experience, and (2) an abiding fear or ambivalence in American culture about technology and its effects.

No description available.

No description available.

Subjects' hypotheses about the purposes of experiments, regardless of the accuracy of such hypotheses, may contaminate research data. Experiment I was designed to assess how readily subjects generate hypotheses about experiments and what effect such hypotheses have on performance. In the context of a personality impressions experiment, forty subjects participated either in one of two bogus hypothesis conditions, in which they were given unauthorized information about the purpose of the experiment by an accomplice posing as a subject, or in a no bogus hypothesis condition, in which they received no unauthorized information but were interviewed at the experiment's termination for self-generated hypotheses. Bogus hypotheses were not found to have affected subjects' task performance and only two of the fourteen subjects interviewed reported an attempt to generate an hypothesis. This latter result was interpreted as contradicting the notion that subjects are strongly motivated to figure out the purpose of an experiment. It was hypothesized that subjects are indifferent towards the purposes of research generally, and that certain types of experimental stimuli must be present in an experiment in order to arouse subjects to speculate about research purposes. Experiment II, designed to test this hypothesis, investigated the speculation arousal function of two such types of stimuli -experimental rationales and sensitization tasks. Thirty-six subjects participated in one of four conditions provided by orthogonal manipulation of the two treatment variables and had their level of suspicion, apprehension, and speculation about the experiment assessed by a brief post-experimental questionnaire. Neither factor was shown to have an arousal function as no significant differences were obtained. Other factors possibly involved in arousing subject speculation were discussed. / Arts, Faculty of / Psychology, Department of / Graduate

Because of patch depletion, there comes a time after entering a patch when the forager should abandon the patch in favor of finding another. I am interested in what information influences the decision to leave a patch and how the information is used. In the past, I and my associates have studied patch departure decisions of blue jays using open economy, operant simulations of foraging. During a typical experiment, food-deprived jays would forage for one or two sessions per day, could exploit a depleting and a nondepleting patch, and would receive supplemental food later in the day to keep body weights consistent over days. A jay foraging in the wild, however, is not artificially deprived, forages for many bouts per day, chooses from multiple depleting patches, and must earn all of its food through foraging so that its weight varies with foraging success. I devised a combination of apparatus and procedure that used a closed economy system as its basis in order to test patch departure decisions under more realistic conditions. A jay foraged in a large operant chamber for multiple sessions per day, choosing from many depleting patches, and earning all of its food through its work (the defining characteristic of a closed economy). The initial experiment showed that the general approach was not only viable but healthier for the jays than open economy procedures. During the second experiment, the patches held differing numbers of prey but had equal prey densities. The jays relied on a combination of the number of prey found and run of bad luck (ROBL) durations to decide when to leave patches. These results were consistent with earlier findings. During the third experiment, the patches held equal numbers of prey but differed in prey densities. The jays used a combined departure rule (prey number and ROBLs) only at medium density, relying only on ROBL durations at high densities. The results showed that the jays' departure rules were largely density dependent and were sensitive enough to information within patches to achieve efficient foraging yet flexible enough to adapt to changing environments.