Three experiments investigated cognitive organization in chess. The conventional view of perception in chess is the recognition-association model which emphasizes perceptual chunking as a basis for expertise. These experiments explored an alternative hypothesis that a higher level cognitive organizing process allows experts to integrate and perceive a position as a whole, rather than merely as a collection of perceptual chunks. In the first two experiments, subjects were presented with chess positions and high level descriptions of those positions either before or after position presentation. In both experiments, recall in the description-before condition was superior, supporting the importance of a higher level cognitive organization. The third experiment contrasted recall of positions presented by chunk with positions presented by pawn structure. Results showed recall was similar in the two conditions, again lending support to the idea that more than chunking is involved in the expert's perception and recall of a chess position.

This study investigates the function word deficits in aphasic patients and, in particular, agrammatic Broca's aphasics. Several explanations for the function word problem are addressed including a function word vocabulary deficit theory, a general syntactic deficit theory, and an abstract word deficit theory. Subjects with varying degrees of agrammatism were tested on a variety of production, comprehension, and reading, and syntactic tests which isolate semantic and syntactic aspects of both function and content words in order to better define the nature of the function word deficits in agrammatism.

The methods which people use to reason about everyday events and the strategies they employ have received much attention throughout the years. One aspect of this history is the debate about whether learning rules or examples most facilitates transfer of knowledge to a different domain. This research attempted to answer this question through two experiments. The first experiment concentrated on defining the dimensions along which subjects perceived problems which embodied statistical heuristics. The results identified a contextual dimension along which subjects classified the problems. The second experiment was conducted to determine if the contextual dimension or the problem domain dimension could best account for transfer of training to novel problems. The results indicated that the training transferred to all novel problems, however, training did not transfer to a different set of problems presented to the subjects as a phone survey. Explanations for this lack of transfer are discussed.

The role of stimulus similarity as an organizing principle in immediate memory was explored in a series of experiments. Each experiment involved the presentation of a short sequence of items. The items were drawn from two distinct physical categories and arranged such that the category changed after each pair of items. Following list presentation, one item was re-presented, and the subjects tried to recall the item that had directly followed it in the list. Recall was more probable if the re-presented item and the item to be recalled had been presented in the same sensory modality (i.e., auditory or visual), the same voice, or in the same spatial location than if they had been presented in a different modality, voice, or location. It is concluded that stimulus similarity plays a broader role in organizing immediate memory than is generally assumed.

Priming is a measure of memory where the influence of studied events is assessed indirectly by a later disguised test (e.g., the effect of studying windmill on the probability of solving the anagram lindwilm). Priming is typically sensitive to the perceptual aspects of studied items (e.g., little priming might be obtained from studying a picture of windmill). This property suggests that priming reflects perceptual operations involved in the identification of words and objects. An investigation of perceptual priming can therefore provide clues about the perception of words and objects. In five experiments, perceptual priming was assessed in picture identification tasks by varying the perceptual attributes of study and test objects. Experiment 1 investigated the effects of priming on the identification of briefly presented fragmented pictures as a function of receiving the intact pictures, reading the names of pictures, or generating the names at study. Substantial priming was obtained from pictures compared to words, which showed negligible priming in both conditions. Experiment 2 investigated priming on the fragment naming task as a function of receiving the same fragment, an intact picture, or a different fragment of the same object at study. Same fragments showed the greatest priming; less priming was obtained from intact versions or different fragments. In Experiments 3 and 4, priming on the identification of briefly presented pictures was examined when study and test objects were different viewing angles of the same object. Same study-test views showed the greatest priming. Priming across different views was greater when subjects studied an unusual view of the object and were tested on a usual view, compared to when subjects studied a usual view and were tested on the unusual view. Experiment 5 indicated that priming across viewing angles of the object was specific to obtaining pictorial information about the object: no priming was observed when subjects studied the names of the test objects. Together, these data support theories of memory and perception that assume that priming primarily involves perceptual operations that are specific to studied events (such as the fragment or view presented at study) rather than reflecting abstract representations of the studied events.

Environments that involve the Command, Control and Communication of Information (C$\sp3$I), necessitate a special method of data display to insure that task relevant information is communicated effectively. The present line of research taps the existing basic perceptual and cognitive knowledge base to propose a method of multivariate data display. The concept of a pseudo-integral, task relevant multidimensional symbol is proposed and tested. Three experiments were performed to determine the effectiveness of the proposed multidimensional symbols, as compared with a textual representation in an identification task and a visual search task. One of the primary questions concerned the information carrying potential of a single multidimensional symbol. The experiments revealed that when trained subjects performed identification and search tasks, performance continued to show improvement as the symbol approached five informational dimensions (each representing binary values). In fact, performance with complex symbolic displays was significantly better than performance with complex textual displays. When, however, three of the five informational dimensions were expanded to include a possible range of four values instead of two, performance deteriorated and was inferior to performance with textual displays. This line of research establishes the feasibility of the multidimensional display concept and confirms that it is worthy of further research attention.

The operation of distributing attention to regions of the visual field was investigated in order to further understand the role of attention in the perception of visually-presented stimuli. In each of three experiments, a target letter was presented somewhere within a precued region of the visual display. The task was to determine which one of two possible targets had been presented. The size of the to-be-attended region of the display, the degree of target eccentricity within each region, and the perceptual difficulty of the stimulus discrimination were manipulated factorially. There was evidence that subjects were able to distribute their attention to regions of varying size, but that the focus of attention could not be confined within the boundaries of a non-circular display region. The size of the region to which attention was distributed was related to the speed and accuracy of responses to attended stimuli. However, the size of the display did not interact with either perceptual difficulty or target eccentricity. The interpretation that is consistent with these findings is that attention facilitates the localization of a visual stimulus rather than affecting the rate at which a stimulus is processed. Consequently, the operation of localizing a stimulus can occur more efficiently when attention is focused on a smaller region of a visual display than on a larger region.

A list of words that occur frequently in everyday language is more recallable than a list of words that occur only rarely. This "word frequency" effect is eliminated, or even reversed slightly, if the common and rare words are mixed together in the same list. This pattern of results is replicated in Experiment 1. The remaining experiments evaluated the hypothesis that the interaction between type of list and word frequency is the result of subjects focusing on the low frequency words during study of the mixed lists. The hypothesis received limited support when a differential-attention strategy was made less likely by requiring that an orienting task be performed during presentation of the list (Experiment 2) and strong support when such a strategy was made even less likely by presenting the words in an incidental memory procedure (Experiments 3 and 4). In the latter case, the high frequency words held no more of a recall advantage over the low frequency words when frequency was varied between lists than when it was varied within lists.

A warning compliance study, conducted on 170 university undergraduates, compared the rates of safety compliance with three forms of instruction and warning information (written, oral, and combination) and two forms of message formality (formal and informal). Under the guise of a cover story, subjects were presented with the material and told to read (or listen to) it before performing routine product tasks. Dependent measures were compliance with the warning and time spent with the material. Compliance with the warning information was significantly affected by product. Predictor information included gender, previous product use, and product hazard rating. Hazard rating of the product was reliably correlated with product and with safety compliance. Time spent with the instruction and warning information was reliably correlated with gender, but was not significantly correlated with safety compliance. The results are discussed with regard to the warning situation and in comparison to previous risk perception research.

Because of the importance of noticeability on subsequent comprehension and compliance to warnings, guidelines suggest increasing the salience or conspicuity of warnings. Surprisingly, little research has examined different methods of increasing the noticeability of warnings. The current research orthogonally manipulated four salience variables (pictorial, color, signal icon and border) to determine their effect on the salience of warnings. Subjects viewed 96 simulated alcohol labels on a computer, half with a warning and half without. Subjects indicated whether or not a warning was on the label and response latencies were recorded. The results showed that all four salience features produced significantly faster response times compared to their absence. More detailed analyses showed interactions between the four salience manipulations. These results demonstrate that salience features can enhance the noticeability of warning information. Moreover, it is clear that these salience manipulations interact with each other and that they should not be used indiscriminately.