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.

Previous research has provided evidence that semantic information significantly influences processing in short-term memory (Jensen, 1987; Shulman, 1970, 1972). This study examined semantically related and associated interference effects in identity probe recognition tasks with undergraduates, older subjects, and brain-damaged patients. Associative interference effects were presumed to result from automatic spreading activation in a word recognition system, and were expected to produce interactions with serial position. No interactions between interference effects and serial position were obtained. Modality of presentation had an influence on the size of the interference effects obtained, with auditory presentation decreasing the interference effect size. These results were interpreted as evidence that interference effects in probe recognition tasks are the result of a process of attribute or feature comparison (Anisfeld and Knapp, 1968). Results from the patient experiments were equivocal and suggest that the probe recognition task is not appropriate for use with brain-damaged patients.

This study explored whether faces are perceived differently than other visual stimuli. Using the speeded-classification task, evidence of holistic processing was found for faces with normal organization but not for the same stimuli when the eyes, nose, and lips were not in their ordinary positions. Sets of interior features (eyebrows, eyes, nose, and lips) were subsequently tested for holistic processing. No evidence for holistic processing was found between eyebrow/eye and nose/lips groups or between the nose and the lips. However, it was found that decisions on the eyebrows could be made independently of the eyes but that decisions on the eyes could not be made independently of the eyebrows. This asymmetric-separable relationship persisted when the eyes and eyebrows were presented by themselves or in the context of a face, when they were presented upright or inverted, and when either a single eye/eyebrow or both eyes/eyebrows were presented. Decisions on inverted eyes were more difficult than decisions on upright eyes. No evidence of holistic processing was found for an eye/eyebrow presented in the context of non-facial stimuli. These results suggest that the asymmetric-separable relationship between the eyes and the eyebrows plays a role in the unique characteristics associated with the perception of faces.

Eight experiments were conducted to investigate the phenomenon of spontaneous recovery, or memory improvement over time without repeated testing. While this phenomenon has been previously studied within the verbal learning tradition, evidence for its existence has been inconclusive. Experiments 1a through 5 demonstrated the reliability of the effect. The procedure was gradually modified throughout these experiments, leading to the following conclusions. First, retroactive interference (which is a necessary condition for recovery) is maximized when subjects are led to believe that their knowledge of the target list will interfere with interpolated learning. Also, assessing spontaneous recovery in a within-, rather than a between-subjects paradigm, is a more powerful approach, and allows for a more sensitive test of the phenomenon. Most importantly, spontaneous recovery was reliably produced. The proposed explanation for the phenomenon involves retrieval inhibition, and its subsequent dissipation, as the processes underlying recovery. More specifically, inhibition prevents subjects from generating target items on immediate tests. As the inhibition dissipates, more items can be recalled on later tests; this occurs despite the presumption that normal forgetting is also operating upon the target list. Experiment 6 attempted to extend spontaneous recovery to an implicit, word-stem completion test. Following study conditions roughly similar to those used in the prior experiments, there was no evidence for either retroactive interference or spontaneous recovery on the implicit test. This demonstrates, at the very least, a study manipulation that dissociates explicit free recall with implicit word-stem completion. More interestingly, it suggests that retrieval inhibition might only operate upon intentional uses of retrieval, although more data would be required to confirm this hypothesis. Experiment 7 applied the spontaneous recovery paradigm to directed forgetting. If subjects are using retrieval inhibition to "block out" to-be-forgotten items, then these items should recover over time. Results provide limited evidence for this conclusion. Retrieval inhibition, and its subsequent dissipation, are hypothesized to be the primary processes underlying directed forgetting.

Four experiments are presented which explore consumer preferences for more detailed, or explicit warning information and the effects of such information on anticipated purchases of products. In Experiments 1 and 2, explicit and nonexplicit warning labels were presented for several common consumer products. Results of these studies indicate that products displaying nonexplicit warnings were preferred to those containing explicit warnings. However, this trend was reversed for one product, and for many products the detail with which a warning described potential consequences had little effect on anticipated purchase decisions. An attempt was made in Experiments 3 and 4 to minimize precursors to hazardousness judgements (e.g., familiarity or experience) by using fictitious products. Results of these latter two experiments indicate that regardless of the perceived benefits of an unfamiliar product or the severity, likelihood and controllability of its injuries, an overwhelming buying preference existed for explicit warnings as well as a need to provide more detailed consequence information in the warnings of such products. Overall these findings suggest that the level of detail with which a warning describes potentially harmful consequences of using a product does influence anticipated purchases when uncertainty exists about product-related danger.

A series of experiments explores the role of willful control over the learning of complex, rule-governed systems such as language. Willful control is operationalized as the enhancement of learning by the deliberate application of cognitive strategies. Subjects studied strings of symbols generated according to the rules of a system known as an artificial grammar. They were then tested on their knowledge of the grammar's rules. In some conditions, symbols drawn from the vocabulary used in the grammar were inserted into each string, rendering the string somewhat ungrammatical. In the informed condition, the inserted symbols were identified; in the uninformed condition, the inserted symbols were not identified. If subjects were able to exert willful control by ignoring the inserted symbols, performance in the informed condition should exceed performance in the uninformed condition. If they were not able to exert willful control, there should no difference between the informed and uninformed conditions. Evidence that the subjects had at least some degree of willful control was obtained in each of 10 experiments. Experiments 1, 2, 3, and 4 included a condition in which the subjects saw strings with no inserted symbols. Performance in this condition was consistently superior to performance in the informed condition, implying that the extent of willful control was less than complete. Experiments 5, 6, 7, and 8 tested the hypothesis that the extent of willful control would depend on the number of symbols inserted. Experiment 9 tested the hypothesis that exposure to strings with no ungrammatical symbols would enhance subjects' ability to ignore such symbols in subsequent strings. Finally, Experiment 10 tested the hypothesis that willful control would be increased if the inserted symbols did not come from the same vocabulary as the grammar. None of these hypotheses was supported. The general conclusion from these experiments is that subjects can exert some degree of willful control over the learning of complex systems, but the extent of that control is substantially limited.