The CS-Preexposure Effect in Conditioned Taste-Aversion Learning in Golden Hamsters

In Experiment 1, golden hamsters were injected with either 0.9% saline or the nausea-inducing agent, lithium chloride (LiCL), immediately after consuming a flavored diet that was either novel or familiar. The LiCl-induced aversion was strong in hamsters for which the flavored diet was novel, but no significant aversion was observed in hamsters that were familiar with the flavored diet. In Experiment 2, the strength of the LiCl-induced aversion was related inversely to the amount of conditioned-stimulus (CS) preexposure and directly to the duration of the preexposure-conditioning interval. Thus, although some previous researchers have suggested that hamsters may not demonstrate the CS-preexposure effect in a conditioned taste-aversion paradigm, they clearly did so under the conditions of the present experiments, and moreover, the characteristics of the CS-preexposure effect in hamsters were generally similar to those observed in rats.     

Memory for Frequency of Bizarre and Common Stimuli: Limitations of the Automaticity Hypothesis

In 2 experiments, the influence of intention to process frequency on accuracy of memory for frequency of bizarre and common sentences was investigated. The results from multiple regression analyses indicated that intentional processing increased the accuracy of frequency judgments when memory for frequency was tested after a 2-min (Experiment 1) and after a 48-hr (Experiment 2) retention interval. Furthermore, the results of Experiment 2 indicated that unintentional processors tended to overestimate frequencies of bizarre relative to common items after a delay. The implications of the results are discussed with regard to L. Hasher and R. T. Zacks's (1984) automaticity hypothesis, human performance, and the accuracy of judgments of frequency of occurrence of unusual events.     

Strategies in the Information Search Process: Interaction Among Task Structure,Knowledge, and Source

The authors explored the information search strategies of 145 individuals in the predecisional stage. Decision-making participants selected pieces of information from a list including relevant and irrelevant data. The authors investigated the influence of the individual's knowledge and information source. In Experiment 1, the authors experimentally manipulated the information source reliability. The results revealed that participants tended to use a sequential strategy when the authors presented information as supplied by a reliable source. In Experiment 2, the authors analyzed the interaction between information source and the individuals' knowledge. When participants believed the source to be reliable, even knowledgeable participants adopted a strategy as sequential as that chosen by naive individuals. In Experiment 3, a mediational model corroborated the hypothesis that the search strategy affects the final judgment. The results were consistent with the constructivist framework, which emphasizes the role of individual, task, and context in the decision-making process.     

The Hemispheric Lateralization for Processing Geometric Word/Shape Combinations: The Stroop-Shape Effect

The authors conducted 4 experiments to test whether hemispheric lateralization occurs for the processing of geometric word–shape combinations. In 3 experiments, participants responded to geometric shapes combined with geometric words (square, circle, triangle). In the 4th experiment, stimuli were combinations of geometric shapes and nongeometric words. The authors predicted that it would take longer to respond in incongruent conditions (e.g., the word “square” combined with the shape of a circle) than in congruent conditions. The authors found the strongest incongruency effects for the dominant hemisphere—that is, the left hemisphere for responding to words and the right hemisphere for responding to shapes. A Shape Interfering Properties hypothesis (SIP) is a possible explanation for these results.     

Reflection-Impulsivity in Mexican Children: Cross-Cultural Relationships

Urban Mexican children aged 5 (n = 23) and 9 (n = 87) years were given the Matching Familiar Figures Test (MFFT). The results indicate that the MFFT was a valid test of cognitive style for Mexican children. The younger children's MFFT performance was characterized as fast and inaccurate in relation to the older children's performance, which was slower and more accurate. Cross-cultural comparisons of Mexican MFFT scores with normative data from America, Japan, and Israel indicated that Mexican children were relatively impulsive in cognitive style in relation to children of other cultures. Potential factors contributing to these cross-cultural differences are discussed here.     

The Origin of Error

The present two experiments were designed to investigate the effects of two competing retrieval strategies—category and position cueing.

One hundred college students participated in Experiment I in which Presentation Rate, List Type, and Stimulus Position were manipulated within an FR paradigm. Sixty students participated in Experiment II in which Formal Response Similarity and Stimulus Position were manipulated within a PA paradigm.

Findings were the following: (a) that greater clustering and FR is obtained at slower presentation rates; (b) that greater than chance clustering occurs with a category list structure; and (c) that HS response learning is more difficult than LS response learning. No support was found for position cueing.

Results were discussed within FR cueing, von Restorff, and intentional versus incidental learning paradigms as possible explanations for the nonsignificant position cueing results in the present experiments. A competing strategy hypothesis of category and position cues was preferred with category recall and clustering as the dominant mode of retrieval.     

A Test of the Overconfidence Phenomenon Using Audio Signals

The existence of the overconfidence phenomenon was examined using a signal detection paradigm. Fifty-five participants were asked to decide whether they heard a signal or noise only, and to rate how certain they were of their decisions. The results confirmed the existence of overconfidence as well as the “hard-easy” effect.     

The Influence of Attitude on Learning

Automaticity theory and the effect of coloring a single element were tested with all or only 1 element colored in Stroop tasks. The 312 participants in 5 experiments indicated stimulus presentation color by key press. Experiments 1 and 2 replicated those of D. Besner, J. A. Stoltz, and C. Boutilier (1997) with some changes, and revealed similar results: less Stroop interference with only 1 letter colored. Besner et al. (1997) interpreted the results as indicating that coloring a single letter eliminates automatic reading processes. The cause of that reduction in Stroop interference was investigated in Experiments 3, 4, and 5 using color words, bars, and rectangles. The effect of coloring 1 element was to increase color-naming time by the same amount for congruent and neutral, nonverbal stimuli, but not for incongruent stimuli. The results are interpreted in terms of automaticity theory, and a continuous flow approach to the Stroop effect is presented.     

Dynamic Visual Acuity

Forty subjects took part in a one-handed catching task in which the period for which the mechanically projected tennis ball was illuminated in flight was varied systematically. Additionally, they were tested for (a) static visual acuity and (b) dynamic visual acuity, in which angular velocity was varied. As expected, both viewing period in the catching task and angular velocity in the acuity task were significant variables in performance. Correlation and principal-components analyses confirmed the findings of a previous experiment in that the correlated static visual acuity tasks were unrelated to both dynamic visual acuity (even when angular velocity was only 75°/sec) and catching performance. Further, dynamic acuity and catching were related under the majority of the combinations, and most frequently at the highest angular velocity, a fact which suggested that the dynamic element in both tasks is the common factor.     

Acquisition of Predictable Vertical Visual Targets: Eye-Head Coordination and the Triggering Effect

The study was designed to investigate target acquisition in the vertical plane with emphasis on establishing strategy differences associated with acquisition triggering methods. Eight subjects were tested. Measurements consisted of target acquisition time, eye-head latency differences, velocity of gaze, eyes and head, and head amplitude. Using 3-way repeated measures analyses of variance the results show that the strategy for acquisition of predictable visual targets in vertical plane with the head unrestrained significantly depended on (a) the direction of the gaze motion with respect to the gravity vector (i.e., there is significant up-down asymmetry), (b) the angular distance of the target, and (c) the method of triggering the command to acquire the target—external versus internal. The data also show that when vertical acquisition is compared with triggering methods in the horizontal plane there is a difference in overall strategy for the acquisition of targets with the same spatial distances from straight ahead gaze when both the eyes and head are used. Among the factors contributing to the difference in strategy for vertical target acquisition are the gravitational vector, the relationship of target displacement and vestibular activitation, biomechanical and neural control asymmetries, and the difference in the vertical field of view.