Models for choice-reaction time

In the two-choice situation, the Wald sequential probability ratio decision procedure is applied to relate the mean and variance of the decision times, for each alternative separately, to the error rates and the ratio of the frequencies of presentation of the alternatives. For situations involving more than two choices, a fixed sample decision procedure (selection of the alternative with highest likelihood) is examined, and the relation is found between the decision time (or size of sample), the error rate, and the number of alternatives.     

Two models of group behavior in the solution of eureka-type problems

A study by Shaw (7) some twenty years ago is frequently cited by social scientists to support the generalization that groups are superior to individuals in problem-solving. Shaw suggests that personal interaction within the group is responsible for the superior performance of groups. This article re-examines her data in the light of two models which propose that the difference in quality of solution between group and individual performance is solely a matter of ability. It is shown that Shaw's data may be considered to have been an outcome of behavior postulated by the models. Since Shaw's observations relate to a special population and to special kinds of problems, the proposed models may not be appropriate under differing experimental conditions. In fact, Lorgeet al. (4) have indicated that experimental demonstration of the superiority of groups over individuals in problem-solving depends not only on the kind of group but also on the kind of problem to be solved. In addition, the diversity of transfer of training for groups and for individuals is considered.Supported in part by the Office of Naval Research under Contract N6 onr 266 (21) and the Air Force Personnel and Training Research Center under Contract AF 18(600)-341.     

Identifying Causes of Disagreement Between Self-Reports and Spouse Ratings of Personality

Self-reports and spouse ratings of personality traits typically show less-than-perfect agreement, but powerful moderators of agreement have not yet been identified. In Study 1, 47 married couples completed the Revised NEO Personality Inventory to describe themselves and their spouses. Extent of agreement was not consistently moderated by response sets; the age, intelligence, or education of the respondent; or the length or quality of the relationship. In Study 2 these couples were interviewed about reasons for substantial disagreements, and an audiotape was content-analyzed. Sixteen reasons were reliably coded, including idiosyncratic understanding of items, reference to different time frames or roles, and unavailability of covert experience to the spouse. Faking good, assumed similarity, and other variables prominent in the psychometric literature were relatively unimportant. Findings (1) suggest that attempts to improve the validity of self-reports and ratings may need to be refocused and (2) underscore the desirability of routinely obtaining multiple sources of information on personality.     

Religious Knowledge and Its Use in Psychiatry

Clinicians' knowledge of and sensitivity to religious issues have been questioned. The present study measures religious knowledge and willingness to utilize such knowledge in clinical practice. We administered a 41-item questionnaire testing religious knowledge and willingness to utilize such knowledge to 28 psychiatric clinicians. The mean religious knowledge score was 61% of the total possible score. In spite of low scores, only 33% of clinicians consistently refrained from initiating discussions of religious issues. Results support a low level of religious knowledge but do not support a contention that clinicians are insensitive to religious issues.     

The indirect McCollough effect: An examination of an associative account

It has been found that viewing, for example, a red-and-black vertical grating alternating with a green homogeneous field produces a color aftereffect—a McCollough effect—on a black-and-white vertical grating (i.e., green). Viewing such colored patterns also produces an aftereffect on a noninduced horizontal grating (i.e., pink)—the indirect McCollough effect. Humphrey, Dodwell, and Emerson (1989) argued that the indirect McCollough effect is caused by opponent properties of the visual system that organize the processing of contour and color along contrasting, probably orthogonal, dimensions. Recently, however, their interpretation of the indirect McCollough effect has been challenged by some findings of Eissenberg, Allan, Siegel, and Petrov (1995). These researchers have proposed that the indirect McCollough effect, like the McCollough effect, can be explained by associative principles. The results reported here question crucial aspects of the hypothesis of Eissenberg et al.     

Introductory psychology laboratories using graphic simulations of virtual subjects

Graphical simulations of the behavior of virtual subjects in laboratory or field microworlds were developed to teach research principles to introductory psychology students. Students conduct studies in laboratory classes, assuming the primary role of being an experimenter. Microworld modules were designed to foster the flexible exploration of important steps in the research process, including hypothesis generation, research planning and design, behavioral observation or testing, and data summarization and analysis. The modules were designed to impart a sense of behavioral “presence” so that students would obtain an appreciation of realistic behavioral observation and of testing methodologies. Microworlds that have been developed include infant preferential looking (cognitive processes), courting behavior of fireflies, personality test development, working memory, operant conditioning, single-cell recording of sensory function, and testing of brain-damaged people. Principles that guided the development of software modules and laboratory class exercises are discussed.     

Daily Mood Variability: Form of Diurnal Patterns and Determinants of Diurnal Patterns

Mood and affect are often assessed in psychological research without regard for the potential influence of time of day or other environmental factors. This study examined the determinants of daily mood variability. Ninety-four subjects completed a diary every 15 min for 1 day, and subjects' moods, activities, and locations were assessed. Diurnal cycles were found for several moods (e.g., happy, tired), activities (e.g., discourse, thinking), and locations (e.g., home, work). Diurnal cycles in most moods were strongly associated with activities and location, yet diurnal cycles of some moods (rushed, sad, and tired) were not dependent on these factors. These findings have implications for mood assessment: Mood assessment performed only at particular times of day, or those relying on point assessment, may be influenced by time of day and by the activities and location of the subject.     

Secondary-task effects on sequence learning

With a repeated sequence of stimuli, performance in a serial reaction-time task improves more than with a random sequence. The difference has been taken as a measure of implicit sequence learning. Implicit sequence learning is impaired when a secondary task is added to the serial RT task. In the first experiment, secondary-task effects on different types of sequences were studied to test the hypothesis that the learning of unique sequences (where each sequence element has a unique relation to the following one) is not impaired by the secondary task, while the learning of ambiguous sequences is. The sequences were random up to a certain order of sequential dependencies, where they became deterministic. Contrary to the hypothesis, secondary-task effects on the learning of unique sequences were as strong or stronger than such effects on the learning of ambiguous sequences. In the second experiment a hybrid sequence (with unique as well as ambiguous transitions) was used with different secondary tasks. A visuo-spatial and a verbal memory task did not interfere with the learning of the sequence, but interference was observed with an auditory go/no-go task in which high- and low-pitched tones were presented after each manual response and a foot pedal had to be pressed in response to high-pitched tones. Thus, interference seems to be specific to certain secondary tasks and may be related to memory processes (but most likely not to visuo-spatial and verbal memory) or to the organization of sequences, consistent with previous suggestions.