Problem structure and the use of base-rate information from experience

This article is concerned with the use of base-rate information that is derived from experience in classifying examples of a category. The basic task involved simulated medical decision making in which participants learned to diagnose hypothetical diseases on the basis of symptom information. Alternative diseases differed in their relative frequency or base rates of occurrence. In five experiments initial learning was followed by a series of transfer tests designed to index the use of base-rate information. On these tests, patterns of symptoms were presented that suggested more than one disease and were therefore ambiguous. The alternative or candidate diseases on such tests could differ in their relative frequency of occurrence during learning. For example, a symptom might be presented that had appeared with both a relatively common and a relatively rare disease. If participants are using base-rate information appropriately (according to Bayes' theorem), then they should be more likely to predict that the common disease is present than that the rare disease is present on such ambiguous tests. Current classification models differ in their predictions concerning the use of base-rate information. For example, most prototype models imply an insensitivity to base-rate information, whereas many exemplar-based classification models predict appropriate use of base-rate information. The results reveal a consistent but complex pattern. Depending on the category structure and the nature of the ambiguous tests, participants use base-rate information appropriately, ignore base-rate information, or use base-rate information inappropriately (predict that the rare disease is more likely to be present). To our knowledge, no current categorization model predicts this pattern of results. To account for these results, a new model is described incorporating the ideas of property or symptom competition and context-sensitive retrieval.     

The role of the right hemisphere in the production of linguistic stress

Recent research has proposed a general prosodic disturbance associated with right hemisphere damage (RHD), one encompassing both affective and linguistic functions. The present study attempted to explore whether the ability to produce linguistic prosody was impaired in this patient population. Productions of phonemic stress tokens (e.g., Re'dcoat vs. red coa't) as well as examples of contrastive stress, or sentential emphasis (e.g., Sam hated the movie), were elicited from eight male speakers with unilateral right hemisphere CVAs and seven male control subjects. Two types of analyses were conducted on these utterances. Acoustic analysis focused on the correlates associated with word stress, namely changes in amplitude, duration, and fundamental frequency. The perceptual saliency of emerging cues to stress was also examined by presentation of test tokens to phonetically trained listeners for identification of stress placement. The patients as a group produced fewer acoustic cues to stress compared to the normal subjects, but no statistical differences were found between groups for either stress at the phrase level or at the sentence level. In the perceptual analysis, stress produced by the patient group was judged to be less salient than that for the normal group, although a high degree of variability was evident in both populations. The data suggest a spared processing mechanism for linguistic prosody in RHD speakers, thus mitigating against the view of a general dysprosody tied to RHD.     

Understanding the central processing limit in consistent-mapping visual search tasks

Effects of load (i.e., the number of stimuli in the display) have been observed in multiple-frame studies using a consistent mapping of stimuli to responses (e.g., Fisher, 1982, 1984). In a series of four experiments, it is shown that these effects are not the consequence of differences across the high- and low-load conditions in either decision noise or peripheral masking. Additionally, it is shown that of two modes of limited capacity (a limited-channel and divided-capacity model) considered as possible explanations of load effects in tasks where subjects are required to locate a target, only one--the limited-channel model--is consistent with the results from all three location tasks. Finally, it is argued that the limited-channel model predicts not only the behavior observed in the four consistent-mapping experiments reported in this article but also the behavior observed in several related consistent-mapping tasks (Kleiss & Lane, 1986; Shiffrin & Gardner, 1972).     

Mental rotation: effects of dimensionality of objects and type of task

The original studies of mental rotation estimated rates of imagining rotations that were much slower when two simultaneously portrayed three-dimensional shapes were to be compared (R. Shepard & J. Metzler) than when one two-dimensional shape was to be compared with a previously learned two-dimensional shape (Cooper and her associates). In a 2 X 2 design, we orthogonally varied dimensionality of objects and type of task. Both factors affected reaction times. Type of task was the primary determiner of estimated rate of mental rotation, which was about three times higher for the single-stimulus task. Dimensionality primarily affected an additive component of all reaction times, suggesting that more initial encoding is required for three-dimensional shapes. In the absence of a satisfactory way of controlling stimulus complexity, the results are at least consistent with the proposal that once three-dimensional objects have been encoded, their rotation can be imagined as rapidly as the rotation of two-dimensional shapes.     

Perceptual organization of acoustic stimuli by budgerigars (Melopsittacus undulatus): III. Contact calls

We trained budgerigars by operant conditioning to discriminate among a set of contact calls in a same-different task and analyzed response latencies from this task by using multidimensional-scaling (MDS) and cluster-analysis procedures. Humans listened to the same calls and indicated the similarity between pairs of calls by a direct rating procedure. An MDS program (sindscal) was used to arrange these complex acoustic stimuli in multidimensional space reflecting perceptual organization. Multiple regression techniques were used to identify the acoustic characteristics of contact calls that were correlated with the perceptual dimensions obtained from MDS. A number of spectral characteristics (e.g., peak frequency, rate of frequency modulation, and concentration of spectral energy) emerged as important for both budgerigars and humans, but the relative salience of these cues differed for the two species. Additional tests with two groups of budgerigars--cagemates and noncagemates--showed that experience with calls can change the salience of various acoustic characteristics used for perceptual organization and individual recognition.     

Expert knowledge as mnemonic cues

It is proposed that expert knowledge can operate as a cognitive cueing structure for the acquisition and retention of new information in memory. Two experiments are reported which demonstrate that expert knowledge about football and clothing can act as mnemonic cues for the recall of information newly associated with that knowledge. In Experiment 1 expert terms from the domains of football and clothing and those neutral nouns paired with them were both better recalled by experts than by non-experts. In Experiment 2 passages containing information contrary to factual knowledge about football and clothing were recalled better by experts than by non-experts, in spite of the fact that information in the passages contradicted what the experts already knew. The results of the two experiments were interpreted as showing that expert knowledge provides mental cues that have desirable mnemonic properties such as constructibility, associability, discriminability and invertibility. Also, the interpretation of expert knowledge as a cognitive cueing structure is compared to Ausubel's ideas regarding advance organizers.     

Counselor Self-Disclosure

Self-disclosure in the counseling-therapy relationship has been an important area of research and study, with considerable emphasis placed on counselor self-disclosure. This study was initiated to explore further the phenomenon of counselor-therapist disclosure through direct assessment of potential clients' desires for disclosure and through development of a measure of counselor disclosure. Implications for counselor disclosure and for the counselor-client therapy relationship are discussed.     

A survey of psychologists employed in business and industry

Responses to a questionnaire from 78 members of the Metropolitan New York Association for Applied Psychology provided the following results. A majority of respondents found their first jobs as applied psychologists through informal networking techniques such as personal recommendations or self-starter methods such as sending out resumes. Over 75% of the respondents rated their graduate institutions as good or excellent. However, an increase in the applied focus of these programs was strongly urged, and opinions about graduate faculties were mixed. Obtaining applied work experience or relevant internships was the most often mentioned advice for seekers of similar positions.Appreciation is expressed to Harold Takooshian of Fordham University who first aroused our interests in this topic as an area for research and to Bruce Biskin of AICPA, Dennis Hawver and Tony Zinsser of the Hawver Group, Ted Grant and Michael Secunda of Manufacturers Hanover, and Tom Novak of Young & Rubicam for serving as pre-test subjects for the questionnaire of this study.     

Personal Versus Vocational Focus in Career Counseling: A Retrospective Outcome Study

In this archival study the authors sought to determine the relationship, if any, between counseling outcomes and the topical focus in career counseling. Twenty-two counselors saw 46 adult clients at a community-based clinic for an average of eight sessions. Counseling outcome and topical focus (the extent to which the actual content of counseling sessions reflected relatively more vocationally or personally focused topics) were assessed from follow-up questionnaires to former career clients and from trained raters' evaluations of the counselors' written progress notes. Results showed that, from the counselors' perspective, outcomes were better when the focus of the sessions was relatively more vocational than personal and when relatively more interviews were held. Client satisfaction, on the other hand, was predictable only from the counselor's level of experience. Satisfaction with occupational status was not associated with any of the client, counselor, or treatment factors. Discussion focuses on the contribution of the results to career counseling practice and on the feasibility and validity of retrospective, archival research.