Absolute identification by relative judgment

In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative relative judgment model (RJM) in which the elemental perceptual units are representations of the differences between current and previous stimuli. These differences are used, together with the previous feedback, to respond. Without using long-term representations of absolute magnitudes, the RJM accounts for (a) information transmission limits, (b) bowed serial position effects, and (c) sequential effects, where responses are biased toward immediately preceding stimuli but away from more distant stimuli (assimilation and contrast).     

Practice increases the efficiency of evidence accumulation in perceptual choice

Most models of choice response time base decisions on evidence accumulated over time. A fundamental distinction among these models concerns whether each piece of evidence is equally weighted (lossless accumulation) or unequally weighted (leaky accumulation). The authors tested a hypothesis derived from A. Heathcote and S. Brown's (2002) self-exciting expert competitor (SEEXC) model of skill acquisition: that evidence accumulation becomes less leaky with practice. The hypothesis was supported by observation that the effects of prime stimuli increased with practice. The authors used metacontrast masked primes, which could not be consciously discriminated by most participants, to avoid methodological problems associated with conscious strategy changes. The form of the law of practice in the data is also shown to be consistent with the SEEXC model.     

Identification and bisection of temporal durations and tone frequencies: common models for temporal and nontemporal stimuli

Two experiments examined identification and bisection of tones varying in temporal duration (Experiment 1) or frequency (Experiment 2). Absolute identification of both durations and frequencies was influenced by prior stimuli and by stimulus distribution. Stimulus distribution influenced bisection for both stimulus types consistently, with more positively skewed distributions producing lower bisection points. The effect of distribution was greater when the ratio of the largest to smallest stimulus magnitude was greater. A simple mathematical model, temporal range frequency theory, was applied. It is concluded that (a) similar principles describe identification of temporal durations and other stimulus dimensions and (b) temporal bisection point shifts can be understood in terms of psychophysical principles independently developed in nontemporal domains, such as A. Parducci's (1965) range frequency theory.     

Comparisons and perceived deprivation in ethnic minority settings

Two studies investigated comparison choices among ethnic minorities and majorities. The perceived status of the self vis-á-vis different comparison targets also was assessed. Antecedents and consequences of comparisons and relative deprivation were examined. Predictions were derived from social comparison, stigma, social identity, and relative deprivation research. Two surveys were conducted, one in London with mainly Asian participants (N = 235) and one in Germany with Turkish and Aussiedler participants (N = 166) and German majority members (N = 351). Participants preferred intragroup and temporal comparisons (with other ingroup members and with the self in the past) to various types of cross-group comparisons (with outgroup members). Perceived similarity and contact with a target positively predicted interest in comparing with this target, and perceived higher status of the target was a negative predictor. Some evidence was found that feelings of deprivation depend on comparison choices. Deprivation negatively predicted self-esteem and life satisfaction. Deprivation and group identification were negatively correlated.     

Cumulating retrieval inhibition in semantic and lexical domains

In 3 experiments the authors examined changes in successive exemplar generation percentages within categories defined semantically (e.g., fruit-P, fruit-A, fruit-M) and by 1st letter (e.g., insect-C, sport-C, car-C), with a mixed control condition (e.g., fruit-P, insect-C, disease-M). Retrieval success declined across 12 successive items in both semantic and letter categories, with no change for the mixed condition. This retrieval inhibition is unrelated to taxonomic frequency of exemplars within either letter or semantic categorical structures. Furthermore, semantic retrieval inhibition appears to be long lasting, suggested by the decline in retrieval percentage across successive 12-item blocks in both the mixed and letter conditions. The authors suggest that different mechanisms underlie the inhibition found in the semantic (suppression) and letter (interference) conditions.     

Symptoms of depression in older home-care patients: patient and informant reports

The purpose of this study was to examine the level of agreement and patterns of disagreement between home-care patient and informant reports of depressive symptoms. The authors interviewed a sample of 355 older home-care patients and their informants using the Structured Diagnostic Interview for DSM-IV (R. L. Spitzer, M. Gibbon, & J. B. Williams, 1995). Informants reported more psychological symptoms than patients, and this type of discrepancy was higher for patients with cognitive impairment and patients who had younger informants. Younger informants also reported more cognitive symptoms, whereas patients were more likely to report suicidal thoughts or ideation if they were not cognitively impaired. The patterns of these discrepancies may reflect age- and cohort-related response bias in the reports of depressive symptoms obtained from older adults.     

Cystic Fibrosis Prenatal Screening in Genetic Counseling Practice: Recommendations of the National Society of Genetic Counselors

For over a decade, prenatal screening for cystic fibrosis (CF) has been considered a model for the integration of genetic testing into routine medical practice. Data from pilot studies and public policy discourse have led to recommendations by some professional organizations that CF screening should be offered or made available to pregnant women and their partners, and to couples planning a pregnancy. It is crucial that genetic counselors gain thorough understanding of the complexities of CF and the implications of positive test results, so that they may serve as a reliable, educated referral base and resource for health care providers and their patients. While not all pregnant women will be referred for genetic counseling prior to CF carrier testing, genetic counselors often will be asked to counsel clients after they have a positive test result, or who are found to be at increased risk. Genetic counselors can play an important role in providing accurate and current information as well as support for patients informed decisions. These recommendations were created by a multicenter working group of genetic counselors with expertise in CF and are based on personal clinical experience, review of pertinent English language medical articles, and reports of expert committees. The recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. These recommendations do not displace a health care providers professional judgment based on the clinical circumstances of a particular client.     

A computer running several psychological laboratories

Seven psychological laboratories, capable of testing 22 human and 4 animal Ss in seven different experiments using a variety of peripheral equipment, are in various stages of operation using an IBM 1800 process-control computer in the Psychology Department at Indiana University. Each experiment utilizes four appropriate software programs: SETUP, PROCEDURE, UI1LITY, and OUTPUT. The programming is usually simple enough to be done by nonprofessional programmers. This simplification was made possible by (1) a set of subroutines written to handle many of the process-control programming complexities, and (2) the IBM-provided Time-Sharing Executive (TSX) program.     

Discrimination and reproduction of patterns: Feature measures and constraint redundancy as predictors

The statistical structure ofsamples ofpatterns [histoforms and polygons) was varied by manipulating constraint redundancy (R_c) at three levels. Both R_c and seven measures of pattern features were evaluated as predictors of reproduction errors and discrimination latency using multiple linearregression techniques. While it was possible to account for a significant proportion of performance variance from knowledge of R_c levels, feature measures accounted for more performance variance under all conditions of testing. The results were interpreted as support for the notion that patterns are processed in terms offeatures.