Calibration of a color monitor for visual psychophysics

It has become common for stimuli used in visual psychophysical experiments to be presented on high-resolution color cathode-ray tubes (CRTs) such as the Barco CDCT 6551. These enable a flexibility of color, spatial-frequency content, temporal-frequency content, duration, size, and position that is not provided by most other media. CRTs are, however, not perfect; they suffer from the effects of temporal instability, spatial variability, lack of phosphor constancy, gun interdependence, and gun nonlinearity. This paper describes methods of assessing these aspects of monitor performance with respect to how significant each may be in psychometric terms. Although every application of CRT use in visual psychophysics is different, some general rules can be formulated to help ensure that unwanted effects are kept to a minimum. For the CRT used in this study (Barco CDCT 6551), a warm-up time of 30-45 min is necessary before chromatic and luminous stability ensues. Restriction of individual gun outputs to within 10%-90% of the possible range ensures that the effects of gun interdependence and lack of phosphor constancy are negligible. Calibration methods dealing with the linearization of gun output are also discussed.     

比较研究-影响中美儿童计算能力差异的认知因素

本研究要确定中美儿童基本计算技能的差异是否与他们使用的解题策略和基本加工过程的速度有关。为此,对中美两国的一年级儿童进行了书面计算能力测验,以及一组计算机呈现的加法作业。中国儿童在计算能力测验上表现出3:1的操作优势。中美儿童使用的解题策略种类一样,但是,中国儿童在策略综合运用的发展程度上超过美国儿童,检索策略的加工速度也超过美国儿童。显然,策略运用和加工速度的差异促成了中国儿童在计算能力测验上的优势.     

Potentiation of the pressor response to stress by tolbutamide in dogs

Tolbutamide has previously been shown to amplify the pressor effects of “exogenous” catecholamines in conscious dogs, possibly due to sensitization of the α₁-adrenoreceptor-mediated vasoconstriction. The objective of this study was to examine if tolbutamide also amplifies the pressor effects of “endogenous” catecholamines released during psychological stress (classical Pavlovian aversive conditioning). Experiments were conducted in β-adrenoreceptor-blocked (propranolol, 1 mg/kg, i.v.) conscious dogs (n=4) trained in classical aversive conditioning. Conditioning was accomplished by following a tone (CS+) with a 1/2 second shock; another tone (CS-) was not followed by any shock and served as control. With saline pretreatment, aversive conditioning (i.e., CS+) increased mean arterial pressure (MAP) only by approximately 4.7% when compared to CS-, whereas with tolbutamide (45 mg/kg, i.v.) pretreatment, the increase in MAP induced by CS+ beyond what was induced by the CS- (approximately 6.2%) was significantly (p<0.05) larger than that with saline pretreatment. In isolated canine femoral arterial segments (n=4), the vasoconstrictor effect of phenylephrine (an α₁-agonist) at 5×10^?6M (which was the EC₅₀ value) was amplified by 2×10^?2M of tolbutamide from 54.0±2.0% to 66.9±2.1%. In conclusion, tolbutamide amplifies the pressor effects of “endogenous” catecholamines in conscious dogs, possibly by sensitization of the α₁-adrenoreceptor-mediated vasoconstriction. This mechanism of action is novel and has not been reported with other agents.     

Distractor clustering enhances detection speed and accuracy during selective listening

The effects of distractor clustering on target detection were examined in two experiments in which subjects attended to binaural tone bursts of one frequency while ignoring distracting tones of two competing frequencies. The subjects pressed a button in response to occasional target tones of longer duration (Experiment 1) or increased loudness (Experiment 2). In evenly spaced conditions, attended and distractor frequencies differed by 6 and 12 semitones, respectively (e.g., 2096-Hz targets vs. 1482- and 1048-Hz distractors). In clustered conditions, distractor frequencies were grouped; attended tones differed from the distractors by 6 and 7 semitones, respectively (e.g., 2096-Hz targets vs. 1482- and 1400-Hz distractors). The tones were presented in randomized sequences at fixed or random stimulus onset asynchronies (SOAs). In both experiments, clustering of the unattended frequencies improved the detectability of targets and speeded target reaction times, Similar effects were found at fixed and variable SO As. Results from the analysis of stimulus sequence suggest that clustering improved performance primarily by reducing the interference caused by distractors that immediately preceded the target.     

Linguistic Phenomena and Language Selection in the REM Dreams of German-English Bilinguals

Sixteen German-English bilinguals were studied in a sleep laboratory for four nonconsecutive nights each. Half were native English speakers living in Zürich, and half native German speakers living in Atlanta. Presleep thought samples were solicited each evening and REM dream reports each night; subjects judged the waking appropriateness of their imagined speech and language phenomena, and also identified waking sources of their dream imagery, the following mornings. Incidences of dreaming and of speech therein generally were similar to those of monolinguals. Whether sessions were conducted in German (two nights) or English (two nights) did directly influence language selection in subjects' dreams. Judged appropriateness of language selection to imagined events was very high for thought samples, and high for REM dreams. Sources for thought samples were generally consonant with the language dominant at study site; for REM dreams this relationship was considerably weaker. Judged waking appropriateness to imagined situations was more strongly related to language selection than was the language reference of the supposed sources of those situations.     

Mental Arithmetic: A Componential Analysis of Speed-of-Processing Across Monolingual,Weak Bilingual,and Strong Bilingual Adults

Two experiments compared rates of solving simple and complex addition and multiplication problems in groups of speakers of French or English in Experiment 1 (n = 35) and Spanish or English in Experiment 2 (n = 84). Subjects were divided into groups of English unilinguals, weak bilinguals, and strong bilinguals according to their performance on a naming task. In both experiments, simple problems consisted of two single-digit numbers. At least three single-digit numbers were used for complex problems in Experiment 1 and double-digit numbers in Experiment 2. Mean solution times, particularly for complex problems, were lowest for the monolingual group, followed in turn by the weak bilingual and strong bilingual groups, but these differences were not statistically reliable in either experiment. In Experiment 2, however, componential analyses of solution times indicated that strong bilingual subjects were slower at executing the carry operation when solving complex problems, relative to the two remaining groups. Results were interpreted in terms of the relationship between bilingualism and the representation and processing of numerical information.     

A Coming-of-Age for Research on Interpersonal Perception

ABSTRACT Research on accuracy and consensus in interpersonal perception has become a major topic in the social sciences. Key methodological issues in this research are research design, statistical measures of agreement, unit of analysis, and data aggregation. I discuss the twelve articles devoted to these topics in this special issue in terms of moderators of agreement, the weighted average model of consensus and accuracy (Kenny, 1991), and methodological innovations.     

Sexual Attitudes of Males and Females as Predictors of Interpersonal Attraction and Marital Compatibility1

Two investigations examine the effect of similarity of sexual attitudes on (a) attraction to a stranger and (b) marital sexual satisfaction. In an experiment using undergraduates, manipulation of subject-stranger similarity in general affective orientation to sexuality affected attraction and other evaluative dependent variables. In the second investigation, married couples revealed sexual attitudes and sexual satisfaction. Husbands and wives were similar (r= 0.58, p < 0.001) in their affective orientations to sexuality. Discrepancy between the partners’ scores predicted sexual dissatisfaction in both partners. In addition, the wife's affective orientation to sexuality predicted more indices of sexual satisfaction and adjustment in both the wife and the husband than did the husband's affective orientation to sexuality. Finally, spouses with a positive affective orientation to sexuality were more accurate when judging their partner's sexual enjoyment, compared to spouses with a negative orientation. The findings have implications for the effects of similarity of attitudes on interpersonal attraction and on relationship quality.     

The Influence of Goal Orientation on Task Performance: A Substantively Meaningful Suppressor Variable1

The present study investigated the relationship between performance goal orientation and performance on a complex task. It was hypothesized that cognitive interference would mediate this relationship. In addition, it was hypothesized that cognitive ability would moderate the relationship between cognitive interference and task performance. A three-variable suppressor relationship indicated that, although the direct effect of performance goal orientation on performance was one that produced better performance, the indirect effect of performance goal orientation indicated that performance orientations were associated with increases in cognitive interference, and these increases in cognitive interference were associated with poorer performance. Thus, the beneficial aspect of performance goal orientation (i. e., the direct effect) was counterbalanced by the dysfunctional aspects of performance goal orientation (i. e., the associated increase in cognitive interference). Support was also found for the proposed moderation of ability on the cognitive interference-task performance relationship for final, but not initial performance. The results are interpreted in light of recent discussions regarding the influence of goal orientation on task performance and cognitive interference.     

Stressors, Stress Mediators, and Emotional Weil-Being Among Spouses of Soldiers Deployed to the Persian Gulf During Operation Desert Shield/Storm

The Family Factors Field Study of Operation Desert Shield/Storm (ODS) was designed to collect data on the impact of the Persian Gulf deployment on soldier/family well-being, and the effectiveness of Army and community resources in assisting and supporting families of deployed soldiers. In October 1990, a task force was assembled, and multi-agency research teams visited several Army installations. Informal individual and group interviews were conducted with spouses, unit family support leaders, unit rear detachment personnel, garrison leaders, and local Army program/service providers. The questions were aimed at identifying key stressors which spouses and children experienced in relation to the sudden deployment, as well a stress mediators such as social supports and personal coping skills. Anecdotal information collected during the site visits, combined with findings from previous research on Army families, was used to develop a questionnaire designed to quantify those variables which emerged as relevant to a study of stressors and stress mediators in the context of the ODS deployment.