On central vision activity and peripheral sensitivity: A method with potentialities for research on a range of problems in visual perception

Peripheral sensitivity of the human eye, P_s, and the processing capacity of the central retina, V_c, are assumed to be inversely related. On this basis, a method was designed, whereby P_s as a function of V_c can be determined and a family of P_s maps for the whole surface of the periphery can be obtained. This can be done by means of an experimental system consisting of a computer-based visual field, a hemisphere, on which tracking patterns with varying degrees of difficulty are displayed centrally (V_c) and multivariate signals (to be detected) are simultaneously presented on the periphery (as indexes of P_s). Since the apparatus is capable of producing and controlling a great number of variables, it can, with slight or no modifications, be used to study a wide range of problems in the field of visual perception and attention.     

The effects of circumferential air-splint pressure on flexor carpi radialis H-reflex in subjects without neurological deficits

The purposes of this study were to investigate the effects of circumferential pressure on flexor carpi radialis (FCR) H-reflex in subjects without neuromuscular deficits and to evaluate the skin's contribution to this effect. FCR H-reflex was assessed in 43 subjects by measuring the peak-to-peak amplitude change before, during, and after circumferential pressure was applied to the forearm. Twelve H-reflexes (H/M ratio: M = 25%, SD = 14) were recorded before pressure application to obtain a baseline value (H(baseline)) to which all data were compared. A pneumatic 15 to 20-cm air splint inflated to 51-60 mmHg provided the pressure around the forearm. H-reflex recordings were taken at 1, 3, and 5 min. during (H(pressure)) and after pressure application. A second smaller study (placebo), in which the air splint was inflated to 0 mmHg, was conducted in 5 subjects to ensure that changes in reflex amplitudes were not a result of cutaneous effects. Two types of responses were observed in the FCR H-reflex following pressure application. One group of subjects significantly increased in H-reflex amplitude while another group decreased in H-reflex amplitude when compared to H(baseline). Regression analysis found that H(max) explained 37.2% of the variance when controlling for H(baseline). Subjects with larger H(max) showed an increase in H(pressure) while subjects with lower H(max) showed decreases in H(pressure) The placebo study revealed no differences in H-reflex amplitude from baseline values, implying that skin stimulation from the air splint has no role in the effects observed. The dichotomous result indicates that pressure influences the upper extremity differently than it does the lower extremity in certain individuals. Clinicians, using circumferential pressure as a therapeutic modality to lower muscle activity of the upper extremity, need to be cognizant that pressure may have contrasting effects on their patients.     

The Person Positivity and Principal Actor Hypotheses1

Data from election studies in Sweden, the Netherlands, and the U.S. were analyzed to test the external validity of Sears' person positivity hypothesis. Although people in Sweden and the Netherlands did not rate their preferred party less favorably than that party's leader, overall the results in those two countries tended to support the person positivity hypothesis. However, the U.S. data indicated, contrary to the person positivity hypothesis, that people rated political parties more favorably than the nominees, or the people competing for the nominations, of those parties. An alternative, the principal actor hypothesis, was offered which is compatible with the data from all three countries. This hypothesis is that positivity or leniency will be extended in judgments that do not involve the principal actors in a political system. This accords with our findings that in the strong party systems of Sweden and the Netherlands, parties are judged less favorably than party leaders, while in the weak party system of the U.S., parties are judged more favorably than the individuals nominated by the parties.     

Support processes in same‐ and mixed‐sex relationships: Type and source matters

Research has established that social support for relationships is an important predictor of well‐being. However, the underlying assumption that social support specifically for relationships is a separate construct from general social support has not been properly tested empirically, nor has the question of whether support processes vary by source (friends vs. family). The current study (N = 1,281) used confirmatory factor analysis and structural equation modeling to address these issues. Support was found for a theoretical model in which social support specifically for relationships predicts relationship well‐being and, in turn, mental and physical health, even while controlling for general social support. Somewhat different patterns were found by source of support (family vs. friends) and by relationship type (same sex vs. mixed sex).     

Self-Injurious Thoughts and Behaviors Interview: development, reliability, and validity in an adolescent sample

The authors developed the Self-Injurious Thoughts and Behaviors Interview (SITBI) and evaluated its psychometric properties. The SITBI is a structured interview that assesses the presence, frequency, and characteristics of a wide range of self-injurious thoughts and behaviors, including suicidal ideation, suicide plans, suicide gestures, suicide attempts, and nonsuicidal self-injury (NSSI). This initial study, based on the administration of the SITBI to 94 adolescents and young adults, suggested that the SITBI has strong interrater reliability (average kappa = .99, r = 1.0) and test-retest reliability (average kappa = .70, intraclass correlation coefficient = .44) over a 6-month period. Moreover, concurrent validity was demonstrated via strong correspondence between the SITBI and other measures of suicidal ideation (average kappa = .54), suicide attempt (kappa = .65), and NSSI (average kappa = .87). The authors concluded that the SITBI uniformly and comprehensively assesses a wide range of self-injury-related constructs and provides a new instrument that can be administered with relative ease in both research and clinical settings.