Production of successive force impulses by the left and right hands

Right-handed participants made ballistic force impulses with the index finger of their left or right hand to match the amplitude of 2 successive visual targets whose onset was separated by 600-850 ms. The targets specified either low- (10% of maximum voluntary contraction; MVC) or high- (25% MVC) force level and were presented in all combinations (low-low, low-high, high-low, high-high). The amplitude of the 1st force impulse affected that of the 2nd, forming an effect that was greatest at the shortest interresponse intervals and that decayed with increasing intervals. This effect was smaller with a shorter time course in the dominant hand than the nondominant hand, suggesting a greater ability of the dominant hand to make successive independent responses.     

Inclusion-exclusion of positive and negative past selves: mood congruence as information

The current research challenges the widespread truism that recalling a positive self necessarily increases self-esteem, whereas recalling a negative self necessarily decreases self-esteem. Four experiments demonstrate that chronically happy people show a relative increase in self-esteem by recalling either a positive or a negative self. Chronically sad people, however, show a relative decrease in self-esteem by recalling either a positive or a negative self. These effects are due to divergent perceptions of mood congruence between the recalled self and the current self. Specifically, happy people perceive high mood congruence between a recalled positive self and the current self but low mood congruence between a recalled negative self and the current self. In contrast, sad people perceive high mood congruence between a recalled negative self and the current self but low mood congruence between a recalled positive self and the current self. Independent of chronic mood, mood congruence leads to perceptions of temporal recency, whereas mood incongruence leads to perceptions of temporal distance. In line with the inclusion-exclusion model of social judgment, perceived temporal recency elicits assimilation effects on self-esteem, whereas perceived temporal distance elicits contrast effects on self-esteem.     

The best-worst scaling approach: an alternative to Schwartz's Values Survey

Traditional self-report ratings have some measurement problems that a relatively new method, best-worst scaling (BWS; Finn & Louviere, 1992), may overcome. This alternative method, based on Louviere's BWS, can be used to measure the relative importance or perceived trade-offs among choice alternatives. The method is illustrated as an alternative to the Schwartz Value Survey (SVS; Schwartz, 1992). In a series of samples, it was found that Schwartz values best-worst survey (SVBWS) reproduced Schwartz's (1992) theoretical value structure and supported hypothesized relationships between values and value-expressive behaviors, ethnocentrism, and environmental-related tourism activities. In addition, the SVBWS approach took significantly less respondent time than the traditional SVS approach.     

Perceptual deterioration is reflected in the neural response: fMRI study of nappers and non-nappers

Repeated training on a perceptual task can result in performance deterioration. In the case of vision, this practice-dependent decrease, or perceptual deterioration is restored by changing the target orientation, spatial location, or by taking a daytime nap. Behavioral studies suggest the locus of these performance changes to be primary visual cortex. We used fMRI to directly probe whether perceptual deterioration and nap-dependent maintenance of performance can be detected at the level of primary visual cortex. We also asked whether these changes are due to a bottom-up, stimulus-driven response or a top-down plasticity of attentional mechanisms. Subjects were scanned while performing a texture-discrimination task. Half the subjects took a nap between sessions. We measured the relationship between changes in performance and changes in BOLD signal modulation between the two groups. Non-nappers showed performance deterioration that was significantly correlated with decreased BOLD signal modulation, exclusively in area V1 and limited to the bottom-up condition. In contrast, no change was detected in performance and BOLD response in the two conditions for nappers. These results indicate that napping prevented performance deterioration, which was reflected in the fMRI response of neurons in V1. Without a nap, perceptual deterioration was related to decreases in the stimulus-driven, bottom-up representation, rather than decreases in attentional modulation to the stimulus.     

The intermixed-blocked effect in human perceptual learning is not the consequence of trial spacing

A robust finding in humans and animals is that intermixed exposure to 2 similar stimuli (AX/BX) results in better discriminability of those stimuli on test than does exposure to 2 equally similar stimuli in 2 separate blocks (CX_DX)--the intermixed-blocked effect. This intermixed-blocked effect may be an example of the superiority of spaced over massed practice; in the intermixed, but not the blocked exposure regime, each presentation of a given stimulus (e.g., AX) is separated from the next by the presentation of its partner (BX). Two experiments with human participants replicated the intermixed-blocked effect and showed that the effect was not due to the spacing of exposure trials. A mechanism for the intermixed-blocked effect is proposed, which combines theories from associative learning and memory.     

Sensing without seeing in comparative visual search

Rensink [Rensink, R. A. (2004). Visual sensing without seeing. Psychological Science, 15(1), 27-32] has presented evidence suggesting visual changes may be sensed without an accompanying visual experience. Here, we report two experiments in which we monitored observers' eye-movements whilst they searched for a difference between two simultaneously presented images and pressed separate response keys when a difference was seen or sensed. We first assessed whether sensing performance was random by collecting ratings of confidence in the validity of sensing and assessing gaze location during sensing. Sensing was not random: fixation position and confidence ratings were different when a difference was present compared to catch trials. Furthermore, the uniformity of objects in the images and the type of difference appear to affect seeing and sensing differently, suggesting that these processes are dissociated. The possibility is discussed of a sensing mechanism that increases vigilance toward unconsciously registered differences, particularly changes to scene layout.     

Health-Related Quality of Life in Women with Eating Disorders: Association with Subjective and Objective Binge Eating

This study examined health-related quality of life (QOL) and its association with different forms of binge eating in 53 women with eating disorders. Participants had enrolled in treatment for anorexia nervosa, bulimia nervosa, binge eating disorder, or other eating disorders not otherwise specified and completed measures of QOL, eating-related psychopathology, and mood disturbance. Eating- and mood-related psychopathology, and to a lesser extent, mental-component QOL scores, were severely impaired in this sample relative to population norms. QOL was significantly and independently predicted by subjective bulimic episodes and compensatory behaviors, including food avoidance, laxative abuse, and self-induced vomiting, accounting for 32% of the variance. Subjective bulimic episodes and food avoidance also independently predicted the physical-component QOL, accounting for 27% of the variance. These findings suggest that subjective bulimic episodes may be independently associated with impairment in QOL and may require specific attention as targets of treatment.     

进化心理学与生态心理学的整合：理解适宜可用性

进化心理学源自达尔文进化论,以分析心理机能及起源为主要研究目的。同样,生态心理学在Brunswik(1956)和Gibson(1979)开创引领下,探讨了有机体的知觉、判断、行为等因素在环境适应中的作用。尽管进化心理学和生态心理学都具有生物机能主义倾向,但过去研究较少探讨二者联系。该文引入适宜可用性观点来整合进化心理学和生态心理学的理论与实证研究。适宜可用性的观点认为,生存与繁衍问题中的代价与利益分析有助于特定种群的动物采取趋近或回避行为来保证潜在适宜性。适宜可用性的观点源自进化生物学中的知觉理论,它解决了认识论中许多传统问题,也整合了进化心理学和生态心理学的实验研究成果。适宜可用性的观点为新世纪的感觉、知觉、认知、情绪和决策的研究提供了新的理论基础