Configural biases and reversible figures: evidence of multilevel grouping effects

Four experiments sought to identify the processes underlying 2 classes of grouping effects that are readily produced with a hierarchical figure type known as ambiguous triangles. Previous work has shown that aligning small equilateral triangles in particular configurations can both facilitate and interfere with observers' ability to report the pointing direction of the individual triangles. We determined that selectively adapting the observer to low-frequency gratings of the same orientation as the aligned triangles markedly altered the interfering and facilitative effects of the global configuration only when an accuracy measure of performance was used. When a response latency measure was used, no effect of the same adaptation condition was found. Results are discussed in terms of multiple levels of grouping effects in the visual system and the differential sensitivity of these levels to basic neural adaptation.     

A measurement theory of illusory conjunctions

Illusory conjunctions refer to the incorrect perceptual combination of correctly perceived features, such as color and shape. Research on the phenomenon has been hampered by the lack of a measurement theory that accounts for guessing features, as well as the incorrect combination of correctly perceived features. Recently, several investigators have suggested using multinomial models as a tool for measuring feature integration. The authors examined the adequacy of these models in 2 experiments by testing whether model parameters reflect changes in stimulus factors. In a third experiment, confidence ratings were used as a tool for testing the model. Multinomial models accurately reflected both variations in stimulus factors and observers' trial-by-trial confidence ratings.     

Action-based and vision-based selection of input: Two sources of control

In the first part of this paper we review evidence suggesting that there exists a mechanism that selects input on the basis of its similarity to the required action. This response-based input selection differs from the more established space- and object-based input selection in that it is not constrained by the structure of the input. Our evidence suggests that the two-choice Stroop effect is caused by this response-based selection mechanism. By contrast, it is known that the flanker effect is determined by the space- and object- based selection mechanisms. We explore whether the conflict resolution of the Stroop and flanker tasks is different as well by embedding these two tasks in a PRP (Psychological Refractory Period) paradigm. We show that the Stroop and the PRP effects are additive whereas the flanker and the PRP effects are underadditive, suggesting that the processes in charge of the conflict resolution in the Stroop and the flanker tasks are indeed different. We discuss possible reasons for this difference, and discuss possible ways in which the response-based mechanism can be implemented in information processing models.     

Measures of self-efficacy and optimism in older adults with generalized anxiety

This study provides initial psychometric data for the Self-Efficacy Scale (SES) and the Life Orientation Test (LOT) in a sample of older adults with generalized anxiety disorder (GAD). Participants included 76 adults, ages 60 to 80, who met Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for GAD. Self-efficacy and outcome expectancies were lower in older adults with GAD relative to published data from younger and older community samples. Both the SES and LOT demonstrated adequate internal consistency. Confirmatory factor analysis provided evidence for optimism and pessimism factors within the LOT and exploratory factor analysis of the SES suggested threefactors that overlap with previous findings. Overall, the data support the potential utility of these instruments in late-life GAD and set the stage forfuture investigations of generalized self-efficacy expectancies and outcome expectancies (or optimism) as they relate to the prediction of affect and behavior in this group.     

Win-shift and win-stay learning in the short-beaked echidna (<Emphasis Type="Italic">Tachyglossus aculeatus</Emphasis>)

Numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. In three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). This is a species and a foraging situation that have not been examined in this way before. Echidnas were better able to learn to avoid a previously rewarding location (to "win-shift") than to learn to return to a previously rewarding location (to "win-stay"), at short retention intervals, but were unable to learn either of these strategies at retention intervals of 90 min. The short retention interval results support the ecological hypothesis, but the long retention interval results do not. Electronic Publication     

Emotional expression and physiology in European Americans and Hmong Americans

Ethnographic and clinical observations suggest that Asians are less expressive than European Americans. To examine whether this difference emerged in online emotional responding, 50 Hmong Americans (HAs) and 48 European Americans (EAs) were asked to relive past episodes of intense happiness, pride, love, anger, disgust, and sadness. Facial behavior and physiological reactivity were measured. For most emotions, more cultural similarities than differences were found. There were some exceptions: During happiness, fewer HAs than EAs showed non-Duchenne smiles (i.e., "social" smiles), despite similarities in reported emotional experience and physiological reactivity. Within-group differences between "less Hmong" and "more Hmong" HAs were also found. Implications of these findings for our understanding of culture-emotion relations are discussed.     

The Factor Structure of the Beavers Interactional Scales

Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly.