Reorienting in images of a three-dimensional environment

Adult humans searched for a hidden goal in images depicting 3-dimensional rooms. Images contained either featural cues, geometric cues, or both, which could be used to determine the correct location of the goal. In Experiment 1, participants learned to use featural and geometric information equally well. However, men and women showed significant differences in their use of distant featural cues and the spontaneous encoding of geometric information when trained with features present. Transformation tests showed that participants could use either the color or the shape of the features independently to locate the goal. Experiment 2 showed that participants could use either configural or surface geometry when searching for the goal. However, their weighing of these geometric cues was dependent on initial training experience.     

Searching in the center: pigeons (Columba livid) encode relative distance from walls of an enclosure

Pigeons (Columba livia) searched for food hidden in the center of a square enclosure. On occasional tests without food, the enclosure was (a) unchanged from training (control tests), (b) moved to different corners of the testing room (corner tests), or (c) doubled in size (expansion tests). The birds showed localized search in the center of the enclosure on control and corner tests. On expansion tests, some birds searched near the center of the enclosure, suggesting relative-distance encoding. Other birds searched at locations that maintained the training distance from walls, suggesting absolute-distance encoding. These results are consistent with previous studies on chicks (Gallus gallus) in similar enclosures and contrast with previous results on pigeons' responses to expansions of discrete landmark arrays.     

Reorientation in a two-dimensional environment: I. Do adults encode the featural and geometric properties of a two-dimensional schematic of a room?

Adults searched for a goal in images of a rectangular environment. The goal's position was constant relative to featural and geometric cues, but the absolute position changed across trials. Participants easily learned to use the featural cues to find the target, but learning to use only geometric information was difficult. Transformation tests revealed that participants used the color and shape of distinct features to encode the goal's position. When the features at the correct and geometrically equivalent corners were removed, participants could use distant features to locate the goal. Accuracy remained above chance when a single distant feature was present, but the feature farthest from the goal yielded lower accuracy than one closer. Participants trained with features spontaneously encoded the geometric information. However, this representation did not withstand orientation transformations.     

Reorientation in a two-dimensional environment: II. Do pigeons (Columba livia) encode the featural and geometric properties of a two-dimensional schematic of a room?

Pigeons (Columba livia) searched for a hidden target area in images showing a schematic rectangular environment. The absolute position of the goal varied across trials but was constant relative to distinctive featural cues and geometric properties of the environment. Pigeons learned to use both of these properties to locate the goal. Transformation tests showed that pigeons could use either the color or shape of the features, but performance was better with color cues present. Pigeons could also use a single featural cue at an incorrect corner to distinguish between the correct corner and the geometrically equivalent corner; this indicates that they did not simply use the feature at the correct corner as a beacon. Interestingly, pigeons that were trained with features spontaneously encoded geometry. The encoded geometric information withstood vertical translations but not orientation transformations.     

There is more to anger coping than "in" or "out"

There is growing dissatisfaction with a dichotomized "anger-in" versus "anger-out" view of anger coping. Three studies using student and community adultsamples revealed a broader understanding of the nature of anger coping styles and led to the development of the new Behavioral Anger Response Questionnaire (BARQ). The BARQ is empirically derived and factorially validated and has good psychometrics. Results suggest that dichotomizing anger responses as "in" versus "out" is too coarse and that a 6-factor model may be more appropriate. The 6 factors identified here are Direct Anger-Out, Assertion, Support-Seeking, Diffusion, Avoidance, and Rumination. Women reported use of a wider range of anger coping styles, especially more social support-seeking and more use of anger diffusion strategies than men.     

Learning about environmental geometry: a flaw in Miller and Shettleworth's (2007) operant model

Many studies have examined how humans and other animals reestablish a sense of direction following disorientation in enclosed environments. Results showing that geometric shape of an enclosure is typically encoded, sometimes to the exclusion of featural cues, have led to suggestions that geometry might be encoded in a dedicated geometric module. Recently, Miller and Shettleworth (2007) proposed that the reorientation task be viewed as an operant task and they presented an associative operant model that appears to account for many empirical findings from reorientation studies. In this paper we show that, although Miller and Shettleworth's insights into the operant nature of the reorientation task may be sound, their mathematical model has a serious flaw. We present simulations to illustrate the implications of the flaw. We also propose that the output of a simple neural network, the perceptron, can be used to conduct operant learning within the reorientation task and can solve the problem in Miller and Shettleworth's model.     

Emotion recognition and expression in young obese participants: preliminary study

This study of the presence of alexithymic characteristics in obese adolescents and preadolescents tested the hypothesis of whether they showed impaired recognition and expression of emotion. The sample included 30 obese young participants and a control group of 30 participants of normal weight for their ages. Stimuli, 42 faces representing seven emotional expressions, were shown to participants who identified the emotion expressed in the face. The Level of Emotional Awareness Scale was adapted for children to evaluate their ability to describe their emotions. Young obese participants had significantly lower scores than control participants, but no differences were found in recognition of emotion. The lack of words to describe emotions might suggest a greater prevalence of alexithymic characteristics in the obese participants, but the hypothesis of a general deficit in the processing of emotional experiences was not supported.     

Empirical evaluation of the MCMI-III personality disorder scales

The MCMI-III personality disorder scales were empirically validated with a sample of 870 clinical patients and inmates. Prevalence rates of personality disorders were in general lower on the MCMI-III than clinical ratings, but trait prevalence was generally higher; thus a base rate of 75 on the MCMI-III could be a guideline in the screening of trait prevalence. However, the sensitivity of some MCMI-III scales was very low. Moreover, the correlations of most personality disorder scales of the MCMI-III were significant and positive with corresponding measures on clinical ratings and MMPI-2 personality disorder scales, but these were, in general, not significantly higher than some other correlations. As a consequence the discriminant validity seems to be questionable. The MCMI-III alone cannot be used as a diagnostic inventory, but the test could be useful as a screening device as a part of a multimethod approach that allows aggregation over measures in making diagnostic decisions.