Inhibition and superconditioning

Superconditioning is said to occur when learning an association between a conditioned stimulus (CS) and unconditioned stimulus (US) is facilitated by pairing the CS with the US in the presence of a previously established conditioned inhibitor. Previous demonstrations of superconditioning have been criticized because their control conditions have allowed alternative interpretations. Using a within–subjects autoshaping procedure, the present study unambiguously demonstrated superconditioning. The results support the view that superconditioning is the symmetric opposite of blocking.     

Pessimism

The problem of pessimism is the secular analogue to the evidential problem of evil facing traditional theism. The traditional theist must argue two things: that the evidence shows that this is on balance a good world and that it is the best possible world. Though the secular optimist who advocates any form of secular moral theory need not argue that the current and future world will likely be the best possible world, she nonetheless must argue that were there a clean solution to the problem of current and future suffering in which all sentient life could be instantly and painlessly eliminated, we would have reasons not to employ the clean solution because the future promises to bring on balance a good world in which the evil of human and animal suffering is outweighed by whatever is good in the world. Pessimism is the view that the evidence argues against secular optimism. It is argued here that it is anything but clear that secular optimism is warranted when viewed from an impersonal point of view. The problem is then evaluated from the personal point of view in which a form of personal optimism is defended even in the face of impersonal pessimism.     

Anxiety-related bias in the classification of emotionally ambiguous facial expressions

High- and low-trait socially anxious individuals classified the emotional expressions of photographic quality continua of interpolated ("morphed") facial images that were derived from combining 6 basic prototype emotional expressions to various degrees, with the 2 adjacent emotions arranged in an emotion hexagon. When fear was 1 of the 2 component emotions, the high-trait group displayed enhanced sensitivity for fear. In a 2nd experiment where a mood manipulation was incorporated, again, the high-trait group exhibited enhanced sensitivity for fear. The low-trait group was sensitive for happiness in the control condition. The mood-manipulated group had increased sensitivity for anger expressions, and trait anxiety did not moderate these effects. Interpretations of the results related to the classification of fearful expressions are discussed.     

Individual differences in stress reactions during a peer entry episode: effects of age, temperament, approach behavior, and self-perceived peer competence

The purpose of the current study was to determine whether a standardized peer entry paradigm would produce stress responses in 3- and 4-year-olds and how such stress responses would relate to temperament, observed approach to peers, and self-perceived peer competence. Physiological stress reactions were measured by activity of the hypothalamic-pituitary-adrenal (HPA) system. The 4-year-old group showed significantly less avoidance of the new peers and was rated higher on approach temperament. This older group also showed larger HPA stress responses to the new peer situation. Finally, discrepancy between self-reported peer competence and behavior in the peer entry situation was associated with larger stress responses on average. These findings support the notion that investment in a salient episode plays a role in determining the magnitude of HPA stress responses. The importance of examining discrepancies between self-perception and action in research on stress is discussed.     

Side preference in adults for holding infants: contributions of sex and handedness in a test of imagination

Five hundred one right-handers (150 men, 351 women) and 53 left-handers (15 men, 38 women) were asked to imagine holding a young infant in their arms. Right-handers reported significant left-side biases--in 68% of the men and 73% of the women. For left-handers, side preferences were weaker, the left-side bias dropping to 47% for men and 60% for women, with neither figure different from chance. The results are discussed in the context of theory and research on the functional neuroanatomy of attention, emotional arousal, and the generation, maintenance, and manipulation of mental images.     

Comparing contrast-modulated and luminance-modulated masking: effects of spatial frequency and phase

The masking of a sinusoidal test grating by contrast-modulated (CM) gratings could, in principle, be attributable to the presence of a distortion product, injected into the stimulus during some nonlinear transformation at an early level of visual processing (e.g. Nachmias, 1989 Vision Research 29 137-142). If so, CM gratings and luminance-modulated (LM) gratings of similar effective contrast and spatial frequency should mask the detection of sinusoids in a similar fashion. We compared the effects of masking by 1 cycle deg-1 CM gratings [both simple beats (8 + 9 cycles deg-1) and amplitude-modulated gratings (8 + 9 + 10 cycles deg-1)], with those of masking by 1 cycle deg-1 LM gratings of low contrast. We found that: (i) CM and low-contrast LM grating masks yielded similar spatial-frequency tuning functions around the modulation frequency of 1 cycle deg-1; (ii) low-contrast LM gratings masked the detection of test sinusoids in a highly phase-dependent fashion, while masking by CM gratings did not vary systematically with relative spatial phase. The results suggest that masking produced by CM gratings cannot simply be explained by the presence of a distortion product at the beat or modulation frequency.     

Turning objects on their heads: the influence of the stored axis on object individuation

We used repetition blindness (RB) as a measure of object recognition and compared the pattern of RB obtained for objects with a well-established upright orientation (mono-oriented objects) and those without a usual upright orientation (polyoriented objects), when the critical objects were either in identical orientations or differed by 30 degrees, 60 degrees, 90 degrees, or 180 degrees. Overall, we found robust RB despite differences in orientation, consistent with the idea that object recognition, as indexed by RB, is largely independent of orientation. However, whereas for polyoriented objects RB was obtained in all orientation conditions, for mono-oriented objects there was no RB between upright and upside-down versions of the stimuli. These findings suggest that the usual orientation of an object-when it exists-is stored in memory and can facilitate orientation processing when the principal axis of a viewed object is aligned with the stored axis orientation. This, in turn, allows for more rapid and successful construction of distinct episodic representations of an object, thus alleviating RB.     

Intervention Groups for Adolescents With Conduct Problems: Is Aggregation Harmful or Helpful?

Past research has suggested that the aggregation of deviant peers during treatment may cause harmful effects (T. J. Dishion, J. McCord, & F. Poulin, 1999). This study compared the effectiveness of problem-solving skills training groups in which all members had conduct problems (pure group condition) with groups that consisted of adolescents with and without behavior problems (mixed group condition). Participants were 139 sixth- and seventh-graders (mean age = 12.7; 63% male; 55% White) enrolled at public middle schools. Pre-, post-, and 6-month follow-up data were collected, along with intervention process variables. Results showed that, contrary to the deviancy training hypothesis, adolescents in the pure-group condition engaged in more adaptive in-session behavior and received lower scores on the parent and teacher ratings of externalizing behavior at postintervention than those in the mixed-group condition. Mediation analyses showed that the deviancy training that occurred in the mixed-group condition accounted for their worse postintervention scores, findings consistent with the deviancy training hypothesis.     

Shape-from-shading depends on visual, gravitational, and body-orientation cues

The perception of shading-defined form results from an interaction between shading cues and the frames of reference within which those cues are interpreted. In the absence of a clear source of illumination, the definition of 'up' becomes critical to deducing the perceived shape from a particular pattern of shading. In our experiments, twelve subjects adjusted the orientation of a planar disc painted with a linear luminance gradient from one side to the other, until the disc appeared maximally convex-that is, until the luminance gradient induced the maximum perception of a three-dimensional shape. The vision, gravity, and body-orientation cues were altered relative to each other. Visual cues were manipulated by the York Tilted Room facility, and body cues were altered by simply lying on one side. The orientation of the disc that appeared maximally convex varied in a systematic fashion with these manipulations. We present a model in which the direction of perceptual 'up' is determined from the sum of three weighted vectors corresponding to the vision, gravity, and body-orientation cues. The model predicts the perceived direction of 'up', contributes to our understanding of how shape-from-shading is deduced, and also predicts the confidence with which the 'up' direction is perceived.