Neural mechanisms of social influence

The present investigation explores the neural mechanisms underlying the impact of social influence on preferences. We socially tagged symbols as valued or not – by exposing participants to the preferences of their peers – and assessed subsequent brain activity during an incidental processing task in which participants viewed popular, unpopular, and novel symbols. The medial prefrontal cortex (mPFC) differentiated between symbols that were and were not socially tagged – a possible index of normative influence – while aspects of the striatum (the caudate) differentiated between popular and unpopular symbols – a possible index of informational influence. These results suggest that integrating activity in these two brain regions may differentiate objects that have become valued as a result of social influence from those valued for non-social reasons.     

An investigation into the temporal dimension of the Mozart effect: evidence from the attentional blink task

In the present study, we examined whether the 'Mozart effect' would influence participants' temporal attention using a visual attentional blink (AB) task that provides a reliable measure of the temporal dynamics of visual attention. The 'Mozart effect' refers to the specific claim that listening to Mozart's Sonata for Two Pianos in D Major, K.448 can improve the performance in spatio-temporal tasks. Participants had to try and identify two target digits (in their correct order of presentation) presented amongst a stream of distractor letters in three different conditions (presented in separate blocks of trials): while listening to the Mozart sonata played normally, while listening to the same Mozart sonata played in reverse, and while in silence. The results showed that the participants were able to detect the second target (T2) significantly more accurately (given the correct detection of the first target, T1) in the AB stream when the Mozart sonata was played normally than in either of the other two conditions. Possible explanations for the differential effects of Mozart's music being played normally and in reverse and potential confounds in previous studies reporting a facilitatory 'Mozart effect' are discussed. Our results therefore provide the first empirical demonstration supporting the existence of a purely temporal component to the 'Mozart effect' using a non-spatial visual AB task.     

Sense of meaning and academic performance: A brief report

This study examined sense of meaning and academic performance among a sample of South African university students (n = 210, mean age = 19.49, SD = 1.99, female = 54.29%). Data on meaning were collected using the Purpose in Life Test. End of semester marks served as the academic attainment measure. Simple regression analysis with post-hoc independent-samples t-tests revealed that meaning predicts academic performance. No significant differences between genders emerged from the data. Sense of meaning is an important factor in supporting students to enhance their academic performance.     

MMPI-2 and MCMI-III characteristics of parental competency examinees

The MMPI-2 (Butcher et al., 2001) and the MCMI-III (Millon, Davis, & Millon, 1997) may contribute to understanding psychological functioning in parental competency examinees. In this study, we sought to identify MMPI-2 and MCMI-III characteristics of this population. We collected data regarding 127 individuals who underwent court-ordered parental competency evaluations. Although test results were generally consistent with findings from the child custody literature, MMPI-2 results indicated the highest Validity scale elevation on the L scale in contrast to the K scale elevations that have often been reported in the custody literature.     

CS-dependent response probability in an auditory masked-detection task: considerations based on models of Pavlovian conditioning.

Experimental studies were performed using a Pavlovian-conditioned eyeblink response to measure detection of a variable-sound-level tone (T) in a fixed-sound-level masking noise (N) in rabbits. Results showed an increase in the asymptotic probability of conditioned responses (CRs) to the reinforced TN trials and a decrease in the asymptotic rate of eyeblink responses to the non-reinforced N presentations as a function of the sound level of the T. These observations are consistent with expected behaviour in an auditory masked detection task, but they are not consistent with predictions from a traditional application of the Rescorla-Wagner or Pearce models of associative learning. To implement these models, one typically considers only the actual stimuli and reinforcement on each trial. We found that by considering perceptual interactions and concepts from signal detection theory, these models could predict the CS dependence on the sound level of the T. In these alternative implementations, the animals response probabilities were used as a guide in making assumptions about the "effective stimuli".     

Young infants' perception of unity and form in occlusion displays

Young infants have been reported to perceive the unity of a center-occluded object when the visible ends of the object are aligned and undergo common motion but not when the edges of the object are misaligned (Johnson & Aslin, 1996). Using a recognition-based paradigm, the authors investigated the possibility that past research failed to provide sufficiently sensitive assessments of infants' perception of the unity of misaligned edges in partial occlusion displays. Positive evidence was obtained in 4-month-olds for veridical perception of the motion and location of a hidden region but not its orientation, whereas 7-month-olds, in contrast to the younger infants, appeared to respond to the orientation of the hidden region. Overall, the results suggest that habituation designs tapping recognition processes may be particularly efficacious in revealing infants' perceptual organization. In addition, the findings provide corroborative evidence for the importance of both motion and orientation in young infants' object segregation and for the difficulty in achieving percepts of the global form of a partly occluded object.     

Seismic sensitivity in the desert golden mole (Eremitalpa granti): a review

Behavioral and anatomical studies relating to possible seismic sensitivity in the desert golden mole (Eremitalpa granti) are reviewed. Field studies in the Namib desert have shown that isolated hummocks of dune grass generate low-frequency vibrations, distinct from the background noise at a distance of many meters. The golden mole apparently uses these cues to orient itself toward the hummocks and the prey species within. An analysis of middle ear morphology suggests that the massive malleus of the golden mole is adapted toward a form of inertial bone conduction, suitable for the detection of seismic cues obtained in this manner. The significance of seismic sensitivity in this golden mole is briefly discussed.     

Against Blameless Wrongdoing

I argue against the standard view that it is possible to describe extensionally different consequentialist theories by describing different evaluative focal points. I argue that for consequentialist purposes, the important sense of the word act must include all motives and side effects, and thus these things cannot be separated.     

The role of good form in young Infants' perception of partly occluded objects

Young infants have been reported to perceive the unity of a center-occluded object when the visible ends of the object undergo common motion, but not on the basis of stationary information (e.g., P. J. Kellman & E. S. Spelke, 1983). We investigated the possibility that 4-month-old infants will attend to and utilize the global configuration (i.e., the "good form") of a partly occluded, moving object to perceive its unity and coherence behind the occluder. In the first experiment, infants viewed a partly occluded circle or cross that translated laterally. Infants who habituated in the minimum number of trials ("fast habituators") showed a reliable posthabituation preference for a broken object over a complete object, indicating perception of unity in the habituation display. Slow habituators exhibited no posthabituation preference. In the second experiment, infants were presented with small ring and cross displays, and the infants looked longer at the broken object. There were no reliable differences in performance between fast and slow habituators. A control group demonstrated no reliable posthabituation preference. In three additional conditions, infants viewed either a partly occluded half ring or a display in which two rod parts were either relatable and nonaligned or nonrelatable. The results indicated that curvature per se provided information in support of completion, in addition to global configuration and motion. Implications for theories of infants' visual development are discussed.     

Cognitive style: problem solving by rhesus macaques (Macaca mulatta) reared with living or inanimate substitute mothers

Cognitive style, reflected in the generation of novel solutions and the use of identifiable response strategies in problem-solving situations, was contrasted in rhesus monkeys (Macaca mulatta) reared individually with either canine companions or inanimate surrogate mothers. Four experiments were conducted over a 5-year period, examining problem solving in relatively unstructured as well as more formal situations. Results indicated that whereas the 2 rearing groups did not differ on most measures of performance, consistent response strategies were identified for the dog-raised monkeys. The results were compared with previously published data from the same monkeys demonstrating rearing group differences in abilities to engage in complex social interaction. The animate nature of the early rearing environment may facilitate-the development of a cognitive style that influences problem-solving abilities in both the social and nonsocial realms.