Lateralized reaching as dynamical symmetry breaking in the bushbaby (Otolemur garnettii): preliminary evidence

Eight bushbabies were subjected to an extensive series of hand preference trials in which they were required to reach for a raisin from a rotating platform approaching from the right- or left-hand side of their visual field. Three principal types of behavior were observed. Several individuals known to be stable in hand preference continued to show a strong preference for a single hand. Another group, including some previously categorized as stable, exhibited "ambidextrous" cross-body reaching behavior. One individual exhibited far more complex behavior, being ambidextrous at low and very high speeds but lateralized at intermediate speeds. A straightforward adaptation of the dynamical neural field theory of Sch?ner et al. (1997) provides a model allowing each type of behavior, except possibly the shift from lateralized behavior to ambidextrous behavior at high speed, which might nonetheless be accommodated with minor modification.     

Measurement and Application of Egoistic and Moralistic Self‐enhancement

Five studies were conducted to develop and validate the Egoistic and Moralistic Self‐enhancement (EMS) scale, a new self‐report measure of egoistic and moralistic self‐enhancement. Exploratory and confirmatory factor analysis provided evidence for a two‐factor structure comprising the tendencies to promote agentic (egoistic) and communal (moralistic) qualities (Study 1). Construct validity was supported by significant correlations with established measures of socially desirable responding, such as the Balanced Inventory of Desirable Responding (Study 2) and the Impression Management scale of the 16 Personality Factors (Study 3). When the EMS scale has been applied in organizational settings, we found that job applicants were more inclined than nonapplicants to promote their own agentic and communal qualities, although differences were more pronounced for egoistic self‐enhancement (Study 4). Findings also suggested that exaggeration of agentic qualities decrease the criterion‐related validity of conscientiousness in predicting job performance (Study 5). Taken together, findings suggest that the EMS scale provides a valid and reliable measure that can be fruitfully used for both theoretical and applied research.     

An Application of Generalizability Theory to the Consistency-Specificity Problem: The Transsituational Consistency of Behavioral Persistence

We assessed the behavioral persistence of 65 elementary school children in five situations to explore further the consistency-specificity, or trait-situation, issue. We predicted that the cross-situational consistency of persistence would co-vary with gender, socioeconomic status, and intelligence. The data were analyzed within the context of generalizability theory, and some of our predictions were supported by the results. We contend that the consistency-specificity issue can be profitably studied by direct behavioral assessments within the context of generalizability theory. The implications of the findings for the consistency-specificity issue, and for personality assessment in general, are discussed.     

Mismatch between what is expected and what actually occurs triggers memory reconsolidation or extinction

In previous experiments on contextual memory, we proposed that the unreinforced re-exposure to the learning context (conditioned stimulus, CS) acts as a switch guiding the memory course toward reconsolidation or extinction, depending on reminder duration. This proposal implies that the system computes the total exposure time to the context, from CS onset to CS offset, and therefore, that the reminder presentation must be terminated for the switching mechanism to become operative. Here we investigated to what extent this requirement is necessary, and we explored the relation between diverse phases in the reconsolidation and extinction processes. We used the contextual memory model of the crab Chasmagnathus which involves an association between the learning context (CS) and a visual danger stimulus (unconditioned stimulus, US). Administration of cycloheximide was used to test the lability state of memory at different time points. The results show that two factors, no-reinforcement during the reminder (i.e., CS re-exposure) and CS offset are the necessary conditions for both processes to occur. Regardless of the reminder duration, memory retrieved by unreinforced CS re-exposure emerges intact and consolidated when tested before CS offset, suggesting that neither reconsolidation nor extinction is concomitant with CS re-exposure. Either process could only be triggered once the definitive mismatch between CS and US is confirmed by CS termination without the expected reinforcement.     

In the face of emotions: event-related potentials in supraliminal and subliminal facial expression recognition

Is facial expression recognition marked by specific event-related potentials (ERPs) effects? Are conscious and unconscious elaborations of emotional facial stimuli qualitatively different processes? In Experiment 1, ERPs elicited by supraliminal stimuli were recorded when 21 participants viewed emotional facial expressions of four emotions and a neutral stimulus. Two ERP components (N2 and P3) were analyzed for their peak amplitude and latency measures. First, emotional face-specificity was observed for the negative deflection N2, whereas P3 was not affected by the content of the stimulus (emotional or neutral). A more posterior distribution of ERPs was found for N2. Moreover, a lateralization effect was revealed for negative (right lateralization) and positive (left lateralization) facial expressions. In Experiment 2 (20 participants), 1-ms subliminal stimulation was carried out. Unaware information processing was revealed to be quite similar to aware information processing for peak amplitude but not for latency. In fact, unconscious stimulation produced a more delayed peak variation than conscious stimulation.     

Trait congruence in the study of the cognitive consequences of emotional arousal

This study investigated the possible influence of mood and emotional vulnerability on recall. Mood was induced by projecting highly emotionally laden slides. In the first experiment, 64 female subjects, rated low or high on emotional vulnerability, were tested on recall of mood-congruent, mood-incongruent and neutral words, under mood induction and non-mood induction conditions. Emotionally low-vulnerable subjects recalled more mood-congruent than mood-incongruent words in the mood induction condition, whereas the opposite was the case in the non-mood induction condition. Highly vulnerable subjects recalled more mood-congruent than mood-incongruent words in the non-mood induction condition and fewer mood-congruent words in the mood induction compared with non-mood induction condition. The results are discussed in terms of ‘mood congruence’ (to explain low-vulnerable (LV) subjects' performance) and in terms of ‘trait congruence’ (to explain highly-vulnerable (HV) subjects' performance). In a second experiment, which investigated LV and HV subjects' galvanic skin responses to highly- and low-emotionally laden slides, the highest values were those for HV subjects when exposed to emotional slides. The different activation of LV and HV subjects led us to reconsider previous reasoning regarding mood congruence and trait congruence in the light of the inverted U theory.     

Vertical jumping and signaled avoidance

This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed.     

Back to Black

This is a brief sequel to Max Black's classic dialogue on the Identity of Indiscernibles. Interlocutor A defends the bundle theory by endorsing the (by now popular) view according to which Black's world does not contain two indiscernible spheres but rather a single, bi‐located sphere. His opponent, B, objects that A cannot distinguish such a world from a world with a single, uniquely located sphere, hence that the view in question adds nothing to A's original response to Black's challenge. A is simply denying that there can be worlds with two or more indiscernible entities.