Individual differences in concept learning and brain event-related potentials

An irrelevant auditory probe procedure was employed to evoke brain event-related potentials (ERPs) in 56 males while they learned concepts presented to them in study booklets. A mastery test was administered to assess concept acquisition. Ss were divided into two groups according to whether or not their achievement test results were above or below the average score for all learners. A one-way multivariate analysis of variance (MANOVA) was computed for each presentation page employing as multiple dependent measures ERP amplitudes which corresponded to specific concepts. MANOVAs and their subsequent statistics revealed that, as theorized, ERPs evoked at the right frontal, temporal and parietal, as well as the left parietal, regions, significantly distinguished below-from above-average concept learners. As hypothesized, poorer concept learners engaged these hemispheric sites less, and manifested more variability at them, than better learners. It was established that the frontal, temporal and parietal areas which are chiefly implicated in crystallized intelligence are engaged during the actual process of concept learning itself.     

Event-related-potential (ERP) correlates of cognitive styles,abilities and aptitudes

Fifty, right-handed males were given 11 psychometric tests of cognitive styles, abilities and aptitudes. Visual (VERP), auditory (AERP) and bimodal (BERP) brain event-related-potential (ERP) amplitudes were recorded from each of these Ss. Canonical and product-moment correlations were computed. These analyses established that VERPs and BERPs elicited in the frontal, temporal, parietal and occipital regions were related to abilities and aptitudes: general aptitude, reading and verbal comprehension and spatial ability; and a cognitive style: field dependence-independence. The results demonstrated the construct validity of ERPs as indicators of individual differences in cognitive characteristics, especially crystallized and fluid intelligence.     

Spatial ability and sensory interaction: Analog and propositional representation

To provide coverging support that the proper integration of analog and propositional representational systems is associated with spatial ability, visual, auditory and bimodal brain event-related potentials were recorded from 50 right-handed Caucasian males. Sensory interaction indices were derived for these Ss who had taken the Surface Development Test of spatial ability. Product-moment correlations were computed between sensory interaction indices for eight cerebral sites and spatial ability test scores. Sensory interaction for left- and right-hemispheric regions was significantly related to spatial ability. As sensory suppression lessened, spatial ability increased. The results substantiated the theory that the visual-imaginal-analog and the auditory-verbal-propositional representational systems are implicated in spatial ability. The extent to which the cortex can inhibit or attenuate the interaction or integration between these dual-symbol systems is associated with complicated spatial task performance.     

A Hierarchy of Classical and Paraconsistent Logics

Journal of Philosophical Logic - In this article, we will present a number of technical results concerning Classical Logic, ST and related systems. Our main contribution consists in offering a...     

Gibbons exploit information about what a competitor can see

Animal Cognition - How much nonhuman animals understand about seeing has been the focus of comparative cognition research for decades. Many social primates (and other species) are sensitive to cues...     

Racism, ideology, and affirmative action revisited: the antecedents and consequences of "principled objections" to affirmative action

In 2 studies, the antecedents and consequences of "principled objections" to affirmative action (specific, "race-neutral" reasons for opposing the policy) among Whites were examined. In Study 1. data from a probability sample of Los Angeles adults indicated the following: (a) that principled-objection endorsement was driven not merely by race-neutral values but also by dominance-related concerns like racism; (b) that principled objections mediated the effects of group dominance; and (c) that education strengthened-rather than attenuated-the relationship between dominance-related concerns and principled objections. whereas it left the relationship between race-neutral values and the latter essentially unchanged. In Study 2, the education findings were conceptually replicated in a panel study of undergraduates: The completion of additional years of college boosted the correlation between racism and principled objections, whereas it had no effect on the predictive power of conservatism. These results provide support for a general group-dominance approach, which suggests that factors like racism continue to shape White opposition to race-targeted policies.     

Stimulus control of predatory behavior by the Iberian wall lizard (Podarcis hispanica, Sauria, Lacertidae): effects of familiarity with prey

The authors examine the relative roles of vision and chemoreception and the influence of previous experience with prey on the predatory behavior of Iberian wall lizards (Podarcis hispanica). Experiment 1 compared the responses to visual, chemical, and a combination of visual and chemical cues of a familiar prey by 2 groups of lizards that had been kept in captivity for either 3 months or 21 days. Experiment 2 assessed the responses of lizards kept in the laboratory for more than 3 months to a novel prey species. The results reveal that feeding on a prey species affects the lizards' responses to chemical stimuli from that prey. The response to chemical cues of a novel prey requires a 1st-feeding experience with that prey. Lizards that have been fed the same prey species for several months cease responding to the chemical stimuli of that particular prey.     

Personal reputation in organizations: Two‐study constructive replication and extension of antecedents and consequences

Personal reputation has been argued to demonstrate important influences on work outcomes. However, substantive research on personal reputation is relatively scarce. This two‐study investigation empirically supports and extends existing theory regarding the temporal development of personal reputation (i.e., antecedents and consequences), and thus contributes to a more informed understanding of both the construct and criterion‐related validity of this important construct. Study 1 is conducted longitudinally, in order to assess the development of personal reputation over time, which is undertaken to demonstrate the effects of human capital and social effectiveness as antecedents of reputation. Study 2 complements and extends the first study by conducting a field investigation examining the effects of time, human capital, and social effectiveness as antecedents of personal reputation, while also exploring the reputation consequences of autonomy, power, and career success. Our findings suggest that human capital, time, and social effectiveness play a part in the development of a reputation. Furthermore, career success, power, and autonomy were shown to be outcomes of the reputation construct. Contributions and strengths of this investigation, limitations, and directions for future research are discussed.     

Access to environmental stimulation via eyelid responses for persons with acquired brain injury and multiple disabilities: a new microswitch arrangement

This study assessed a new microswitch arrangement for eyelid responses using an optic sensor placed above the cheekbone and a small sticker on the person's eyelid. This new arrangement, which was designed to avoid interference of the microswitch with the person's visual functioning, was tested on three adults with acquired brain injury and multiple (consciousness, communication, and motor) disabilities. The study was carried out according to a non-concurrent multiple baseline design across participants. Data showed the new microswitch arrangement was suitable for all three participants, who increased their responding during the intervention phase of the study when their responses allowed them to access preferred stimulation. Practical implications of the findings are discussed.     

BDNF serum levels in subjects developing or not post-traumatic stress disorder after trauma exposure

Post-traumatic stress disorder (PTSD) is a syndrome resulting from exposure to a severe traumatic event that poses threatened death or injury and produces intense fear and helplessness. The neural structures implicated in PTSD development belong to the limbic system, an important region for emotional processing. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that serves as survival factor for selected populations of central nervous system (CNS) neurons and plays a role in the limbic system by regulating synaptic plasticity, memory processes and behavior. Impaired BDNF production in the brain can lead to a variety of CNS dysfunctions including symptoms associated with PTSD. However, so far fewer studies have investigated this neurotrophin in patients with PTSD. Furthermore, given the multiple role of BDNF in various CNS disorders, it cannot be excluded that traumatic events per se may influence neurotrophin levels, without a direct association to the PTSD syndrome.