BDNF reverses the CTA memory deficits produced by inhibition of protein synthesis

Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators of not only central synaptic plasticity, but also behavioral interactions between an organism and its environment. Our previous studies on the insular cortex (IC), a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA), have demonstrated that intracortical microinfusion of BDNF induces a lasting potentiation of synaptic efficacy in the projection from the basolateral nucleus of the amygdala (Bla) to the IC of adult rats in vivo. Recently, we found that intracortical microinfusion of BDNF previous to CTA training enhances the retention of this task. In this work, we present experimental data showing that acute intracortical delivery of BDNF (2 microg/2 microl per side) reverses the deficit in CTA memory caused by inhibition of insular cortex protein synthesis due to anisomycin administration (100 microg/microl per side) in male adult Wistar rats. These findings suggest that BDNF is a protein synthesis product essential for neocortical long-term memory storage.     

Left-right differences on timed motor examination in children.

Age-related change in the difference between left- and right-side speed on motor examination may be an important indicator of maturation. Cortical maturation and myelination of the corpus callosum are considered to be related to increased bilateral skill and speed on timed motor tasks. We compared left minus right foot, hand, and finger speed differences using the Revised Physical and Neurological Assessment for Subtle Signs (PANESS; Denckla, 1985); examining 130 typically developing right-handed children (65 boys, 65 girls) ages 7-14. Timed tasks included right and left sets of 20 toe taps, 10 toe-heel alternation sequences, 20 hand pats, 10 hand pronate-supinate sets, 20 finger taps, and 5 sequences of each finger-to-thumb apposition. For each individual, six difference scores between left- and right-sided speeded performances of timed motor tasks were analyzed. Left-right differences decreased significantly with age on toe tapping, heel-toe alternations, hand pronation-supination, finger repetition, and finger sequencing. There were significant gender effects for heel-toe sequences (boys showing a greater left-right difference than girls), and a significant interaction between age and gender for hand pronation-supination, such that the magnitude of the left-right difference was similar for younger, compared with older girls, while the difference was significantly larger for younger, compared to older boys. Speed of performing right and left timed motor tasks equalizes with development; for some tasks, the equalization occurs earlier in girls than in boys.     

Cognitive Deficits in the Early Stages of Alzheimer's Disease

ABSTRACT— Evidence from longitudinal, experimental, and neuroimaging studies converge to indicate that psychological functions other than episodic memory are affected very early in the course of Alzheimer's disease and, indeed, may predate or influence the apparent memory deficits. Changes in personality and difficulty in executive function, especially in terms of attentional and inhibitory control, are especially prominent. Deficits in other types of memory (i.e., semantic memory, conditioning) can also be detected in the early stages of the disease. It is time to update existing diagnostic criteria for this form of dementia in terms of current knowledge of multiple and interacting brain systems.     

Can infants map meaning to newly segmented words? Statistical segmentation and word learning

The present experiments investigated how the process of statistically segmenting words from fluent speech is linked to the process of mapping meanings to words. Seventeen-month-old infants first participated in a statistical word segmentation task, which was immediately followed by an object-label-learning task. Infants presented with labels that were words in the fluent speech used in the segmentation task were able to learn the object labels. However, infants presented with labels consisting of novel syllable sequences (nonwords; Experiment 1) or familiar sequences with low internal probabilities (part-words; Experiment 2) did not learn the labels. Thus, prior segmentation opportunities, but not mere frequency of exposure, facilitated infants' learning of object labels. This work provides the first demonstration that exposure to word forms in a statistical word segmentation task facilitates subsequent word learning.     

The Moderating Effects of Justice on the Relationship Between Organizational Politics and Workplace Attitudes

Research suggests that perceptions of organizational politics consistently result in negative outcomes for individuals. In the current study, distributive and procedural justice are explored for their effects on the relationships between perceptions of organizational politics and turnover intentions and job satisfaction. We tested these relationships in a sample of 311 employees of a water management district. Results indicated the politics––turnover intentions and politics––job satisfaction relationships were weaker when perceptions of both forms of justice are high. Further, and potentially more interestingly, politics mattered the most when the distribution of outcomes was unfair (distributive justice) as opposed to when procedures were unfair (procedural justice). Implications for future research and management practice are discussed.     

Forgiving the September 11th terrorists: associations with coping, psychological distress, and religiosity

Two studies examined how non-interpersonal forgiveness (when there is no social relationship between the transgressor and forgiver) related to coping and involuntary responses to stress, psychological distress, and religiosity. Three to six weeks after September 11th, 2001, forgiveness had non-linear associations with other responses to the terrorist attacks. Among college students (N=488), those who were trying or had forgiven (pro-forgiveness) the terrorists reported less involuntary engagement, more primary and secondary control coping, and more meaning finding than those who were unsure about forgiveness (ambivalent) and those who did not believe the perpetrators should be forgiven (anti-forgiveness). Ambivalent students reported the most distress, even after controlling for religion. Anti-forgiveness students reported less religiosity than ambivalent and pro-forgiveness students. Most findings were consistent among middle schoolers (N=154), particularly regarding psychological distress and responses to stress. Also, forgiveness of strangers for acts against one's community functioned separately from religion.     

Unemployment and civil commitment: a test of the intolerance hypothesis

We theorize that the reported association between economic indicators and the incidence of civil commitment for mental illness may result, at least in part, from reduced tolerance in the community for impaired behavior among minorities. Earlier work suggests that economically induced intolerance will be focused primarily on minority males. Based on this literature, we hypothesize that the median level of functioning among African-American males subjected to civil commitment will vary positively with earlier changes in the unemployment rate. The test applies Box-Jenkins methods to 156 months (August 1985-July 1998) of data from California. Consistent with theory, results support the hypothesis.     

Nasal consonant production in Broca's and Wernicke's aphasics: speech deficits and neuroanatomical correlates

The present study investigated the articulatory implementation deficits of Broca's and Wernicke's aphasics and their potential neuroanatomical correlates. Five Broca's aphasics, two Wernicke's aphasics, and four age-matched normal speakers produced consonant-vowel-(consonant) real word tokens consisting of [m, n] followed by [i, e, a, o, u]. Three acoustic measures were analyzed corresponding to different properties of articulatory implementation: murmur duration (a measure of timing), amplitude of the first harmonic at consonantal release (a measure of articulatory coordination), and murmur amplitude over time (a measure of laryngeal control). Results showed that Broca's aphasics displayed impairments in all of these parameters, whereas Wernicke's aphasics only exhibited greater variability in the production of two of the parameters. The lesion extent data showed that damage in either Broca's area or the insula cortex was not predictive of the severity of the speech output impairment. Instead, lesions in the upper and lower motor face areas and the supplementary motor area resulted in the most severe implementation impairments. For the Wernicke's aphasics, the posterior areas (superior marginal gyrus, parietal, and sensory) appear to be involved in the retrieval and encoding of lexical forms for speech production, resulting in increased variability in speech production.