AIDS knowledge among black drug users: an issue of reliability

This study examined the reliability of an inventory measuring AIDS-related knowledge among 553 black drug users. Data were collected from a socially high-risk community in Birmingham, Alabama. The KR-20 reliability scores were computed from the inventory for each drug-use group. The KR-20 reliabilities ranged from .39 to .57. These findings may suggest that the inconsistent reports of the predictive power of AIDS knowledge among drug users reported in previous studies might be related to the low internal consistencies of the inventory.     

The Development of Early Externalizing Problems Among Children from Low-Income Families: A Transformational Perspective

The present study examined pathways leading to early externalizing problems from age 1 to 31/2 in a design that took advantage of our knowledge of normative progression and normative socialization as well as findings from research on risk. A sample of 130 low-income participants was followed longitudinally from 12 to 42 months using observational measures of developmentally salient parenting and child disruptive behavior to predict early externalizing problems. Results are best accommodated by concepts such as transformation and transaction from developmental psychology. For boys, both child and parent variables predicted later externalizing. For girls and boys, the interaction between child noncompliance and maternal rejection was significant.     

Goal Characteristics and Satisfaction: Personal Goals as Mediators of Situational Effects on Task Satisfaction1

This study modeled the process underlying the experience of satisfaction by examining the interrelationships among the task situation, intention characteristics, and satisfaction. The central proposition of the model was that the effect of the situation on satisfaction is fully mediated by the nature and status of one's own intentions that result from that context. The proposed model, in which the task situation indirectly determines satisfaction only through intention characteristics, was compared to a model in which the situation both directly and indirectly determines satisfaction and to a model which contained no intention characteristics. The intention characteristics assessed in this study included their number, valence, value, commitment, probability, and perceived attainment. Two aspects of the task situation were examined: task enrichment and assigned performance goals. A total of 192 subjects were randomly assigned to 1 of 4 conditions according to goal (no goal vs. assigned goal) and task type (enriched vs. unenriched). Intentions and their characteristics were assessed before the task period, and satisfaction with the task was measured afterward. The results provided support for a model in which the task situation and intention characteristics have independent effects on satisfaction.     

Compensatory changes in striatal dopamine neurons following recovery from injury induced by 6-OHDA or methamphetamine: a review of evidence from microdialysis studies

This paper presents evidence from microdialysis experiments that three different behavioural outcomes of depletion of striatal dopamine (DA) by either 6-hydroxydopamine or methamphetamine (sparing of function, recovery of function, and loss of function) may be related to differences in the ability of residual DA neurons to maintain extracellular concentrations of DA. It is shown that when up to 80% of the mesostriatal DA system is destroyed, the remaining DA terminals maintain normal extracellular dopamine concentrations. Following a lesion in the 80-95% range, most animals maintain a relatively normal extracellular concentration of DA, but the ability to respond to increased demand is reduced in some animals. When over 95% of the normal DA input to the striatum is destroyed, there is a sharp drop in the extracellular concentration of DA and a nearly complete loss in the ability to increase DA release upon demand. Thus, this new method of sampling extracellular DA and its metabolites in freely moving animals provides insights into the behavioural capacities of animals and into the neural mechanisms that underlie recovery of function following brain damage.     

A neurobiological model for near-death experiences

The authors present a neurobiological model for near-death experiences (NDEs) in an attempt to correlate the biological and psychological domains. This model is based on temporal lobe dysfunction, hypoxia/ischemia, stress, and neuropeptide/neurotransmitter imbalance. They describe and discuss the fundamental contribution of the language system in the construction of verbal reports of NDEs. This model could be seen as a complement to other explanatory domains.     

pCREB in the neonate rat olfactory bulb is selectively and transiently increased by odor preference-conditioned training

Early olfactory preference learning in rat pups occurs when novel odors are paired with tactile stimulation, for example stroking. cAMP-triggered phosphorylation of cAMP response element binding protein (pCREB) has been implicated as a mediator of learning and memory changes in various animals (Frank and Greenberg 1994). In the present study we investigate whether CREB is phosphorylated in response to conditioned olfactory training as might be predicted given the proposed role of the phosphorylated protein in learning. On postnatal day 6, pups were trained for 10 min using a standard conditioned olfactory learning paradigm in which a conditioned stimulus, Odor, was either used alone or paired with an unconditioned stimulus, Stroking (using a fine brush to stroke the pup). In some instances stroking only was used. The pups were sacrificed at 0, 10, 30, or 60 min after the training. Using Western blot analysis, we observed that the majority of olfactory bulbs in conditioned pups (Odor + Stroking) had a greater increase in pCREB activation at 10 min after training than pups given nonlearning training (Odor only or Stroking only). The phosphorylated protein levels were low at 0 min and at 60 min after training. This is in keeping with the slightly delayed and short-lived activation period for this protein. The localization of pCREB increases within the olfactory bulb as seen by immunocytochemistry. Naive pups were not exposed to odor or training. There was a significantly higher level of label in mitral cell nuclei within the dorsolateral quadrant of the bulb of pups undergoing odor-stroke pairing. No significant differences were observed among nonlearning groups (Naive, Odor only, or Stroking only) or among any training groups in the granule or periglomerular cells of the dorsolateral region. The localized changes in the nuclear protein are consistent with studies showing localized changes in the bulb in response to a learned familiar odor. The present study demonstrates that selective increases in pCREB occur as an early step following pairing procedures that normally lead to the development of long-term olfactory memories in rat pups. These results support the hypothesized link between pCREB and memory formation.     

Post-training brain catecholamine levels: lack of response to water-motivated training

Rats were trained in a one-trial appetitive task using water motivation. Brain catecholamine and metabolite levels were assessed in samples collected 10 min after training. There was no evidence that brain NE levels were modified by training, although catecholamine levels increased when the animals were placed in a novel environment. These results differ from those obtained after avoidance training where the extent of a post-training decrease in brain norepinephrine predicts later retention performance.     

Perinatal indicators of sudden infant death syndrome: A study of 34 Rhode Island Cases

Pre- and perinatal characteristics of 34 victims of Sudden Infant Death Syndrome (SIDS) were compared with those controls matched for sex, race, birthdate, and hospital. Data were collected retrospectively from hospital records. Factors which reliably differentiated the SIDS group from controls included low birth-weight, short second stage of labor, fewer years of maternal schooling, and maternal anemia during pregnancy. The constellation of findings was interpreted as reflecting the interaction of physiological predispositions and environmental “setting conditions”, culminating in sudden and unexpected death. The efficacy of a previously established SIDS risk scale was assessed for these cases. Some issues concerning prediction of outcome from perinatal variables are discussed.