The sandwich effect reassessed: Effects of streaming, distraction, and modality

The degree of disruption from interleaving auditory irrelevant items within a sequence of to-be-remembered items--the sandwich effect--was examined in two experiments. Previous demonstrations of the effect have shown that the penalty for interleaving items is small and that changing irrelevant tokens is no more damaging than repeating ones (contrary to the classic changing state effect of irrelevant sound). The results of Experiment 1 suggest that these earlier results were due to the lack of tokens in the irrelevant sequence (in part, the result of using a span method). The results of Experiment 2 also show that the sandwich effect was marked and, further, that it comprised two elements, one due to the partitioning of relevant from irrelevant streams (which may be promoted by similarity of identity within sequence or pitch disparity between sequences), and the other a classic irrelevant sound effect (with effects of changing state). The results are discussed in terms of the role of perceptual organization within and between modalities in short-term memory.     

Predictors of cognitive change from preclinical to clinical Alzheimer's disease

We examined individual-difference variables in relation to the rate of change in global cognitive performance, measured by the MMSE, from 3 years prior to diagnosis of Alzheimer's disease (AD) to the time of diagnosis. The population-based sample consisted of 230 incident AD persons who were followed over a 3-year interval. The average annual decline in MMSE was 1.81 points. Being older and acquiring additional diseases during the 3 years preceding diagnosis predicted a faster rate of decline in global cognitive functioning. However, other individual difference variables such as sex, education, depression, vitamin levels (vitamin B12 and folic acid), apolipoprotein status, and social network did not precipitate the rate of decline in the preclinical phase of AD.     

The effect of situation-evoked anxiety and gender on pain report using the cold pressor test

The aims of the present study were to investigate the influence of anxiety on pain perception and to test whether gender differences in pain perception are anxiety dependent. Sixty male and female university students exposed to situation-evoked anxiety or a control procedure were measured for their pain threshold, tolerance, and perceived intensity during a cold pressor test. Both subjective and autonomic responses indicated that anxiety was successfully induced in participants exposed to the anxiety condition. Increased situational anxiety had no significant effect on pain threshold or pain tolerance. Significant increases in pain intensity were found for the anxiety group. Levels of anxiety, however, did not correlate with this increased intensity, raising doubt as to the role of anxiety in producing this effect. No gender differences were found for pain tolerance or pain intensity. Gender differences were found for pain threshold in the anxiety group with, contrary to past findings, females showing significantly higher pain thresholds than males. The results are discussed in the light of related studies.     

Race-related stress,quality of life indicators,and life satisfaction among elderly African Americans

This article examined the relationships among race-related stress, quality of life indicators, and life satisfaction among elderly African Americans. A sample of 127 elderly African Americans, consisting of 87 women and 26 men (and 14 missing values), were administered the Index of Race-Related Stress, the Satisfaction With Life Scale, and the 36-item Short-Form Health Survey. Results indicated that elderly African American men and women differed significantly with regard to institutional and collective racism-related stress. In addition, the authors found that institutional racism-related stress was a significant predictor of psychological health in this sample of elderly African Americans.     

Laminar-dependent dendritic spine alterations in the motor cortex of adult rats following callosal transection and forced forelimb use

Previously, the authors found that partial denervation of the motor cortex in adult animals can enhance this region's neuronal growth response to relevant behavioral change. Rats with partial corpus callosum transections that were forced to rely on one forelimb for 18 days had increased dendritic arborization of layer V pyramidal neurons in the opposite motor cortex compared to controls. This was not found as a result of denervation alone or of forced forelimb use alone. However, it seemed possible that each independent manipulation (i.e., forced forelimb use alone and callosal transections alone) resulted in neural structural alterations that were simply not revealed in measurements of dendritic branch number and/or not inclusive of layer V dendrites. This possibility was assessed in the current study with a reexamination of the Golgi-Cox impregnated tissue generated in the previous study. Tissue was quantified from rats that received either partial transections of the rostral two-thirds of the corpus callosum (CCX) or sham operations (Sham) followed either by 18 days of forced use of one forelimb (Use) or unrestricted use of both forelimbs (Cont). Measurements of apical and basilar dendrites from pyramidal neurons of layer II/III and layer V were performed to detect spine addition resulting from either increased spine density or the addition of dendritic material. As hypothesized, significant spine addition was found following forced forelimb use alone (Sham+Use) and callosal transections alone (CCX+Cont). However, forced use primarily increased spines on layer II/III pyramidal neurons, whereas callosal transections primarily increased dendritic spines on layer V pyramidal neurons in comparison to Sham+Cont. A much more robust increase in layer V dendritic spines was found in animals with the combination of forced forelimb use and denervation (CCX+Use). In contrast to the effects of forced use alone, however, CCX+Use rats failed to show major net increases in spines on layer II/III neurons. These results indicate that while callosal denervation may greatly enhance the neuronal growth and synaptogenic response to behavioral change in layer V, it may also limit spine addition associated with forced forelimb use in layer II/III of the motor cortex.     

Maternal and paternal parenting during adolescence: forecasting early adult psychosocial adjustment

This study investigated the relationship of maternal and paternal parenting behavior (acceptance and firm control) during adolescence to four domains of early adult functioning (internalizing problems, externalizing problems, prosocial competence, and cognitive competence). Twenty-one females and 29 males from intact families, along with their mothers and fathers, participated. Assessments were conducted in adolescence and early adulthood, separated by approximately five and one-half years. Higher levels of maternal firm control during adolescence were associated with more secure early adult romantic attachment and lower levels of educational achievement. There were no main effects for fathers, but paternal parenting behavior interacted with maternal parenting behavior to predict both early adult romantic attachment and delinquency. Clinical implications and directions for future research are discussed.     

Noncontingent peer attention as treatment for disruptive classroom behavior

A functional analysis isolated peer attention as the primary maintaining variable for disruptive behavior displayed by a student with attention deficit hyperactivity disorder. Using a brief reversal design, noncontingent reinforcement was then shown to reduce disruptive behavior relative to the peer attention condition. Implications for assessing behavior disorders in mainstream school settings are discussed.     

A note on Corballis (1997) and the genetics and evolution of handedness: developing a unified distributional model from the sex-chromosomes gene hypothesis

A unified, quantitative model for sex, twin, parent, and grandparent influences on handedness is presented. Recent research modeling the evolutionary development of genetic mechanisms for the transmission of handedness on the basis of genotype fitness has appeared to lead to the conclusion that a handedness gene cannot be located on the sex chromosomes. It is shown in this article, however, that this conclusion is not of general validity. The sex-chromosomes hypothesis is developed further, and it is demonstrated that a wide-ranging, detailed, and parsimonious account of the distribution of handedness is obtained when left-handedness is assumed to be associated recessively, and with low penetrance, with genetic variation located on the X chromosome.     

Relationship between emotional state and performance during international field hockey matches

The present study examined the relationship between the emotions experienced by 15 international hockey players, both immediately before and during competition, and their performance levels. Data were collected on the players' emotional states using a revised version of the Feelings Scale of Butler, which was completed retrospectively after the match was played. Players reported more annoyance and less tension during the match than before. A logistic regression correctly classified 70.2% of players from the emotional ratings immediately before the match and 85.1% of the players from the ratings during the match as either a good or poor performer. Those individuals who performed well retrospectively reported feeling Nervous and 'Quick/Alert/Active' before the game and Confident and Relaxed during the game. The results indicate that emotions fluctuate over the competition period, and in long duration sports assessment of emotion during competition predicts variation in performance better than assessment prior to competition.