Interactive effects of APOE and CHRNA4 on attention and white matter volume in healthy middle-aged and older adults

In the present study, we investigated age-related changes in interactions between efficiency of neuronal repair mechanisms and efficiency of cholinergic neurotransmission in the context of attentional orienting. In addition, we explored white matter volume changes as possible neuronal underpinnings. A sample of 230 healthy middle-aged (53–64 years) and older (65–75 years) adults was genotyped for polymorphisms of APOE and CHRNA4, a nicotinic receptor subunit gene. Participants were administered a visuospatial attention task involving letter discrimination with location cues of varying validity. Genotype effects on white matter volume were also investigated in a subset of participants who received MRI scans. APOE interacted with CHRNA4, such that APOE-ε4 carriers who were also CHRNA4 TT homozygotes showed disproportionately slowed reaction time (RT) following invalid location cues. The interaction was stronger in the middle-aged participants than in the older participants. There was also a trend for individuals with combined APOE-ε4/CHRNA4 TT genotypes to show both lower white matter volume and slower overall RT on the attention task. The interaction of a neurotransmission gene (CHRNA4) and a susceptibility gene (APOE) suggests that the efficiency of neuronal repair mechanisms may modulate the cholinergic system to influence attentional function.     

Thinking styles in relation to personality traits: an investigation of the Thinking Styles Inventory and NEO-PI-R

This study is an investigation of the Sternberg-Wagner Thinking Style Inventory (TSI), with regard to cross-cultural replication and relation to the five-factor personality model (FFM). TSI and NEO-PI-R were administered to 107 participants from USA and 114 participants from Norway. Inter-correlations between NEO-PI-R dimensions and TSI-scales and factors were not very strong, few exceeding 0.40, and the correlations were in predicted directions. Joint factor analyses of TSI and NEO-PI-R showed that TSI covers variance that NEO-PI-R does not explain. Thus, it is argued that the thinking styles give an independent contribution beyond FFM dimensions. However, TSI did not relate to FFM in the same manner in the two samples. Finally, the TSI-scales and factors were replicable across samples by Procrustes rotation. The question whether thinking style may be regarded as a valid and reliable construct is discussed.     

Cognitive function of youths born to mothers with opioid and poly-substance abuse problems during pregnancy

Previous research has provided inconclusive evidence regarding the neuropsychological difficulties of children born to mothers partaking in opioid or poly-drug use during pregnancy. Little is known about how these children fare as they get older. The present longitudinal study includes follow-up data on 45 children born to mothers who used heroin and poly-drugs and a group of 48 children without prenatal drug exposure. Most of the drug-exposed youths were placed in permanent foster or adoptive homes before one year of age. The youths (ages 17 to 21) were administered 10 neuropsychological tests. The drug-exposed youths had cognitive and fine motor functions within the normal range compared to population norms but performed significantly worse than the non-exposed group. There were indications of generally lower cognitive functions rather than specific problems with executive functioning. Lower mean birthweight in the risk group (619 grams mean difference, p < .001) only partially mediated the group differences in cognitive functioning. There was a tendency for youths who had few and early changes in their caregivers or who were born to mothers who had used the least number of different drugs during pregnancy to have the best cognitive scores. The study indicates that youths born to mothers who used multiple drugs during pregnancy are vulnerable relative to their peers within a wide range of cognitive functions. The vulnerability seems to be related not only to the mother’s drug use during pregnancy but also to factors such as birthweight and unstable parental care during infancy.     

COGNITIVE AND SOCIOEMOTIONAL FUNCTIONING AT 4½ YEARS IN CHILDREN BORN TO MOTHERS WHO HAVE RECEIVED TREATMENT FOR SUBSTANCE‐ABUSE PROBLEMS WHILE PREGNANT

Cognitive and socioemotional functioning at 4½ years of age were examined in children born to mothers with substance‐abuse problems (n = 22) recruited from residential treatment institutions while pregnant, and then compared to children born to mothers with mental health problems (n = 18) and children from a low‐risk group (n = 26). No significant group differences in cognitive functioning were found, but the children born to mothers with substance‐abuse problems showed more caregiver‐reported socioemotional problems than did the low‐risk children, like the children born to mothers with mental health problems. Birth weight had an effect on internalizing problems at 4½ years and mediated the relation between group and socioemotional problems, although not when controlling for caregiver education, single parenthood, and anxiety and depression. At 4½ years, 7 children born to mothers with substance‐abuse problems were placed in foster care. These children had lower birth weight and higher caregiver‐rated internalizing problems. In addition to emphasizing the importance of the quality of the prenatal environment, this study suggests that families with previous substance abuse are in need of long‐term follow‐up to address socioemotional problems and enhance further positive child cognitive development. The foster‐placed children may be in particular need of long‐term follow‐up.     

Basic information processing of neurotics and stables: an experimental ERP approach to personality and distractibility

The aim of the study was to investigate the effects of level of neuroticism on electrophysiological event-related potentials (ERPs) to different kinds of stimuli. The neuroticism items from the NEO-PI-R were administered to 168 female, right-handed undergraduates between 19 and 29 years of age. 20 highly neurotic and 22 highly stable persons underwent an ERP task that was designed to be a combination of an auditory P3a and a visual P3b oddball task. No significant differences in the P3a and P3b were detected. It is concluded that highly neurotic and highly stable persons do not differ in fast neurocognitive processing of neutral stimuli, and that cognitive differences between the groups may be located at another level in the sequence of information processing stages.     

Risk- and protective factors for memory plasticity in aging

ABSTRACT

Risk and protective factors for cognitive function in aging may affect how much individuals benefit from their environment or life experiences by preserving or improving cognitive abilities. We investigated the relations between such factors and outcome from episodic-memory training in 136 healthy young and older adults. Tested risk factors included carrying the ?4 variant of the apolipoprotein E allele (APOE), age, body mass index, blood pressure, and cholesterol. Protective factors included higher levels of education, intelligence quotient (IQ), physical activity, fatty acids, and vitamin D. Average increases in memory performance were seen after training, with ample variation between individuals. Being young, female, and having higher IQ were positive predictors of memory improvement. No other relationships were observed. Similar benefit was observed across APOE allelic variation. This indicates that beyond IQ, age, and sex, known risk -and protective factors of cognitive function in aging were not significantly related to memory plasticity.