Aging and input processing in dual-task situations

The psychological refractory period (PRP) paradigm was used to test whether older participants suffer from input interference in dual-task situations. Young (24 years) and older (57 years) adults gave speeded responses to 2 successively presented stimuli. The results showed increased susceptibility of older participants to input interference. Further experiments revealed that this input interference is related to the salience of the 2nd stimulus and that it is specific to older participants. Our findings indicate that parallel processing at the input stages of dual-task performance requires cognitive control. An age-related decline in the control of input processes should be considered as one source of age effects in dual-task performance.     

The use of the MacAndrew Alcoholism Scale in detecting substance abuse and antisocial personality

We evaluated the hypothesis that characterological factors, particularly antisocial personality, influence scores on the MacAndrew Alcoholism Scale (MAC). Using the Washington University research criteria to establish diagnoses, the following subgroups were defined: subjects who received no psychiatric diagnoses; subjects who received diagnoses other than alcoholism, drug dependence, or antisocial personality; and subjects who received a diagnosis of alcoholism, drug dependence, and/or antisocial personality, alone or in combination with other psychiatric diagnoses. The highest MAC scores were obtained by subjects diagnosed as having antisocial personality without alcoholism or drug dependence and subjects diagnosed with antisocial personality, drug dependence, and alcoholism. Alcoholics without antisocial personality or drug dependence, and subjects with other psychiatric diagnoses scored lowest. Although higher MAC scores were obtained by males, MAC scores greater than 24 correctly classified the greatest number of males and females as alcoholic, drug dependent and/or antisocial. These findings are interpreted as consistent with MacAndrew's reinterpretation of the scale as assessing a dimension of personality, rather than solely a tendency to addiction.     

Age-specific differences of dual n-back training

Age-related decline in executive functions can be decisive in performing everyday tasks autonomously. Working memory (WM) is closely related to executive functions, and training of WM has yielded evidence toward cognitive plasticity in older adults. The training effects often transfer to untrained tasks and functions. These effects have mostly been shown in processes such as WM and attention, whereas studies investigating transfer to executive functions have been scarce. We trained older adults aged 57–73 years in a WM training task that was reported to be effective in producing transfer in young adults. The training intervention consisted of a dual n-back task including independently processed auditory and visual n-back tasks. We investigated transfer to tasks engaging executive functions, and compared the effects in older adults to those reported in young adults. We found that both training groups improved in the training task. Although the training effect in older adults was smaller than the training effect in young adults, the older adults still showed a notable improvement so that after training they performed on the same level as young adults without training. The older adults also showed transfer to an untrained WM updating task, a result that was in accordance with the findings in young adults; other transfer effects in older adults were lacking. We conclude that although transfer effects were scarce, the present study provides encouraging evidence toward the possibilities to compensate for age-related decline in executive functions by a WM training intervention.     

Family size effects: a review

Larger families are more frequent with early marriage and rapid birth of the first child. In larger families, child rearing becomes more rule ridden, less individualized, with corporal punishment and less investment of resources. Smaller families tend to result in higher IQ, academic achievement, and occupational performance. Large families produce more delinquents and alcoholics. Perinatal morbidity and mortality rates are higher in large families as birth weights decrease. Mothers of large families are at higher risk of several physical diseases. Common methodological errors are indicated and exemplary studies are described.