Handedness and dementia

Some researchers have speculated that left-hand dominance is more prevalent among patients suffering from dementia of the Alzheimer's type which began prior to age 65 yr. and that, in those patients, the disease runs a more rapid course. In the present study, seven left-handed dementia patients were matched with seven right-handed dementia patients on the basis of age and years of education and were compared with regard to neuropsychological compromise. While the left-handed group was somewhat more impaired than the right-handed subjects, the difference between the two groups was not statistically significant.     

ALTERNATIVE WORK SCHEDULES: TWO FIELD QUASI-EXPERIMENTS

In the first ( N = 140) of two quasi-experimental field studies, trial group employees were changed from a 5/40 to a 4/40 work schedule for four months then returned to a 5/40 schedule. In a second study ( N = 102), trial group employees were changed from 5/40 to flextime. Reactions were evaluated using a model for understanding the impact of work schedules. The effects of schedule changes matched those anticipated by pre-intervention surveys of employees. Factors related to organizational effectiveness were enhanced where specific organizational needs were met. Interference with personal activities was reduced where employees had experienced specific difficulties. The most powerful effect, however, was on worker attitudes toward specific work schedules. In addition, a mild positive (perhaps Hawthorne) effect was evident for a wide range of general worker reactions.     

Specific temporal-lobe signs and enhanced delayed cross-modal matching performance

Structural damage to the amygdala severely retards delayed cross-modal (tactile-to-sight) matching in primates. Conversely, we hypothesized that people who display signs suggestive of specific temporal lobe lability should show enhanced delayed cross-modal matching performance. The hypothesis was supported. In a single experiment involving 25 subjects, significant negative correlations obtained between the numbers of errors on the cross-modal matching task and numbers of affirmative responses within clusters of items that contained themes of meaningfulness, religious beliefs or ictal, complex partial epileptic (limbic) states. On the other hand, the numbers of errors were not significantly correlated with either clusters of control items or items that are presumed to reflect the function of other temporal-lobe structures. Both matching and questionnaire data were collected under double-blind conditions.     

The Effects of Flavor-Aversion Learning on Instrumental Performance

Two experiments investigated the role of lithium-mediated environmental conditioning on instrumental performance. Experiment 1 demonstrated that a novel taste consumed in one arm of a T maze prior to lithium-induced toxicosis reduced performance in this environment whereas similar aversions conditioned in the home cage failed to alter maze performance. Experiment 2 showed that maze performance in a straight alleyway was decremented during extinction only in a group that actually traversed the alley prior to drinking saccharin and receiving lithium injections. This demonstrated that the instrumental decrement observed in Experiment 1 was due not only to the presence of an unpalatable flavor in the goalbox during the test.

     

Book Reviews

The Psychological Record -     

Intellectual functioning and aggression

In a 22-year study, data were collected on aggressiveness and intellectual functioning in more than 600 subjects, their parents, and their children. Both aggression and intellectual functioning are reasonably stable in a subject's lifetime and perpetuate themselves across generations and within marriage pairs. Aggression in childhood was shown to interfere with the development of intellectual functioning and to be predictive of poorer intellectual achievement as an adult. Early IQ was related to early subject aggression but did not predict changes in aggression after age 8. On the other hand, differences between early IQ and intellectual achievement in middle adulthood were predictable from early aggressive behavior. A dual-process model was offered to explain the relation between intellectual functioning and aggressive behavior. We hypothesized that low intelligence makes the learning of aggressive responses more likely at an early age, and this aggressive behavior makes continued intellectual development more difficult.