Interference Resolution in the Elderly: Evidence Suggestive of Differences in Strategy on Measures of Prepotent Inhibition and Dual Task Processing

ABSTRACT

The ability to effectively resolve interference was investigated in young and elderly participants using a test of inhibition and a dual task measure. The tasks stressed the ability to suppress prepotent responding, and balance primary and secondary task demands, respectively. Successful performance on both measures hinged on the ability to minimize the distraction generated between competing aspects of each task. Increasing demands resulted in performance decrements despite titration for individual differences in span size and generalized slowing. These were more pronounced on the hardest condition of each task, especially in older participants. Furthermore, the nature of the decrements suggested the use of different strategies between groups. It is argued that a fundamental source of the age-associated variability in cognition is due to compromised ability to effectively resolve interference, and cannot be sufficiently explained by memory span differences or generalized slowing.     

Interference resolution in the elderly: evidence suggestive of differences in strategy on measures of prepotent inhibition and dual task processing

The ability to effectively resolve interference was investigated in young and elderly participants using a test of inhibition and a dual task measure. The tasks stressed the ability to suppress prepotent responding, and balance primary and secondary task demands, respectively. Successful performance on both measures hinged on the ability to minimize the distraction generated between competing aspects of each task. Increasing demands resulted in performance decrements despite titration for individual differences in span size and generalized slowing. These were more pronounced on the hardest condition of each task, especially in older participants. Furthermore, the nature of the decrements suggested the use of different strategies between groups. It is argued that a fundamental source of the age-associated variability in cognition is due to compromised ability to effectively resolve interference, and cannot be sufficiently explained by memory span differences or generalized slowing.     

Clumping distractors around the target facilitates performance on the visual search task in the elderly

Fifteen elderly participants and 15 young controls were tested on a version of the visual search task to determine if stimulus location had an effect on reaction time (RT). Location was manipulated by presenting the distractors clumped around a target or spread apart on the screen. Elderly participants performed worse overall. Clumping proved to be an important manipulation in the target absent (p < .001), but not the target present, condition. The manipulation of array size (6 versus 12 distractors) proved significant regardless of probe presence (p < .001) or absence (p < .001). Since clumping the distractors significantly improved the search times in the elderly, this suggests that a deficit in attention contributes to an inefficient search strategy in the elderly.     

Neural correlates of temporal-order judgments versus those of spatial-location: deactivation of hippocampus may facilitate spatial performance

The retrieval of temporal-order versus spatial-location information was investigated using fMRI. The primary finding in the hippocampus proper, seen in region of interest analyses, was an increase in BOLD signal intensity for temporal retrieval, and a decrease in signal intensity for spatial retrieval, relative to baseline. The negative BOLD signal change with spatial memory processing, while unexpected, is consistent with the recent fMRI literature indicating decreased BOLD can be associated with neuronal activation, and it is argued that the deactivation observed here may facilitate spatial performance. Spatial-location judgments also yielded a stronger (positive) response in the right midfrontal gyrus, while temporal-order judgments (autobiographic condition only) showed greater activity in the left superior temporal gyrus, suggesting greater working memory demands and greater semantization for each judgment type, respectively. Finally, all conditions activated the left midfrontal gyrus, although autobiographic memories showed additional activity in the medial frontal gyrus.     

"I find you to be very attractive..." Biases in compliance estimates to sexual offers

The classic experiments by Clark and Hatfield on sex differences in compliance to offers of dates, apartment visits, and casual sex, and the related informal project of Molzer served as the foundation for the present study. However, whereas individuals in these previous investigations directly approached opposite-sex participants, our research employed surveys to gauge compliance. A sample of 195 male and 179 female Austrian adults were provided with written forms of the Clark and Hatfield scenarios and asked to predict the rates of compliance on a thermometer scale ranging from 0% to 100%. Results indicated that compliance estimates are largely effected by the sex of the receiver to these offers, and to a lesser degree, participants' age and relationship status. The sex of the participant did not significantly effect the results. Relative to the previous work, the compliance rate of males was overestimated, while that of females was underestimated. We offer explanations for the differences in findings between the original investigations and our research, discuss the importance of contextual factors as well as the generality of the Clark-Hatfield findings, especially with respect to females' near-zero receptivity to explicit sexual offers, and point out the relevance of the current findings for health psychology.