Mixing compatible and incompatible mappings: Elimination, reduction, and enhancement of spatial compatibility effects

In two-choice tasks, the compatible mapping of left stimulus to left response and right stimulus to right response typically yields better performance than does the incompatible mapping. Nonetheless, when compatible and incompatible mappings are mixed within a block of trials, the spatial compatibility effect is eliminated. Two experiments evaluated whether the elimination of compatibility effects by mixing compatible and incompatible mappings is a general or specific phenomenon. Left-right physical locations, arrow directions, and location words were mapped to keypress responses in Experiment 1 and vocal responses in Experiment 2. With keypresses, mixing compatible and incompatible mappings eliminated the compatibility effect for physical locations and arrow directions, but enhanced it for words. With vocal responses, mixing significantly reduced the compatibility effect only for words. Overall, the mixing effects suggest that elimination or reduction of compatibility effects occurs primarily when the stimulus-response sets have both conceptual and perceptual similarity. This elimination may be due to suppression of a direct response-selection route, but to account for the full pattern of mixing effects it is also necessary to consider changes in an indirect response-selection route and the temporal activation properties of different stimulus-response sets.     

Cognitive slowing in decision tasks in early and advanced Parkinson's disease.

Ten untreated patients with recently diagnosed Parkinson's disease (PD), 9 treated patients with more advanced pathology, and 17 matched normal controls were investigated with three reaction tasks with increasing cognitive load but identical motor requirements: simple reaction, choice reaction with indicative stimuli, and choice reaction with ambiguous stimuli. Times required until a home key was released (= reaction time) and from then until a response key was pressed (= movement time) were recorded. Estimates of pure decision time (overall response time minus movement time in a simple reaction time task) revealed a difference between advanced and early PD patients. Advanced PD patients showed an overall slowing of decision time in the reaction time tasks, but the effect of the cognitive load of the tasks on the decision time was comparable to a control group. The untreated early PD patients performed quite normally in the more simple decision tasks but showed a disproportionate slowing of decision time in tasks with higher cognitive load.     

Aging and memory for expected and unexpected objects in real-world settings.

Adult age differences in the consistency effect were examined in 3 experiments. The consistency effect refers to items inconsistent with expectations being better remembered than items consistent with expectations. Younger and older adults walked into an office room and viewed objects that varied in their consistency with expectation. Immediate and delayed recognition tests on item information (i.e., distractors were defined by their semantic identity) revealed that both age groups recognized unexpected items better than expected items. However, when recognition of token information was requested (i.e., distractors were defined by their physical appearance), younger adults, in contrast to older adults, exhibited consistency effects. Also, under divided attention, young adults revealed the same pattern of data as did elderly adults under full attention. The results are discussed in terms of capacity-related differences in distinctive encoding.     

Cognitive-behavioral stress management intervention decreases the prevalence of depression and enhances benefit finding among women under treatment for early-stage breast cancer.

The authors tested effects of a 10-week group cognitive-behavioral stress management intervention among 100 women newly treated for Stage 0-II breast cancer. The intervention reduced prevalence of moderate depression (which remained relatively stable in the control condition) but did not affect other measures of emotional distress. The intervention also increased participants' reports that having breast cancer had made positive contributions to their lives, and it increased generalized optimism. Both remained significantly elevated at a 3-month follow-up of the intervention. Further analysis revealed that the intervention had its greatest impact on these 2 variables among women who were lowest in optimism at baseline. Discussion centers on the importance of examining positive responses to traumatic events--growth, appreciation of life, shift in priorities, and positive affect-as well as negative responses.