Exercise therapy for depression in middle-aged and older adults: predictors of early dropout and treatment failure.

Psychosocial factors predicting treatment dropout or failure to benefit from treatment were identified in a randomized trial of exercise therapy and pharmacotherapy for major depression. One hundred fifty-six men and women over age 50 diagnosed with major depressive disorder were assigned to a 16-week program of aerobic exercise, medication (sertraline), or a combination of exercise and medication. Thirty-two patients (21%) failed to complete the program and were considered treatment "dropouts." At the end of 16 weeks, 83 patients (53%) were in remission; the remaining patients not in remission were considered treatment "failures." Baseline levels of self-reported anxiety and lift satisfaction were the best predictors of both patient dropout and treatment success or failure across all treatment conditions.     

Detecting variety: what's so special about uniformity?

People and pigeons were taught to make 1 of 2 responses to 16-icon arrays that differed in their visual variability. In 2 experiments, participants had to (a) discriminate a collection of identical items from a collection in which 2 or more items were different or (b) discriminate a collection of different items from a collection in which 2 or more items were identical. In Experiment 1, humans found it much easier to discriminate uniformity from all levels of diversity. In Experiment 2, pigeons also found it easier to discriminate uniformity from all levels of diversity, but the size of this effect was smaller than that observed in people. These and other results suggest that both species are predisposed to notice differences rather than similarities.     

Delayed working memory consolidation during the attentional blink

After the detection of a target (T1) in a rapid stream of visual stimuli, there is a period of 400–600 msec during which a subsequent target (T2) is missed. This impairment in performance has been labeled the attentional blink. Recent theories propose that the attentional blink reflects a bottleneck in working memory consolidation such that T2 cannot be consolidated until after T1 is consolidated, and T2 is therefore masked by subsequent stimuli if it is presented while T1 is being consolidated. In support of this explanation, Giesbrecht & Di Lollo (1998) found that when T2 is the final item in the stimulus stream, no attentional blink is observed, because there are no subsequent stimuli that might mask T2. To provide a direct test of this explanation of the attentional blink, in the present study we used the P3 component of the event-related potential waveform to track the processing of T2. When T2 was followed by a masking item, we found that the P3 wave was completely suppressed during the attentional blink period, indicating that T2 was not consolidated in working memory. When T2 was the last item in the stimulus stream, however, we found that the P3 wave was delayed but not suppressed, indicating that T2 consolidation was not eliminated but simply delayed. These results are consistent with a fundamental limit on the consolidation of information in working memory.     

Being accepted for who we are: evidence that social validation of the intrinsic self reduces general defensiveness

Three studies examined the possibility that being liked intrinsically by others--for who one is--reduces self-esteem defense, whereas being liked for what one has achieved does not. All 3 studies contrasted the effects on self-esteem defense of liking based on intrinsic or achievement-related aspects of self. Study 1 showed that thoughts of being liked intrinsically reduced defensive bias toward downward social comparison. Study 2 demonstrated that being liked for intrinsic aspects of self reduced participants' tendency to defensively distance themselves from a negatively portrayed other. Study 3 revealed that being liked for intrinsic aspects of self encouraged a preference for upward over downward counterfactuals for a negative event. In all 3 studies, similar reductions in defensiveness were not found when liking was based on achievements. Discussion focuses on implications for understanding the functional value of different bases of self-worth.     

Inductive Reasoning in Alzheimer''s Disease

We evaluated knowledge of basic level and superordinate semantic relations and the role of cognitive resources during inductive reasoning in probable Alzheimer's disease (AD). Nineteen mildly demented AD patients and 17 healthy control subjects judged the truthfulness of arguments with a premise and a conclusion that contain familiar concepts coupled with "blank" predicates, such as "Spiders contain phosphatidylcholine; therefore all insects contain phosphatidylcholine." Like healthy control subjects, AD patients were relatively insensitive to the typicality of the premise category when judging the strength of arguments with a conclusion containing a basic-level concept, but were relatively sensitive to typicality during judgments of arguments containing a superordinate in the conclusion. Moreover, AD patients resembled control subjects in judging arguments with an immediate superordinate in the conclusion compared to arguments with a distant superordinate. AD patients differed from control subjects because they could not take advantage of two premises in an argument containing basic-level concepts. We conclude that semantic knowledge is sufficiently preserved in AD to support inductive reasoning, but that limited cognitive resources may interfere with AD patients' ability to consider the entire spectrum of information available during semantic challenges.     

When insight just won't come: The failure of visual cues in the nine-dot problem

The nine-dot problem is a classic in the field of human problem solving. Cognitive accounts of the problem's difficulty have been criticized on the grounds that the experimental methods on which they rely for support involve a qualitative change to the task requirements of the problem. The three experiments reported here utilize visual and visual-procedural hints to examine the notion that its difficulty is rooted in a mismatch between problem shape and solution shape. Experiment 1 demonstrated that a perceptual cue to the shape of the solution in the form of shading gave rise to only minimal improvements in performance; an additional hint about the relevance of the shading gave rise to modest, but not statistically significant, improvements. Experiment 2 replicated these findings against an additional control condition in which a solely verbal hint to violate the perceptual boundary of the problem shape was given. Furthermore, when both the verbal and visual hints were provided, performance improved only slightly. Experiment 3 provided participants with experience in producing the shape of the correct solution in problem variants closely related to the nine-dot problem. Performance on the transfer task, the basic nine-dot problem, remained at floor, however. These data suggest that visual constraint relaxation is unlikely to be the sole process by which the insight required to find a solution is achieved. The results are interpreted in terms of a previously proposed computational model of performance.     

Visual Search Remains Efficient When Visual Working Memory is Full

Many theories of attention have proposed that visual working memory plays an important role in visual search tasks. The present study examined the involvement of visual working memory in search using a dual-task paradigm in which participants performed a visual search task while maintaining no, two, or four objects in visual working memory. The presence of a working memory load added a constant delay to the visual search reaction times, irrespective of the number of items in the visual search array. That is, there was no change in the slope of the function relating reaction time to the number of items in the search array, indicating that the search process itself was not slowed by the memory load. Moreover, the search task did not substantially impair the maintenance of information in visual working memory. These results suggest that visual search requires minimal visual working memory resources, a conclusion that is inconsistent with theories that propose a close link between attention and working memory.     

Attribute Framing and Goal Framing Effects in Health Decisions

Levin, Schneider, and Gaeth (LSG, 1998) have distinguished among three types of framing—risky choice, attribute, and goal framing—to reconcile conflicting findings in the literature. In the research reported here, we focus on attribute and goal framing. LSG propose that positive frames should be more effective than negative frames in the context of attribute framing, and negative frames should be more effective than positive frames in the context of goal framing. We test this framework by manipulating frame valence (positive vs negative) and frame type (attribute vs goal) in a unified context with common procedures. We also argue that the nature of effects in a goal-framing context may depend on the extent to which the research topic has “intrinsic self-relevance” to the population. In the context of medical decision making, we operationalize low intrinsic self-relevance by using student subjects and high intrinsic self-relevance by using patients. As expected, we find complete support for the LSG framework under low intrinsic self-relevance and modified support for the LSG framework under high intrinsic self-relevance. Overall, our research appears to confirm and extend the LSG framework.