Walking While Memorizing: Age-Related Differences in Compensatory Behavior

This study investigated predictions of the life-span theory of selection, optimization, and compensation, focusing on different patterns of task priority during dual-task performance in younger and older adults. Cognitive (memorizing) and sensorimotor (walking a narrow track) performance were measured singly, concurrently, and when task difficulty was manipulated. Use of external aids was measured to provide another index of task priority. Before dual-task testing, participants received extensive training with each component task and external aid. Age differences in dual-task costs were greater in memory performance than in walking, suggesting that older adults prioritized walking over memory. Further, when given a choice of compensatory external aids to use, older adults optimized walking, whereas younger adults optimized memory performance. The results have broad implications for systemic theories of cognitive and sensorimotor aging, and the costs and benefits of assistive devices and environmental support for older populations.     

The development of functional response units: the role of demarcating stimuli.

An experiment with rats examined the roles of demarcating stimuli and differential reinforcement probability on the development of functional response units. It examined the development of units in a probabilistic, free-operant situation in which the presence of demarcating stimuli was manipulated. In all conditions, behavior became organized into two-response sequences framed by changes in local reinforcement probability. A tone demarcating the beginning and end of contingent response sequences facilitated the development of functional response units, as in chunking, but the same units developed slowly in the absence of the tone. Complex functional response units developed even though reinforcement contigencies remained constant. These findings demonstrate that models of operant learning must include a mechanism for changing the response unit as a function of reinforcement history. Markov models may seem to be a natural technique for modeling response sequences because of their ability to predict individual responses as a function of reinforcement history; however, no class of Markov chain can incorporate changing response units in their predictions.     

Suicide notes of Chinese youth.

Examination of 17 suicide notes from youthful Chinese suicides indicated the common appearance of anger, self-criticism, and interpersonal friction as precipitant.     

Mindfulness-based cognitive therapy reduces overgeneral autobiographical memory in formerly depressed patients

Previous research on depressed and suicidal patients and those with posttraumatic stress disorder has shown that patients' memory for the past is overgeneral (i.e., patients retrieve generic summaries of past events rather than specific events). This study investigated whether autobiographical memory could be affected by psychological treatment. Recovered depressed patients were randomly allocated to receive either treatment as usual or treatment designed to reduce risk of relapse. Whereas control patients showed no change in specificity of memories recalled in response to cue words, the treatment group showed a significantly reduced number of generic memories. Although such a memory deficit may arise from long-standing tendencies to encode and retrieve events generically, such a style is open to modification.     

Syntactic processing of Hebrew sentences in normal and dyslexic readers: electrophysiological evidence

The authors examined differences in brain activity as measured by amplitudes and latencies of event-related potential (ERP) components in Hebrew-speaking adult dyslexic and normal readers. The participants were measured while processing words' syntactic functions during reading of sentences with subject-verb-object syntactic order. The results suggested that among dyslexic and normal readers, N100 and P300 ERP components were sensitive to certain constituents of syntactic analysis for target words in accordance with their grammatical roles. The findings further demonstrated significant differences in ERP measures between dyslexic and normal readers. Compared with normal readers, dyslexic readers exhibited consistently higher amplitudes and longer latencies in both ERP components for the subject of the sentence. Significant, though less consistent, ERP variations were observed for other sentence elements. In addition, dyslexic readers differed from normal readers in their processing strategies. For normal readers, the verb-oriented, morphologically based strategy was found to be the most efficient for sentence processing in Hebrew, whereas the dyslexic readers demonstrated a more primitive mode of identification of words' grammatical roles, namely, the word-order strategy. The results support the hypothesis that there is a syntactic processing "weakness" in dyslexics.     

Verbal transformation: habituation or spreading activation?

Experiment 1 tested the habituation hypothesis of the Verbal Transformation Effect, an auditory illusion in which a repeating verbal stimulus undergoes perceptual transformation, by varying stimulus dimensions which might be expected to retard habituation. Transformations were found to increase as a function of imagery value and word length, failing to support the habituation hypothesis. Experiment 2, in which transformations were found to vary as a function of number of activated semantic representations of a physically invariant homophone stimulus, provided support for a new dual-process explanation of the Transformation effect, based on spreading activation between cognitive representations.     

Dynamic and consequential consistency of choices between paths of decision trees

The generally prescribed procedure for choosing a decision strategy from a decision tree employs a backward induction analysis that entails 3 fundamental consistency principles: dynamic, consequential, and strategic. The first requires the decision maker to follow through on plans to the end, the second requires the decision maker to focus solely on future events and final consequences given the current state of events, and the third is the conjunction of the first 2. Five experiments were reported to test these principles using different subject populations, different procedures for estimating consistency, and different factors for manipulating the attractiveness of the gamble at the final stage of the tree. The main findings were that strategic and dynamic consistency principles were violated at rates that exceeded choice inconsistency.