Word association in early Alzheimer's disease

The hypothesis that Alzheimer's disease (AD) degrades semantic representations predicts that AD qualitatively alters spontaneous thoughts. In two experiments contrasting free associations to words with strong (e.g., bride-groom) versus weak (e.g., body-leg) associates participants with AD produced less common responses (e.g., bride-pretty) than normal controls but only for words with strong associations, and only on the first (but not on second or third) association response. Furthermore, all participants produced fewer semantically related responses to words with weak associates. Because strong associations should be retrieved more easily than weak associations these results are problematic for retrieval-based accounts of AD. Instead we propose that AD entails a semantic deficit, and that strong associations involve more semantic processing than weak associations (in all speakers).     

Punishment insensitivity and parenting: temperament and learning as interacting risks for antisocial behavior

We review ideas about individual differences in sensitivity or responsiveness to common disciplinary behaviors parents use to correct aggressive and antisocial behavior in children. At extremes, children may be seen as punishment-insensitive, an heuristic with some value relevant to models of the development of antisocial and aggressive behavior disorders. Literature from diverse fields, such as psychopathy, child temperament, socialization and the development of moral conscience, conditioning theory, and personality theory, have all utilized the idea that humans differ in their sensitivity to aversive stimuli and the cues that signal their occurrence, as well as their ability to inhibit reward-driven behavior, in the presence of punishment cues. Contemporary thinking places these dispositions squarely as basic biological aspects of temperament that moderate the effects of the environment (e.g., parenting) on outcomes (e.g., mental health). We review a largely forgotten literature that shows clearly that sensitivity to punishment is also reliably influenced by the environment itself. An attempt is then made to model the interactional processes by which parenting and punishment sensitivities in children magnify or diminish each other's progress toward healthy or antisocial development. Implications for parenting of children with low responsiveness to punishment strategies are discussed.     

A comparison of sentence- and discourse-level semantic processing: an ERP study

Eighteen subjects listened to sentences ending with semantically congruent or incongruent words. Each congruent sentence was embedded at the end of a short story so that the final word was semantically acceptable at the sentence level but incongruent in terms of discourse context. The same stories were also presented with congruent endings. Auditory ERPs elicited by the final words in these sentences and stories were compared. Both sentence- and discourse-level semantic integration were associated with N400 and Late Positive Component (LPC) effects in addition to a new component, P550. Local and global semantic processing, although evoking the same components, were characterized by differential effects on ERP amplitudes according to the amount of text integrated and its congruence. These results indicate similar cognitive processes of context build up, underlying sentence- and discourse-semantic processing.     

Monitoring the Changing Status of Semantic Memory in Alzheimer's Disease: An Evaluation of Several Process Measures

The deficits in generating correct words on verbal fluency tasks exhibited by patients with Alzheimer's disease (AD) are accompanied by fewer switching responses, smaller phonemic and semantic cluster sizes, and greater than normal percentages of errors and category labels. On category fluency tasks, patients generate a greater proportion of words that are prototypical of their semantic class. To determine whether any of these supplementary measures of verbal fluency performance might be useful in revealing processes involved in the decline of semantic memory in AD, we studied 219 patients with AD and 115 elderly control participants longitudinally. Previously reported group differences between patients and controls were replicated, but changes in average cluster size, error rates, and prototypicality were not related to changes in overall severity of dementia and test-retest stability was only modest. The change in the percentage of labels generated on the Supermarket task was related to changes in dementia severity, but test-retest stability on this measure was quite low. All of these process measures appear to reflect only the current status of the patient's attention to the task and access to semantic knowledge, but they do not forecast future performance. The numbers of switching responses on the fluency tasks were sensitive to differences between clinically deteriorated and clinically stable patients and showed fairly high test-retest stability. However, the number of switching responses is so highly correlated with the number of correct words that it contributes little to the understanding of the processes involved in the progressive decline in performance on fluency tasks by patients with AD.     

Patients' intentions in primary care: Measurement and preliminary investigation

Abstract

A questionnaire to assess patients' intentions in primary care was completed by 206 patients. Patients also rated the amount of help with their presenting problem which they thought could be provided by each of 11 secondary services. A principal components analysis of the intentions revealed 4 components: “Explanation and understanding,” “Support,” “Medical treatment” and “Information-seeking.” Individual patients' intentions were quantified on each of these dimensions. Requests for “Explanation and understanding” did not correlate with expectation of help from any of the 11 sources. In contrast, each of the remaining 3 types of request correlated with expectation of help from a number of sources. These results show, first, a way of measuring patients' intentions on multiple independent dimensions. Secondly, they indicate that patients look solely to the general practitioner for general information and reassurance about their problems. For emotional support they look to additional, mainly psychiatric, sources. This calls into question the view that general practitioners are seen by patients as more appropriate providers of emotional support than specialist services.