Issues in exercise,fitness, and subjective perceptions of fitness of physical education teachers

Several issues arise on reading the paper by Netz and Raviv. Their role in interpretation of the data and stimulating questions for further study is mentioned.     

Frontal-Lobe Involvement in Spatial Memory: Evidence from PET,fMRI, and Lesion Studies

Many studies have identified the prefrontal cortex as the brain area that is critical for spatial memory, both in humans and in other primates. Other studies, however, have failed to establish this relation. Therefore, the aim of this paper was to review the literature regarding the role of the human prefrontal lobe in spatial memory. This was done by examining the evidence obtained from neuropsychological patients and from studies using brain-imaging techniques (PET and fMRI). Evidence supporting the notion that the prefrontal cortex is extensively involved in spatial working memory was found. The majority of these studies, however, suggests that frontal-lobe involvement is not related to the type of material that is being processed (e.g., spatial vs. nonspatial), but to process-specific functions, such as encoding and retrieval. Theoretically, these functions could be linked to the central executive within Baddeley's working-memory model, or to recent theories that emphasize the various processes that play a role in working memory. Also, methodological issues were discussed. Further research is needed to enhance our understanding of the precise interaction of domain-specific and general processes.     

Task demands and limb apraxia in stroke

The present study was designed to examine the frequency and severity of apraxia in patients with left- or right-hemisphere stroke in both pantomime and imitation conditions and to compare the frequency of apraxia in each stroke group across the three patterns of apraxia described in Roy's model (Roy, 1996). Ninety-nine stroke patients and 15 age-matched healthy adults performed eight transitive gestures to pantomime and to imitation. Gestural performance was quantified as accuracy on five performance dimensions; a composite score, an arithmetic combination of the five performance dimensions, was used as an index of the overall accuracy. Analyses revealed a comparable proportion of patients in each stroke group were classified as apraxic in the imitation condition, but a higher proportion of left stroke patients were apraxic in the pantomime condition. The severity of apraxia in each stroke group and the performance dimensions affected were, however, comparable. Analyses of the patterns of apraxia (pantomime alone, imitation alone or apraxia in both conditions) revealed a higher frequency of apraxia in both stroke groups for the pattern reflecting apraxia in both conditions, indicating that a disruption at the movement execution stage of gesture performance was most common.     

Social exclusion impairs self-regulation

Six experiments showed that being excluded or rejected caused decrements in self-regulation. In Experiment 1, participants who were led to anticipate a lonely future life were less able to make themselves consume a healthy but bad-tasting beverage. In Experiment 2, some participants were told that no one else in their group wanted to work with them, and these participants later ate more cookies than other participants. In Experiment 3, excluded participants quit sooner on a frustrating task. In Experiments 4-6, exclusion led to impairment of attention regulation as measured with a dichotic listening task. Experiments 5 and 6 further showed that decrements in self-regulation can be eliminated by offering a cash incentive or increasing self-awareness. Thus, rejected people are capable of self-regulation but are normally disinclined to make the effort.     

Ernst Mach and B. F. Skinner: Their similarities with two traditions for verbal behavior

Ernst Mach is most closely associated with a positivism that demanded a language of close contact with reality. Mach linked this view with the tradition of the quest for an ideal language in which meaning is a property of a word. Logical positivism and the S-R psychology of the early B. F. Skinner also participated in this ideal-language positivism. In addition, Mach showed an affinity with another tradition-a pragmatic-selectionist tradition-although that tradition and Mach's similarities with it were not as well developed. Mach showed no difficulty in jointly maintaining both of these traditions although they have been regarded as deeply incompatible. When the later Skinner adopted a pragmatic selectionism for his later views on verbal behavior, he rejected his earlier views that were aligned with S-R psychology as well as with logical positivism and its sympathizers. Nevertheless, some statements consistent with "meaning is a property of a word" remained for some time in Skinner's writing.     

The treatment of neuropathic pain

Neuropathic pain is responsible for a significant amount of the morbidity associated with generalized and focal peripheral neuropathies. It is a consequence of alterations in neuronal function, chemistry, and structure that occur secondary to nerve injury. These manifestations of neuronal plasticity occur in the peripheral nerve, spinal cord, and brain. A variety of agents from diverse pharmacologic classes, the so-called adjuvant analgesics, have been used to treat neuropathic pain. These include antidepressants, first- and second-generation anticonvulsants, antiarrhythmic agents, topical agents, N-methyl-D-aspartate receptor antagonists, and opioid analgesics. The use of these adjuvant analgesics, either alone or in combination, should result in the alleviation of neuropathic pain in most patients. Recent advances in the understanding of pain mechanisms at multiple central nervous system levels should pave the way toward more effective treatment modalities.     

When does word meaning affect immediate serial recall in semantic dementia?

Patients with semantic dementia can show superior immediate recall of words that they still understand relatively well, as compared with more semantically degraded words, suggesting that conceptual knowledge makes a major contribution to phonological short-term memory. However, a number of studies have failed to show such a recall difference, challenging this view. We examined the effect of several methodological factors on the recall of known and degraded words in 4 patients with semantic dementia, in order to investigate possible reasons for this discrepancy. In general, our patients did exhibit poorer recall of the degraded words and made more phonological errors on these items. In addition, set size affected the magnitude of the recall advantage for known words. This finding suggests that semantic degradation influenced the rate of learning in the immediate recall task when the same items were presented repeatedly. The methods used to select known and degraded items also impacted on the recall difference. List length, however, did not affect the advantage for known words. The coherence of items in phonological short-term memory was affected by their semantic status, but not by the length of the material to be retained. The implications of these findings for the role of semantic and phonological representations in verbal short-term memory are discussed.