Correlations between glucose metabolic rates in brain regions of healthy male adults at rest and during language stimulation

This study examines the effect of different behavioral conditions on patterns of correlation between regional cerebral metabolic rates for glucose. Cerebral glucose metabolism was determined with positron emission tomography and (11C)-deoxyglucose in 29 normal subjects between the ages of 23 and 55. Seventeen subjects were studied in an unstimulated (resting) condition and 12 subjects during a phoneme monitoring language stimulation. Partial correlation coefficients, controlling for whole brain glucose metabolism, were calculated for pairs of metabolic rates in 14 cortical and 2 subcortical regions. Both stimulated and unstimulated subjects showed statistically significant correlations between left and right hemisphere homologs. The stimulated subjects also showed significant within-hemisphere correlations between left but not right hemisphere regions. These included left perisylvian regions classically associated with language functions (left inferior frontal, left superior temporal and left transverse temporal cortical regions) as well as other regions. Significant correlations between left regions and a right superior temporal region were also found. In general, these findings show a pattern of cross-hemisphere symmetry at rest and of hemisphere asymmetry during stimulation. Moreover, the asymmetry observed during stimulation appears to be superimposed upon a pattern of cross-hemisphere symmetry similar to that observed in the unstimulated state.     

Spatial constraints on attention to speech in the blind

When sighted persons try to identify one of two speech utterances coming from different directions, they display both a frontal position advantage, i.e., better recognition of inputs from the front than of those from the rear, and a right-side advantage, better recognition of inputs from the right than of those from the left. The present study demonstrates a dissociation of the two effects in blind subjects (N = 10) who showed no frontal position advantage together with a right-side advantage superior to that of control sighted subjects (N = 16). There was no systematic difference between congenitally blind subjects and noncongenitals. The absence of frontal position advantage in the blind is consistent with the notion that this effect originates in the habit of sighted listeners to orient toward the source of heard speech. The occurrence of at least normal right-side advantage in the blind does not support recent suggestions of reduced lateralization of language functions in such subjects.     

The interaction of stressful life events and chronic strains on community mental health

One of the possible adaptive costs of coping with stress is diminished capacity to respond to subsequent adaptive demands. This paper examined the complex interplay between major life events and one source of chronic strain. Residents of the greater Los Angeles metropolitan area exposed to higher levels of smog, who had also experienced a recent stressful life event, exhibited poorer mental health than those exposed to pollution who had not experienced a recent stressful life event. There were, however, no direct effects of smog levels on mental health. These patterns of results were replicated in both a cross-sectional and a longitudinal study. The interplay of psychosocial vulnerability and environmental conditions is discussed.     

Psychosocial characteristics of preschool siblings of handicapped and nonhandicapped children

This project examined psychosocial characteristics of 24 preschool-aged siblings of handicapped children in relation to a control group of 22 siblings of nonhandicapped children. Subjects were matched on family size and income, sibling age, birth order, sex, age spacing, and marital status of their parents. Results indicated no statistically significant differences between groups of children on measures of perceived self-competence and acceptance, understanding of developmental disabilities, empathy, and child care responsibility. Significant group differences were found where brothers of handicapped children were rated by their mothers as being more depressed and aggressive than brothers of nonhandicapped control children. Sisters of handicapped children were rated by mothers as being more aggressive than sisters of nonhandicapped children. Sisters of handicapped children and brothers of nonhandicapped children had significantly fewer privileges and more restrictions on their home activities than other groups. Results are discussed in relation to previous research on older silbings of handicapped children and the general literature on family stress and childhood disability and disease. The importance of examining sibling functioning via multiple measures of child behavior is stressed.The authors are grateful to the children and families who participated in the project. The assistance of Dr. Ricardo Barrera, Christine DiBlasio, Lisa Kaye, Paola Bellabarba, Jeanne Logozzo, Donna Motley, Jennifer Harter, and Tina Meisell is also gratefully acknowleged. This project was funded by Grant Number G008300345 from the U.S. Department of Education.     

Electromagnetic articulography: use of alternating magnetic fields for tracking movements of multiple points inside and outside the vocal tract

The purpose of this paper is to present a new electromagnetic device which uses alternating magnetic fields for tracking movements of multiple points inside and outside the vocal tract. It is biologically safe, noninvasive, it does not interfere with speech movements, allows for multiple recording in the same subject, and for easy collection of large amounts of data. It is especially suitable for evaluation of patients with speech motor impairments.     

The principle of charity and the problem of irrationality (translation and the problem of irrationality)

Common formulations of the principle of charity in translation seem to undermine attributions of irrationality in social scientific accounts that are otherwise unexceptionable. This I call the problem of irrationality. Here I resolve the problem of irrationality by developing two complementary views of the principle of charity. First, I develop the view (ill-developed in the literature at present) that the principle of charity is preparatory, being needed in the construction of provisional first-approximation translation manuals. These serve as the basis for explanatory accounts and associated refinements in the translation manual. In developing such explanatory accounts, the principle of charity is no longer constraining. Thus, the principle of charity applies only in the early stages of constructing translation manuals, and there is no problem of irrationality in the later stages of constructing translation manuals. Second, I reduce the principle of charity, where it does apply, to a special case of what I call the principle of explicability: so translate as to attribute explicable beliefs and practices to the speakers of the source-language. I show that the appropriate formulation of the principle of charity counsels just what the principle of explicability requires in the early stages of social scientific investigation.I am grateful to Robert Barrett, Roger Gibson, and Paul Roth for their generous assistance.     

The effects of commitment to threats and promises upon bargaining behaviour and outcomes

The course of bargaining is determined in part by interdependent individuals exchanging messages so as to influence other's behaviour, and thereby to increase the likelihood of achieving outcomes consistent with their own goals. The communication of threats and promises are two major message strategies that are employed to influence the behaviour of others in a bargaining relationship. The present study examines the effects of players' level of commitment to these forms of message strategies upon behaviour in a duopoly bargaining task. Past research has oprationalized commitment in terms of the consistency with which an individual has followed through on threats or promises in the past. In the present research, Becker's (1960) concept of a side-bet is employed to provide an alternative means for defining and manipulating commitment. A side-bet obtains when either a threatener or a promiser posts a valued resource, say a bond, which they forfeit if they do not follow through on their stated threat or promise. The main expectations of the present study were that increased commitment to threat meassages would lead to more competitive behaviour and outcomes within a duopoly bargaining task, whereas increased commitment to promise messages would produce more cooperative behaviour and outcomes. Partial support for these major expectations, as well as confirmation of a number of secondary expectations, was obtained.     

Neuropsychological analysis of a typewriting disturbance following cerebral damage

Following a left CVA, a skilled professional typist sustained a disturbance of typing disproportionate to her handwriting disturbance. Typing errors were predominantly of the sequencing type, with spatial errors much less frequent, suggesting that the impairment was based on a relatively early (premotor) stage of processing. Depriving the subject of visual feedback during handwriting greatly increased her error rate. Similarly, interfering with auditory feedback during speech substantially reduced her self-correction of speech errors. These findings suggested that impaired ability to utilize somesthetic information--probably caused by the subject's parietal lobe lesion--may have been the basis of the typing disorder.     

Strategic hand use preferences and hemispheric specialization in tactual reading: impact of the demands of perceptual encoding

Four reading-related, information-processing tasks were administered to right-handed blind readers of braille who differed in level of reading skill and in preference for using the right hand or the left hand when required to read text with just one hand. The tasks were letter identification, same-different matching of letters that differed in tactual similarity, short-term memory for lists of words that varied in tactual and phonological similarity, and paragraph reading with and without a concurrent memory load of digits. The results showed interactions between hand preference and the hand that was actually used to read the stimulus materials, such that left preferrers were significantly faster and more accurate with their left hands than with their right hands whereas right preferrers were slightly but usually not significantly faster with their right hands than with their left hands. In all cases, the absolute magnitude of the left-hand advantage among left preferrers was substantially larger than the right-hand advantage among right preferrers. The results suggest that encoding strategies for dealing with braille are reflected in hand preference and that such strategies operate to modify an underlying but somewhat plastic superiority of the right hemisphere for dealing with the perceptual requirements of tactual reading. These requirements are not the same as those of visual reading, leading to some differences in patterns of hemispheric specialization between readers of braille and readers of print.     

On comprehension of active/passive sentences and language processing in a Polish agrammatic aphasic

This paper presents the results of a study of active/passive sentence comprehension by a Polish-speaking agrammatic aphasic. The patient showed good performance on canonically ordered active and passive structures, but performed poorly on inverted variants. The systematically normal and deviant comprehension patterns observed are accounted for by normal interpretative strategies applied to syntactic structures built around verbs with reduced inflectional morphology. The differences between our Polish data and the English data discussed in the literature are explained by the fact that Polish possesses a richer derivational verb morphology. The interpretation of inverted sentences demonstrates the importance of S-V-O word order preference. Our analysis draws upon the notion of grammatical functions to explain the data.