Effect of speech task on intelligibility in dysarthria: a case study of Parkinson's disease

This study assessed intelligibility in a dysarthric patient with Parkinson's disease (PD) across five speech production tasks: spontaneous speech, repetition, reading, repeated singing, and spontaneous singing, using the same phrases for all but spontaneous singing. The results show that this speaker was significantly less intelligible when speaking spontaneously than in the other tasks. Acoustic analysis suggested that relative intensity and word duration were not independently linked to intelligibility, but dysfluencies (from perceptual analysis) and articulatory/resonance patterns (from acoustic records) were related to intelligibility in predictable ways. These data indicate that speech production task may be an important variable to consider during the evaluation of dysarthria. As speech production efficiency was found to vary with task in a patient with Parkinson's disease, these results can be related to recent models of basal ganglia function in motor performance.     

Effects of right and left hemisphere damage on performance of the "Right Hemisphere Communication Battery"

A Hebrew adaptation of Gardner and Brownell's (1986) "Right Hemisphere Communication Battery" (HRHCB) was administered to 27 right brain-damaged (RBD) patients, 31 left brain-damaged (LBD) patients, and 21 age-matched normal controls. Both patient groups showed deficits relative to controls and overall there was no difference between the two patient groups. A factor analysis of patients' scores on the HRHCB yielded two interpretable factors, a verbal and a nonverbal one. These factors were not lateralized. Performance of patients on the HRHCB correlated significantly and positively with performance on most tests of basic language functions, measured with a Hebrew adaptation of the "Western Aphasia Battery" (HWAB) and with other cognitive functions measured with standardized neuropsychological tests. There were stronger correlations of HRHCB with subtests of the HWAB in LBD patients and with nonlanguage cognitive tests in RBD patients. In the LBD group, HRHCB subtests' scores correlated negatively with lesion extent in frontal and temporal perisylvian regions. Such localization was not observed in RBD patients. The results argue against selective right hemisphere (RH) involvement in the RHCB, alleged to measure pragmatic aspects of language use, and show, instead, bilateral involvement. The results also argue against a modular organization of these functions of language use, especially in the RH.     

Action-based and vision-based selection of input: Two sources of control

In the first part of this paper we review evidence suggesting that there exists a mechanism that selects input on the basis of its similarity to the required action. This response-based input selection differs from the more established space- and object-based input selection in that it is not constrained by the structure of the input. Our evidence suggests that the two-choice Stroop effect is caused by this response-based selection mechanism. By contrast, it is known that the flanker effect is determined by the space- and object- based selection mechanisms. We explore whether the conflict resolution of the Stroop and flanker tasks is different as well by embedding these two tasks in a PRP (Psychological Refractory Period) paradigm. We show that the Stroop and the PRP effects are additive whereas the flanker and the PRP effects are underadditive, suggesting that the processes in charge of the conflict resolution in the Stroop and the flanker tasks are indeed different. We discuss possible reasons for this difference, and discuss possible ways in which the response-based mechanism can be implemented in information processing models.     

College-educated women's personality development in adulthood: perceptions and age differences

Adulthood encompasses a large time span and includes a series of psychosocial challenges (E. H. Erikson, 1950). Five aspects of personality (identity certainty, confident power, concern with aging, generativity, and personal distress) were assessed in a cross-sectional study of college-educated women who at the time of data collection were young adults (age: M = 26 years), middle-aged adults (age: M = 46 years), or older adults (age: M = 66 years). Respondents rated each personality domain for how true it was of them at the time, and they then rated the other 2 ages either retrospectively or prospectively. Results are discussed with attention to the ways in which women's adult development may have been shaped by experiences particular to both gender and birth cohort, and to how these women fit with E. H. Erikson's theory of adult development.     

Synesthetic color experiences influence memory

We describe the extraordinary memory of C, a 21–year–old student who experiences synesthetic colors (i.e., photisms) when she sees, hears, or thinks of digits. Using three matrices of 50 digits, we tested C and 7 nonsynesthetes to evaluate whether C's synesthetic photisms influence her memory for digits. One matrix consisted of black digits, whereas the other two matrices consisted of digits that were either incongruent or congruent with the colors of C's photisms. C's recall of the incongruently colored digits was considerably poorer than her recall of either the black or the congruently colored digits. The 7 nonsynesthetes did not show such differences in their recall of the matrices. In addition, when immediate recall of the black digits was compared with delayed recall of those digits (48 hr), C showed no decrease in performance, whereas each of the nonsynesthetes showed a significant decrease. These findings both demonstrate C's extraordinary memory and show that her synesthetic photisms can influence her memory for digits.     

Psychopathy screening of incarcerated juveniles: a comparison of measures

How well do brief screening measures correspond with a full-scale assessment of psychopathy among juvenile offenders? This study compared 3 independent screening measures (the Antisocial Process Screening Device [APSD] Self-Report [A. A. Caputo, P. J. Frick, & S. L. Brodsky, 1999], the APSD Staff Rating [P. J. Frick & R. D. Hare, 2001], and the Psychopathy Content Scale [D. C. Murrie & D. G. Cornell, 2000] on the Millon Adolescent Clinical Inventory [T. Millon, 1993]) with the Psychopathy Checklist: Youth Version (PCL:YV; A. E. Forth, D. S. Kosson, & R. D. Hare, in press) in a sample of 117 incarcerated male juveniles. Modest correlations (.30-.49) were found between PCL:YV scores and those of the 3 screening measures, and there was moderate accuracy (67%-82%) in identifying youth who scored relatively high (> or = 25) on the PCL:YV. Although these results support the construct of adolescent psychopathy, they indicate substantial limitations in the use of psychopathy screening measures with juvenile offenders.     

Extending the ALCOVE model of category learning to featural stimulus domains

The ALCOVE model of category learning, despite its considerable success in accounting for human performance across a wide range of empirical tasks, is limited by its reliance on spatial stimulus representations. Some stimulus domains are better suited to featural representation, characterizing stimuli in terms of the presence or absence of discrete features, rather than as points in a multidimensional space. We report on empirical data measuring human categorization performance across a featural stimulus domain and show that ALCOVE is unable to capture fundamental qualitative aspects of this performance. In response, a featural version of the ALCOVE model is developed, replacing the spatial stimulus representations that are usually generated by multidimensional scaling with featural representations generated by additive clustering. We demonstrate that this featural version of ALCOVE is able to capture human performance where the spatial model failed, explaining the difference in terms of the contrasting representational assumptions made by the two approaches. Finally, we discuss ways in which the ALCOVE categorization model might be extended further to use “hybrid” representational structures combining spatial and featural components.     

Cholinesterase-inhibitor therapy for dementia: novel clinical substrates and mechanisms for treatment response

Historically, drugs that increase central cholinergic transmission have primarily been investigated for relieving cognitive symptoms in mild-to-moderate Alzheimer's disease. These efforts have led to the somewhat unexpected findings that cholinergic therapy has a beneficial effect on selected neuropsychiatric symptoms in AD across disease stages. In Parkinson's disease with dementia and dementia with Lewy bodies, cholinergic deficits are more severe than in AD, and there is emerging evidence that cholinesterase inhibitors are efficacious in treating core symptoms of attentional disturbance and psychosis. Recent data also suggest a rational basis for cholinergic therapy in vascular dementia. The cognitive and neuropsychiatric effects of cholinergic therapy observed in AD and other dementias form the crux of an integrative model of cholinergic therapeutic efficacy that encompasses the diverse central nervous system actions of acetylcholine and its complementary interactions with central monoamine transmitters. This heuristic framework highlights the broader therapeutic potential of cholinergic therapy for symptom-based indications in other neuropsychiatric disorders.