It has previously been reported that unfamiliar face recognition memory is impaired in Parkinson’s disease (PD) (Dewick, H. C., Hanley, J. R., Davies, A. D. M., Playfer, J. R. & Turnbull, C. J., ...Perception and memory for faces in Parkinson’s disease. Neuropsychologia, 1991, 29, 785–802), (Haeske-Dewick, H. C., Are perception and memory for faces influenced by a specific age at onset factor in Parkinson’s disease? Neuropsychologia, 1996, 34, 315–320), (Levin, B. E., Llabre, M. M. & Weiner, W. J., Cognitive impairments associated with early Parkinson’s disease. Neurology, 1989, 39, 557–561). In the work reported here, we consider the possible mechanisms that might underlie this impairment. 28 PD patients and 28 controls were given a two-part test of recognition memory for words and faces, and two perceptual tests to measure their configural and componential processing ability. We found that PD patients were significantly worse than controls on the recognition memory test for faces, but not when the stimuli were words. In addition, PD patients were significantly impaired relative to controls on the closure test (FCT) used to measure configural processing, but there was no difference between the two groups on a test of componential processing ability. Multiple regression analyses revealed that even after accounting for the influence of age, intelligence and level of depression, configural processing ability was the important predictor of unfamiliar face recognition memory in Parkinson’s disease. There was no effect of Parkinson’s disease specific variables on either face recognition or FCT performance. In addition, some recently diagnosed patients were poor at face recognition. It is suggested that face configuration skills may be affected very early in the course of Parkinson’s disease, and that this may be connected to the fact that considerable nigrostriatal degeneration and alteration in brain neurotransmitter levels occur before the clinical symptoms of PD appear.
Objectives: Although it is well known that informal caregiving can have negative outcomes, and is an important factor in institutionalization, there is currently no common model to assess ...psychological distress in caregivers. In this study, we considered the conceptualization of caregiving distress, and present a five‐dimension, 17‐item Caregiving Distress Scale (CDS).
Design: The CDS was developed by administering several scales from the caregiving literature to a sample of 80 Parkinson's disease caregivers longitudinally.
Method: A total of 58 items from published questionnaires were reduced initially by a hierarchical cluster analysis, then by factor analysis.
Results: This procedure produced five distinctive subscales ‐ relationship distress, emotional burden, care‐receiver demands, social impact, and personal cost ‐ that also had high internal reliability.
Conclusion: The CDS is quick to administer and score, and has the potential to be used to profile an individual caregiving situation. Of critical importance for the application of findings from the caregiving literature, the scale can be used to target the type of intervention for the amelioration of caregiving distress.
This paper describes the novel application of an evolutionary algorithm to discriminate Parkinson's patients from age-matched controls in their response to simple figure-copying tasks. The reliable ...diagnosis of Parkinson's disease is notoriously difficult to achieve with misdiagnosis reported to be as high as 25% of cases. The approach described in this paper aims to distinguish between the velocity profiles of pen movements of patients and controls to identify distinguishing artifacts that may be indicative of the Parkinson's symptom bradykinesia. Results are presented for 12 patients with Parkinson's disease and 10 age-match controls. An algorithm was evolved using half the patient and age-matched control responses, which was then successfully used to correctly classify the remaining responses. A more rigorous 'leave one out' strategy was also applied to the test data with encouraging results.
This article links two formerly separate areas of research associated with Parkinson's disease (PD): speech and memory. It is proposed that speech deficits occur in PD not merely at the level of ...muscular control, as is commonly termed dysarthria, but also at the level of speech planning and programming, more aptly described as a form of apraxia. It is further argued that PD patient groups exhibit small deficits in verbal span, and the link between apraxic speech and verbal span is elucidated via Baddeley's (1986) model of working memory. An experiment is described in which aspects of speech of 36 PD and 43 healthy control subjects were rated and classified, and measures of span and articulation rate for words of different syllable lengths were taken. Twenty-three PD subjects had dysarthric speech, while 14 of them had apraxic speech, which was associated with lower memory span scores for longer words. It is concluded that apraxic speech can be a source of reduced memory span in PD. In addition to implications for rehabilitation and therapeutic work with PD sufferers, these findings advance our theoretical understanding of the Parkinsonian syndrome.
A cluster of multi-anode photomultiplier tubes (MaPMTs) equipped with focusing lenses in front of the tubes was tested in a prototype ring imaging Cherenkov (RICH) detector in a charged particle ...beam. The readout electronics were capable of capturing the data at 40
MHz. The effects due to charged particles and magnetic field on the MaPMT performance were also studied. The results are used to evaluate the MaPMT as a possible photodetector for the LHCb RICH detectors.
We report the observation of the decay $B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}$ based on $342 \mathrm {\,fb}^{-1}}$ of data collected at the $\Y4S$ resonance with the BABAR ...detector at the PEP-II $e^{+}e^{-}$ storage rings at SLAC. A simultaneous fit to three $D^{+}_{s}$ decay chains is performed to extract the signal yield from measurements of the squared missing mass in the B meson decay. We observe the decay $B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}$ with a significance greater than five standard deviations (including systematic uncertainties) and measure its branching fraction to be $\BR(B^{-} \rightarrow D^{(*)+}_{s} K^{-} \ell^{-} \bar{\nu}_{\ell}) = 6.13^{+1.04}_{-1.03}(\mathrm{stat.})\pm0.43(\mathrm{syst.}) \pm 0.51(\BR(D_{s}))\times10^{-4}$, where the last error reflects the limited knowledge of the $D_{s}$ branching fractions.
We report a direct measurement of $D^0-overline{D}^0$ mixing parameters through a time-dependent amplitude analysis of the Dalitz plots of $D^0 \rightarrow K_S^0 \pi^+ \pi^-$ and, for the first time, ...$D^0 \rightarrow K_S^0 K^+ K^-$ decays. The low-momentum pion $\pi_s^+$ in the decay $D^{*+} \rightarrow D^0 \pi_s^+$ identifies the flavor of the neutral $D$ meson at its production. Using 468.5 fb$^{-1}$ of $e^+e^-$ colliding-beam data recorded near $\sqrt s = 10.6$~GeV by the BABAR detector at the PEP-II asymmetric-energy collider at SLAC, we measure the mixing parameters $x= 1.6 \pm 2.3 ({\rm stat.}) \pm 1.2 ({\rm syst.}) \pm 0.8 ({\rm model}) \times10^{-3}$, and $y= 5.7 \pm 2.0 ({\rm stat.}) \pm 1.3 ({\rm syst.}) \pm 0.7 ({\rm model}) \times 10^{-3}$. These results disfavor the no-mixing hypothesis with a significance of 1.9 standard deviations, and provide the best measurement to date of $x$.
The reported prevalence of absent ankle jerks in elderly people varies greatly. This variation may be due to differences in the method of testing. Eight physicians examined 12 patients for the ...presence of ankle jerks using two techniques: plantar strike and tendon strike. Both intra-observer agreement (kappa 0·47 vs 0 20; p=0·01) and inter-observer agreement (0 57 vs 0 21;p<0·001) were greater with plantar strike. Reliability of ankle jerk assessment was greater for more experienced examiners. Differences in technique may explain some of the discrepancy between studies examining the prevalence of absent ankle jerks in elderly people.
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