Most comparative studies of performance in psychodiagnostic classification contrast novices with very experienced clinicians, and do not include a group with an intermediate level of experience. We describe an empirical study involving 41 clinicians with three levels of experience. We asked novices, intermediates, and very experienced psychodiagnosticians to give the diagnostic (DSM) classification for 10 written cases. We found an intermediate effect in diagnosticians' decision time and correctness: Intermediates performed worse and faster than both novices and very experienced clinicians. In line with most other studies, we found that experienced diagnosticians were not significantly more accurate than novices.

The ability to share time and to shift attention between bimanual simultaneous motor tasks were studied in 18 patients with Parkinson's disease (PD) and 19 age-and intelligence-matched controls. The task consisted of drawing triangles with the dominant hand and squeezing a rubber bulb with the nondominant hand. Motor performance was measured using the variables: amplitude of squeezing, frequency of squeezing and velocity of drawing triangles. After eliminating variance due to baseline differences in single-handed performance, the bimanual simultaneous performance of PD and controls turned out to be similar to the frequency of squeezing and the velocity of drawing triangles. The amplitude of squeezing, however, differed between the two groups: it was significantly reduced in PD. Arguably the disturbance in the bimanual performance of PD patients was not due to a disorder of time sharing, but to a decreased ability to shift attention from the visually cued task to the non visually cued task. The results agree with current evidence that PD patients are more impaired when they have to rely upon internal control for the regulation of shifting attention than when external cues are available.

No abstract

The communication profiles of individuals with Down's syndrome (DS), Angelman syndrome (AS) and pervasive developmental disorder (PDD) were investigated and contrasted. Seventy-seven individuals participated in the study. A within-group analysis revealed that those with DS performed better on tacting or labelling and echoing than on manding or requesting. No other effects were found, apart from an absence of echoing in those with AS, a result that is hardly surprising. A between-groups analysis revealed no differences between the aetiological groups in terms of their use of mands or requests and tacts. Individuals with DS and PDD did not differ in their scores on echoic functioning. The implications of these findings for the study of behavioural phenotypes and for communication intervention are discussed.

No abstract