The evaluation of a computer-assisted attention training program is compared with a cognitive group training program. Both programs were devised to reduce cognitive deficits in schizophrenics. The training programs were given to 30 acute schizophrenics and 30 healthy subjects. Both were shown to be effective in reducing distraction of schizophrenics in reaction-time tasks. By means of training, schizophrenics may attain the same results in reaction time tasks as healthy individuals. The results are discussed under theoretical, methodical and practical aspects.

The generalizability of the model relating P300 amplitudes to subjective probabilities, developed by Squires et al. (1976) for random series of events, was examined with respect to long sequences of repetitions, which had been restricted in randomness, allowing only for sequences of between 4 and 12 frequent clicks. Subjects were asked to silently count either the rarer of two clicks, presented with a probability of .10, or light stimuli occurring with the same temporal distribution. Within these limits there was an increase in P300 amplitude not only to the rare clicks, but also—contrary to predictions from the model—to the frequent non‐target clicks following longer series of repetitions, provided that clicks had to be counted. A plausible interpretation might be that the longer the series of repetitions in long non‐random sequences with low predictability, the more the subjects become involved in the “stimulus evaluation” of both kinds of events. A similar increase across serial position was found for the N100 component to frequent clicks when the auditory modality was defined as task relevant, and was interpreted as progressive focusing of selective attention. For the rare clicks there occurred a decrease in a slow Negative Shift with peak amplitude at 220 msec after long series of non‐targets, possibly reflecting a facilitative effect of the focused attention on decision processes related to target detection. There were no differences between normals and chronic alcoholics with respect to the above‐mentioned effects.

Contradictory evidence as to the effects of alcohol on early information processing stages has been obtained from behavioral and psychophysiological investigations. In the present study, choice reaction times, error rates, and event-related potentials (ERPs) were recorded in a task in which variations in stimulus discriminability and of the (task irrelevant) correspondence between stimulus location and response location were orthogonally combined. Both discriminability and stimulus-response correspondence affected reaction time and electrophysiological chronometric measures as expected. However, no behavioral effects of alcohol were observed, possibly because of strategic adjustments. Psychophysiological chronometric measures indicated that alcohol leaves the initial flow of perceptual evidence to motor stages unimpaired, whereas it appears to increase the duration of stimulus evaluation. Interestingly, a number of alcohol effects appeared in the ERP amplitudes. Decrements in early ERP components indicate alcohol-induced impairments of involuntary visual attention and/or the automatic stimulus location-dependent activation of response channels. In contrast, a strong enhancement of a late slow-wave component under alcohol may reflect the investment of processing resources in order to maintain normal performance levels.

No abstract

Physical activity may be a trigger for panic attacks in patients with panic disorder, while exercise may have an antidepressant effect in patients with major depression. In order to examine reactions to rest as well as to exercise periods, we assessed physiological responses (heart rate, blood pressure), subjective responses on a visual analogue scale, and attentional responses with the span of apprehension test. Twenty participants met the diagnostic criteria for panic disorder, 20 patients had major depression, and 20 participants served as controls. Patients with major depression showed slower reaction times than participants in the other groups; this difference was more pronounced with increased task difficulty. Physical activation led to lower depression scores in all groups. Patients with panic disorder had elevated anxiety scores after physical activation, but also after rest. Heart rate as well as systolic blood pressure showed the expected acceleration after physical activation, but there were no differences between the groups. Activation did not seem to influence attentional performance as measured by the span of apprehension test. Results are consistent with a cognitive view of panic disorder. In contrast to patients with panic disorder, patients with major depression seem to have an attentional deficit which is more pronounced with more complex cognitive processing.