Choice reaction time with a random foreperiod

Choice reaction latencies were measured at three different a priori probabilities for two stimulus alternatives. Unlike the results of some other studies, the mean latency of a given response was nearly the same whether the response was correct or incorrect. The discriminable stimuli were a 1000- or a 1700-Hz tone presented at 70 dB SPL. Latencies and standard deviations, based on about 17,000 observations, are reported for three observers. The data are compared with predictions of the optimum sequential model of Wald and Stone and two modifications of that random-walk model, one proposed by Link and Heath and the other proposed by Laming. Fast-guess analyses were also carried out. The three-parameter version of either the sequential or the modified random-walk models provided reasonably accurate predictions of the mean data for each observer. The parameters estimated by the fast-guess analysis were unrealistic. There are three obvious differences between this experiment and most previous choice reaction-time experiments. First is stimulus modality#x2014;we used an auditory signal, whereas most of the previous studies used a visual signal. Second, the observers practiced more in this experiment than in most previous experiments. Finally, there was a random foreperiod with a heavy penalty for anticipations. One or more of these factors is the probable reason for the discrepancy between our results and those of previous studies.     

The MMPI'S of left- and right-handed subjects

Previous research has suggested that left-handedness relates to delinquency and violence. In an effort to pinpoint the nature of this apparent relationship, we compared the MMPIs of 72 left- and 687 right-handed men 60 yr. old or less on an alcohol treatment ward. No significant differences appeared. The results are compared to earlier research and hypotheses for further research are suggested.     

Clinical, electroencephalographic and computer tomographic studies of children with West and Lennox-Gastaut syndrome

The results of clinical, electroencephalographic and repeated computed tomographic examination of 14 children suffering from epileptic seizures in connection with the West and Lennox-Gastaud syndrome are analyzed and compared. Computed tomography yields little information regarding the etiology of such forms of epilepsy. Distinct clinical and electroencephalographic findings were accompanied by normal computed tomographic results in a large proportion of the cases. To avoid misinterpretation of computed tomographic findings and consequent prognostic errors in these epileptic cases it is necessary to take possible side effects of ACTH and corticosteroid treatment into account. At the climax of hormone treatment computed tomography revealed imposing changes in the form of generalized atrophy in 10 of the 14 children examined. These receded completely upon termination of hormone treatment.     

The sociodynamogram--a contribution to the objectivization of group process

Two simple sociometric techniques for practical use are described which are derived from the data given in the sociogram. Compared with the conventional sociogram, the group rank score we use everyday therapy has the advantage that it can be published. It permits members of the group to better identify the social situations which cause specific psychic impulses. The sociogram is reserved for the therapist. In our opinion the sociodynamogram has certain advantages over both methods because it provides an insight into spheres which are inaccessible in the sociogram and group rank score.     

Quantitative amino acid determination in the serum and cerebrospinal fluid in endogenous depressions

The levels of 20 amino acids were measured in the plasma and cerbrospinal fluid of 41 patients with endogenic depressions. The plasma levels of 12 amino acids were found to be significantly lower in the patients than in the control group, but cerebrospinal fluid levels were significantly lower only in the case of taurine, glutamine, phenylalanine and aginine. Comparison of the same amino acid levels in treated and non-treated patients showed that serine and alpha-aminobutyric acid serum concentrations were higher in the nontreated patients. The tyrosine and phenylalanine levels in the cerebrospinal fluid of the patients who had received medicamentous treatment were higher than in the other group.