Minicomputers in the Signal-Averaging Laboratory

Discusses the structure of event-related potential (ERP) experiments and some problems encountered in installing a computer-based signal averaging laboratory, based on the PDP-11/40. Appropriate hardware and software features are outlined

The Independence of the P300 and the CNV Reviewed: A Reply to Wastell

The relationship of P300 to the CNV was investigated by Donchin, Tueting, Ritter, Kutas and Heffley (1975) who concluded that these two components of the event-related brain potential (ERP) are independent. Wastell (1979) questioned the validity of the data analysis procedures and of the experimental design used by Donchin et al. In this report we examine Wastell\u27s criticisms and find them to be unfounded. In support of this conclusion we note the differences between principal component analysis and factor analysis. We clarify points about Donchin et al.\u27s experimental design, and we review evidence for the independence of the P300 and the CNV that has accumulated since 1975

PEARL II: Portable Laboratory Computer System for Psychophysiological Assessment using Event Related Brain Potentials

The PEARL II (Portable Environmental Assessment and Research Laboratory) computer integrates hardware and software to serve as an online, real-time experimental control and data acquisition system. Although the system can be used in many areas of research, PEARL II development has emphasized investigation of physiological responses from human Ss performing complex experimental tasks. The special feature of the PEARL test battery is its suitability for the measurements of event-related brain potentials in these tasks, although other physiological indices such as heart rate may be monitored. The PEARL system also includes a versatile library of laboratory control subroutines that can be used to develop new applications

On the Independence of the CNV and the P300 Components of the Human Averaged Evoked Potential

We report an experiment designed to assess the interactions between the CNV and the P300 components of human event-related potential. Eight subjects were each presented with series of experimental trials on all of which either a 1200 c/sec or an 800 c/sec tone was presented. There were three independent variables: (a) The presence or absence of a warning flash 1000 msec prior to the tone. (b) The task assigned to the subject—that is subjects were either to make a discriminative response to the tone or, on half the series, to predict prior to the trial which of the two tones would be presented. (c) The predictability of the tone frequency. On half the series high and low tones alternated from trial to trial. On the other series, tones were chosen randomly on each trial. The data show that the amplitude of the P300 component is not affected by the presence or absence of a warning stimulus. Furthermore, the distributions of P300 and the CNV over the scalp are quite different. These conclusions are supported by a principal component and a discriminant analysis of the data

Is Handwriting Posture Associated with Differences in Motor Control?: An Analysis of Asymmetries in the Readiness Potential

Levy and Reid\u27s [1] hypothesis that person who write using the inverted posture have ipsilateral control of distal limb movements, particularly those involved in handwriting, was tested in three experiments in which asymmetries in the readiness potential (RP) were measured. In the first experiment, each subject executed a self-paced repetitive squeeze. Contralaterally larger RPs were recorded from all subjects, irrespective of handwriting posture. In two other experiments, subjects performed the self-paced squeeze in one condition and wrote a single word repetitively in an analogous condition. Larger RPs were recorded over the contralateral cerebral hemisphere in most inverted-writing subjects in both conditions. Ipsilaterally larger RPs were recorded, however, from some left-handers while writing. These findings suggest that, although control of certain movements may originate from the ipsilateral motor cortex in a small proportion of left-handers, handwriting posture does not index this difference

The Event-Related Brain Potential as an Index of Attention Allocation in Complex Displays

The advantages of employing the event-related brain potential (ERP) in the assessment of allocation of attention in dynamic environments are discussed. Three experiments are presented in which the P300 component of the ERP is demonstrated to be a useful index of subjects\u27 locus of attention. The first two experiments were concerned with the allocation of atttention during discrete and continuous visual monitoring tasks. The results indicated that a P300 was elicited only by stimuli to which the subject had to attend in order to perform successfully the task. The third experiment was conducted to assess the sensitivity of P300 to the manner in which attention is allocated to different aspects of a display during the performance of a 3-dimensional target acquistion task. The amplitude of the P300 was found to reflect differences between two levels of workload, as well as the task relevance of the stimuli. The results of the experiments are discussed in terms of their utility in the evaluation of the design of man-machine systems as well as in the study of the allocation of attention in operational environments