Automated psychophysiology laboratory

A laboratory has recently been established in University Hospital based on a PDP-11 /40 processor running a real-time Executive (RSX-ll/D) which has storage and data acquisition peripherals to handle on-line processing of psychophysiological data from patients receiving biofeedback. A data acquisition program has been written which permits the sampling of eight simultaneous channels of data coming from a Hewlett-Packard 7700 electrophysiological recorder system. Input from the patient includes switch closures and variable resistors, thermistors, GSR, electrocardiogram, respiration rate, and a variety of others. Feedback to the patient includes a variety of types of lights, a cathode ray tube storage screen, a character-oriented CRT monitor, and a variety of audio signals. Developers are presently involved in writing the biofeedback section of the programs and an on-line decision-making dependent upon patient response. Simultaneously with laboratory operation, a number of other users are served. These include the Admitting Department and Respiratory Function Laboratory. A rat laboratory will be served also by this facility in the near future via a front-end microprocessor.     

Dual on-line computers for research in cognitive psychophysiology

A laboratory configuration is described in which two compatible minicomputers are used to collect psychophyiological data and to generate a complex visual display. The two computers are part of independent systems used by different research groups for psychophysiological experimentation and cognitive reaction time research. With minimal additional requirements, however, it is possible to link the function of the two machines and greatly expand experimental possibilities. Two real-time applications are discussed, as well as other advantages of having compatible processors, such as simplified program development.     

Error-related psychophysiology and negative affect

The error-related negativity (ERN/Ne) and error positivity (Pe) have been associated with error detection and response monitoring. More recently, heart rate (HR) and skin conductance (SC) have also been shown to be sensitive to the internal detection of errors. An enhanced ERN has consistently been observed in anxious subjects and there is some suggestion that the ERN is related to general negative affective experience (NA). The ERN has been source localized to the anterior cingulate cortex-a structure implicated in the regulation of affective, response selection, and autonomic resources. Thus, the findings that autonomic measures and affective distress are related to response monitoring are consistent with anterior cingulate cortex function. In the present experiment, we sought to evaluate more comprehensively the relationship between self-reported negative affect and error-related physiology in a between-groups design. Results indicate that high NA was associated with significantly greater ERN and error-related SCR, and smaller Pe. These results are discussed in terms of anterior cingulate cortex function, psychopathology, and response monitoring.     

A Macintosh II psychophysiology system

An integrated data-acquisition and -analysis system for doing psychophysiology on Macintosh II computers is described. Plug-in cards allow the system to meet the technical demands of psychophysiological research—including 24-channel, 12-bit resolution and sampling of scalp potentials taken at a sampling rate of 400 Hz. Use of a compiled graphical data-flow language to program this equipment brings the implementation of sophisticated methods within the reach of many experimenters. Some applications of this system to multichannel evoked potential research are described, including P50 conditioned-disinhibition and augmenting/reducing experiments. Extensions of the system into such areas as topographical brain mapping are also noted.     

Instrumentation for an electrocutaneous communication device

The device described is a prototype that uses spatiotemporal resolution for electrocutaneous stimulation. Signals initiated through a keyboard activate a matrix of four electrodes that may be applied to the fingers, forearm, abdomen, back, or other parts of the integument. The instrumentation described includes a pulse generator, the active time and delay time controls, the control of the total length of a pulse train, and the constant-current generators whose output is fed into the electrodes. This device may be used as an interface with an alphanumeric device (e.g., a calculator or computer) and as a basic instrument in research investigating the spatial and temporal resolving capacities of the skin senses.     

Personality research and psychophysiology: General considerations

A general discussion of psychophysiological methods in relationship to personality research is presented for the investigator without an extensive knowledge of psychophysiology. The paper is organized in four sections: (a) advantages inherent in the use of psychophysiological measures (e.g., continuous measurement, sensitivity to sublimal responses); (b) psychophysiological constructs that are particularly well suited to personality research (e.g., different kinds of physiological arousal, normal/pathological distinctions, perceptual states); (c) how to choose a set of psychophysiological measures and special considerations involved with their use (e.g., obstrusiveness, context and timing of measurement, costs, and capabilities); and (d) whether or not to “psychophysiologize” personality research. Within each section, illustrative applications of psychophysiology to personality research are described.     

Trends in the psychophysiology of individual differences

Pavlov’s typology of higher nervous activity was the first systematic approach to the psychophysiology of individual differences. Pavlov’s theory has been further developed by Teplov, Nebylitsyn and their pupils in the Institute of Psychology in Moscow. In particular, Nebylitsyn has delineated a new property of the nervous system and has shown that it is different from strength of nervous system. In the Western research context we can compare the relationship between these two parameters to that between arousal and conditioning level. Eysenck’s theory of the physiological bases of extraversion/introversion is discussed in relation to Nebylitsyn ’s theses and Gray’s conception of arousability. Finally, it is suggested that future work in the psychophysiology of individual differences should stress the study of the ontogenetic development of the physiological variables.     

A short critique of the psychophysiology of individual differences

This paper was prepared by the Authors as a Discussion paper, designed to identify the main themes and methodological problems raised by other contributors to the Symposium. The key assumptions underlying the psychophysiological approach to individual differences are specified. Ideally, such assumptions should determine the characteristics of the research. Several sources of error in research strategy are discussed, including: psychometrics, physiological measurement, task conditions, statistical modelling, and the laboratory environment. The paper concludes with an appeal for more process-related investigations, focused on the interactive and integrative properties of the nervous system. Biologically- determined characteristics are unlikely to be revealed in any magnitude, under simple conditions of testing.     

A wireless portable physiology recorder for psychophysiology research based on a personal digital assistant

Psychophysiology research is increasingly relying on portable instruments that can assess physiological responses during real-life situations at locations outside of research labs, such as at school, home, work, and outdoors. In this article, I report on the feasibility of a personal digital assistant-based portable physiology recording system with online signal graphing and wireless digital telemetry for psychophysiology research. I demonstrate that such a system can measure electrocardiogram and electrodermal activity and send this data over a wireless communication link to a PC. It enables users to inspect the integrity of the acquired signals on the portable device and on a PC base station, and it allows users to place time markers for online data analysis.     

The psychophysiology of posttraumatic stress disorder: a meta-analysis

This meta-analysis of 58 resting baseline studies, 25 startle studies, 17 standardized trauma cue studies, and 22 idiographic trauma cue studies compared adults with and without posttraumatic stress disorder (PTSD) on psychophysiological variables: facial electromyography (EMG), heart rate (HR), skin conductance (SC), and blood pressure. Significant weighted mean effects of PTSD were observed for HR (r = .18) and SC (r = .08) in resting baseline studies; eyeblink EMG (r = .13), HR (r = .23), and SC habituation slope (r = .21) in startle studies; HR (r = .27) in standardized trauma cue studies; and frontalis EMG (r = .21), corrugator EMG (r = .34), HR (r = .22), and SC (r = .19) in idiographic trauma cue studies. The most robust correlates of PTSD were SC habituation slope, facial EMG during idiographic trauma cues, and HR during all study types. Overall, the results support the view that PTSD is associated with elevated psychophysiology. However, the generalizability of these findings is limited by characteristics of the published literature, including its disproportionate focus on male veterans and neglect of potential PTSD subtypes.