Anthony Gale

Evidence of more rapid stimulus evaluation following cigarette smoking

Experienced male smokers (greater than 15 cigarettes daily) performed a rapid visual information processing (RVIP) task requiring the detection of sequences of three consecutive odd or even digits in a series presented singly on a TV screen, at a rate of 100 digits/minute. Approximately 80 targets occurred every 10 minutes. All subjects took part in three test sessions: (a) Baseline of 10 minutes on the RVIP task, (2) treatment phase of 10 minutes smoking one cigarette (0.9mg or 1.5mg standard machine delivery of nicotine) or not smoking (NS), (3) posttreatment phase of 20 minutes on the task. Before these morning sessions subjects abstained from smoking for at least 12 hours. Smoking increased the number of correct detections and decreased response time compared with pre-smoking baseline and NS sessions. Analysis of vertex Event-Related Potentials to correct detections revealed a significant reduction in P300 latency following smoking compared to NS sessions. It is suggested that smoking has speeded up stimulus evaluation processes in these individuals. These data are consistent with the common self-report by smokers that smoking aids concentration.

Electroencephalographic studies of extraversion-introversion: a case study in the psychophysiology of individual differences☆

Abstract Electroencephalogram (EEG) studies of Extraversion-Introversion are reviewed and all known studies are tabulated. H.J. Eysenck claims that this personality factor is to be found in most major studies of personality and that its ubiquity demonstrates its biological foundations. The review is set within the framework of Eysencks (1967) theory of the neurophysiological basis of Extraversion-Introversion and Neuroticism-Stability. There are more than 30 studies relating the EEG to Extraversion. All may be criticized on a variety of grounds: 1. (i) Comprehension of the theory is poor and predictions are often arbitrary. 2. (ii) Personality is measured in an unsystematic fashion. 3. (iii) The EEG is measured in several different ways and these are not necessarily related. 4. (iv) Sampling and scoring often lack a sound basis. 5. (v) Procedures employed owe little to the theory and can therefore yield surprising findings. 6. (vi) Statistical procedures are typically weak. 7. (vii) The data are misinterpreted. 8. (viii) Few authors develop their work beyond the initial stages; therefore, research is repetitive and fails to evolve. Each study is scored on a 5-point scale for quality. While this field of study illustrates many of the faults to be found in the psychophysiological study of personality, Eysencks theory may be extended to account for even discrepant findings. It is argued that the stimulus seeking of extraverts and the stimulus avoidance of introverts, interacts with task conditions in a systematic fashion. Future research should sample the behavioural domain more thoroughly and relate physiological trends to performance data.

Can judges agree on the personality of horses

Do stable personnel agree on the personality characteristics of horses in their care? Working independently and under experimenter supervision, nine stable personnel rated the personality characteristics of each of 10 individual horses using a questionnaire adapted from the NEO-PI-FFI of Costa and McCrae [Costa Jr., P. T. & McCrae, R. R. (1992) Revised NEO Personality Inventory (NEO-PI-R) and NEO Five Factor Inventory (NEO-FFI) professional manual. Odessa FL: Psychological Assessment Resources]. Raters achieved high inter-correlations in the ranking of the horses for all the Big Five dimensions, with the strongest agreement being achieved for Neuroticism and Extraversion. While previous research has demonstrated individual differences reminiscent of human personality characteristics, relatively few studies have explicitly used a human personality inventory for application to another species. It is also relatively rare for raters to be amateurs, rather than sophisticated research personnel and even human studies have rarely used more than two raters of the same individual. Our findings provide support for claims that personality is dependent upon biological factors with a long evolutionary history, such as brain anatomy and chemistry. The reliability of assessments by the participants and their ability to utilise personality descriptors with another species also raises interesting questions regarding the legitimacy of everyday use of psychological terms to describe animal behaviour.

Extraversion–introversion, neuroticism–stability, and EEG indicators of positive and negative empathic mood

Thirty female participants were instructed to empathise with 24 male and female photographs displaying positive and negative emotion and to rate each face following its presentation. EEG was recorded from homologous frontal, temporal and occipital sites. Positive and negative facial expressions were differentiated in frontal leads, with greater activation of the left hemisphere during negative mood experience. In higher order interactions, differentiation of positive and negative affect was observed within the right hemisphere in both frontal and temporal leads. However, direction of effect depended on participant personality and on the gender of the face viewed; for temporal EEG, male faces elicited larger inter-hemispheral differences in activation than female faces. Extraversion was associated with widespread enhanced alpha amplitude and neuroticism with greater inter-hemispheral differences in voltage. When rating the photographs, participants with high neuroticism scores rated female faces as more sad than male faces; also the higher the neuroticism score, the higher the standard deviation of overall ratings. The personality data support Eysenck’s claim that extraverts have lower levels of cortical arousal than introverts (Eysenck, 1967). Personality differences in reaction to emotional stimuli reveal that in the field of emotion research, neglect of individual differences is likely to inflate the error term.

Cortical arousal and social intimacy in the human female under different conditions of eye contact.

The EEG was monitored from pairs of female subjects while they engaged in varied eye contact under experimenter instruction (direct gaze, smile, averted gaze). The nine conditions of gaze were related monotonically to EEG abundance (9.5-20.0 Hz). It is suggested that the gradient of arousal or activation so obtained is evidence of a physiological substrate of social intimacy.

The factor structure of horse personality

Abstract Two hundred and ten owners or carers completed a specially modified version of the NEO-Personality Inventory-Five Factor Inventory (NEO-PI-FFI, a well established personality questionnaire for humans) for their chosen horse. Three and five-factor Principal Components Analysis (PCA) solutions are reported and compared with published studies on the factor structure of human personality. Participants were asked how confident they were in using each of the different Big Five scales in describing their horse: neuroticism and extraversion were rated with most confidence and openness to experience with least confidence. Taking both our own factors above and the NEO scales, some comparisons between the working roles of the horse were significant; for example, horses used for teaching were less extraverted than show jumpers. Sophistication of working role also related to personality; for example, international horses were less extraverted than novices. We conclude that the study provides some evidence for cross-species similarity in the structure of personality.

Psychophysiology and individual differences: Theory, research procedures, and the interpretation of data

Abstract A number of critics have suggested that the psychophysiology of individual differences suffers from a poor quality of research endeavour. We examine the assumptions underlying biological approaches to individual differences and show how these assumptions, if properly interpreted, can lead to valuable research. Much of the existing research is confounded by a variety of errors including poor development of theory, inadequate psychometrics, weak physiological measurement, limited experimentation and an over-interpretation of empirical findings. We suggest that the research can alter direction by investing in process oriented studies backed by multivariate parametric and programmatic research. Illustrative examples are offered of good and bad practice. However, we are forced to conclude that at this stage of development, there are few bodies of coherent data which may be described with any confidence. Because both psychophysiology and individual differences sample physiological, behavioural and expe...

A systematic investigation of same and cross modality priming using written and spoken responses.

Effects of presentation modality and response format were investigated using visual and auditory versions of the word stem completion task. Study presentation conditions (visual, auditory, non-studied) were manipulated within participants, while test conditions (visual/written, visual/spoken, auditory/written, auditory/spoken, recall-only) were manipulated between participants. Results showed evidence for same modality and cross modality priming on all four word stem completion tasks. Words from the visual study list led to comparable levels of priming across all test conditions. In contrast, words from the auditory study list led to relatively low levels of priming in the visual/written test condition and high levels of priming in the auditory/spoken test condition. Response format was found to influence priming performance following auditory study in particular. The findings confirm and extend previous research and suggest that, for implicit memory studies that require auditory presentation, it may be especially beneficial to use spoken rather than written responses.

A short critique of the psychophysiology of individual differences

Abstract 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.

Electrophysiological measures of cognition in biological psychiatry: some cautionary notes

Research into the electrophysiological correlates of mental illness is currently expanding, largely because of the availability of relatively inexpensive and powerful computers. However, improvements in technology do not always lead to enhanced methodological procedures; thus, there are concerns over the proper interpretation of the results of these investigations. Our argument is that electroencephalographic (EEG) research into psychopathology of psychiatric diseases should adopt a cognitivist model of mental dysfunction rather than a neurologist model of brain disease. Cognitive science has significant potential as an integrative framework for theorizing and researching psychiatric disorders and their treatment. Models of human cognitive functioning have rather special and unique features; these will make their impact upon the nature of both the analysis and interpretation of EEG data. The adoption of a sound model of brain function has implications for the methods to be used at different successive stages of the research process. We address a number of methodological requirements pertaining to: the recording and analysis of EEG signals, the laboratory context, the nature of the tasks, and the attribution of obtained effects. However, there are grounds for great caution. Even if the mapping of electrical changes in brain activity leads to a good approximation of the temporal and spatial dynamics of higher brain function, exploitation of such information presupposes a deeper understanding of both human cognition and the physiological basis of the EEG than is often displayed in the literature. To demonstrate this fundamental point, we draw a number of comparisons between traditional neurological approaches to brain assessment and contemporary cognitive psychophysiology.