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Wilson (1967, 1974) indicated that when successive measurements are obtained in psychophysiologicai investigations, analysis of the data with repeated measures F tests will very likely result in positively biased tests of the repeated factor null hypothesis. The present paper demonstrates how the Greenhouse and Geisser (1959) three-step approach to significance testing, a procedure intended to control the probability of a false positive, can be applied to experimental designs containing any number of repeated measures variables. In addition, the paper contains a short computer program for obtaining a numerical solution. [ABSTRACT FROM AUTHOR]

Heart rate is a dependent variable used widely in psychological and psychophysiological research. Several statistical problems arise in the analysis of heart rate data, many of them specific to infancy research. The present paper discusses the problems of a statistically appropriate cardiac measure, the Law of Initial Values, the problem of differential variability in heart rate scores, and the use of multivariate statistical methods in analyzing heart rate data. Special attention is given to those problems and solutions which have potential application to the analysis of infant heart rate data. A flowchart is presented which may guide the researcher in the appropriate use of the several statistical techniques reviewed in this paper. [ABSTRACT FROM AUTHOR]

Humans display a trait-like response to sleep loss. However, it is not known whether this trait-like response can be captured by a mathematical model from only one sleep-loss condition to facilitate neurobehavioural performance prediction of the same individual during a different sleep-loss condition. In this paper, we investigated the extent to which the recently developed unified mathematical model of performance ( UMP) captured such trait-like features for different sleep-loss conditions. We used the UMP to develop two sets of individual-specific models for 15 healthy adults who underwent two different sleep-loss challenges (order counterbalanced; separated by 2-4 weeks): (i) 64 h of total sleep deprivation ( TSD) and (ii) chronic sleep restriction ( CSR) of 7 days of 3 h nightly time in bed. We then quantified the extent to which models developed using psychomotor vigilance task data under TSD predicted performance data under CSR, and vice versa. The results showed that the models customized to an individual under one sleep-loss condition accurately predicted performance of the same individual under the other condition, yielding, on average, up to 50% improvement over non-individualized, group-average model predictions. This finding supports the notion that the UMP captures an individual's trait-like response to different sleep-loss conditions. [ABSTRACT FROM AUTHOR]

In the analysis of psychological and psychophysiological data, the relationship between two variables is often assumed to be a straight line. This may be due to the prevalence of the general linear model in data analysis in these fields, which makes this assumption implicitly. However, there are many problems for which this assumption does not hold. In this paper, we show that, in the analysis of event-related potential ( ERP) data, the assumption of linearity comes at a cost and may significantly affect the inferences drawn from the data. We demonstrate why the assumption of linearity should be relaxed and how to model nonlinear relationships between ERP amplitudes and predictor variables within the familiar framework of generalized linear models, using regression splines and mixed-effects modeling. [ABSTRACT FROM AUTHOR]

In this editorial, I discuss the advantages of interpreting brain data in the context of other bodily systems. I also discuss current research challenges that may greatly benefit from a psychophysiological approach in which multiple methods-both peripheral and central-are used to improve our understanding of brain function, its underlying physiology, and its relationship to psychological constructs. In closing, I summarize the major changes and policy highlights regarding papers published in Psychophysiology. [ABSTRACT FROM AUTHOR]

Objectives This article reviews evidence regarding effects of psychotherapy on overall cancer survival time. Special emphasis is given to research on adverse effects of depression on cancer survival, breast cancer, and mediating psychophysiological pathways linking psychosocial support to longer survival. Design It reviews all published clinical trials addressing effects of psychotherapy on cancer survival, emphasizing depression, breast cancer, and psychophysiological evidence linking stress, depression, and support to cancer survival. Methods Systematic literature review and synthesis. Results Eight of 15 published trials indicate that psychotherapy enhances cancer survival time. No studies show an adverse effect of psychotherapy on cancer survival. Potential psychophysiological mechanisms linking stress to shorter survival include dysregulation of diurnal cortisol, increased pro-inflammatory cytokines, reduced natural killer cell activity, shorter telomeres and lower telomerase activity, glucocorticoid-mediated suppression of p53 and Br CA1 gene expression, and sympathetic nervous system activation of vascular endothelial growth factor. Conclusions Stress and support affect the course of cancer progression. Statement of contribution What is known? Stress and support have been thought to be related to cancer risk and progression, but evidence has been mixed., Depression is a natural co-morbid condition with cancer., It has not been clear how stress and support could physiologically affect the rate of cancer progression., Immune function was not thought to have much relevance to cancer progression., Few other physiological mechanisms linking stress to cancer progression were known., What does this paper add? There is evidence from 15 RCTs indicating that effective psychosocial support improves quantity as well as quality of life with cancer., There is evidence that chronic depression predicts poorer prognosis with cancer., Dysregulated circadian cortisol patterns predict more rapid cancer progression., Inflammatory processes affect cancer growth and progression., Sympathetic nervous system activity, telomere length, telomerase activity, and oncogene expression are affected by stress and can affect cancer growth. [ABSTRACT FROM AUTHOR]

Researchers have made significant progress in the investigation of how physiological measures can inform the study of adolescent peer functioning, including peer processes involving antisocial behavior, victimization, and peer social status. This paper highlights how the inclusion of physiological processes in research studies can address several critical questions regarding adolescent peer relations, with a particular emphasis on (1) developmental processes; (2) subtypes of adolescent peer relations; (3) gender differences; (4) biosocial interactions; and (5) the role of within-person variability. In addition, several important directions for future research, including longitudinal studies assessing bidirectional effects and the incorporation of additional indices of peer functioning and additional psychophysiological systems, are discussed. [ABSTRACT FROM AUTHOR]

This paper reviews the earliest documented manual and postural asymmetries, in the fetus and during the first months of life. I attempt to analyze which genetic and/or environmental factors are likely to trigger each one, as well as its consequences for the other ones. I conclude that right-handedness is prevalent in all cultures because an intrinsic tendency toward right-handedness has many occasions to be reinforced, from the uterine to the perinatal environment and from the familial to the cultural environment. Finally, the combination of potential genetic factors-direct (motoric) or indirect (postural)-with varied biological and cultural environmental influences over various periods during development may explain the high variability of handedness in typical populations (as long as hand preference is not equated with the hand used for writing). [ABSTRACT FROM AUTHOR]

ABSTRACT The new paradigm that the brain is able change itself (neuroplasticity) is acknowledged and teased out in terms of the ramifications for mental illnesses. Parallel studies in pain (central sensitization) and mirror neurones are examined to conceptually clarify these ramifications in relation to mental health, and to expand our understanding of empathy and social inclusion beyond good ideas to being a part of our nature. The paper then focuses on making clear what the concepts, challenges, and opportunities for mental health nursing might be; even advancing possibilities for recovery through better understanding the third space or intersubjective. What ramifications this has for mental health nursing is reviewed in terms of a paradigm change and the necessity for conceptual clarity, as it relates to the uniqueness of the person right before our very eyes. The author contends that to embrace this new paradigm is not only necessary but ethically obligatory, as it opens up new possibilities for understanding ourselves and this changeable person. [ABSTRACT FROM AUTHOR]

Intergroup anxiety has become important in understanding the success or failure of intergroup contact. In this paper, we suggest that intergroup anxiety is made up from two constructs: self-anxiety (anxiety over thinking or doing something that is prejudiced) and other-anxiety (anxiety that the other might do something to you). Over four studies, we show how these two dimensions have different correlates and independently predict psychophysiological reactivity to an intergroup interaction. Other-anxiety was associated with negative intergroup attitudes and negative affect. In contrast, self-anxiety had no simple relationship with conventional measures of intergroup attitudes but was associated with a flattening of responses that were indicative of freezing (Study 3) and simultaneous approach and avoidance (Study 4). We suggest that whereas other-anxiety is associated with negative affect and avoidance, self-anxiety is associated with 'freezing' responses to intergroup interaction. Thus, the distinction between these two constructs has important repercussions. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Aims: This paper aims to provide an overview of the ethical issues that have been raised by The Longitudinal Youth at Risk Study, which is being led by the Institute of Mental Health in Singapore as part of a multi-centre and multinational study in translational and clinical research in psychosis. This project is designed to identify the biomarkers of the trajectory to psychosis. As well as providing insights into the psychopathology and psychophysiology of the disease, the study will prospectively identify those in the Singaporean population with an ultra-high risk of developing psychosis. The project will collect both observational and clinically relevant data from an at-risk group: adolescents and young adults. Methods: A normative analysis was used to consider the ethical issues that arise as a result of this study, its methods, sample population and clinical management policy. Results: The project was found to raise particular and sensitive ethical and legal issues relating to the conduct of research with vulnerable populations who may be entering the prodromal phase of psychosis. Issues raised included notions of consent, privacy, confidentiality, stigmatization, duty of care and therapeutic misconception. Conclusion: Whereas some of the issues raised by this study present with manageable solutions, others may be justifiable within the cultural context of Singapore and warrant further discussion. [ABSTRACT FROM AUTHOR]

This paper is an author response to two commentaries on 'Defining Synaesthesia' (Simner, 2012) by David M. Eagleman ('Synesthesia in its protean guises', 2012), and Roi Cohen Kadosh and Devin B. Terhune ('Redefining synaesthesia?', 2012). Together with these authors, I seek to more closely examine existing criteria on which definitions of synaesthesia have been based. In particular, I focus on the fact (a) that existing definitions paint synaesthesia as an overly homogenous condition, (b) synaesthesia may have multiple neurological causes, and (c) synaesthetes and non-synaesthetes may lie on a continuum. [ABSTRACT FROM AUTHOR]

In a thought-provoking paper, highlights and criticizes a number of assumptions concerning synaesthesia. She specifically takes issue with the following assumptions: (1) synaesthesia is strictly a sensory-perceptual phenomenon; (2) consistency of inducer-concurrent pairs is the gold standard for establishing the authenticity of an individual's synaesthesia; and (3) synaesthesia is not heterogeneous. In the wake of this critique, Simner advances a working definition of synaesthesia as a neurological hyper-association that aims to be more inclusive of its variants. We are very sympathetic to Simner's approach and believe that it raises important points that will advance our understanding of synaesthesia. Here we supplement, and sometimes challenge, some of these ideas. [ABSTRACT FROM AUTHOR]

This study tested the hypothesis that the degree of psycho-physiological development is related to performance level in world-class athletes. We compared physiological and psychological patterns of 33 Norwegian world-class athletes to patterns in 33 average performing athletes. The subjects were matched for gender, age, and type of sport. Electroencephalography activity was recorded to measure brain integration; skin conductance was recorded to measure habituation to a loud stimulus; and paper-and-pencil tests were given to assess self-development, moral development, and frequency of peak experiences. A factor analysis (varimax rotation) reduced the eight variables to three factors that together accounted for 65.3% of the total variance: (1) physiological integration - brain integration and habituation rates, (2) self- and moral development, and (3) peak experiences. A MANOVA conducted on the factor scores showed a significant main effect for the experimental group collapsing across the three factors ( P<0.0001). Individual ANOVAs showed significantly higher values for development ( P=0.021) and physiological integration ( P<0.0001) factor scores for the world-class athletes. The above measures can be seen as different expressions of an underlying dimension - human development. These data support the concept that higher psycho-physiological growth underlies higher performance. [ABSTRACT FROM AUTHOR]

Weber’s law is one of the basic laws in psychophysics, but the link between this psychophysical behavior and the neuronal response has not yet been established. In this paper, we carried out an analysis on the spike train statistics when Weber’s law holds, and found that the efferent spike train of a single neuron is less variable than a Poisson process. For population neurons, Weber’s law is satisfied only when the population size is small (< 10 neurons). However, if the population neurons share a weak correlation in their discharges and individual neuronal spike train is more regular than a Poisson process, Weber’s law is true without any restriction on the population size. Biased competition attractor network also demonstrates that the coefficient of variation of interspike interval in the winning pool should be less than one for the validity of Weber’s law. Our work links Weber’s law with neural firing property quantitatively, shedding light on the relation between psychophysical behavior and neuronal responses. [ABSTRACT FROM AUTHOR]

Vision research has made very substantial progress towards understanding how we see. It is one area of psychology where the three-way thrust of behavioural measurements (psychophysics), brain imaging, and computational studies have been combined quite routinely for some years. The purpose of this paper is to demonstrate a relatively unusual form of computational modelling that we characterise as involving image descriptions. Image descriptions are statements about structures in images and relationships between structures. Most modelling in vision is either conceived in fairly abstract terms, or is done at the level of images. Neither is entirely satisfactory, and image descriptions are a simple formulation of age-old ideas about a Vocabulary of image features that are detected and parameterized from actual digital images. For our example, we use the domain of the visual perception of printed text. This is an area that has been characterized by thorough, robust psychophysical experiments. The fundamental requirements of visual processing in this domain are: grouping of some parts if the image into words; at the same time segmenting words from each other. We show how these are readily understood in terms of our model of image descriptions, and show quantitatively that typographical practice, refined over centuries, is about optimum for the visual system at least as represented by our model. In addition, we show that the same notion of image descriptions could, in principle, support word recognition in certain circumstances. [ABSTRACT FROM AUTHOR]

Background: This paper examined children’s fearful, sad, and angry reactivity to interparental conflict as mediators of associations between their exposure to interparental aggression and physiological functioning. Methods: Participants included 200 toddlers and their mothers. Assessments of interparental aggression and children’s emotional reactivity were derived from maternal surveys and a semi-structured interview. Cortisol levels and cardiac indices of sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activity were used to assess toddler physiological functioning. Results: Results indicated that toddler exposure to interparental aggression was associated with greater cortisol levels and PNS activity and diminished SNS activity. Toddler angry emotional reactivity mediated associations between interparental aggression and cortisol and PNS functioning. Fearful emotional reactivity was a mediator of the link between interparental aggression and SNS functioning. Conclusions: The results are interpreted within conceptualizations of how exposure and reactivity to family risk organize individual differences in physiological functioning. [ABSTRACT FROM AUTHOR]

Abstract: This paper draws upon the psychological, psycho-physiological, and numerical cognition literature(s) to suggest that numerical difference perceptions may be influenced by the physical distance between two prices. In the context of four experiments, we find that a greater horizontal separation of prices leads to greater difference (and hence price-discount) perceptions. The greater price-discount perceptions are linked to a higher perceived value and increased purchase likelihood. The effect is not observed for prices separated by large versus small vertical distances. The processing mechanisms driving our results involve the automatic and non-conscious encoding of “magnitude representations” (i.e., judgments of relative size) related to both relevant (numerical difference) and non-relevant (physical distance) dimensions. [Copyright &y& Elsevier]

Whereas the contextual basis of psychophysical responding is well founded, the compound influence of sensory and perceptual frames of reference constitutes a challenging issue in comparative one- and multidimensional psychophysics (e.g., Sarris, 2004, 2006 ). We refer to previous investigations, which tested the assumption that the chicken's relational choice in the one-dimensional case is systematically altered by context conditions similar to the findings stemming from human participants. In this paper mainly the context-dependent stimulus coding was investigated for the important, but largely neglected, two-dimensional case in humans and chickens. Three strategies were predicted for the generalization of size discriminations, which had been learned in a different color context. In two experiments, which varied in the testing procedure, both species demonstrated profound contextual effects in psychophysics; they differed, however, in the way the information from either dimension was used: Chickens throughout used color as a cue to separate the respective size discriminations and generalizations. Whereas humans predominantly generalized according to size information only or according to absolute stimulus properties, the chickens showed some important species-specific differences. Common and heterogeneous findings of this line of comparative research in multidimensional psychophysics are presented and discussed in various ways. [ABSTRACT FROM AUTHOR]

This paper describes the development of a new 139-item behavioral questionnaire (PAL) assessing the frequency and enjoyability of pleasant activities occurring in the natural environment of patients with substance use disorders. The sample consisted of 265 patients with mainly substance use disorders and 272 healthy controls. Group comparisons indicated that patients reported lower frequency, enjoyability, and cross-product activity scores than controls. This study confirms previous findings that addiction is associated with a decreased level of engagement in pleasant activities. The PAL seems to be a standardized, feasible, and valid instrument to sample non-substance-related rewarding activities in patients' everyday lives. [ABSTRACT FROM AUTHOR]

Web site visibility has become important because of the rapid dissemination of the World Wide Web, and combinations of foreground and background colors are crucial in providing high visibility. In our previous studies, the visibilities of several web-safe color combinations were examined using a psychological method. In those studies, simple stimuli were used because of experimental restriction. In this paper, legibility of sentences on web sites was examined using a psychophysiological method, point-of-regard measurement, to obtain other practical data. Ten people with normal color sensations ranging from ages 21 to 29 were recruited. The number of characters per line in each page was arranged in the same number, and the four representative achromatic web-safe colors, that is, #000000, #666666, #999999, and #CCCCCC, were examined. The reading time per character and the gaze time per line were obtained from point-of-regard measurement, and the normalized with the reading time and the gaze time of the three colors were calculated and compared. It was found that the time of reading and gaze become long at the same ratio when the contrast decreases by point-of-regard measurement. Therefore, it was indicated that the legibility of color combinations could be estimated by point-of-regard measurement. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 35–42, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20612 [ABSTRACT FROM AUTHOR]

The effect of sleep loss on reaction time (RT) performance varies as a function of age, with RTs of older subjects typically showing less decrement (relative to rested baseline) than those of younger subjects. In the current paper, we examined the nature of this relationship in a 7-day sleep restriction study. The number of repeated measures made it possible to model both intra-individual trajectories over days and individual differences in these trajectories. Results revealed (a) consistent individual differences in RT patterns over time after controlling for experimental design effects; (b) less cumulative RT decline among older individuals regardless of the degree of sleep restriction; and (c) consistent individual variability in performance patterns even after accounting for the effects of age. [ABSTRACT FROM AUTHOR]

In this paper the author describes how, in his analytic work with difficult personality disorders, he uses a neo-Spinozan position or attitude of alpha-thinking and functioning to understand, clarify, and so to manage confused and confusing psychosomatic ‘body-mind’ and emotional relations, both internally and inter-personally. Two case examples are given, followed by reflections on technique and on the limits of mourning, transformation and irony. The author suggests that a private, ideational double-aspect, mind-body position may be helpful in working with these analysands. This analytic mode may create a radically different understanding by incorporating a relational system of containment, self-containment, observation and memory. In addition, the author gives his own version of the aetiology and dynamics of borderline states and relations, and weaves the two cases he reports on into reflections on his countertransferential responses, reactions, inter-actions and ‘reverie’ through the lens of a neo-Spinozan conceptual system. [ABSTRACT FROM AUTHOR]

Presents abstracts of papers to be presented at the Forty-Fifth Annual Meeting of the Society for Psychophysiological Research which will be held in Lisbon, Portugal from September 21-24, 2005. "The Effects of Negative Emotion on Reaction Time and ERP-P3," by Aki Akamine and Mitsuro Kida; "Perceptual Completion in Toxoplasmosis Chorioretinitis," by Denise P. Alvarenga, Marcia F. Couto and Valdir F. Pessoa; "A Unique and Effective Algorithm for Detecting Cardiac R-Waves From Noisy Data Implemented in Matlab," by Kristopher L. Anderson and Keith W. Berg; "Event-Related Potentials of Novel Metaphor Comprehension," by Yossi Arzouan, Abraham Goldstein and Miriam Faust.

The concept of ‘hidden observer’ is one of the most controversial issues in hypnosis research. Green, Page, Handley and Rasekhy (this issue) approach it by using an ideomotor task which has not previously been used in association with the hidden observer. We regard their experiment as interesting; however, there are conceptual and methodological problems that hamper the impact of their study. In our commentary, we take the opportunity to point out some problems in their paper as well as to stress the importance to integrate concepts used in hypnosis research to mainstream cognitive neuroscience and consciousness research. [ABSTRACT FROM AUTHOR]

Abstract The purpose of the present paper was to clarify the link between the attention and arousal level that supports the basis of the cognitive dysfunction in schizophrenia, by investigating the relationship between the simple reaction time and the closed-eye eye movements in 30 patients with schizophrenia and 20 healthy controls. In terms of closed-eye eye movements during the simple reaction time test, healthy controls showed an increase of s-type (small and slow) eye movements after the end of the preparatory interval (PI) in both regular and irregular series, while the patients with schizophrenia, particularly those in whom the cross-over phenomenon was observed, showed no changes and maintained a hyperarousal level during the regular PI test. These results indicate that the patients with schizophrenia could not maintain appropriate attention during the burden tasks and their hyperarousal level persisted. It is therefore suggested that there is a close relationship between attentional deficit and hyperarousal among patients with schizophrenia. [ABSTRACT FROM AUTHOR]

Abstract Standard least squares analysis of variance methods suffer from poor power under arbitrarily small departures from normality and fail to control the probability of a Type I error when standard assumptions are violated. These problems are vastly reduced when using a robust measure of location; incorporating bootstrap methods can result in additional benefits. This paper illustrates the use of trimmed means with an approximate degrees of freedom heteroskedastic statistic for independent and correlated groups designs in order to achieve robustness to the biasing effects of nonnormality and variance heterogeneity. As well, we indicate when a boostrap methodology can be effectively employed to provide improved Type I error control. We also illustrate, with examples from the psychophysiological literature, the use of a new computer program to obtain numerical results for these solutions. [ABSTRACT FROM AUTHOR]

Psychophysiological measures hold great potential for informing clinical assessments. The challenge, before such measures can be widely used, is to develop test procedures and analysis strategies that allow for statistically reliable and valid decisions to be made for any particular examinee, despite large individual differences in psychophysiological responding. Focusing on the evaluation of memory in clinical, criminal, and experimental contexts, this paper reviews the rationale for and development of ERP-based memory assessment procedures, with a focus on methods that allow for statistically supported decisions to be made in the case of a single examinee. The application of one such procedure to the study of amnesia in Dissociative Identity Disorder is highlighted. To facilitate the development of other psychophysiological assessment tools, psychophysiological researchers are encouraged to report the sensitivity and specificity of their measures where possible. [ABSTRACT FROM AUTHOR]

Real data often do not approximate the normal distribution. Under nonnormal conditions, psychophysiologists who use parametric statistics may be testing with inadequate power and/or testing a measure of location (i.e., the mean) that does not represent the desired portion of the distribution for statistical comparison. The purpose of this paper is: first, to provide psychophysiologists with a method to investigate group distributional characteristics; second, to evaluate the distributional characteristics of heart period and respiratory sinus arrhythmia in human adults and newborns; third, to demonstrate the increased statistical power that can accompany the selection of an alternative statistical analysis for nonnormal data. Suggestions are provided on how to analyze nonnormal data. [ABSTRACT FROM AUTHOR]

Author and title index for the November 1998 issue of the journal Psychophysiology has been provided in this article. The article by psychologist Richard J. Davidson is titled "Anterior Electrophysiological Asymmetries, Emotions, and Depression: Conceptual and Methodological Conundrums. Psychologists Tomas Furmark et al. have contributed their article "Functional Neuroanatomical Correlates of Electrodermal Activity: A Positron Emission Tomographic Study" to this issue. The journal also includes the research paper "On the Status of Individual Response Specificity," by researchers Michael Marwitz and Gerhard Stemmler.

This paper proposes a theoretical framework and conceptual model for clinicians and investigators working with people who have a chronic physical illness. The framework is based upon nursing theory and classical propositions from psychology and physiology. The major premise of the model is that individuals with limited psychosocial attributes and a preponderance of unmet basic needs are more likely to perceive events as threatening and experience a maladaptive stress response, such as heightened symptoms and acute exacerbations of their illness. Conversely, those with strong attributes and a perception of need satisfaction are more likely to view events as challenging, thus avoiding symptomatic discomfort and enhancing personal growth. Implications for nursing practice and research are addressed. [ABSTRACT FROM AUTHOR]

Although sleep has been identified as an activity generally considered necessary for normal functioning, the nursing literature on the subject is relatively scanty. This paper is an attempt to review sleep and its relationship to nursing practice. A discussion of nursing interventions that are likely to ensure that adequate sleep is maintained is included. [ABSTRACT FROM AUTHOR]

We used quantitative methodology to examine the first three decades of the journal Psychophysiology from a standpoint of historic interest. A bibliometric analysis was conducted on 1,781 works published during this period, In total, 2,537 authors have published in the journal. The distribution of their productivity matches approximately what would be expected based on previous bibliometric investigations. A constant increase in the collaboration between researchers was evident (reaching an average of 2.56 authors per paper). The literature cited in these articles dates back between 4.53 and 8.12 years (M = 6.48 years). These bibliometric results show that this journal can he placed among the most experimentally oriented group within the field of psychology. [ABSTRACT FROM AUTHOR]

This paper presents a modification of the quantitative "three-process model of alertness regulation" to predict sleep latency in connection with irregular sleep/wake patterns. This model uses a circadian and a homeostatic component(sleep loss) that are summed to yield predicted alertness (on a scale of 1 to 20) across a specified time span. The timing of sleep from two studies of irregular sleep were used as input to the model. The predicted alertness at bedtime was regressed on empirical sleep latency from two studies. The maximum R[SUP2] (0.88) was reached for an exponential function, with the model acrophase set to 2048. The predictions were cross validated on another set of sleep latency data from an irregular sleep study and a maximum R[SUP2] of 0.65 was obtained. In both studies, the prediction from the model explained more variance that did self-rated alertness at bedtime. Cross validation was also carried out successfully with published data from two studies of shift work. It was concluded that sleep latency on irregular schedules may be predicted with accuracy from knowledge of the prior sleep/wake pattern. This may have practical consequences for rest/activity management. [ABSTRACT FROM AUTHOR]

The selection of heart period versus heart rate as a chronotropic metric has been considered from quantitative and statistical perspectives, which have not yielded a universal preference for either metric. In the present paper, we discuss biometric considerations that bear on the selection of the optimal chronotropic metric. Biometric evidence reveals that the transfer functions relating autonomic nerve traffic to chronotropic effects on the heart are more nearly linear for heart period than for heart rate. This confers considerable advantage on heart period as a chronotropic metric and can facilitate the study of psychophysiological relationships. We further show that heart period offers greater flexibility, because heart period data can be evaluated in cardiac time units (beats) or in real-time units (s), whereas heart rate data can only be analyzed in real time. These considerations suggest clear advantages to heart period as a chronotropic metric. [ABSTRACT FROM AUTHOR]

In this paper, we describe the first field tests of a home-based sleep monitoring system, the Nightcap, which uses eyelid and body movement sensors to discriminate wake, NREM, and REM sleep automatically. Ten normal young adults were studied in the sleep laboratory and at home to allow comparison of Nightcap-derived measures with those obtained by traditional polysomnography. The agreement between the two techniques was 87% based on I-min epochs-93% for NREM, 80% for REM, and 72% for wake. When the values for sleep latency, REM latency, wake time, NREM time, and REM time calculated from polysomnograph records were compared with the values calculated from Nightcap data, no significant differences were seen. In cases of extremely poor sleep, objective sleep efficiency estimates correlated well with subjective reports, suggesting that the Nightcap is sensitive to clinically relevant changes in the quality of sleep. This new device should prove useful to researchers wishing to study the psychophysiology and pathophysiology of sleep in more naturalistic and cost-effective paradigms than possible in the traditional sleep laboratory. [ABSTRACT FROM AUTHOR]

Contemporary findings reveal that autonomic control of dually innervated target organs cannot adequately be viewed as a continuum extending from parasympathetic to sympathetic dominance. Rather, a two-dimensional autonomic space, bounded by sympathetic and parasympathetic axes, is the minimal representation necessary to characterize the multiple modes of autonomic control. We have previously considered the theoretical implications of this view and have developed quantitative conceptual models of the formal properties of autonomic space and its translation into target organ effects. In the present paper, we further develop this perspective by an empirical instantiation of the quantitative autonomic space model for the control of cardiac chronotropy in the rat. We show that this model (a) provides a more comprehensive characterization of cardiac response than simple measures of end-organ state, (b) permits a parsing of the multiple transformations underlying psychophysiological responses, (c) illuminates and subsumes psychophysiological principles, such as the Law of Initial Values, (d) reveals an interpretive advantage of expressing cardiac chronotropy in heart period rather than heart rate, and (e) has fundamental implications for the direction and interpretation of a broad range of psychophysiological studies. [ABSTRACT FROM AUTHOR]

Developments in technologic and analytical procedures applied to the study of brain electrical activity have intensified interest in this modality as a means of examining brain function. The impact of these new developments on traditional methods of acquiring and analyzing electroencephalographic activity requires evaluation. Ultimately, the integration of the old with the new must result in an accepted standardized methodology to be used in these investigations. In this paper, basic procedures and recent developments involved in the recording and analysis of brain electrical activity are discussed and recommendations are made, with emphasis on psychophysiological applications of these procedures. [ABSTRACT FROM AUTHOR]

Guthrie and Buchwald (1991) proposed an adhoc procedure for assessing the statistical significance of waveform difference potentials that may arise in a variety of psychophysiology research contexts. In our paper, an alternative method is presented and demonstrated that has fewer underlying assumptions than does the Guthrie-Buchwald test and may, therefore, produce better results in some situations. In particular, the test proposed here (a) is distribution free, (1,) requires no assumption of an underlying correlation structure (e.g., first order autoregressive), (c) requires no estimate of the population autocorrelation coefficient, (d) is exact, (e) produces p values for any number of subjects and time points, and (1) is highly intuitive as well as theoretically justifiable. This procedure may be used to carry out multiple comparisons with exact specification of experiment wise error, however, this test is based on permutation principles and may require large amounts of computer time for its implementation. [ABSTRACT FROM AUTHOR]

In studies of event-related potentials (ERPs), short interstimulus intervals (ISIs) are often employed to investigate certain neural or psychological phenomena. At short, ISIs, however, the ERP responses to successive stimuli may overlap, thereby distorting the ERP averages. This paper describes a signal processing approach for analyzing the distortion of ERP averages due to such overlap. In general, the distortions modeled in terms of mathematical convolutions of the ERP waveform elicited by each type of adjacent stimulus with the corresponding distribution in time of those stimuli relative to the averaging epoch.

This paper describes efforts to reduce measurement error in the assessment of cardiovascular reactivity by standardizing task requirements and by aggregating data across tasks and testing sessions. Using these methods, reliable measures of reactivity (.80 or greater) were obtained on five different measures of cardiovascular function (heart rate, systolic blood pressure, diastolic blood pressure, stroke volume, pre-ejection period) in samples of college students and community volunteers. Methodological limitations may have hampered previous efforts in this area. Current findings are consistent with a dispositional model of cardiovascular reactivity, and they suggest productive future strategies for obtaining reliable assessments. [ABSTRACT FROM AUTHOR]

This paper presents a new model of alcohol drinking based on the observation that alcohol drinking often occurs following uncontrollable events. The psychological concepts of compensatory opponent process systems and learned helplessness give new insights into the biobehavioral response of organisms to environmental events and how these events can affect alcohol drinking. Finally by integrating these behavioral data with biochemical data which demonstrate that alcohol stimulates endorphin activity, it is proposed that organisms drink alcohol to reduce deficiencies in endorphin activity. [ABSTRACT FROM AUTHOR]

Information for "tone duration" (duration information) is an important parameter in representing the representing the temporal sequence. This paper reports on the results of a Basic auditory psychophysical experiment which was executed in order to estimate how information is represented in the process to be perceived and retained in the brain. The experiment focuses on the "gradual change of the retained duration information," which has been intentionally excluded in the past acoustic psychology, in order to focus on the perception process. The subjects is instructed to compare the durations of two successively presented tones. The experiment demonstrated that the interval of uncertainty, which is the index of forgetting the retained information, depends on the duration of the first tone as well as the interstimulus interval between the two tones. It is then suggested that there oils a "duration which is especially easily forgotten." A result is also obtained that is consistent with the conjecture that the presented duration information is handled almost as a continuous value a clue to the modeling of temporal sequence processing in the brain. [ABSTRACT FROM AUTHOR]

This paper reports the results of a series of reaction-time measurements in response to light flashes which stimulate preferentially either the rod or the cone receptor mechanisms in human vision. The average response latency between rod- and cone-generated signals as determined from these measurements was found to be 80 ms. Similar response latency values were also obtained from measurements involving only visual responses to real- and apparent-motion stimuli. The results show that the rod Ä cone response latency, measured by reaction-time or visual methods is relatively constant for target presentation locations between 4 and 90 of visual angle from the fovea along the horizontal meridian. [ABSTRACT FROM AUTHOR]

On the basis of the authors' own research it is suggested boredom may be viewed as having cognitive and affective components. The cognitive component is subjective monotony and the affective component is a high level of frustration. An attempt is made to integrate the evidence supporting this view of boredom with other evidence from the literature to present an integrated model of boredom in which the roles of personality, situational and task characteristics influencing boredom are outlined. Psychophysiological changes occurring during the performance of boring tasks are examined. It is argued that the nature and extent of changes in heart rate and heart-rate variability are not a consequence of boredom but of a task feature (mental load). It is concluded that no clear psychophysiological component of boredom can be detected at present. In this paper we attempt to integrate our own research findings (Perkins, 1981; Perkins & Hill, 1985) with those of other investigators to offer a tentative account of the nature and origins of boredom. [ABSTRACT FROM AUTHOR]

Senile dementia in the early is a prevalent condition which require ongoing medical treatment. This disease causes a deterioration of cognitive processes and, consequently, it is likely to impair the capacities required to give informed consent to needed medical care. However, a diagnosis of senile dementia does not necessarily indicate that the afflicted individual is incompetent. The means of assessing competency id dementia patients and their likely impairments according to five standards is described in this paper. Recommendations for obtaining consent from the competent dementia patient are made and mechanisms for providing special protection to the incompetent patient in the consent process are discussed. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to show that the familiar principal component analysis (PCA) of event-related potentials is identical to an easily formulated least squares method. This correspondence permits interpretation of several criticisms of PCA and clearer presentation of its strengths and shortcomings. Because data analysis based on PCA compares amplitudes of empirically derived components, it is necessary that the shape of the components be similar under the experimental conditions. We present and illustrate a statistical method for comparison of principal components across groups and between conditions within subjects. [ABSTRACT FROM AUTHOR]

This paper reviews the actual and potential benefits of a marriage between cognitive psychology and psychophysiology. Psychophysiological measures, particularly those of the event-related brain potential, can be used as markers for psychological events and physiological events. Thus, they can serve as "windows" on the mind and as "windows" on the brain. These ideas are illustrated in the context of a series of studies utilizing the lateralized readiness potential, a measure of electrical brain activity that is related to preparation for movement. This measure has been used to illuminate presetting processes that prepare the motor system for action, to demonstrate the presence of the transmission of partial information in the cognitive system, and to identify processes responsible for the inhibition of responses. The lateralized readiness potential appears to reflect activity in motor areas of cortex. Thus, this measure, along with other psychophysiological measures, can be used to understand how the functions of the mind are implemented in the brain. [ABSTRACT FROM AUTHOR]

This paper describes a procedure, Vector filter, based on a multiple regression model, which decomposes the event-related brain potential into components on the basis of scalp distribution. It is assumed that the voltage values observed at several electrode sites at any point in time are given by the linear combination of a set of components and background noise and that the scalp distribution of each component is invariant and known. Each component's scalp distribution is expressed by a set of weights, one for each electrode. The amplitude of the component, at any point in time, is then derived using a least squares criterion. Unlike other component decomposition procedures, Vector filter can be applied when the latency of a component varies as a function of trial, condition, or subject population. We review two problems in the use of the procedure: the selection of the set of components, and the derivation of the scalp distribution of each of the components. Two applications of the procedure are discussed: identification of the component structure of an event-related potential waveform, and filtering of a waveform for a particular component. [ABSTRACT FROM AUTHOR]

This paper presents the statistical technique known as the bootstrap to the general audience of psychophysiologists. The bootstrap, introduced by Efron (1979), allows data analysts to study the distribution of sample statistics that might otherwise be too complicated to consider. The technique, which requires simple calculations, involves drawing repeated samples (with replacement) from the empirical--or the actual--data distribution and then building a distribution for a statistic by calculating a value of the statistic for each sample. The bootstrap can be used to obtain confidence intervals, standard errors, and even higher moments for the statistic. It is similar to the well-known jackknife of Quenouille and Tukey. After discussing the history and theory of both the bootstrap and the jackknife, we illustrate the use of the bootstrap in the statistical analysis of correlation coefficients and the general linear model. [ABSTRACT FROM AUTHOR]