bluuebunny/crossref_metadata_2025 huggingface dataset:
Event‐Related Potential Indices of Selective Attention and Cortical Lateralization in Schizophrenia
Authors: Michie Patricia T. , Fox Allison M. , Ward Philip B. , Catts Stanley V. , McConaghy Neil
Published: February 2007

Auditory event‐related potentials (ERPs) from a multidimensional selective attention task were recorded from 10 unmedicated schizophrenic patients and 10 age‐ and sex‐matched healthy controls. Tone pip stimuli varying on the dimensions of pitch (high or low) and location (left or right ear) formed four ‘channels’ of stimuli: left low, left high, right low, and right high. The pitch difference was considerably more difficult to discriminate than the location difference. Subjects were instructed to pay attention to a designated channel and press a button whenever they detected a long‐duration, rare target tone that occurred amongst frequent short‐duration standard tones. There were a number of differences between unmedicated schizophrenics and controls in processing negativity elicited by standard tones. There was no evidence of hierarchical processing of stimulus dimensions in the early processing negativity component, and the late frontal component was virtually absent in schizophrenics. Furthermore, there was evidence that in schizophrenics the processing of the location dimension was delayed for standard tones having the same pitch as the target. The P300 component to attended target tones was substantially reduced in schizophrenics over parietal sites but there was no difference between the two groups over frontal sites. The results are interpreted in terms of multiple attentional deficits in schizophrenics that are indicative of a failure in the planning and execution of selective listening strategies. Such a failure may result from a dysfunction in the prefrontal regions of the brain.
Effects of Stimulus Repetition, Duration, and Rise Time on Startle Blink and Automatically Elicited P300
Authors: Putnam L. E. , Roth W. T.
Published: February 2007

Intense auditory stimuli of sudden onset evoke not only startle blinks but also an event‐related potential component resembling classic P300, even when subjects have no assigned task. To more closely examine the relationship of this P300 to startle, event‐related potentials and eyeblink were recorded from 16 young adults in three paradigms designed to produce wide variation in startle amplitude: an Habituation series of 30‐ms, 105dBA white noise bursts, a Duration paradigm which presented 105dB noise bursts for 3, 10, 30, or 90 ms, and a Rise Time paradigm which varied the rise/fall times (3, 15, 30, and 45 ms) of 110dBA, 1000‐Hz tone bursts. Subjects received two runs of each paradigm. Only on the final Duration and Rise Time runs were stimuli explicitly task relevant: on those runs subjects rated verbally, midway in each 8.4‐s interstimulus interval, the disturbingness of the prior sound.

Although even the briefest noise bursts evoked parietal P300 as well as startle blink, P300 did not behave like startle, P300 habituated more slowly than did blink amplitude, was more responsive to sustained noise than were blink, N110, and P190, and most importantly, did not show the sensitivity to stimulus rise time manifested by these measures. These findings suggest that the amplitude of automatically elicited P300 is not governed by the same mechanisms as startle amplitude, but behaves more like a defense response.
Voluntary Facial Action Generates Emotion‐Specific Autonomic Nervous System Activity
Authors: Levenson Robert W. , Ekman Paul , Friesen Wallace V.
Published: February 2007

Four experiments were conducted to determine whether voluntarily produced emotional facial configurations are associated with differentiated patterns of autonomic activity, and if so, how this might be mediated. Subjects received muscle‐by‐muscle instructions and coaching to produce facial configurations for anger, disgust, fear, happiness, sadness, and surprise while heart rate, skin conductance, finger temperature, and somatic activity were monitored. Results indicated that voluntary facial activity produced significant levels of subjective experience of the associated emotion, and that autonomic distinctions among emotions: (a) were found both between negative and positive emotions and among negative emotions, (b) were consistent between group and individual subjects' data, (c) were found in both male and female subjects, (d) were found in both specialized (actors, scientists) and nonspecialized populations, (e) were stronger when the voluntary facial configurations most closely resembled actual emotional expressions, and (f) were stronger when experience of the associated emotion was reported. The capacity of voluntary facial activity to generate emotion‐specific autonomic activity: (a) did not require subjects to see facial expressions (either in a mirror or on an experimenter's face), and (b) could not be explained by differences in the difficulty of making the expressions or by differences in concomitant somatic activity.
Assessing Attentional Control of Breathing by Reaction Time
Authors: Gallego Jorge , Perruchet Pierre , Camus Jean‐Françlois
Published: February 2007

The reaction time (RT) to an auditory stimulus was measured in 27 subjects during spontaneous breathing and during controlled breathing, which consisted of maintaining a set inspiratory duration. During spontaneous breathing, reaction times were unrelated to the time the stimulus was delivered during the breathing cycle. During controlled breathing, reaction times were longer than during spontaneous breathing. Peak reaction times were observed at the transition from inspiration to expiration. After the end of controlled breathing, reaction times gradually became shorter until they reached their initial level. The findings are discussed in terms of varying allocation of attentional resources to breathing. It is argued that probe RT methodology provides a suitable means for investigating attentional control of breathing.
Significance Testing of Difference Potentials
Authors: Guthrie Donald , Buchwald Jennifer S.
Published: February 2007

This note provides a statistical‐graphical method for the evaluation of the statistical significance of difference potentials from a group of subjects, and for the comparison of difference potentials between two groups. A table of the lengths of statistically significant intervals for various sampling interval lengths, numbers of subjects, and autocorrelation parameters is presented.
Behavioral Modulation Patterns Fit an Animal Model of Vagus‐Cardiac Pacemaker Interactions
Authors: Somsen Riek J.M. , Molenaar Peter C.M. , Van der Molen Maurits W. , Jennings J. Richard
Published: February 2007

The present study used a computer model of the dynamic interaction between the vagus nerve and the sinoatrial pacemaker membrane potential in the heart of the rabbit to reconstruct heart rate changes under vagal excitation conditions. We asked whether a hypothetical pattern of vagal acetylcholine (ACh) release, which was based on human heart rate results in a reaction time task, could be fit to this model. The reconstructed heart rate results showed changes that were highly consistent with experimental human heart rate changes. The model reliably reproduced effects of parameters such as intrinsic heart rate level, ACh stimulus intensity, and ACh stimulus duration. In addition, the effects of anticipatory vagal ACh release, stimulus‐induced ACh, and subsequent blocking of ACh, which usually interact in human cardiac cycle time functions, could be untangled in the reconstructed heart rate results. We concluded that the mathematical model may be useful for formulating hypotheses and constructing experimental task designs for studies of human heart rate.
Active‐Passive Coping and Skin Conductance and Heart Rate Changes
Authors: Sosnowski Tytus , Nurzynska Monika , Polec Miroslaw
Published: February 2007

Sixty subjects were administered 33 tasks, selected from the Raven Progressive Matrices, in conditions that differed by type of monetary reinforcement (reward, frustration, and control group). Subjects were tested in pairs. One subject, assigned as the active one, was asked to solve a problem while the other was only a passive observer. Heart rate level and the amplitude of evoked skin conductance responses were measured. Statistical analysis detected a higher heart rate level in active versus passive subjects at the beginning stage of the experiment, as well as a faster heart rate decrease in the former versus the latter group during subsequent blocks of four tasks. Changes in skin conductance response magnitude during the ensuing task phases exhibited a descending trend in passive subjects and an ascending trend in active subjects. The monetary reinforcement manipulation was not effective. The results support a concept put forward by Fowles (1988), who maintained that tonic heart rate and skin conductance response amplitude may serve as indices of the behavioral activation system and behavioral inhibition system, respectively, as postulated by Gray's model of arousal.
P300 in Patients with Unilateral Temporal Lobectomies: The Effects of Reduced Stimulus Quality
Authors: Scheffers Marten K. , Johnson Ray , Ruchkin Daniel S.
Published: February 2007

The effects of stimulus quality on the amplitude, peak latency, onset latency, and duration of the P300 component of the event‐related brain potential were studied in patients with either a left or a right anterior temporal lobectomy and in normal controls. Stimulus quality was reduced by adding “noise” letters to words which signalled either a left or a right hand button press. Consistent with an interpretation that stimulus quality affects the subject's degree of equivocation, P300 peak latency, reaction time, and errors were all inversely related to stimulus quality, whereas P300 amplitude was directly related to stimulus quality. There were no significant differences between normal controls and either patient group for any of the ERP parameters or reaction time. Right temporal lobectomy patients made, however, significantly more errors, particularly on the catch trials, which suggests that they did not process the stimuli as thoroughly and accurately as the subjects in the other two groups. The absence of significant group differences in either the lateral symmetry or overall P300 amplitude extends the evidence against the idea that anterior temporal lobe structures make any substantial contribution to the scalp P300 in a visual discrimination paradigm. Because of observed delays in the onset of P300 in the low‐quality stimulus condition, procedures were developed to quantify both P300 onset latency and P300 duration. Reduced stimulus quality significantly increased P300 onset latency whereas P300 duration remained unaffected, indicating that stimulus categorization must occur prior to, and not during, P300.
Exaggerated Sympathetic Nervous System Response to Extended Psychological Stress in Offspring of Hypertensives
Authors: Miller Sydney B. , Ditto Blaine
Published: February 2007

The cardiovascular responses of 24 healthy young adult males with a parental history of hypertension and 24 males without a parental history of hypertension to an extended active‐coping psychological stressor were compared under three drug conditions: placebo, the beta 1‐blocking agent metoprolol, and the alpha 1‐blocking agent prazosin. In the placebo condition, off spring of hypertensives exhibited significantly greater heart rate, blood volume pulse, and forearm blood flow responses to the task. They also exhibited a significantly greater initial decrease in forearm vascular resistance, which, in contrast to the offspring of normotensives, was no longer significantly different from baseline levels by the end of the session. No group differences in blood pressure response were observed. Metoprolol eliminated the differences in heart rate and forearm vascular resistance responses. Prazosin eliminated the difference in blood volume pulse response and elicited a sustained group difference in forearm vascular resistance. These results implicate the sympathetic nervous system in the exaggerated cardiovascular responsivity to psychological stress in individuals with a family history of essential hypertension. They also suggest that the pattern of increasing vascular resistance in response to this stressor observed in this and other studies in this laboratory reflects alpha‐adrenergic activity and not neurohumorally independent autoregulation.
Autonomic Correlates of Illness Imagery
Authors: Brownlee Susan , Leventhal Howard , Balaban Marie
Published: February 2007

Psychophysiological responses to imagery of self‐relevant illness threats were examined for high and low extreme groups of hypervigilants and health care utilizers. Heart rate, skin conductance, and respiration were the physiological measures recorded; self‐reports of perceived illness vulnerability, negative affect, image clarity, and image realness were the psychological measures obtained. Responses to neutral, exercise, and illness threat scenes were compared. Hypervigilants showed an increased heart rate response to imagery of illness scenes, whereas all other groups returned more quickly to baseline levels. The results are similar to those reported by Lang for snake phobics. They also lend some support to Horowitz's theory of intrusive imagery, in which self‐relevant, anxiety provoking events tend to continuously intrude upon one's thoughts, and this intrusive imagery was reflected cardiovascularly. There could be several possible underlying mechanisms for these findings.
Developmental Changes in the Duration of Attention to Unfamiliar Stimuli in the Rat
Authors: Hayne Harlene , Richardson Rick , Campbell Byron A.
Published: February 2007

The purpose of the present study was to examine developmental changes in the duration of attention to novel auditory stimuli in rats from infancy to adulthood. In all experiments, the cardiac component of the orienting reponse was used as the index of attention. In the first experiment 16‐, 23‐, 30‐, and 75‐day‐old rats were exposed to a novel auditory stimulus for 60 s. Animals of all four ages exhibited a marked decrease in heart rate in response to this stimulus. Although there were no significant effects of age on the magnitude of the cardiac response, there were dramatic developmental differences in the persistence of the response. The 16‐day‐old maintained a decrease in heart rate for the entire stimulus period, whereas heart rate returned to baseline in the 75‐day‐olds after only 40 s. The duration of the cardiac response of the 23‐and 30‐day‐olds was between these extremes.

In Experiments 2A and 2B the effect of stimulus complexity on duration of the cardiac response was examined. Increasing stimulus complexity prolonged the deceleratory response in the 30‐day‐olds (Experiment 2A), and decreasing stimulus complexity decreased the duration of the cardiac response in the 16‐day‐olds (Experiment 2B).

The results of these experiments were discussed in the context of Cohen's and Porges's two‐phase theories of attention. The findings demonstrate that the initial attention‐getting or reactive phase decreased substantially during development.
Blushing as a Function of Audience Size
Authors: Shearn Don , Bergman Erik , Hill Katherine , Abel Andy , Hinds Lael
Published: February 2007

Almost no experimental analysis of blushing has been done since Darwin's observations in 1872. Forty‐eight college women watched a videotape intended to elicit blushing, and a videotape not intended to elicit blushing, but elicit physiological responses. A subject was alone, or with one or four persons present. Blushing, which was measured directly with a photoplethysmograph probe on the cheek, was greater during the blushing than nonblushing stimulation. Blushing increased as audience size increased from one to four, but not from zero to one. Audience size and kind of stimulation interacted statistically. Similar results were obtained with ear coloration, cheek temperature, and skin conductance responses, although confidence levels were lower. Cheek coloration and temperature were significantly correlated during nonblushing stimulation, and the zero and one audience conditions, but not during the four audience condition, when blushing was greatest. These results may be placed within the context of emotional effects of audience size generally, including stuttering and speech disturbance, disruption of learning, and self‐reported tension.
Reflex Modification in Psychosis‐Prone Young Adults
Authors: Simons Robert F. , Giardina Barbara D.
Published: February 2007

The present study examined modification of the startle reflex in psychosis‐prone and normal control subjects, using a continuous pure tone prestimulus (S1) and an intense white noise startle stimulus (S2). Reflex modification conditions consisted of stimulus pairs with onset asynchronies of 60, 120, and 2000 ms with a startle‐alone condition as control. Startle was indexed by the eyeblink, which was measured by vertical electro‐oculography. Subjects were identified as psychosis‐prone by their high scores on the Perceptual Aberration or the Physical Anhedonia scales.

Group differences in blink magnitude inhibition were observed between perceptual aberration and control subjects during short stimulus onset asynchronies, with perceptual aberrators showing significantly less inhibition than controls at 120 ms. No differences were evident between anhedonic and control subjects at the two short onset asynchronies nor were there any significant between‐group differences when the interval between stimuli was long (2000 ms). These results suggest that subjects with perceptual aberrations may share with schizophrenics and other schizophrenia‐spectrum subjects an underdeveloped mechanism which in normal subjects is presumed to operate during preattentive processing and functions to protect sensory information from the interfering effects of subsequent stimuli.
Reliable Measures of Behaviorally‐Evoked Cardiovascular Reactivity from a PC‐Based Test Battery: Results from Student and Community Samples
Authors: Kamarck Thomas W. , Jennings J. Richard , Debski Thomas T. , Glickman‐Weiss Ellen , Johnson Paul S. , Eddy Michael J. , Manuck Stephen B.
Published: February 2007

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.
P300, Food Consumption, and Memory Performance
Authors: Geisler Mark W. , Polich John
Published: February 2007

The effects of food intake on the P300 (P3) component of the event‐related brain potential (ERP) were assessed in two studies. Experiment 1 compared 24 subjects who had not eaten within 6 hours of testing with 24 subjects who had consumed food within 3 hours of testing. P3 target stimulus amplitude was reduced significantly for the subjects who had not eaten relative to those who had eaten, whereas peak P3 latency was only moderately affected by the recency of food consumption over task conditions. In Experiment 2, P3 measurements, memory performance in a word recall task, and blood glucose levels were obtained from 24 subjects at three different times: 1) after a 14‐hour fast, 2) 5 min after consuming lunch, and 3) 30 min after consuming lunch. P3 target stimulus amplitude increased initially after food intake and decreased slightly at the third measurement time, while peak P3 latency became somewhat shorter immediately after food intake but then returned to baseline. Recall for recently presented items mimicked the P3 amplitude changes, whereas blood glucose levels increased monotonically across food conditions. The results from both studies suggest that: 1) target stimulus P3 amplitude is affected by the recency of food intake; 2) food‐related P3 amplitude changes appear related to memory function; and 3) subjects should eat within several hours before ERPs are acquired to ensure that P3 component measurements reflect values indicative of normal bodily functioning.
P300 and Individual Differences: Morning/Evening Activity Preference, Food, and Time‐of‐Day
Authors: Geisler Mark W. , Polich John
Published: February 2007

To determine how individual differences stemming from activity preference, previous food intake, and time‐of‐day affect the P300 or P3 event‐related brain potential (ERP), subject groups who varied orthogonally on these factors were compared using a simple auditory discrimination task to elicit the ERPs. Amplitude of the P3 component for morning‐preferring subjects who had eaten recently was relatively large for both the morning and evening measurement time groups. P3 amplitude for the morning‐preferring subjects who had not eaten recently was large for those measured in the morning and relatively small for those subjects measured in the evening. For evening‐preferring subjects who had eaten recently, P3 amplitude was again relatively large for both the morning and evening measurement time groups. Evening‐preferring subjects who had not eaten recently produced very small P3 components for those measured in the morning compared to the large components produced by those subjects measured in the evening. P3 latency tended to be longer for all subjects who had not eaten recently compared to those who had. The results suggest that the P3 component is sensitive to physiological and psychological changes originating from individual differences related to bodily state, which perhaps stems from individual differences in arousal level.
Data‐dependent filter characteristics of peak‐valley respiratory sinus arrhythmia estimation: A cautionary note
Authors: BYRNE EVAN A. , PORGES STEPHEN W.
Published: February 2007

Filter characteristics of the peak‐valley respiratory sinus arrhythmia estimation method are described. To identify filter characteristics of this method, models were generated that combined signals of different frequencies with trends of varying slopes. These models simulate the influence of trend and changing respiratory frequency on the accuracy of peak‐valley estimates. The transfer function of the peak‐valley method, unlike that of other time domain filters, is not solely dependent upon signal frequency. Two factors interact to determine the relative accuracy of the peak‐valley method: (a) slope of the signal component and (b) slope of the underlying trend. Combinations of these factors may result in significant distortion to the input signal. The direction of error is a function of the direction of the trend (i.e., overestimation with deceleration and underestimation with acceleration). In many situations when respiratory sinus arrhythmia amplitude is low in special populations (e.g., cardiovascular disorders, high‐risk infants, or human fetuses) or under conditions that greatly reduce respiratory sinus arrhythmia amplitude (e.g., exercise, drugs, pharmacological manipulations), use of the peak‐valley method may result in significant measurement error. The use of this method to evaluate respiratory sinus arrhythmia over short epochs (i.e., less than 2 min) or to quantify changes in respiratory sinus arrhythmia due to discrete stimulation (e.g., breath by breath) may result in inconsistent measurement error. Recommendations are made for detrending heart rate data prior to application of the peak‐valley method.
Backward masking and skin conductance responses after conditioning to nonfeared but fear‐relevant stimuli in fearful subjects
Authors: SOARES JOAQUIM J. F. , ÖHMAN ARNE
Published: February 2007

The present study examined two issues. Are skin conductance responses conditioned to fear‐relevant stimuli, as contrasted with responses conditioned to fear‐irrelevant stimuli, elicited after merely an automatic, nonconscious analysis of the stimulus content? Do fearful subjects show better conditioning to nonfeared but fear‐relevant stimuli (e.g., conditioning to spiders in snake‐fearing subjects) than do nonfearful subjects? Subjects afraid of snakes, but not of spiders, or vice versa (n= 32) and nonfearful subjects (n= 32) were shown either fear‐relevant stimuli (snakes or spiders and rats) or fear‐irrelevant stimuli (flowers and mushrooms) in a differential conditioning paradigm, where one of the stimuli was followed by an electric shock. During a subsequent extinction phase, the conditioned stimuli were presented under backward masking conditions, preventing their conscious recognition. Consistent with our hypothesis, during the masked extinction of the conditioned stimuli, differential skin conductance responses to conditioning and control stimuli remained only for subjects conditioned to fear‐relevant stimuli. Both fearful and nonfearful control subjects had significantly larger differential electrodermal responses to fear‐relevant than to fear‐irrelevant stimuli. However, contrary to our hypothesis, fearful subjects did not show enhanced conditionability to their nonfeared but fear‐relevant stimuli as compared with nonfearful control subjects.
An alternative method for significance testing of waveform difference potentials
Authors: BLAIR R. CLIFFORD , KARNISKI WALT
Published: February 2007

Guthrie and Buchwald (1991) proposed an ad hoc 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, (b) 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 (f) is highly intuitive as well as theoretically justifiable. This procedure may be used to carry out multiple comparisons with exact specification or experimentwise error, however, this test is based on permutation principles and may require large amounts of computer time for its implementation.
Does activation of the baroreceptors reinforce differential Pavlovian conditioning of heart rate responses?
Authors: ROBERTS LARRY E. , RAU HARALD , FUREDY JOHN J. , BIRBAUMER NIELS
Published: February 2007

High‐ and low‐pitched tones (CS+ and CS−) signalled baroreceptor stimulation or inhibition (US+ and US‐) on 6‐s conditioning trials (n= 128). Baroreceptor stimulation was induced by the phase‐related external suction (PRES) method of Rau et al. (1992) in which a brief pulse of negative external pressure is applied to the neck at systole and one of positive pressure at diastole within each cardiac cycle (the reverse sequence is used for baroreceptor inhibition). Changes in heart period (R‐R intervals) confirmed that PRES manipulated the baroreceptors in the presence of CS+ and CS− without habituation over conditioning trials. However, conditioned heart period responses were not observed on test trials (n= 32) in which CS+ and CS− were presented with the baroreceptor manipulation removed. Subjects were unable to state which CS had signalled baroreceptor stimulation and inhibition when given PRES‐alone trials after the conditioning phase (differential attention thus controlled). These results (a) confirm that the differential effect of the two PRES stimuli was specific to the baroreceptors and (b) support earlier studies that have found that differential conditioning is impaired when CS−US relations are not processed in attention. We discuss implications regarding when baroreceptor firing might be discriminable and reinforcing.
Guidelines for the recording and quantitative analysis of electroencephalographic activity in research contexts
Authors: PIVIK R. T. , BROUGHTON R. J. , COPPOLA R. , DAVIDSON R. J. , FOX N. , NUWER M. R.
Published: February 2007

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.
Signal‐detection outcomes on heartbeat and respiratory resistance detection tasks in male and female subjects
Authors: HARVER ANDREW , KATKIN EDWARD S. , BLOCH ELISABETH
Published: February 2007

Male and female subjects were compared on heartbeat, respiratory resistance, and light‐tone signal‐detection tasks. Subjects judged whether a series of 10 tones was coincident with their heartbeats; whether an external load added to the airway was either present or absent during targeted inspiratory cycles; and whether a series of 10 light flashes was matched with auditory tones presented following a fixed delay of either 50 or 100 ms. Nonparametric indices of perceptual sensitivity and response bias indicated that men were more sensitive than women on the resistive load task (p < .05) and on the heartbeat task (p= .07). Performance on the light‐tone task was virtually identical. All subjects used a stricter criterion on the respiratory resistance task than on either the heartbeat or the light‐tone task; women employed a stricter criterion than men on the heartbeat task. The gender differences may be understood in terms of lateralization of central processing of somesthetic sensory information.
Intermodal selective attention: Evidence for processing in tonotopic auditory fields
Authors: WOODS DAVID L. , ALHO KIMMO , ALGAZI ALAIN
Published: February 2007

Auditory event‐related brain potentials (ERPs) were recorded for 250‐ and 4,000‐Hz tone bursts in an intermodal selective attention task. Tonotopic changes were evident in the scalp distribution of the rising phase of the auditory N1 (mean peak latency 116 ms); the N1 was more frontally distributed following the 4,000‐Hz than following the 250‐Hz tone bursts, and it included a contralateral P90 component that was absent following 250‐Hz tones. ERPs related to intermodal selective attention were isolated as negative and positive auditory difference waves (Nda and Pdas). Neither the Nda nor the Pda showed changes in distribution with tone frequency, but both showed Ear × Frequency changes in distribution. ERPs for deviant tones included mismatch negativities (MMNs) and, in attend auditory conditions, N2b and P3 components. These components did not change in scalp distribution with tone frequency. One possible explanation is that tonotopic displacements of ERP distributions on the scalp surface depend on angular displacements in generator fields on gyral convexities. The results are consistent with the possibility that auditory processing radiates outward with increasing latency from tonotopic fields on Heschl's gyri to more gyrus‐free regions of the planun temporale and anterior superior temporal plane.
Temporal stability of smooth‐pursuit eye tracking in first‐episode psychosis
Authors: GOODING DIANE C. , IACONO WILLIAM G. , BEISER MORTON
Published: February 2007

We evaluated the temporal stability of smooth‐pursuit eye tracking in 38 schizophrenic, 42 nonschizophrenic psychotic (bipolar, depressive, paranoid psychotic, and schizophreniform), and 49 normal subjects. Pursuit performance was evaluated on two testing occasions separated by approximately 9.5 months. Retest reliability coefficients of root mean square (RMS) error scores for schizophrenic and normal subjects were .68 and .57, respectively. The reliability coefficients of RMS error scores for the nonschizophrenic psychotic patients ranged from .44 to .51. Level of psychological functioning was not significantly related to tracking performance, and most patients' pursuit performance remained stable despite changes in medication and clinical status. These results support the hypothesis that eye tracking dysfunction is a trait characteristic that can serve as a vulnerability indicator of schizophrenia.
An event‐related potential study of sensory representations of unfamiliar tonal patterns
Authors: SCHRÖGER ERICH
Published: February 2007

Tonal patterns were delivered to 17 subjects instructed to read a self‐selected book and to ignore the auditory stimuli. The standard pattern contained eight 50‐ms segments differing in frequency. Infrequent changes of single segments within the pattern elicited negative modulations of the event‐related brain potentials (ERPs) as compared with the ERPs elicited by the standard pattern. The change consisted of either a duplication of a single segment or an interchange of two segments within the pattern. Because of the nature of the change, the ERP modulation cannot be explained by a simple refractoriness mechanism or by assuming that the mechanism generating the negative modulation relies on representations of only the spectral but not the temporal information of the pattern. Therefore, the spectral and the temporal information of the tonal patterns were represented by the information processing system on a grain of single segments.
Resting EEG in first‐episode schizophrenia patients, bipolar psychosis patients, and their first‐degree relatives
Authors: CLEMENTZ BRETT A , SPONHEIM SCOTT R. , IACONO WILLIAM G. , BEISER MORTON
Published: February 2007

We evaluated the resting electroencephalogram (EEG) of 50 first‐episode schizophrenia patients and 55 of their relatives, 31 first‐episode bipolar patients and 35 of their relatives, and 113 nonpsychiatric subjects and 42 of their relatives. The frequency characteristics of the EEG showed moderate stability for a subgroup of these subjects (n= 106) who were tested twice, approximately 9 months apart. Both the schizophrenia and bipolar patients showed a generalized pattern of increased delta and theta and decreased alpha activity. The bipolar patients demonstrated additional right hemisphere activity that was not present among the schizophrenia patients and nonpsychiatric subjects, a finding consistent with hypotheses concerning nondominant hemisphere involvement in the regulation of elated mood. The schizophrenia patients' female relatives and/or relatives with affective disorders and the bipolar patients had significantly reduced peak alpha frequencies. This finding may be related to reduced information processing capacity among these subjects.
Emotional imagery and physical anhedonia
Authors: FIORITO EVELYN R. , SIMONS ROBERT F.
Published: February 2007

A previous study by Fitzgibbons and Simons (1992) confirmed that subjects identified as anhedonic consistently report a reduced experience of pleasure when confronted with hedonic stimuli (i.e., color slides). Evidence that this emotion‐processing deficit extended from the verbal report to the physiological and behavioral domains was mixed but suggested that poor imagery might be associated with the reduced capacity to experience pleasure. The present experiment was designed to test this hypothesis more directly. Anhedonic and normal control subjects were presented scripts, which they were to imagine as vividly as possible. During both script presentation and imagery, heart rate, skin conductance, and facial muscle activity were recorded. Verbal reports of emotional experience were obtained subsequent to each image. The physiological data, as well as an imagery questionnaire, were consistent with the poor imagery hypothesis and also with data from other laboratories (Lang, 1984), which suggests that imagery may be a fundamental aspect of emotion processing in humans.
Baseline respiratory sinus arrhythmia and heart rate responses during sustained visual attention in preterm infants from 3 to 6 months of age
Authors: RICHARDS JOHN E.
Published: February 2007

Three groups of preterm infants were studied longitudinally at 14, 20, and 26 weeks of age (corrected for gestational age). The groups included infants with no perinatal medical complications, those with mild respiratory problems requiring ventilatory assistance, and those with respiratory distress syndrome. Baseline heart rate and respiratory sinus arrhythmia (RSA) were recorded for 5 min, and heart rate was also recorded while the infants engaged in sustained visual attention to stimuli presented on video monitors. The heart rate response during stimulus orienting and sustained attention was smaller in those infants with respiratory distress syndrome than in the other preterm infants and in comparison with the response seen in full‐term infants in previous research. Magnitude of RSA was positively correlated with the attention responses irrespective of the preterm group assignment. There was greater stability in baseline heart rate and RSA for the preterm infants than has been found with full‐term infants. These data suggest that the cardiorespiratory functioning of the preterm infant indexes a stable individual difference characteristic that is correlated with heart responses during sustained attention, and heart rate attention systems may be damaged in the high‐risk preterm infant.
Needle electromyographic evaluation of trigger point response to a psychological stressor
Authors: McNULTY WALTER H. , GEVIRTZ RICHARD N. , HUBBARD DAVID R. , BERKOFF GREGORY M.
Published: February 2007

Fourteen subjects were evaluated by needle electromyography in a trapezius myofascial trigger point and simultaneously in adjacent nontender trapezius muscle fibers during a control condition (forward counting), a stressful condition (mental arithmetic), and resting baselines. Based on recent data implicating autonomic innervation in muscle function, we hypothesized that the trigger point would be more responsive than the adjacent muscle to psychological stress. The results showed increased trigger point electromyographic activity during stress, whereas the adjacent muscle remained electrically silent. These results suggest a mechanism by which emotional factors influence muscle pain. This may have significant implications for the psychophysiology of pain associated with trigger points.
ERPs for infrequent omissions and inclusions of stimulus elements
Authors: NORDBY HELGE , HAMMERBORG DAG , ROTH WALTON T. , HUGDAHL KENNETH
Published: February 2007

A negative event‐related potential (ERP) wave called mismatch negativity (MMN) is elicited by an infrequent deviant stimulus in a sequence of frequent standard stimuli. Omission of a stimulus in a sequence of stimuli, however, has been considered to elicit a negativity different from MMN. The present study addressed this issue by examining ERPs for infrequent omissions and inclusions of compound stimuli or their elements. Three kinds of stimuli were presented: a 1000‐Hz sine wave tone (Sine), white noise with the 1000‐Hz frequency sharply filtered out (Noise), and a composite of the pure tone and the filtered white noise (SiNoise). All stimuli had 50 ms duration and were presented with a regular interstimulus interval of 650 ms. Intensities were 75 dB SPL for the tone and noise stimuli and slightly higher for the composite stimulus. The three kinds of stimuli were presented on separate runs, either as the frequent stimulus or one of two infrequent stimuli, each with 10% probability. Infrequent omission of the large stimulus element (Sine deviant to SiNoise) tended to elicit later MMN than inclusion of the same element (SiNoise deviant to Sine). Omission of the small stimulus element (Noise deviant to SiNoise) elicited a smaller and later MMN than did inclusion of the same element (SiNoise deviant to Noise). These data suggest that MMNs are also elicited by partial stimulus omissions, although they seem to be more sensitive to other kinds of stimulus deviances.
Emotion and psychopathy: Startling new insights
Authors: PATRICK CHRISTOPHER J.
Published: February 2007

Abnormal affective response in psychopaths is conceptualized within a broad theory of emotion that emphasizes reciprocal appetitive and defensive motivational systems. The startle response is proposed as a specific measure of the directional component of emotional activation. I review the literature that indicates that criminal psycho‐paths do not show the expected potentiation of the startle reflex that normally occurs during processing of aversive stimuli such as unpleasant photgraphs or punishment cues. Evidence is presented to demonstrate that this deviant response pattern is specific to individuals who display the classic affective symptoms of psychopathy. The core emotional deviation in psychopathy could be a deficit in fear response, which is defined as a failure of aversive cues to prime normal defensive actions. This emotional deficit may represent an extreme variant of normal temperament.
Intracranial topography of event‐related potentials (N400/P600) elicited during a continuous recognition memory task
Authors: GUILLEM FRANçOIS , N'KAOUA BERNARD , ROUGIER ALAIN , CLAVERIE BERNARD
Published: February 2007

To isolate the anatomical locus of the neural activity most important for generating or modulating the scalp‐recorded N400 and P600 components elicited during continuous recognition memory tasks, intracranial event‐related potentials (ERPs) were recorded from medial and lateral aspects of the temporal, frontal, parietal, and occipital lobes in 25 patients undergoing stereoelectroencephalography for seizure localization. Large‐amplitude and polarity‐inverted ERPs were recorded from various temporal, frontal, and parietal structures, whereas the memory‐related ERP modulation assessed by the ERP repetition effect was present only in those brain areas that play the most important role in memory processing. These data suggest that the scalp‐recorded N400 and P600 components may represent the most readily observable aspect of synchronous activity occurring across widely distributed brain structures and neural systems underlying different cognitive mechanisms, which all contribute to some aspect of information processing during recognition memory.
Mismatch negativity to auditory stimulus change recorded directly from the human temporal cortex
Authors: KROPOTOV J. D. , NÄÄÄNEN R. , SEVOSTIANOV A. V. , ALHO K. , REINIKAINEN K. , KROPOTOVA O. V.
Published: February 2007

Mismatch negativity (MMN) is an event‐related potential (ERP) component elicited by any discernible change in a repetitive sound even in the absence of attention. Previous studies have established that MMN is generated by change detection in a process comparing the deviant sensory input with the neural memory trace encoding the physical features of the repetitive sound. In the present study, we recorded MMNs to tonal frequency changes directly from the human temporal cortex of patients with electrodes implanted in the brain for diagnosis and therapy. The intracranially recorded MMN was found to be attention independent and modality specific. It was confined to a rather small area in temporal cortex, which was different from the structures where attention‐dependent N2 and P3 responses to the frequency change could be recorded.
Dimensional analysis of resting human EEG II: Surrogate‐data testing indicates nonlinearity but not low‐dimensional chaos
Authors: PRITCHARD WALTER S. , DUKE DENNIS W. , KRIEBLE KELLY K.
Published: February 2007

Surrogate‐data testing has recently been proposed as one way to detect the presence of nonlinearity and low‐dimensional chaos in experimental time series. Such testing involves estimating correlation dimension for both the original data and surrogate data from which nonlinearity has been removed. We applied such testing to the same resting, eyes‐closed, and eyes‐open electroencephalogram (EEG) data set that was originally analyzed using dimension estimation applied only to the original data (Pritchard & Duke, 1992). Two kinds of surrogate‐data sets had higher estimated dimension and poorer saturation. This indicates that the normal resting human EEG is nonlinear and therefore not a linear‐stochastic system. Because nearly complete saturation at some loci was not differentially affected by the surrogate‐data procedures, our results also indicate that the normal resting human EEG is high dimensional and does not represent low‐dimensional chaos.
Fear conditioning, preparedness, and the contingent negative variation
Authors: REGAN MARTIN , HOWARD RICK
Published: February 2007

Psychophysiological research on preparedness has previously focused on autonomic nervous system parameters. The present study used electrocortical indices of fear conditioning. Subjects (n= 10) were tested under fear‐relevant and fear‐irrelevant conditions (1 week apart, order of conditions counterbalanced). Each condition comprised acquisition and extinction sessions. The contingent negative variation (CNV) was elicited in anticipation of forewarned slides (fear relevant: small animals; fear irrelevant: landscapes). In acquisition, reinforced conditioned stimulus (CS+) (but not nonreinforced conditioned stimulus [CS‐]) slides were followed by white noise as an unconditioned stimulus (UCS). In extinction, the UCS was omitted. In the fear‐relevant condition, CNV amplitude was significantly larger for CS+ than CS‐ in both acquisition and extinction. In the fear‐irrelevant condition, CNV differentiation between CS+ and CS‐ was weak in both sessions. CNV was significantly larger in the fear‐relevant than in the fear‐irrelevant condition, for CS+ but not CS‐. The findings are consistent with a preparedness interpretation and suggest that CNV under such circumstances may represent an automatic affective response to fear‐relevant stimuli. Electrocortical measures could be particularly useful in examining information processing mechanisms in phobia and cognition‐affect relationships generally.
Counteracting driver sleepiness: Effects of napping, caffeine, and placebo
Authors: HORNE J. A. , REYNER L. A.
Published: February 2007

Sleepy drivers should “take a break,” but the efficacy of feasible additional countermeasures that can be used during the break is unknown. We examined a shorter than 15 min nap, 150 mg of caffeine in coffee, and a coffee plalcebo, each given randomly across test sessions to 10 sleepy subjects during a 30‐min rest period between two 1‐hr monotonous early afternoon drives in a car simulator. Caffeine and nap significantly reduced driving impairments, subjective sleepiness, and electroencephalographic (EEG) activity indicating drowsiness. Blink rate was unaffected. Sleep during naps varied, whereas caffeine produced more consistent effects. Subjects acknowledged sleepiness when the EEG indicated drowsiness, and driving impairments were preceded by self‐knowledge of sleepiness. Taking just a break proved ineffective.