bluuebunny/crossref_metadata_2025_split huggingface dataset:
EEG Landscapes: An Application of Computer Cartography
Authors: Coupland Stuart G. , Taylor Margo J. , Koopman Raymond F. 
Published: February 2007

ABSTRACTTwo three‐dimensional computer mapping programs were utilized for the display of EEG data from two studies. Advantages of these forms of data presentation include the ease with which the data can be meaningfully condensed for inspection of changes across trials. In addition, the uses of perspective cues for feature detection and latency determination are demonstrated.
Electrocortical Signs of Levels of Processing: Perceptual Analysis and Recognition Memory
Authors: Sanquist Thomas F. , Rohrbaugh John W. , Syndulko Karl , Lindsley Donald B. 
Published: February 2007

ABSTRACTThe electrocortical manifestations of levels of perceptual processing and memory performance were investigated by recording event related potentials (ERPs) during a verbal comparison task and a subsequent test of recognition memory. Two words were judged, on each trial, to be the same or different according to an orthographic, phonemic, or semantic criterion. Orthographic processing of words led to poor performance on a test of recognition memory whereas phonemic and semantic processing led to increasingly better performance. “Same” judgments led to better memory performance for phonemically and semantically processed items. The ERP waveforms included a late positive component (LPC) and a slow wave, both of which were responsive to the comparison criterion and the type of judgment. Further, the LPC appeared to index recognition accuracy in the memory test. The ERP data are interpreted as reflecting associative activation in the human memory system.
Two Procedures for Training Cardiac Discrimination: A Comparison of Solution Strategies and Their Relationship to Heart Rate Control
Authors: Ross Alvin , Brener Jasper 
Published: February 2007

ABSTRACTTwenty subjects were trained to detect cardiac activity on two superficially similar discrimination procedures. One group was first trained (to a criterion of 80% correct discriminations) to distinguish between tones that were either contingent or independent of their heart beats and then to distinguish between tones that followed each heart beat with either a short delay or a long delay. The other group was trained on the two procedures in the reverse order. Discrimination strategies were assessed by physiological recordings and questionnaires. No transfer of training was found between the two procedures. Furthermore subjects tended to adopt either an “active” or a “passive” solution strategy depending upon the procedure to which they were first submitted. Subjects who adopted an active discrimination strategy displayed significantly greater voluntary heart rate increases in a post‐discrimination test of heart rate control than did subjects who adopted a passive discrimination strategy.
The Symmetry of Emotional and Deliberate Facial Actions
Authors: Ekman Paul , Hager Joseph C. , Friesen Wallace V. 
Published: February 2007

ABSTRACTAsymmetries of the smiling facial movement were more frequent in deliberate imitations than spontaneous emotional expressions. When asymmetries did occur they were usually stronger on the left side of the face if the smile was deliberate. Asymmetrical emotional expressions, however, were about equally divided between those stronger on the left side of the face and those stronger on the right. Similar findings were obtained for the actions involved in negative emotions, but a small data base made these results tentative.
Relationships ol Pulse Transmission Times to Pre‐ejection Period and Blood Pressure
Authors: Newlin David B. 
Published: February 2007

ABSTRACTThis research addressed the question of whether pulse transmission time to the ear (E‐PTT) serves as a satisfactory estimate of pre‐ejcction period (PEP) and whether the intracardiac or arterial components of pulse transmission times are correlated with hlood pressure. A median correlation of .86 was found for within‐suhject correlations between E‐PTT and PEP, and a correlation of .97 was found on trial means across subjects. Pulse transmission times to the ear and finger (measured from the Q‐wave) were substantially correlated with systolic but not diastolic blood pressure. PEP, the intracardiac component of pulse transmission time, was moderately correlated with systolic blood pressure, but the arterial components were not. It was concluded that E‐PIT estimates PEP in within‐subject comparisons, and that the association of the pulse transmission times with systolic blood pressure is by virtue of the fact that these intervals encompass PEP rather than the arterial components. It was further concluded that pulse transmission times more directly reflect sympathetic cardiac influences than they do blood pressure.
A Dose‐Response and Time‐Action Analysis of Autonomic and Behavioral Effects of Methylphenidate in Attention Deficit Disorder with Hyperactivity
Authors: Solanto Mary V. , Conners C. Keith 
Published: February 2007

ABSTRACTEmpirical attempts to correlate behavioral and physiological responses of hyperactive children to methylphenidate treatment have been complicated by methodological issues, including the demonstrated heterogeneity in the pool of hyperactive children, and the need to consider both dose‐response and timeaction parameters of drug action. Ten hyperactive children, selected according to objective behavioral criteria, were each assessed in 3 placebo days and 3 drug treatment days varying in methylphenidate dosage. Heart rate, finger temperature, electrodermal variables, gross motor activity, serial reaction time (as a measure of attention), and impulsive errors of commission were measured before and at varying intervals following drug or placebo administration. Time‐action curves of methylphenidate's effects on reaction time and on activity were dissimilar, with changes in reaction time more closely paralleling changes in the cardiovascular variables. These findings suggested that attentional deficit and inadequate motor inhibition represent divergent behavioral manifestations of hyperactivity, possibly corresponding to divergent neurophysiological substrates.
Somatosensory Evoked Potential Changes With a Selective Attention Task
Authors: Josiassen Richard C. , Shagass Charles , Roemer Richard A. , Ercegovac Dragoslav V. , Straumanis John J. 
Published: February 2007

ABSTRACTSomatosensory evoked potential (SEP) changes associated with selective attention were investigated. In 16 subjects, SEPs were recorded from five locations while they counted electrical stimuli to one of four randomly stimulated fingers. Sequential SEP events measured included peaks P30 (positivity at 30 msec). P45, N60, P100. N140. P190. N230, P400. Counting was associated with greater P45, P100. P190, N230, and P400 amplitudes; effects were not attributable to eye or tongue activity. Analyses designed to reveal changes associated with two conceptualized “channels” (finger class, hand) showed that the P45, P100, and P190 amplitude increases involved both channels. The P400 effect was limited to the target finger. Channel effects for N60 and N140 amplitudes resulted from decreases localized to the unattended element of one channel, suggesting “inhibition.” Latency effects involved mainly the hand channel; counted hand latencies were shorter for P30, P45, P100 and P190. The findings indicate modifications of both early and late electrocortical events with selective attention, and that changes can be of several kinds. They support the view that attention proceeds in more than one stage.
The Effects of Instructions on Electrodermal Habituation
Authors: Iacono William G. , Lykken David T. 
Published: February 2007

ABSTRACTThe effects of instructions to ignore or attend to stimuli on electrodermal habituation were examined in 122 males who were divided between two groups (Ignore and Attend). One third of the subjects in each group were exposed to seventeen 70, 90, or 110 dB tones while they listened to a radio play. The Ignore subjects were exhorted to immerse themselves in the story and forget about the tones. The Attend group was instructed to count the tones and to be certain they all sounded the same. Another group (Neutral, N = 20, exposed to 110dB tones) was told only that they would hear some tones; no story was presented. The Ignore groups were less responsive and habituated faster than the Attend groups. When the Neutral subjects were compared to the others at 110dB, they were found to have response characteristics that were similar to those of the Attend group, indicating that the specific instructions to attend to the stimuli did not augment responding and that differences between the Attend and Ignore groups are more likely due to the effort of the latter to ignore the stimuli. These findings show that instructions can have important effects on electrodermal responsivity.
The Cardiac and Vascular Components of Pulse Transmission Time: A Computer Analysis of Systolic Time Intervals
Authors: Steptoe Andrew , Godaert Guido , Ross Alvin , Schreurs Paul 
Published: February 2007

ABSTRACTSystolic time interval methodology was used to explore the relative contributions of intracardiac and vascular delays to modifications in pulse transmission time elicited by a series of behavioural and physical challenges. The following variables were recorded on every cardiac cycle: interbeat interval (IBI), the interval between Q and R wave of the EKG, Q wave to pulse arrival (QPT) at the ear and wrist, left ventricular ejection time, and cardiac pre‐ejection period (PEP). The true arterial pulse transit time (PTT), inversely related to pulse wave velocity, was calculated by subtracting PEP from QPT.Modifications of QPT were generally associated with PEP rather than PTT responses. But QPT to the ear and wrist were not equivalent; PEP showed closer correlations with QPT to the ear, while PTT was correlated more consistently with QPT to the wrist. Similar patterns were observed with monitoring from the Q and R waves of the EKG. Important differences also emerged between individuals in the degree to which QPT reactions were correlated with the cardiac or vascular components.A supplementary analysis of correlations between blood pressure and the components of QPT was carried out through hand‐scoring of systolic time intervals. Both PEP and PTT contributed to the correlations of systolic pressure with QPT. The uses of pulse transmission times as indices of pulse wave velocity, or alternatively of PEP and ventricular contractility, are considered.
“…'t was ten to one; And yet we ventured…”1: P300 and Decision Making
Authors: Karis Demetrios , Chesney Gregory L. , Donchin Emanuel 
Published: February 2007

ABSTRACTIn some situations subjects' predictions of future events do not accurately reflect the subjective probability associated with these events. We set up such a situation by manipulating the payoff structure in a prediction paradigm, and found that P300 provides an index of the processes responsible for subjective probability, or expectancy, not obtainable from overt predictions. Sixteen subjects were required to predict, on each trial, whether a 1, 2, or 3 would appear on a display. The numbers appeared randomly with probabilities .45, .10, and .45, respectively. In one condition subjects were given bonuses according to an all‐or‐none payoff function in which they received one cent if they predicted correctly, and nothing if they were incorrect. In a second condition bonuses were determined by a linear payoff function in which subjects were paid one cent if they predicted correctly, and one‐half cent if they were off by one (e.g., predict 1 and 2 appears). After each condition subjects estimated the actual number of stimuli presented. These estimates were the same for both conditions, although predictions differed radically, with 2 predicted much more frequently in the linear condition. P300 area was largest for the rare event (2), and the relationship between P300 and probability was unaffected by payoffs. Our design did introduce differences between conditions in the overall “riskiness’ of predictions, and the strategies adopted by most subjects also resulted in differences in the salience, or task relevance, of the feedback stimuli. These differences resulted in an overall increase in P300 in the all‐or‐none condition. A relationship also emerged between the subjects' strategies and their ERPs. Subjects who adopted more effective strategies responded differentially to feedback from high and low risk predictions, whereas the others did not.
Lateralization of ERP Components during Verbal Dichotic Information Processing
Authors: van de Vijver F.R. , Kok A. , Bakker D.J. , Bouma A. 
Published: February 2007

ABSTRACTTwo experiments are described in which subjects were requested to recall dichotic digit pairs. The results of both experiments showed a significant right ear advantage for the digits. In the EEG a strongly lateralized sustained positive wave was present in the pre‐response period. The asymmetry of this component appeared to be both task dependent, and related to individual differences in ear asymmetry. It is suggested that the sustained wave is a manifestation of differential mobilization of resources of the two hemispheres that compete for limited capacity in a particular stage of the task.
Bioelectric and Potentiometric Measures of Eyeblink Amplitude in Reflex Modification Paradigms
Authors: Clarkson Marsha G. , Keith Berg W. 
Published: February 2007

ABSTRACTRecent investigations of reflex modification in humans have employed several measurement techniques to record reflexive eyeblink responses. To facilitate comparisons across measurement techniques, three experiments evaluated the congruence between eyelid displacement and bioelectric measures of blink amplitude under lead stimulus conditions designed to facilitate, inhibit, or not alter blink amplitude. A potentiometric measure of eyelid displacement was recorded from the right eye of 53 undergraduates, while electrodes centered above and below the left eye detected the bioelectric changes that accompany blinking. In each experiment, lead stimuli altered blink amplitude in a similar manner regardless of measurement technique (i.e., no significant measure by condition interaction emerged). Furthermore, the direction and magnitude of blink amplitude change for the two measurement techniques correlated highly and significantly. These results support the implicit assumptions of researchers that the bioelectric and potentiometric measures provide equivalent information about blink amplitude in reflex modification situations and that reflex‐modification findings can be generalized across measurement techniques.
Electrodermal Nonresponding, Antisocial Behavior, and Schizoid Tendencies in Adolescents
Authors: Raine Adrian , Venables Peter H. 
Published: February 2007

ABSTRACTMost studies which have tested the hypothesis of autonomic hyporeactivity in antisocial groups using skin conductance orienting response (SCOR) amplitudes have failed to confirm this prediction. However, frequency measures may represent more stable and complete indices of responsivity than amplitude measures and, therefore, provide a better test of an antisociality‐hyporeactive relationship. This possibility was tested by relating electrodermal responding‐nonresponding to a series of 65dB tones in 101 15‐yr‐old males to measures of antisocial behaviour and undersocialization. While SCOR amplitudes were unrelated to antisociality, frequency of response and incidence of nonre‐sponding were significantly related in the predicted direction. A second analysis demonstrated antisocial nonresponders to be characterised by schizoid tendencies, but not by sensation‐seeking. These data indicate that equating nonresponding with antisociality and interpreting such a relationship in motivational/arousal terms may be over‐simplistic, and that it may be specifically a schizoid subsection of antisocials who are characterised by nonresponding. It is hypothesised that the frequently cited link between antisociality and psychosis‐proneness may be underpinned by a disturbance of sustained attention as indexed by nonresponding.
Autonomic Nervous System Function and Essential Hypertension: Individual Response Specificity With and Without Beta‐Adrenergic Blockade
Authors: Fredrikson Mats , Danielssons Tomas , Engel Bernard T. , Frisk‐Holmberg Marianne , Ström Gunnar , Sundin ÖRjan 
Published: February 2007

ABSTRACTThe aim of the present research was to study individual response specificity in 22 male patients having essential hypertension (HT) and to compare these patients with age‐matched male normotensive controls (NT). Four stimuli, letter identification, mental arithmetic, cold pressor and isometric exercise, were administered while recordings were made of: systolic and diastolic blood pressures, heart rate, respiration, forearm and hand blood flows, and skin conductance level and fluctuations. After each session urine samples were collected and epinephrine and norepinephrine levels were analyzed. Twelve subjects in the HT group were given beta‐adrenergic blocking agents and retested 1 to 21 months (X̄= 12 months) after the first session. Each response was standardized, using NT as the reference group. Intraclass correlations were computed to evaluate whether HT males reacted with a more consistent hierarchy of responses than did NT. Intraclass correlations were significantly higher among the patients than in the control group, regardless of whether the blood pressure response was included or excluded in the computation of the intraclass correlations. Thus, we conclude that male HT patients show more individual response specificity than NT controls. Beta‐adrenergic receptor antagonists reduced levels of cardiovascular activity and attenuated reactivity but did not affect amount of specificity. Thus, intraclass correlations provide unique and useful information, since they are not related to blood pressure reactivity or to urinary catecholamine levels, nor affected by beta‐adrenergic blockade.
Standardization Within Individuals: A Simple Method to Neutralize Individual Differences in Skin Conductance
Authors: Ben‐Shakhar Gershon 
Published: February 2007

ABSTRACTThe present paper suggests a method to neutralize individual differences in skin conductance responsivity. The method suggested is a standardization of the responses within individuals. This method was compared to the range correction transformation suggested previously. The comparison was based on data from two experiments which evaluated differences between electrodermal responses to relevant and neutral stimuli in information detection tasks. In the first experiment the range correction transformation used the maximal skin conductance response evoked by the subject to one of the regular stimuli presented in the information detection task. The second experiment included responses to unpleasant tones and the range correction transformation was defined as the skin conductance response evoked by the subject to a given stimulus, divided by the response to the unpleasant stimulus. A bootstrap analysis was carried out on five data sets gathered from the two experiments, to statistically compare the transformations. In all cases standard scores better discriminated relevant and neutral stimuli, than range corrected scores. The advantage of standardization was much more salient in the second experiment, where only standard scores produced a statistically significant difference between strong and weak experimental conditions. The analysis demonstrated that the advantage of the method of standard scores is related mainly to its reliance upon the mean, which is a more stable and reliable statistic than the maximal response.
The Asymmetry of Facial Actions is Inconsistent with Models of Hemispheric Specialization
Authors: Hager Joseph C. , Ekman Paul 
Published: February 2007

ABSTRACTSeveral models of hemispheric specialization have been used to explain asymmetries in facial actions. This study measured the asymmetry of several different muscular actions individually, alone and in combination, and under different eliciting conditions. The findings did not fit any of the theoretical models. In the deliberate actions, some of the asymmetries were lateralized with greater intensity on the left side; others, on the right side. Spontaneous actions were more symmetrical than the deliberate, requested actions. We rejected specialization for emotion as a cause of the facial asymmetry observed, and discussed the weaknesses of other models.
P300 and Long‐Term Memory: Latency Predicts Recognition Performance
Authors: Johnson Ray , Pfefferbaum Adolf , Kopell Bert S. 
Published: February 2007

ABSTRACTThe study‐test paradigm was used to investigate memory acquisition processes and the effects of repetition on long‐term recognition memory. In this procedure, subjects are presented with a list of words (“targets”) to be memorized (Study series). They are later tested for recognition on a word list comprised of the target words mixed randomly with an equal number of new, distractor words (Test series). Both reaction time and the P300 component of the event‐related brain potential were used as measures of processing time. During the Study series, large P300s were elicited despite a word category probability of 1.0. When the words from the Study series were divided on the basis of recognition performance, words that were subsequently recognized elicited P300s with shorter latencies than unrecognized words. P300 amplitude to words in the Study series increased with repetition while maintaining a constant latency. During the Test series, P300 latency and reaction time decreased with repetition for both target and distractor words. P300 amplitude to all words increased substantially over Test repetitions with target words eliciting larger P300s than distractor words. Words that were recognized more consistently during the Test series elicited larger and earlier P300s than words that were recognized less consistently. The P300 amplitude and latency results from both the Study and Test series are interpreted as reflecting the increased discriminability of the target words as the memory trace increases in strength.
Cardiovascular Reactivity in Borderline Hypertensives during Behavioural and Orthostatic Stress
Authors: Drummond Peter D. 
Published: February 2007

ABSTRACTBlood pressure and heart rate were measured in 16 borderline hypertensive and 10 normotensive subjects during mental arithmetic and reaction time tests, on standing, and during the pre‐test period and instructions preceding these tests. The reliability of responses was assessed on 3 consecutive days. Increases in systolic blood pressure and heart rate during mental arithmetic instructions, increases in systolic blood pressure during the mental arithmetic test, and increases in diastolic blood pressure on standing were greater in borderline hypertensives. These differences persisted throughout the 3 experimental sessions. Apart from stress ratings for the reaction time test, other behavioural measures, including number of mental arithmetic mistakes and reaction times, did not differ between normotensives and borderline hypertensives. The possibility that the parasympathetic nervous system exerts a restraining influence on sympathetic overactivity in borderline hypertension was discussed.