bluuebunny/crossref_metadata_2025_split huggingface dataset:
Classically Conditioned Blood Pressure Decreases Induced by Electrical Stimulation of Posterior Lateral Hypothalamus in Rabbits
Authors: Brickman Andrew L. , Schneiderman Neil 
Published: February 2007

ABSTRACTAn experimental group of 5 rabbits received 5 acquisition sessions during which repeated presentation of a 550 Hz tone for 10 sec as the conditioned stimulus (CS) was always followed immediately by 25 pulse per sec, 10 sec train‐duration stimulation of the posterior lateral hypothalamus as the unconditioned stimulus (US). A control group of 5 rabbits received random presentations of the CS and US. The unconditioned responses (URs) to intracranial stimulation consisted of tachycardia and a depressor response; conditioned responses (CRs) consisted of depressor responses unaccompanied by systematic changes in heart rate. Neither systematic heart rate nor blood pressure responses occurred to the CS in the control group.The present results contrast with those of previous studies in rabbits in which higher frequency, shorter pulse‐train hypothalamic stimulation as US induced a pressor response and reflexive bradycardia as URs, and bradycardia unaccompanied by blood pressure changes as CRs. It is concluded that hypothalamic stimulation as US permits more than one cardiovascular response pattern to be studied under controlled conditions during classical conditioning.
Effect of EMG Biofeedback and Progressive Muscle Relaxation Training on Awareness of Frontalis Muscle Tension
Authors: Sime Wesley E. , DeGood Douglas E. 
Published: February 2007

ABSTRACTAwareness of muscle tension, as estimated by a modification of the Kinsman et al. (1975) procedure for determining probability of correct estimation (P(c)) of absolute differences in muscle tension between adjacent trials, was examined before and after volunteer subjects underwent 4 sessions of either: 1) EMG biofeedback (BF) training, 2) progressive muscle relaxation (PMR) training, or 3) a placebo‐control (MC) procedure which involved listening to music as an alleged guide for relaxation. The subjects were 30 females (mean age = 28.3 yrs) responding to an offering of experimental treatment for anxiety and tension. Measurements of frontalis muscle tension (EMG) and P(c) were made before and after training. The results showed that EMG was significantly reduced by BF and PMR training but not by the MC procedure. Increases in P(c) after training were significantly greater for BF than for PMR or MC training. There were no group differences for subjective report of tension. Correlations between pre‐ to post‐training EMG and P(c) change scores were significant only for the BF group and the combined group of BF and PMR subjects. These results suggest that: 1) both BF and PMR training were effective in producing frontalis EMG reductions, 2) the following relationship may exist among training groups in terms of relative influence upon awareness of tension—BF training > PMR training > MC training, and 3) awareness of tension appears to be related to the ability to reduce EMG although the exact nature of this relationship remains unclear.
Event Related Potentials of Brain (CNV and P300) In A Paired Associate Learning Paradigm
Authors: Peters Jon F. , Billinger Thomas W. , Knott John R. 
Published: February 2007

ABSTRACTCortical electrical activity as reflected by CNV and P300 was examined in paired associate learning and discriminative reaction time paradigms. The CNV amplitude following the first of a pair of trigrams showed an inverse relationship to acquisition; P300 amplitude increased monotonically. Amplitude of both waveforms was larger in the central‐parietal area than the frontal area in the paired associate learning paradigm, while in the discriminative reaction time paradigm CNV was maximal in the frontal area and P300 was maximal in the parietal area. The CNV data are interpreted as reflecting early arousal and attentional processes, whereas P300 may reflect the subject's decision about the relevance of the stimulus.
Oxygen Consumption and Ambulation During Operant Conditioning of Heart Rate Increases and Decreases in Rats
Authors: Brener Jasper , Phillips Keith , Connally Samuel R. 
Published: February 2007

ABSTRACTUsing a shock‐avoidance procedure, large discriminated increases and decreases in mean heart rate (HR) were conditioned respectively in two groups of free‐moving rats. Accompanying the conditioned HR responses were equally significant variations in Oxygen Consumption and Ambulation indicating a nonspecific effect of the experimental contingencies. Ambulation and Oxygen Consumption were found to be correlated in some but not all experimental conditions. Thus, partial indices of somatomotor activity may not provide an adequate reflection of variations in general activity (energy consumption) and therefore may not be employed to draw meaningful conclusions regarding the integration of cardiac and somatomotor processes. Discriminated HR responses were acquired more rapidly by subjects in the Increase condition than by subjects in the Decrease condition. However, the latencies of the discriminated HR changes were considerably longer for the Increase than for the Decrease subjects. An unexpected result was that 5 of the 6 Decrease subjects developed profound bradycardic arrhythmias. These arrhythmias were under strong stimulus control and were exhibited only during a stimulus (SD) signalling that the reinforcement contingencies were in effect.
Development of a Neuromuscular Blocking Procedure for Heart Rate Conditioning in Immobilized Pigeons
Authors: Migani‐Wall Sandra A. , Cabot John B. , Cohen David H. 
Published: February 2007

ABSTRACTPharmacological neuromuscular blockade has been used for some years in behavioral experiments to eliminate somatomotor responding. However, such blockade has other pharmacological actions, particularly on the autonomic nervous system, that confound its use in such experiments. The present study develops an immobilization procedure for the pigeon that allows heart rate conditioning with acquisition rates and response dynamics equivalent to those of non‐immobilized animals. Part I describes preliminary screening of four classes of blocking agents: curariform, depolarizing, steroidal, and a blocker of excitation‐contraction coupling. None alone were satisfactory in inducing and maintaining immobilization free of undesirable cardiovascular effects. However, these experiments led to a promising regimen in which immobilization was induced with pancuronium bromide and maintained with pancuronium and gallamine triethiodide. Part II describes this regimen and presents conditioning data showing that, for a majority of immobilized animals, conditioned heart rate change differed in no respect from that of non‐immobilized controls. Moreover, there were no differences between immobilized and non‐immobilized sensitization groups, and baseline heart rates neither differed among groups nor changed over training.
Electromechanical Switching of Preamplifier Input Leads: A Method of Increasing the Usefulness of Electrophysiological Recording Instruments
Authors: Milligan W. Lloyd 
Published: February 2007

ABSTRACTExperiments involving electrophysiological recording frequently consist of a trial interval during which a response is measured and a longer duration intertrial interval during which the response returns to its tonic level. If it is not necessary to record a response during the intertrial interval, the recording instrument is wasted during this time. This article describes a circuit which permits automatic switching of input leads so that responses can be recorded from more than one set of subjects sequentially. This arrangement results in more efficient utilization of laboratory instrument resources. An increase in data is obtained at minimal cost.
Extraversion and Individual Differences in Auditory Evoked Response
Authors: Stelmack Robert M. , Achorn Edwin , Michaud Aurelda 
Published: February 2007

ABSTRACTThe auditory evoked response to low (0.5K Hz) and high (8.0K Hz) frequency tones at three levels of intensity (40, 55, and 80 dB) were recorded for subjects differing in degree of extra‐version. Introverts were observed to have greater N1‐P2 amplitude than extraverts with the low frequency tones at 55 and 80 dB intensity. The results support Eysenck's general proposal relating introversion to higher levels of cortical activity.
Effects of Alpha Feedback Training on Occipital EEG, Heart Rate, and Experiential Reactivity to a Laboratory Stressor
Authors: Chisholm Ronald C. , DeGood Douglas E. , Hartz Mary A. 
Published: February 2007

ABSTRACTThe intent of this study was to examine whether brief alpha biofeedback training would alter the degree of physiological and experiential stress evidenced in an aversive laboratory situation. While occipital alpha and heart rate were monitored, 36 subjects underwent 8 presentations of a warning tone preceding fingertip electric shock by 30 sec. Subjects were then placed into one of three treatments taking place in dim light with eyes open. Group 1 received 24 min of contingent feedback. Group 2 received an equivalent amount of non‐contingent feedback and Group 3, a no‐feedback control condition, listened to music. Following the treatment period, 12 additional tone‐shock pairings were presented, equally divided between eyes‐open and eyes‐closed trials, also with and without continuation of the treatment period “signal” (i.e. contingent, non‐contingent feedback, or music). The results revealed that, in general, enhanced alpha density was maintained by the contingent feedback group during the post‐treatment aversive situation. However, the reduction in alpha suppression was not systematically accompanied by corresponding heart rate and self‐report reductions in situational reactivity. It was concluded that alpha feedback training was not sufficient to produce a generalized relaxation to the aversive situation. Alternative accounts of the results, focusing primarily on independence of response systems, are discussed.
The Psychopath and the Lie Detector
Authors: Lykken David T. 
Published: February 2007

ABSTRACTThe article by Raskin and Hare (1978) asserts or very plainly implies that: 1) the control question lie test is extraordinarily accurate; 2) that this high accuracy can be achieved by objective scoring of the polygraph charts; 3) that the theory of this test is psychologically reasonable and was confirmed by the experiment reported; 4) that subjects give qualitatively different autonomic responses when lying than they do when telling the truth; and 5) that the experiment described shows that psychopaths can no more “beat” the lie detector than non‐psychopaths. All of these socially important claims or implications are critically examined and all of them are found to be untenable.
Autoregressive Spectral Estimates of Newborn Brain Maturational Level: Classification and Validation
Authors: Crowell David H. , Kapuniai Linda E. , Jones Richard H. 
Published: February 2007

ABSTRACTIn order to examine the reliability and validity of classification of EEG maturational levels, brain activity before and after peripheral sensory stimulation was measured in two groups of full‐term newborn infants (N=50 and 48). Autoregressive coefficients from two derivations (C‐A, O‐A) were classified by means of logistic discrimination relative to three age groups: a low birthweight group of less than 35 weeks gestational age, a comparable two‐day‐old group, and a group 6 weeks to 3 months of age. Results demonstrated that EEG maturational level of two‐day‐old full‐term neonates can be reliably and validly classified. Autoregressive spectral analysis may function as a major technique for the hypothesis testing and classification of infant EEG.
Auditory Brainstem Recovery Processes From Birth to Adulthood
Authors: Salamy A. , McKean C. M. , Pettett G. , Mendelson T. 
Published: February 2007

ABSTRACTTwo treatments‐by‐subjects with repeated measures experiments were performed to determine maturational changes in the recovery processes along the classical auditory pathway.Subjects ranged in age from birth to adulthood. Brainstem evoked potentials (BEPs) recorded from the surface of the scalp were obtained at stimulus presentation rates of 10–40/sec for all subjects. In addition, some newborns and adults received repetition rates of 50–80/sec.The amplitude and latency of selected BEP components which reflect discrete levels of brainstem integration, were measured. At stimulus rates of 10–40/sec strong age and rate effects evinced but significant interactions emerged only for those waves representative of rostral brainstem activity. A test of trend revealed that the newborns, in comparison with all other age groups, displayed slower recovery to increasing rates of stimulation (10–40/sec). The differential response of the individual BEP components conforms to the known caudo‐rostral maturation of the brainstem.Stimulus rates above 50/sec (50–80/sec) produced a relatively uniform depression (refractoriness) in the early BEP components irrespective of age. Only potentials generated in rostral structures continued to covary with rate of stimulation.These studies indicate that in the human brainstem the mechanisms responsible for neuronal recovery are essentially mature in the neonatal period.
Background Noise Levels and Heart Rate Orienting: Response Detection Using Time Series Analysis
Authors: Lobstein Tim , Webb Bob , Cort Janet 
Published: February 2007

ABSTRACTThe purpose of this paper is two‐fold. The first is to introduce a method of analyzing single trials of beat‐to‐beat heart rate in adult subjects, by which significant changes in heart rate following a stimulus may be detected. The second is to demonstrate the economy of this form of analysis by presenting it in the context of a small‐scale experiment. The experiment examined heart rate orienting responses to a standard auditory signal, comparing the effects of high and low continuous background noise. The higher background noise level was found to enhance the accelerative component of the heart rate response to auditory signals.
Prestimulus Effects on Human Startle Reflex in Normals and Schizophrenics
Authors: Braff David , Stone Claudia , Callaway Enoch , Geyer Mark , Glick Ira , Bali Likh 
Published: February 2007

ABSTRACTGraham (1975) demonstrated that a weak prestimulus could effectively inhibit or facilitate the eyeblink component of the startle reflex in humans, depending on the temporal duration of the prestimulus. This study had three goals: 1) to replicate the findings of Graham, 2) to establish the reliability of this phenomenon by a test‐retest comparison, and 3) to compare the eyeblink reflex response of normal subjects with schizophrenic subjects. Seven prestimulus durations of continuous tone (from 0 to 2000 msec) were presented to 20 normal subjects and the results confirmed that maximal inhibition of eyeblink amplitude occurred in the 120 msec prestimulus condition. Increased amplitude occurred nonsignificantly when the prestimulus lasted for 2000 msec. On retest, 14 normal subjects showed a significant degree of reliability. When 20 normal subjects were compared to 12 schizophrenic subjects, significant differences in eyeblink response were found for blink amplitude and latency in the 60 msec prestimulus condition. This change is consistent with information processing “overload” theories of sensory overstimulation in schizophrenia. The blink reflex is a rather stable phenomenon and is probably altered in schizophrenia and/or by antipsychotic medication.
Reactivity to Heteromodal Stimulation as a Function of Stimulus Intensity and Inner Arousal
Authors: Alexander Robert , Epstein Seymour 
Published: February 2007

ABSTRACTIn a preliminary study, it was observed that when increasingly intense light stimuli were presented simultaneously with a loud noise, magnitude of the skin conductance response increased over the first three levels of increasing light intensity, and then exhibited a paradoxical decrease. The present study extended the previous one by adding more intense stimuli and by examining the influence of inner sources of arousal in the form of motor effort and tonic skin conductance. Twenty subjects, half of whom squeezed a dynamometer during stimulus presentations, were presented with four intensities of noise combined with four intensities of light in all combinations in a randomized Latin Square design. Compared to the previous study, an increase in paradoxical responding was observed. However, the results could not be interpreted by simply assuming a reflexive inhibitory response to high levels of total stimulation. Rather they suggested the occurrence of what we have referred to as “intensity learning,” which involves a selective diminution in reactivity to high intensity stimuli while reactivity and alertness are retained to low intensity stimuli.
Coronary‐Prone Behavior Pattern and Cardiovascular Response
Authors: Manuck Stephen B. , Craft Suzanne , Gold Kenneth J. 
Published: February 2007

ABSTRACTTwo studies were carried out examining the relationship between coronary‐prone behavior pattern and cardiovascular responses to an experimental stressor. Among 52 subjects of the Type A (coronary‐prone) and Type B (non‐coronary‐prone) behavior patterns in Study I, Type A males showed greater elevations of systolic blood pressure than Type B males on exposure to a difficult cognitive task; no reliable differences were found for Type A and B females. Due to a conceptual similarity of the coronary‐prone behavior pattern and the personality dimension of Internal External locus of control, 48 male subjects in Study II were selected with respect to four subject groups: Type A‐Internals, Type A‐Externals, Type B‐Internals, and Type B‐Externals. Again, Type As showed a more pronounced systolic response than subjects of the Type B pattern, though diastolic blood pressure and heart rate responses did not vary by coronary‐prone behavior pattern. While locus of control‐Internals tended to show greater task‐related systolic elevations than Externals, this effect was not significant. Self‐reports of anxiety increased during the period of the task, but revealed no differences among Type A and B subjects of either study. It was concluded that for male subjects the Type A‐Type B dimension constitutes a salient variable of individual differences mediating the systolic pressor response.
The Distribution of Attention Across Auditory Input Channels: An Assessment Using the Human Evoked Potential
Authors: Hink Robert F. , Fenton Wayne H. , Pfefferbaum Adolph , Tinklenberg Jared R. , Kopell Bert S. 
Published: February 2007

ABSTRACTIn order to determine the extent to which distraction disrupts performance when attention is divided, the distribution of attention across five auditory input channels was assessed using the N1 component of the human auditory evoked potential. In addition, the possibility that methylphenidate (Ritalin) affects the distribution of attention across input channels was tested. Sixteen subjects performed a tone discrimination task under conditions of focused attention and divided attention, both with and without the presence of stimuli interposed between the points to be attended. The subjects performed in two sessions during which they received either methylphenidate (10 mg) or a placebo in a double‐blind design. The results showed that the interposed stimuli were receiving some attention resulting in a disruption of performance. Methylphenidate did not affect the distribution of attention as reflected in the N1 wave. The data are interpreted as showing that: 1) distraction plays a major role in producing performance deficits observed with divided attention; and 2) methylphenidate does not appreciably affect the distribution of attention across input channels.
Overhabituation and Dishabituation Responses as a Function of Stimulus Intensity and Amount of Overhabituation Training
Authors: Smith Barry D. , Council James 
Published: February 2007

ABSTRACTSeveral important issues regarding overhabituation and its effects have been raised. Of particular interest are the effects of amount of overhabituation on responses during overhabituation, the existence of important individual differences in response frequency and amplitude during overhabituation, and the effect of varied amounts of overhabituation training and of stimulus intensity on test and dishabituation response amplitudes. In the present study, each of 108 subjects was randomly assigned to one of three overhabituation exposure conditions (60, 120, or 180 trials) and one of two auditory stimulus intensities (60 or 85 dB). After reaching a phasic electrodermal habituation criterion, each subject received the appropriate number of overhabituation presentations of the standard stimulus (SS), followed by a test stimulus and an additional SS (the dishabituation stimulus). Results showed significantly higher frequencies and amplitudes of electrodermal responses to tonal stimuli with increasing numbers of overhabituation trials, but no significant changes over trial blocks. Individual differences were found. Subjects in a group defined by numerous overhabituation responses showed slower habituation, larger responses and higher frequencies of nonspecific responses during overhabituation, and larger test responses. Finally, the amplitude of test responses increased with increasing length of overhabituation and with increased intensity.
Electrodermal Indices of Stress and Cognition: Possible Hydration Artifacts
Authors: Bundy Robert S. , Mangan Steven M. 
Published: February 2007

ABSTRACTThe study was designed to examine the relationship between electrodermal frequency (EF) and skin conductance level (SCL) in a paradigm that has previously demonstrated that these measures can operate independently. Electrodermal activity was recorded during 3 10‐min periods. All subjects rested during the first and last periods. Half of the subjects rested during the second period, and half were in a shock‐threat condition. Between the second and third periods a fresh electrode set was applied, and the subjects either inflated a balloon, operated a pursuit rotor, or were interviewed. Both measures were low for the rest periods and high during the shock‐threat condition except during the last rest period when SC was unexpectedly high, thus replicating previous research. However, application of new electrodes in the last period demonstrated that this high SCL was due to a time dependent effect, probably hydration, and was not due to the differential effects of stress and cognitive activity on the two electrodermal measures.