bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sources of P300 attenuation after head injury: Single‐trial amplitude, latency jitter, and EEG power
Authors: UNSAL AYSE , SEGALOWITZ SIDNEY J. 
Published: February 2007

AbstractSingle trial amplitude, latency jitter, and electroencephalographic (EEG) power were examined as sources of the group difference in averaged P300 amplitude among 15 traumatically brain injured and 20 control individuals in an auditory oddball paradigm. Mean amplitude of the individual trials was highly correlated with the amplitude of the averaged P300, with little additional unique variance attributable to latency jitter or EEG power. The group difference in P300 amplitude was also explained by the mean amplitude of the single trials. These results support the robustness of the event‐related potential averaging technique within the paradigm used.
Left movers' advantage in heartbeat discrimination: A replication and extension
Authors: VIOLANI C. , LOMBARDO C. , DE GENNARO L. , DEVOTO A. 
Published: February 2007

AbstractLateral eye movers are subjects who consistently shift their gaze either leftward or rightward while reflecting on visuospatial or verbal questions. When reliably assessed, prevalent direction of gaze can be assumed as a valid index of hemispheric asymmetry. The present study evaluated discrimination of heartbeat (HB) and of spontaneous changes of finger temperature in 24 right‐handed females reliably selected as lateral movers. Results replicate and extend previous findings by showing that left movers' superiority in HB discrimination is present also in females and concerns the perception of a different vascular function, that is, peripheral finger temperature. Differences between right movers and left movers were not due to activation level during the test or to body composition.
Effects of operantly conditioning the amplitude of the P200 peak of the SEP on pain sensitivity and the spinal nociceptive withdrawal reflex in humans
Authors: DOWMAN ROBERT 
Published: February 2007

AbstractThis study attempted to replicate and extend earlier work that reported that the amplitude of the P200 peak of the human somatosensory evoked potential (SEP) can be increased and decreased when reward is made contingent upon change and that these changes are accompanied by alterations in pain sensitivity. Twenty‐one subjects were able to make the amplitude of the P200 peak evoked by sural nerve stimulation larger during increased training (up‐training) than during decreased training (down‐training). There were no differences in the sural nerve compound action potential between up‐training and down‐training. This finding demonstrates that the change in P200 amplitude was not due to a change in stimulus efficacy, but rather to a change within the central nervous system. Subjective pain ratings and a nociceptive spinal reflex were the same in up‐training as in down‐training. Thus, conditioned changes in P200 amplitude do not alter pain sensitivity.
Long‐term extension to sleep ‐Are we really chronically sleep deprived?
Authors: Harrison Y. , Horne J. A. 
Published: February 2007

AbstractDuring 26 consecutive nights, electroencephalographic recordings and/or actigraphs were used to monitor the nighttime sleep of 10 asymptomatic healthy sleepers (mean age = 23.6 years). The schedule comprised: 7 nights of base line sleep, 14 nights of extended sleep (up to 10 hr/night), and 5 nights of recovery sleep. During extended sleep, subject1, slept significantly longer (approximately 1 hr), but sleep latency and interim wakefulness deteriorated. Extended sleep produced no improvements to sell‐rated mood or subjective sleepiness. Vigilance tests showed a small but significant reduction in reaction time following extended compared with both baseline and recovery nights. Ability to detect target tones did not change significantly. Multiple Sleep Latency Test scores during extended sleep showed small (about 1 min) reductions. These findings give little support to the view of chronic sleep deprivation in the average 7.5‐hr sleeper.
Developmental and pharmacological analysis of the cardiac response to an acoustic startle stimulus
Authors: Richardson Rick , Wang Peiyin , Campbell Byron A. 
Published: February 2007

AbstractThe purpose of this research was to study the cardiac response of preweanling and adult rats to 10 presentations of an acoustic startle stimulus (0 ms rise time, 100 ms, 130 dB, white noise stimulus). The first presentation of the startle stimulus produced a decrease in heart rate (HR) at both ages. With continued stimulus presentations, the response shifted to tachycardia in the adults but remained bradycardia in the preweanlings. Pharmacological analysis revealed that the startle stimulus activated only the parasympathetic system in the preweanling rats on all 10 trials. In contrast, the startle stimulus produced coactivation of the parasympathetic and sympathetic systems in the adults on the first trial, with the parasympathetic system predominating, and solely sympathetic activation on later trials. These results are discussed in terms of current psychophysiological models of (a) the cardiac response to startle stimuli and (b) autonomic space.
The effects of task type and task requirements on the dissociation of skin conductance responses and secondary task probe reaction time
Authors: Sidle David A. T. , Lipp Ottmar V. , Dall Patricia J. 
Published: February 2007

AbstractAlthough task‐irrelevant events elicit smaller skin conductance responses (SCRs) than do task‐relevant events, secondary task probe reaction time (RT) is often slower during the former. Three experiments (N = 48 in each) examined the effects of task demands, instructions, and stimulus discriminability on this dissociation effect. SCRs were larger to task‐relevant stimuli in all experiments regardless of experimental manipulation. Subjects in Experiment I counted either all tones of one pitch (high/low group) or longer‐than‐usual tones of one pitch (longer group). There was more RT slowing during task‐irrelevant tones at a 250‐ms probe position in the high/low group and at a 150‐ms probe position in the longer group. Experiment 2 employed differential Pavlovian conditioning in which the offset of task‐relevant stimuli (CS+) coincided with the onset of a shock stimulus. Half the subjects were told which stimulus would be followed by shock (information group), whereas the others received no information (no‐information group). Increased RT slowing during CS− was restricted to the no‐information group. Experiment 3 employed visual conditioned stimuli that were easy or difficult to discriminate. RT slowing at 4,000 ms was greater during CS+, whereas there was a tendency for more RT slowing during CS− at 150 ms. There was no effect for CS discriminability. The results suggest that during both simple discrimination and during Pavlovian conditioning, task‐irrelevant stimuli are more actively processed than task‐relevant stimuli within the first 250 ms of stimulus presentation.
Timing and amplitude of saccades during predictive saccadic tracking in schizophrenia
Authors: Mcdowell Jennifer E. , Clementz Brett A. , Wixted John T. 
Published: February 2007

AbstractSchizophrenia patients have ocular motor abnormalities. It has been hypothesized that these abnormalities are associated with frontal eye field pathology. If so, schizophrenia patients should have difficulties decreasing saccadic reaction times in response to predictably moving targets. To evaluate the frontal eye field hypothesis. 25 schizophrenic and 26 nonpsychiatric subjects completed predictive saccadic tracking tasks. The groups demonstrated equivalent decreases in saccadic reaction times over consecutive trials. Schizophrenia patients, however, had faster reaction limes and shorter amplitude saccades than nonpsychiatric subjects. The shorter amplitude saccades were made regardless of reaction time, perhaps an antipsychotic medication effect. The reaction time results are unlikely to be an effect of treatment with antipsychotic medication and are inconsistent with the hypothesis that schizophrenia patients have frontal eye field pathology.
Autonomic activity in relation to cerebrospinal fluid neurochemistry in obsessive and disruptive children and adolescents
Authors: ZAHN THEODORE P. , KRUESI MARKUS J. P. , SWEDO SUSAN E. , LEONARD HENRIETTA L. , RAPOPORT JUDITH L. 
Published: February 2007

AbstractElectrodermal activity and heart rate were recorded during rest, simple tones, and a reaction time task in 43 male and female adolescents and children with obsessive compulsive disorder and 30 male adolescents and children with disruptive behavior disorders who had lumbar cerebrospinal fluid drawn during the same week. Partial correlations controlling for age and sex showed that in the obsessive group metabolites of serotonin and dopamine, but not of norepinephrine, were positively correlated with electrodermal responsivity, most consistently in the reaction time task. This result was not replicated in disruptive boys. Adrenocorticotropic hormone was positively related to electrodermal activity and heart rate throughout the session. The results for the obsessive adolescents suggest that nigrostriatal dopamine turnover and central serotonin turnover affect electrodermal activity, generally confirming and extending conclusions from pharmacological studies. Diagnosis may affect these relationships.
Anticipatory EMG responses of pericranial muscles in relation to heart rate during a warned simple reaction time task
Authors: VAN BOXTEL A. , DAMEN E. J. P. , BRUNIA C. H. M. 
Published: February 2007

AbstractObrist's cardiac‐somatic coupling hypothesis predicts a widespread inhibition of heart rate and task‐irrelevant muscle activity during expectancy situations. This hypothesis was tested by measuring heart rate and pericranial electromyographic (EMG) activity during a warned simple reaction time task with visual or auditory reaction signals and hand or foot responses. In each of three groups of 24 participants, EMG activity of three different facial, masticatory, or neck muscles was recorded. During the warning interval preceding the presentation of the reaction signal, masticatory and lower facial muscles predominantly showed a gradual inhibition in acitivity concomitant with heart rate deceleration. In contrast, two upper facial muscles showed increasing activity. Pericranial EMG responses were little affected by reaction signal modality and were independent of responding limb. Greater heart rate deceleration was associated with greater inhibition and weaker facilitation of EMG responses. The results suggest a functional role of inhibitory EMG responses in increasing the perceptual sensitivity to expected signals.
Effects of stress and shock anticipation on prepulse inhibition of the startle reflex
Authors: GRILLON CHRISTIAN , DAVIS MICHAEL 
Published: February 2007

AbstractThe effects of shock anticipation and attention to external stimuli on prepulse inhibition (PPI) were compared. In the threat‐of‐shock experiment, acoustic startle stimuli were presented with and without prepulses when aversive shocks were or were not anticipated. In the control experiment, startle and prepulse stimuli were delivered during periods with attended or ignored external stimuli. In the threat‐of‐shock experiment, startle was potentiated (fear‐potentiated startle) and PPI was increased by shock anticipation. A gradual reduction in the overall PPI throughout the experiment was also found. In the control experiment, only PPI was increased in the attend condition. The PPI level remained constant throughout the experiment. The increase in PPI in the threat and attend conditions may have resulted from an increase in the general level of alertness that facilitated the processing of the prepulse. The gradual decrease in PPI in the threat experiment was hypothesized to result from a progressive deficit in sensory functioning due to the stressful nature of repeated shock anticipation.
Attention modulates auditory pattern memory as indexed by event‐related brain potentials
Authors: ALAIN CLAUDE , WOODS DAVID L. 
Published: February 2007

AbstractThe role of selective attention on auditory pattern processing was investigated using the mismatch negativity, an event‐related brain potential component associated with sensory memory. Participants responded to changes in an alternating tone pattern in a designated ear while a similar auditory pattern was presented in the opposite ear. Participants were also presented with the same sequences while reading a book (no response required). In all conditions, changes in the pattern elicited a mismatch negativity (MMN) that peaked at 160–220 ms poststimulus. MMN amplitude varied with attention: the amplitude was higher in response to deviant stimuli presented in the attended ear than to the deviant stimuli presented in the unattended ear or during reading. The results show that selective attention modulates auditory pattern memory.
Left hemisphere advantage for classical conditioning to auditory verbal CSs: Effects of nonattended extinction
Authors: SABAN SARA , HUGDAHL KENNETH , STORMARK KJELL MORTEN , HAMMERBORG DAG 
Published: February 2007

AbstractThe effects of brain laterality, or hemispheric asymmetry, on electrodermal classical conditioning during both attended and nonattended stimulus conditions were studied. Participants were conditioned to consonant‐vowel (CV) syllables during an acquisition, or learning, phase of the experiment. During a subsequent extinction phase, the conditioned stimuli (CS) were presented in a dichotic mode of presentation. Half of the participants attended to the left car (right hemisphere) during the extinction phase and the other half of the participants attended to the right ear (left hemisphere). The results showed effects of conditioning for all participants during the acquisition phase. During dichotic extinction, the left hemisphere group showed remaining learning effects in both the attended and nonattended conditions, whereas the right hemisphere group demonstrated conditioning only in the attended condition.
Characteristics of open‐ and closed‐loop smooth pursuit responses among obsessive‐compulsive disorder, schizophrenia, and nonpsychiatric individuals
Authors: FARBER ROBERT H. , CLEMENTZ BRETT A. , SWERDLOW NEAL R. 
Published: February 2007

AbstractTwenty obsessive‐compulsive disorder patients and comparison samples of 20 schizophrenia and 20 nonpsychiatric individuals were presented with (a) a step‐ramp task designed to measure smooth pursuit initiation and (b) a regular ramp task designed to measure steady‐stale tracking performance. Obsessive‐compulsive disorder and non‐psychiatric individuals had statistically similar pursuit reaction time and average eye accelerations during the open‐loop interval. They also had similar closed‐loop performance. Schizophrenia patients, however, had delayed pursuit reaction times and reduced eye acceleration during the last 60 ms of the open‐loop interval. These findings suggest that brain regions supporting smooth pursuit performance are unimpaired among obsessive‐compulsive disorder patients. Furthermore, the deficits found in the schizophrenia patients replicate and extend the results of previous smooth pursuit studies.
Mismatch negativity during objective and subjective sleepiness
Authors: SALLINEN MIKAEL , LYYTINEN HEIKKI 
Published: February 2007

AbstractThe mismatch negativity (MMN) and P.3 of auditory event related potentials were studied during subjectively and objectively (physiologically) defined sleepiness under optimal stimulus conditions for MMN elicitation. The MMN and P3 were elicited by either small or large unattended auditory deviants presented to the left ear The participant's task was to defect either rare auditory targets presented to the right ear or rare changes in the light Hashes Eleven young adults served as participants in a nighttime experiment. The MMN declined especially at Fz and Cz bin not so markedly at the right mastoid as either subjective or objective alertness decreased The amplitude of P3 also decreased during sleepiness The attenuation of the MMN was paralleled by a decline in behavioral performance The results show that the MMN is attenuated by a decrease in alertness even before an actual sleep stale is reached.
Event‐related potential (ERP) asymmetries to emotional stimuli in a visual half‐field paradigm
Authors: KAYSER JÜRGEN , TENKE CRAIG , NORDBY HELGE , HAMMERBORG DAG , HUGDAHL KENNETH , ERDMANN GISELA 
Published: February 2007

AbstractTo investigate the hypothesis of a right hemispheric superiority in negative emotional processing, event‐related potentials (ERPs) were recorded from 17 sites (Fz, Cz, Pz, F3/4, F7/8, C3/4, T7/8, P3/4, P7/8, O1/2) in a visual half‐field paradigm. While maintaining fixation, right‐handed women viewed pictures of patients with dermatological diseases before (negative) and after (neutral) cosmetic surgery. A principal components analysis with Varimax rotation performed on ERPs revealed factors identified as N1, N2, early P3, late P3, late P3, and slow wave. Repeated measures analyses of variance performed on factor scores revealed a significant effect of emotional content for all factors except for N1. However, asymmetries in emotional processing were restricted to N2 and early P3, with maximal effects over the right parietal region. N2–P3 amplitude was augmented for negative and reduced for neutral stimuli over right hemisphere regions. Visual field presentation interacted with these asymmetries in enhancing amplitudes contralaterally for early but ipsilaterally for late ERP components. Overall, findings for N2 and P3 support theories of an asymmetry in emotional processing.
Disrupting human auditory change detection: Chopin is superior to white noise
Authors: LEVANEN SARI , SAMS MIKKO 
Published: February 2007

AbstractA deviant sound in a sequence of standard sounds elicits a neuromagnetic mismatch field (MMF) reflecting change detection based on the auditory sensory memory trace. To illuminate the nature of this trace, we investigated the effects of white noise and music maskers on the MMF. The stimuli were delivered to the participant's right ear, and the maskers were delivered to the same or contralateral ear. Only maskers containing transients (music) presented to either car abolished the MMF. In parallel, the ability to discriminate the deviants decreased dramatically, probably because of integration of transient features of the music to the neural representations of standards and deviants. As a result, the similarity of these representations prevents change detection. White noise affected the MMF amplitude only when presented to the same ear to which the stimuli were presented. All maskers decreased the M100 but not the M50 amplitude, suggesting that the neural generators behind these responses are functionally separate.
The cardiovascular startle response: Anxiety and the benzodiazepine receptor complex
Authors: BERNTSON GARY G. , HART SHERI , SARTER MARTIN 
Published: February 2007

AbstractBenzodiazepine receptor (BZR) agonists are prototypic anxiolytic agents, whereas BZR inverse agonists exert anxio‐genic effects. The effects of these compounds offer a potentially important pharmacological model system to examine the central mechanisms of anxiety. In accord with its putative anxiogenic properties, we previously found that the BZR partial inverse agonist, FG 7142, enhances the cardiovascular defensive response to a nonsignal acoustic stimulus in rats. In contrast, we found in the present study that this agent attenuates both the somatic and cardiovascular components of the acoustic startle response. BZR agonists and inverse agonists are known to modulate the basal forebrain cortical cholinergic system, and we consider the potential involvement of this system in the disparate psychophysiological actions of FG 7142 and in anxiety states in general.
Fear and the startle reflex: Blink modulation and autonomic response patterns in animal and mutilation fearful subjects
Authors: HAMM ALFONS O. , CUTHBERT BRUCE N. , GLOBISCH JUTTA , VAITL DIETER 
Published: February 2007

AbstractThe present study was designed to examine the pattern of startle reflex modulation and autonomic responses for individuals high in animal or blood‐injury fear when viewing pictures of their feared objects. Sixteen individuals in each fear group and 16 low‐fear control individuals viewed 32 color slides depicting fear‐relevant, unpleasant but fear‐unrelated, neutral, and pleasant scenes. Free viewing times were assessed in a second phase of the procedure as an index of avoidance behavior. Exposure to pictures of feared objects resulted in a consistent startle reflex potentiation and behavioral avoidance in both fear groups. This activation of the basic aversive system was independent of the autonomic pattern of the fear responses, which differed for the high‐fear groups. These results suggest that the probe startle response indexes the organism's basic motivational disposition and add new information to the assessment of fear.
Psychophysiological response of ADHD children to reward and extinction
Authors: IABONI FIORELLA , DOUGLAS VIRGINIA I. , DITTO BLAINE 
Published: February 2007

AbstractIn this study, we examined heart rate and skin conductance levels of 18 children with attention‐deficit hyperactivity disorder (ADHD) and 18 normal children as they performed a repetitive motor task during reward and extinction conditions. Fowles (1980, Psychophysiology, 17, 87–104; 1988, Psychophysiology, 25, 373–391) suggested that psychophysiological responsivity reflects activity in two of Gray's (1982, The neuropsychology of anxiety, Oxford University Press; 1987, The psychology of fear and stress, Cambridge University Press) motivational systems; heart rate reactivity during reward reflects activity in the behavioral activation system, and skin conductance reactivity during extinction reflects activity in the behavioral inhibition system. As predicted, control children showed increased heart rate when reward was present and increased skin conductance when reward was removed. Compared with controls, ADHD children failed to show increased skin conductance levels during extinction, suggesting a weak behavioral inhibition system. ADHD children also displayed faster heart rate habituation to reward.
A plethysmographic method for demonstrating the response specificity of the oral vascular bed
Authors: GOLDSTEIN HARRIS S. , EDELBERG ROBERT 
Published: February 2007

AbstractIn this paper, we describe a new method for measuring the oral plethysmogram, and we assess its sensitivity and specificity under differing psychological stimulation. Finger and palate pulse amplitudes and blood pressure were monitored while individuals (N= 13) performed several tasks: mental arithmetic, nausea imagery, fear imagery, and anger imagery. Pulse pressure, having a major effect on pulse amplitude, was partialed out in analyses. Palate pulse amplitude increased significantly in response to the degree to which the individual felt irritated, judged, nauseated, or angry. In contrast, finger pulse amplitude changed significantly only in the arithmetic task and, unlike the palate, showed a decreased amplitude with increased irritation and being judged. Results indicate that the oral plethysmogram can serve as a reliable measure of oral mucosal vasomotor reactivity and that it has a different pattern of response specificity than does the finger.