bluuebunny/crossref_metadata_2025 huggingface dataset:
Resting EEG in first‐episode and chronic schizophrenia
Authors: SPONHEIM SCOTT R. , CLEMENTZ BRETT A. , IACONO WILLIAM G. , BEISER MORTON
Published: February 2007

We examined the frequency characteristics of the electroencephalogram (EEG) in 102 schizophrenic patients (44 first‐episode and 58 chronic patients) and 102 normal comparison subjects. EEGs of schizophrenic patients had more delta (1–3 Hz) and theta (3.125–8 Hz) activity and less alpha (8.125–13 Hz) activity than normal comparison subjects. There were no significant differences in the EEG frequency composition of first‐episode and chronic patients. Because first‐episode and chronic patients were characterized by different disorder durations and treatment histories, the similarity of their EEGs suggests that EEG abnormalities are stable characteristics of schizophrenia and are not treatment‐related epiphenomena. A principal components analysis of EEG power bands identified an augmented low frequency‐diminished alpha component and a beta component. Schizophrenic patients had significantly higher scores on the augmented low frequency‐diminished alpha component than did normal comparison subjects, and there was no significant group difference in scores on the beta component. The findings of this investigation suggest that EEG abnormalities in schizophrenia reflect aspects of brain dysfunction.
Mental processing during reactions toward and away from a stimulus: An ERP analysis of auditory congruence and S‐R compatibility
Authors: RAGOT RICHARD , FIORI NICOLE
Published: February 2007

In its first usage, stimulus‐response (S‐R) compatibility defined strict S‐R relationships. The later use of more complex two‐dimensional stimuli led to the formulation of the Simon effect as a tendency to respond toward the side of stimulation. Ragot and Guiard (1992, European Journal of Cognitive Psychology, 4, 219–232) observed an inversion of the Simon effect in the auditory modality. The present study was undertaken to present a more thorough observation of this seemingly paradoxical inversion through the use of brain event‐related potentials (ERPs). Two experimental variables were manipulated: (a) stimulus congruence, expressing the degree of correspondence between two randomly varying conflictual or nonconflictual attributes of the stimulus (spoken word droite or gauche presented to the right or left ear), and (b) S‐R compatibility as such, expressing the relationship between the relevant stimulus attribute (word) and the responding hand. Results show that the nature of the spoken word acts on N100 latency and is therefore the first stimulus attribute to be processed. Data on P300 indicate that S‐R compatibility is the last variable to be taken into account. The observed results are integrated into a cascade/parallel model.
The psychophysiology of crying
Authors: GROSS JAMES J. , FREDRICKSON BARBARA L. , LEVENSON ROBERT W.
Published: February 2007

Two conflicting views have emerged as to why people cry when they are sad. One suggests that crying serves homeostasis by facilitating recovery; the other suggests that crying produces an aversive high‐arousal state that motivates behavior aimed at ending the tears. To test hypotheses drawn from these views, we showed a short film known to elicit sadness to 150 women. During this film, 33 subjects spontaneously cried and 117 did not. Subjects who eried exhibited more expressive behavior and reported feeling more sadness and pain than did subjects who did not cry. Crying also was associated with increases in somatic and autonomic nervous system activity. The increases in autonomic activity could not be accounted for solely by the increases in somatic activity. Crying is thus associated with an aversive state, including negative emotion and a complex mixture of sympathetic, parasympathetic, and somatic activation, and we speculate about the functional implications of these findings.
For Distinguished Contributions to Psychophysiology: John Stern
Authors: Porges Stephen W.
Published: February 2007

At the Thirty‐Third Annual Meeting of the Society for Psychophysiological Research, the award for Distinguished Contributions to Psychophysiology was presented to John Stern by Stephen W. Porges, on behalf of the Society's Awards Committee. The following is the text of the citation given at the meeting on October 23, 1993.
Two separate frontal components in the N1 wave of the human auditory evoked response
Authors: ALCAINI M. , GIARD M. H. , THÉVENET M. , PERNIER J.
Published: February 2007

Scalp current density analysis of the auditory evoked response to 1‐kHz tone bursts delivered at various interstimulus intervals (ISIs) (from 1 s to 2 min in separate runs) shows that two different frontal components can be observed and functionally dissociated in the N1 time range: one is elicited for all ISIs, peaks at about 95 ms poststimulus, and has a full recovery time below 8 s; the second is elicited only by infrequent stimuli (ISIs > 4 s), peaks around 140 ms, and significantly increases in amplitude with increasing ISIs. The first component can be considered a new obligatory component in N1 elicited simultaneously with the responses in auditory cortex; the later component could correspond to the orienting Component III of Näätänen and Picton (1987).
Focusing on the N400: An exploration of selective attention during reading
Authors: GUNTER THOMAS C. , JACKSON JANET L. , KUTAS MARTA , MULDER GIJSBERTUS , BUIJINK BERNARDINA M.
Published: February 2007

In a series of two experiments, subjects read sentences wherein words were flanked in the lower visual field by irrelevant words (i.e., flankers). The visual angle between the words in the sentence and the flanker words was manipulated (i.e., 0.57°, 0.97°, 1.37°). Sentence endings were either congruent or inconguruent; incongruent endings elicited a large N400 component. Flanker effects were observed for sentence final words on electrophysiological measures during the reading task and on subsequent recognition memory performance for sentence final and new words. For both measures, the flanker effect interacted with the congruency of the sentence ending as well as the visual angle between the sentence final word and its flanker. The largest and earliest flanker effects were observed for congruent endings at the smallest visual angle (0.57°); congruent endings and flankers in intermediate visual angle (0.97°) conditions displayed a similar flanker‐related negativity but with a longer onset latency (490 vs. 280 ms). Congruent endings and their flankers in the largest visual angle (1.57°) conditions revealed no flanker effect.
Developmental dyslexia and attention dysfunction in adults: Brain potential indices of information processing
Authors: DUNCAN CONNIE C. , RUMSEY JUDITH M. , WILKNISS SANDRA M. , DENCKLA MARTHA B. , HAMBURGER SUSAN D. , ODOU‐POTKIN MARTHA
Published: February 2007

Event‐related brain potentials (ERPs) were recorded from a group of 13 men with severe developmental dyslexia and 15 matched normal controls. Auditory and visual stimuli, presented in separate reaction time tasks of graded difficulty, were used to elicit ERPs. No group differences in P300 were seen under relatively undemanding task conditions. However, as task demands increased, visual P300 was reduced in the dyslexic men as compared with the normal readers. An Abbreviated Conners Parent Rating Scale was used to assess retrospectively childhood symptoms of attention‐deficit hyperactivity disorder (ADHD). Additional analyses revealed that the dyslexics with a history of many symptoms of ADHD in childhood (high ADHD) accounted for the group differences in P300; the dyslexics with a history of few or no such symptoms (low ADHD) were indistinguishable from the controls at all electrode sites. Furthermore, whereas the low‐ADHD dyslexics showed the same himispheric asymmetry in auditory P300 as did the controls (right > left), auditory P300 was more symmetrically distributed in the high‐ADHD dyslexics. The results are interpreted as suggesting that a distinct brain organization may characterize dyslexic men with a history of concomitant deficits in attention.
Autonomic indicators of information processing related to conditioning
Authors: KIRSCH PETER , BOUCSEIN WOLFRAM , BALTISSEN RÜDIGER
Published: February 2007

The aim of the present study was to quantitatively investigate the role of information processing in conditioning using stimuli with varying amounts of information content. A letter reproduction task varying in complexity served as the unconditioned stimulus. In the first experiment, we tested the indicator function of electrodermal and car‐diovascular variables. The amount of information processing resources required emerged most clearly in electrodermal reactions (EDRs), showing an increase with increasing stimulus information content. A second experiment was performed using the same design to confirm the role of processing resources allocation during conditioning by means of an independent indicator. A reaction time task was introduced as a measure of information processing resources utilized. The results paralled the dependence of EDRs on stimulus information content, as was found in the first experiment.
Variation in the latencies and amplitudes of N400 and NA as a function of semantic priming
Authors: DEACON DIANA , MEHTA ASHESH , TINSLEY CLAYTON , NOUSAK JO MANETTE
Published: February 2007

The purpose of this study was to determine whether the latencies of two event‐related potential (ERP) components, the NA and N400, were sensitive to semantic priming. Subjects performed a semantic judgment task, which was designed in such a way that the N400 could be examined without overlap from the P3. Priming effects on the latencies of both NA and N400 were most apparent at frontocentral sites. The amplitude of NA was not significantly affected by priming. The amplitude of N400 was smaller for primed than for unprimed words, but the effect was significant only at centroposterior sites. Current source density (CSD) analyses performed on the ERP data suggested the activation of multiple generators in the N400 time region. The ERP and CSD data were consistent with the existence of two types of N400, a frontal N400 that varies in latency as a function of semantic priming, and a posterior N400 that varies in amplitude.
Assessment of female sexual arousal: Response specificity and construct validity
Authors: LAAN ELLEN , EVERAERD WALTER , EVERS ANDREA
Published: February 2007

Specificity of vaginal pulse amplitude and vaginal blood volume in reaction to visual sexual stimuli was investigated by comparing responses to sexual, anxiety‐inducing, sexually threatening, and neutral film excerpts. Subjective sexual arousal, body sensations, emotional experience, skin conductance, and heart rate were monitored along with the genital measures. Self‐report data confirmed the generation of affective states as intended. Results demonstrated response specificity of vaginal vasocongestion to sexual stimuli. In terms of both convergent and divergent validity, vaginal pulse amplitude was the superior genital measure. Skin conductance discriminated among stimuli only to a small degree, whereas heart rate failed to discriminate among stimuli altogether.
Language, memory, and aging: An electrophysiological exploration of the N400 during reading of memory‐demanding sentences
Authors: GUNTER THOMAS C. , JACKSON JANET L. , MULDER GIJSBERTUS
Published: February 2007

Twenty‐four young and 24 middle‐aged academics carried out a language recognition task in which sentences were presented that made either a high or a low demand on working memory (WM). The sentences ended either normally (i.e., congruent) or with an incongruous word. Middle‐aged subjects had smaller WM scores, a marginally slowed down recognition performance, and a smaller and delayed N400 component. The event‐related potential (ERP) difference between congruent and incongruent endings was smaller in the high‐load condition for younger subjects and totally disappeared for the middle‐aged subjects. ERPs for all subjects showed a WM‐related positivity in the middle of the sentence and a WM‐related negativity at the sentence ending. These shifts could be associated with either storage and retrieval processes or with clause wrap‐up processes. Most ERP‐effects were dependent on WM capacity. Age differences in sentence processing are not simply explained by age itself but depend to a large extent on individual memory capacity.
Sources of P300 attenuation after head injury: Single‐trial amplitude, latency jitter, and EEG power
Authors: UNSAL AYSE , SEGALOWITZ SIDNEY J.
Published: February 2007

Single 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

Lateral 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

This 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.
Albert F. Ax (1913–1994)
Authors: Stein John , Fetzner Joanne
Published: February 2007

Al Ax's contributors to psychology and psychophysiology span almost 40 years. He had many colleagues with whom he communicated openly and generously about his early psychophysiological research. One of these, John Stern, comments below. Joanne Fetzner, a close associate of Al's during his years as director of the Psychophysiology Laboratory of the Lafayette Clinic in Detroit, Michigan, and as founder of the Society for Psychophysiological Research and founding editor of Psychophysiology, provides a more detailed account of Al' life and his contributions to psychophysiological research as well as his untiring efforts to gather together this research into a scientific journal and its scientists into a formal society, both dedicated to the furtherance and scientific recognition of psychophysiological research.
Long‐term extension to sleep ‐Are we really chronically sleep deprived?
Authors: Harrison Y. , Horne J. A.
Published: February 2007

During 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

The 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

Although 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

Schizophrenia 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

Electrodermal 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

Obrist'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

The 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

The 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

The 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

Twenty 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

The 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

To 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

A 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

Benzodiazepine 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

The 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

In 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

In 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.
Acid inputs from the atmosphere in the United Kingdom
Authors: Fowler D. , Cape J.N. , Leith I.D.
Published: February 2007

Abstract. Inputs of acidity to the ground arise through two distinct routes: wet deposition which includes all acidity deposited in rain and snow and dry deposition, the direct sorption of SO2, NO2 or HNO3 gases by vegetation or soil surfaces. The acidity from dry deposition of SO2 and NO2 is created during the oxidation of deposited SO2 and NO2 to SO24 and NO3− respectively. The areas of Britain experiencing the largest wet deposition of acidity are the high rainfall areas of the west and north, in particular the west central highlands of Scotland, Galloway and Cumbria where inputs exceed 1 kp H+ ha−1 annually. Wet deposited acidity in the east coast regions of Britain is in the range 0.3–0.6 kg H+ ha−1 a−1. Monitoring data for rainfall acidity at rural sites throughout northern Britain show a decline in deposited acidity of about 50% during the last six years. Dry deposition is largest in the industrial midlands and southeast England and in the central lowlands of Scotland, where concentrations of SO2 are largest. In these regions the dry deposition of SO2 following oxidation may lead to acid inputs approaching 3 kg H+ ha−1 a−1 and greatly exceeding wet deposition.
Acid rain: a review of current controversy
Authors: SASANOW STEVE
Published: February 2007

IN 1984, there was no more body debated scientific issue than ‘acid rain’—the somewhat amorphous term covering a number of industrial‐based airborne pollutants that chemically alter the pH of precipitation and, thus eventually, of soil and water resources.
Improvement of native grassland in the uplands
Authors: Newbould P.
Published: February 2007

Abstract. Recent progress in the techniques for improving the quality and quantity of herbage produced from indigenous hill pasture is described. There is general agreement on the main technical requirements for most situations. Knowledge of hill soils and vegetation and of the proposed grazing strategies for hill sheep are required initially so that the most economical and biologically appropriate method can be selected.

In brief, soil pH must be raised by liming to at least 5.5; for each hectare, between 40–60 kg P and 80–100 kg K must be added plus a starter dressing of between 50–100 kg N after which a seeds mixture of grasses and white clover (25–30 kg seed ha−1) should be sown. Inoculation of clover seed with rhizobia is advised for all hill soil types but is essential for white clover sown in deep peat. Seeds must be sown in April or May, cultivation should be limited as far as possible for both technical and financial reasons, and new pastures should be grazed lightly initially, with subsequent rest periods to aid the persistence of white clover. Maintenance dressings of lime and fertilizer are required, more so in wetter areas. Careful monitoring of stock grazing recently improved hill pasture is advised to check for the occurrence of trace element problems.

It is clear that the key to more efficient livestock rearing in the hills and uplands lies in pasture improvement and optimum utilization and maintenance of the upgraded pastures.
An assessment of the bracken problem in relation to hill farming in Scotland
Authors: Birnie R.V.
Published: February 2007

Abstract. The reasons for bracken encroachment in Scottish hill land are examined. The cost effectiveness of bracken control methods are discussed and it is shown how the real cost of aerial spraying, the most practical method, has increased in the last decade. The waiving of the follow‐up requirements under the DAFS grant schemes may alter this cost situation in the future. The need for more accurate estimates of the extent of the bracken problem is highlighted by the possible link between bracken and cancer in humans. Recent surveys utilizing remote sensing techniques are described and the cost of a full bracken eradication programme is estimated to be c.£80 million which is contrasted with the current level of grant assistance of c.£135 000 a−1. The use of bracken as biofuel is considered as an alternative to eradication.
The use of plaster of Paris in the study of soil structure
Authors: Patrick E. A. Fitz , Mackie L. A. , Mullins C. E.
Published: February 2007

Abstract. Plaster of Paris (CaSO4½H2O) infiltration was used (i) to study the continuity of cracks and pores and the variation of macroporosity and crack width with depth and (ii) to maintain an undisturbed seedbed for subsequent resin impregnation. Examples are also given in which the remains of gaps between and at the bottom of the furrow slice can be clearly seen. The method is a useful qualitative visual technique, limited to the larger soil pores. Due to this limitation, it is more useful for showing pore continuity than for quantifying porosity.
A drainage experiment on a peaty gley soil at Kershope Forest, Cumbria
Authors: Pyatt D.G. , Anderson A.R. , Stannard J.P. , White I.M.S.
Published: February 2007

Abstract. The effects of ditch spacing (10, 20 and 40 m) and depth (60 and 90 cm) on watertable depth were measured in a Sitka spruce plantation before and after drainage and finally after part of the plantation had been clearfelled. No significant differences in watertable depth were recorded between drainage treatments mainly because the ditch spacings were too large but also because of inadequate calibration of the site before the drainage treatments were applied. By the time of felling, the site had been thoroughly calibrated for the behaviour of the watertable, enabling sensitive comparisons to be made, and a significant rise in the watertable was recorded after felling.
A trial to determine the lime requirement for reseeded grassland on a peaty hill soil
Authors: Dampney P.M.R.
Published: February 2007

Abstract. Lime was applied in summer 1981 at rates up to 201 ha−1 prior to reseeding an unimproved peaty hill soil. A marked pH gradient with depth developed showing that 3 years after application lime had very little effect below a depth of 5 cm. Soil pH values for 0–7.5 cm samples were: nil lime‐4.2; 1 t ha−1‐pH 4.3; 2 tha−1‐pH 4.6; 4 t ha−1‐pH 5.0; 6 t ha−1‐pH 5.6. In the 0–2.5 cm layer pH values were much higher.

In all years at least 80% of maximum yield was achieved from an initial application of 21 ha−1 lime. Botanical analysis showed that maximum persistence of sown species, perennial ryegrass and timothy, occurred from 2 t ha−1 lime; 6 t ha−1 lime was necessary for maximum persistence of clover. Lime application had only small effects on the mineral composition of the herbage.
The nitrate issue—a review
Authors: THOMPSON ROBIN
Published: February 2007

IT IS now almost two years since the Royal Society published its authoritative study group report, The Nitrogen Cycle of the UK, the first comprehensive account of the nitrate issue. For the first time a complete picture was revealed of the nitrogen cycle in the UK and the Study Group was able to make a wide‐ranging series of recommendations for future research.
Soil acidification during more than 100 years under permanent grassland and woodland at Rothamsted
Authors: Johnston A. E. , Goulding K. W. T. , Poulton P. R.
Published: February 2007

Abstract Soil samples have been taken periodically from unlimed plots of the 130‐year‐old Park Grass Experiment and from the 100‐year‐old Geescroft Wilderness at Rothamsted. Changes in the pH of the samples show how acidification has progressed. The soils are now at, or are approaching, equilibrium pH values which depend on the acidifying inputs and on the buffering capacities of the soils. We have calculated the contributions to soil acidification of natural sources of acidity in the soil, atmospheric deposition, crop growth and nutrient removal, and, where applicable, additions of fertilizers. The relative importance of each source of acidification has changed as the soils have become more acid. Acid rain (wet deposited acidity) is a negligible source, but total atmospheric deposition may comprise up to 30% of acidifying inputs at near neutral soil pH values and more as soil pH decreases. Excepting fertilizers, the greatest causes of soil acidification at or near neutral pH values are the natural inputs of H+ from the dissolution of CO2 and subsequent dissociation of carbonic acid, and the mineralization of organic matter.

Under grassland, single superphosphate and small amounts of sodium and magnesium sulphates have had no effect on soil pH, whilst potassium sulphate increased soil acidity slightly. All of these effects are greatly outweighed under grassland, however, by those of nitrogen fertilizers. Against a background of acidification from atmospheric, crop and natural inputs, nitrogen applied as ammonium sulphate decreased soil pH up to a maximum of 1.2 units at a rate in direct proportion to the amount added, and nitrogen applied as sodium nitrate increased soil pH by between 0.5 and 1 unit.
The influence of soil macroporosity on water retention, transmission and drainage in a clay soil
Authors: Leeds‐Harrison P.B. , Shipway C.J.P. , Jarvis N.J. , Youngs E.G.
Published: February 2007

Abstract. Reductions in hydraulic conductivity and specific yield (drainable porosity) of large cores of Evesham clay soil were observed for periods up to 40 days under continuous ponding. A strong linear relationship (r2= 0.94) found between these two variables was used as parameter input to a layered drainage model for mole drained soils. Model results indicated that soils of lower drainable porosity and hydraulic conductivity produced higher peaked hydrographs widi faster recessions. These results are discussed in relation to the effects of soil loosening on drain response in heavy clay soils.
Drainage guidelines for the soils of Scotland
Authors: Morris R.J.F. , Shipley B.M.
Published: February 2007

Abstract. Guidelines are proposed to indicate the range of drainage problems encountered under Scottish conditions, along with some of the main factors to be considered for the treatment of these problems. The identified categories are briefly discussed, together with the potential application of the guidelines.
Measurement, interpretation and modelling of soil compaction
Authors: Smith D.L.O.
Published: February 2007

Abstract. The analysis of some experimental field results is used to illustrate the problem of measuring and evaluating compaction treatment effects below wheel ruts of different depths. A solution to the problem is described which traces vertical soil movement to allow comparisons between treatments to be made using soil elements which derive from the same depth in the undisturbed profile, irrespective of their depths in the compacted profile.

A soil compaction model, which predicts the changes in dry bulk density resulting from the passage of wheels, is briefly described. Examples are given of its use in comparing the compaction caused by various types and arrangements of wheels and in assessing the contribution made by a particular input variable.
Is regression what you really want?
Authors: Webster R.
Published: February 2007

Abstract. Regression is frequently abused in soil research. Its proper use is for statistical prediction. It may also be used to calculate equations for calibration. A regression equation may be used to express a functional relation between two soil variables that are thought to be related by some simple mathematieal law but only where one of the variables is known exactly. In most other circumstances regression is inappropriate. Where departures from a functional relation are due to errors of measurement and sampling fluctuation it should be replaced by a structural analysis to find the best equation. Where the underlying relation is truly bivariate it should be described as such.