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PubMed2004

Cognitive potentials in the basal ganglia-frontocortical circuits. An intracerebral recording study.

We studied cognitive functions related to processing sensory and motor activities in the basal ganglia (BG), specifically in the putamen and in cortical structures forming the BG-frontocortical circuits. Intracerebral recordings were made from 160 brain sites in 32 epilepsy surgery candidates. We studied P3-like potentials in five different tests evoked by auditory and visual stimuli, and two sustained potentials that are related to cognitive activities linked with movement preparation: BP (Bereitschaftspotential) and CNV (contingent negative variation). We compared the presence of a potential with a phase reversal or an amplitude gradient to the absence of a generator. All of the studied cognitive potentials were generated in the BG; the occurrence in frontal cortical areas was more selective. The frequency of all but one potential was significantly higher in the BG than in the prefrontal and in the cingulate cortices. The P3-like potentials elicited in the oddball paradigm were also more frequent in the BG than in the motor/premotor cortex, while the occurrence of potentials elicited in motor tasks (BP, CNV, and P3-like potentials in the CNV paradigm) in the motor cortex did not significantly differ from the occurrence in the BG. The processing of motor tasks fits with the model by Alexander et al. of segregated information processing in the motor loop. A variable and task-dependent internal organisation is more probable in cognitive sensory information processing. Cognitive potentials were recorded from all over the putamen. The BG may play an integrative role in cognitive information processing.

Acoustic Stimulation↗
PubMed2002

The movement-related potential in children with migraine and tension-type headache.

Migraine is characterized by an elevated contingent negative variation (CNV) in adults and children. In the present study the movement-related potential preceding self-initiated movements, the Bereitschaftspotential, was investigated in 30 children (mean age 12 years) who were suffering from migraine and tension-type headache and in 16 healthy age-matched controls. Children pressed a button 80 times with the right index finger while movement-related potentials were recorded from frontal and central electrodes. Whereas healthy children evidenced positive movement-related potentials at left and midline positions, children with migraine and tension-type headache showed negative movement-related potentials at midline leads without lateralization. Negativity was even more pronounced in cases of migraine with than without aura symptoms.

Child↗
PubMed2006

Location of brain rhythms and their modulation by preparatory attention estimated by current density.

To test the hypothesis that there is a functional modulation of conventional EEG bands associated with preparatory attention, putative changes in the spontaneous brain rhythms and their associated cerebral sources were addressed. The goals of the present report were, first, to find the brain areas with maximal rhythmic activity before warning and imperative stimuli in a classic contingent negative variation (CNV) paradigm, and, second, to study the modulation of the EEG rhythms of these areas during the preparatory attention interval which precedes the S2 (imperative) stimulus. Trial by trial LORETA analysis found similar brain rhythm generators during both pre-S1 and pre-S2 intervals. Each theta, alpha and beta traditional EEG rhythm originates in several anatomically distinct brain structures. Preparatory attention is associated with a decrease in power in alpha (right and left occipital and temporal areas) and low-beta (left frontal, bilateral occipital and middle frontal areas) EEG bands. In these structures power changes associated with preparatory attention modulated either a dominant or a non-dominant oscillatory band, suggesting that non-dominant rhythms of a cerebral area have some functional relevance. Our results imply distributed regional sources for brain rhythms and support the view that during preparatory attention there is a modulation of the brain sources generating alpha and beta brain rhythms. Moreover, the proposed combined approach makes it possible to explore the definition of a given brain area not only anatomically, but also by the frequency content and the functional reactivity of the electrical rhythms that it generates.

Adolescent↗
PubMed2003

Short-term mobilization of processing resources is revealed in the event-related potential.

This study investigates whether an occasional effortful improvement of performance, as asked for by a precue, is reflected in event-related potential (ERP) changes. To estimate the limits of possible effort-induced behavioral and ERP changes, we manipulated the time between precue and imperative stimulus (IS; precue interval, PCI). The subjects could, in fact, improve their performance in the effort trials, with all but the shortest PCI. The postcue ERP revealed a fronto-central contingent negative variation (CNV), which was preceded by a frontal positive/occipital negative wave (P2/N2). Both the P2/N2 and the CNV were larger for effort than for standard trials for all PCIs. For the shortest PCI (300 ms), the CNV increase was seen after the IS. The CNV increase for PCIs 600 and 300 began at about 400 ms postcue. The results suggest that effortful performance improvement is associated with prior increase of a frontocentral CNV and a preceding P2/N2. The CNV increase is thought to reflect the activity of a frontal executive process by which additional processing resources can be mobilized on a trial-to-trial basis within less than 500 ms.

Adult↗
PubMed2007

Effects of ageing on cognitive task preparation as reflected by event-related potentials.

OBJECTIVE: The anticipation of complex cognitive tasks involves effortful preparation being reflected in the contingent negative variation (CNV) of the event-related potential. In the literature there are contradictory results concerning the effect of age on this potential. We wanted to investigate effects of age, time-on-task, and task difficulty on the CNV. METHOD: Young and middle-aged participants performed a visual search and a non-search task during an early and a late phase of a 6-h session. RESULTS: Performance data revealed increased response times and error rates for middle-aged vs. young participants. Most importantly, an increased frontal CNV amplitude was found for the older participants, especially pronounced in the search task. A late positivity which was elicited to the offset of the preceding stimulus was increased for the middle-aged vs. young group in the visual search task only. There was no effect of time-on-task on performance, but the CNV became larger with time-on-task in the search task while it became smaller in the non-search task. CONCLUSIONS: The results suggest an enhancement of effortful task preparation for middle-aged participants especially when the task is difficult. SIGNIFICANCE: This underlines the role of the CNV as a neurophysiological indicator for effortful cognitive preparation.

Adolescent↗
PubMed2000

Are the periodic changes of neurophysiological parameters during the pain-free interval in migraine related to abnormal orienting activity?

OBJECTIVE AND METHODS: Migraine patients are characterized by increased amplitude and reduced habituation of contingent negative variation (CNV). Furthermore, the CNV underlies periodic changes during the pain-free interval, being maximal before attack. The periodicity of CNV is related to periodic changes in habituation, probably due to variation of orienting activity during the pain-free interval. CNV and orienting response (OR) were studied in 20 females suffering from migraine without aura and in 12 matched healthy females. The neurophysiological recordings in the group of patients were performed 1-4 days before and 4 days after a migraine attack. The amplitudes and habituation of early and late components and total CNV were calculated. The OR was assessed using the habituation of the skin conductance response (SCR) and alpha blocking (AB). The non-parametric tests were employed for statistical analysis. RESULTS: There were no differences between the two groups for habituation of all CNV components and of SCR following an attack. However, the habituation of AB was significantly reduced in migraine. Before attack we observed a significantly reduced habituation of the early and total CNV and of the AB compared to controls and recordings performed after an attack. The habituation of the late component and of SCR remained unchanged. CONCLUSIONS: The abnormal habituation could be explained by the periodic changes of physiological parameters during the pain-free interval. The impaired habituation of early CNV in migraine is associated with increased orienting activity seen only in the central component (AB) of OR.

Adult↗
PubMedDate not supplied

Event-related covariances during a bimanual visuomotor task. II. Preparation and feedback.

Event-related covariance (ERC) patterns were computed from pre-stimulus and feedback intervals of a bimanual, visuomotor judgment task performed by 7 right-handed men. Late contingent negative variation (CNV) ERC patterns that preceded subsequently accurate right- or left-hand responses differed from patterns that preceded subsequently inaccurate responses. Recordings from electrodes placed at left frontal, midline antero-central, and appropriately contralateral central and parietal sites were prominent in ERC patterns of subsequently accurate performances. This suggests that a distributed cortical 'preparatory network,' composed of distinct cognitive, integrative motor, somesthetic, and motor components, is essential for accurate visuomotor performance. ERC patterns related to feedback about accurate and inaccurate responses were similar to each other in the interval immediately after feedback onset, but began to differ in an interval spanning an early P300 peak. The difference became even greater in an interval spanning a late P300 peak. For both early and late P300 peaks, ERC patterns following feedback about inaccurate performance involved more frontal sites than did those following feedback about accurate performance. Together with the stimulus- and response-locked results presented in part I, results of this study on the preparatory and feedback periods suggest that ERCs show salient features of the rapidly shifting, functional cortical networks that are responsible for simple cognitive tasks. ERCs thus provide a new perspective on information processing in the human brain in relation to behavior--a perspective that supplements conventional EEG and ERP procedures.

Adult↗
PubMed1999

Slow cortical potentials in migraine: a comparison of adults and children.

Amplitudes of contingent negative variation (CNV) in 40 migraine patients were studied during the pain-free period and compared with healthy controls (n = 24). The early component (initial CNV) is especially more negative in migraine patients. Within the migraine group, 14 children with migraine without aura (mean age 13.6 years) were compared with 11 healthy children (mean age 12.4 years). Migraine children differ from healthy children in the same manner that adult migraine patients differ from healthy adults. The CNV of five healthy children did not differ from the CNV of their siblings suffering from migraine. We suggest that there is a family-related cortical hypersensitivity which does not necessarily lead to the development of migraine.

Adolescent↗
PubMed2003

Assessment of the state of activation of the cortical zones in humans during visual attention and selection.

The state of cortical activation during visual symbol shape and position selection tasks was assessed in humans in terms of the magnitude of prestimulus negativity (contingent negative variation, CNV) and the amplitude of the N1-P3 complex in evoked potentials (EP). Evoked potentials in the frontal parietal, occipital, and temporal leads were recorded in 18 young healthy subjects in two sets of experimental conditions: in a screened chamber and in an "open field" beside the experimenter, who communicated the results to the subjects and guided them towards quicker and more precise responses to the target stimuli. The maximum magnitudes of CNV and evoked potentials during selective attention were seen in the parietal areas, and additional increases of activation indexes were observed in the "open field," where subjects' motivation was enhanced. The state of readiness (CNV) was an informative measure of cortical activation, as it determined the parameters of subsequent evoked potentials; the more marked the readiness, themore marked and stable were EP. Comparison of the situations of passive observation and selective reactions to stimuli revealed a reciprocal relationship between CNV in these conditions: the greater the magnitude of CNV in "passive" conditions, the smaller the difference between CNV in "passive" conditions and during selective attention and vice versa. We termed this "additivity of involuntary and voluntary attention." The fact that activation indexes were greatest in the parietal areas suggests that the occipital-parietal system is dominant in visual selection tasks in humans.

Attention↗
PubMed1994

Motor and non-motor aspects of slow brain potentials.

In order to study motor and non-motor aspects of the contingent negative variation (CNV), fifteen right-handed subjects were asked to perform tightly controlled responses in a WS-S1-S2 paradigm. WS was a non-informative warning signal; S1 and S2 provided information about the response required at S2. This information was either delivered before a block of trials (Simple), at S1 (Precued), or at S2 (Choice). Negativity was larger prior to the informative than to the non-informative stimulus, suggesting the presence of a component called stimulus-preceding negativity (SPN). This finding supported the hypothesis that the late CNV consists of a readiness potential and an SPN. The scalp distribution of the SPN was different before S1 and before S2. The significance of these components is discussed in terms of motor preparation, stimulus anticipation and energetical processes.

Adult↗
PubMed1995

Programming the duration of a motor sequence: role of the primary and supplementary motor areas in man.

Event-related potentials were recorded in a reaction time (RT) paradigm, where the duration of a learned interval (either 0.7 s or 2.5 s) delimited by two brief button-presses was to be accurately controlled. A preparatory signal (PS) either did not give or gave prior information concerning the duration of the following response (neutral condition or primed conditions, respectively). In the latter case, the information was either validated (valid condition) or invalidated (invalid condition) by the response signal (RS). When duration was not known in advance (invalid and neutral conditions), RTs were longer before a response of short than long duration. This difference was not found under the valid condition. During the preparatory period (PP), the amplitude of the contingent negative variation (CNV) was larger when the duration was primed than when it was not. A larger CNV appeared when the PS primed a short rather than a long duration. This effect occurred in the early part of the PP over the supplementary motor area (SMA) and in its latest part over the primary motor area (MI). The RT and the electrophysiological pattern were interpreted as revealing the occurrence of programming operations regarding the temporal dimension of the response. The time course of the CNV over the SMA and MI suggested that these two areas were hierarchically organized. Between the RS and the onset of the response, differences probably related to programming effects were still found over MI: the activities were larger under the valid than under the neutral condition. However, no sign of deprogramming (expected in the invalid condition) was observed: similar amplitudes were found under the neutral and invalid conditions. Deprogramming operations seemed to be postponed during response execution where the invalid condition evoked larger activities than the two other conditions over the SMA. Finally, MI but not the SMA yielded a Bereitschaftpotential before the second press ending the response (i.e., during response execution). These results suggest that the duration of a motor response can be a part of the motor program and that the SMA plays a major role in programming processes but not in response execution, contrary to MI.

Algorithms↗
PubMed2001

Wait and see.

Anticipatory behavior is aimed at goals that can be reached in the near future. Underlying this behavior are neurophysiological processes, which realize a setting of brain structures involved in the future perception, information processing and action. Anticipatory behavior is accompanied by slow brain potentials, which are generated in the cerebral cortex. They are known as the readiness potential (RP), the contingent negative variation (CNV) and the stimulus preceding negativity (SPN). The RP reflects the timing of a future voluntary movement. The CNV reflects the preparation of a signaled movement and the simultaneous anticipatory attention for the imperative stimulus. The SPN reflects partly the anticipatory attention for the upcoming stimulus. Although these slow potentials are generated in the cortex, the paper shows that a subcortical input from basal ganglia, and in the case of the RP also from the cerebellum, is a necessary condition for their emergence. Slow cortical potentials are the result of concerted activity in a number of cerebral networks, in which the thalamus forms a crucial node. It is suggested that the reticular nucleus of the thalamus plays a pivotal role in anticipatory attention.

Attention↗
PubMed2006

Brain potentials indicate poor preparation for action in schizophrenia.

Impaired antisaccade performance in schizophrenia (SZ) may originate from poor task preparation, suggested by low amplitudes of the contingent negative variation (CNV) before antisaccades. To dissociate components of preparation we measured the CNV in standard pro- and antisaccades and a stimulus preceding negativity (SPN) in delayed pro- and antisaccades. In healthy controls the SPN had lower amplitudes than the CNV, reflecting mere stimulus expectation in SPN and combined stimulus expectation and action readiness in CNV. SZ patients had lower CNV amplitudes than controls, but there was no reliable indication of a general SPN reduction, suggesting a particular impairment of action readiness. The CNV and SPN amplitudes of controls were larger if tasks had incongruent (anti) compared to congruent (pro) S-R mappings. This difference was absent in SZ patients, suggesting a failure to activate specific resources for incongruent S-R mappings.

Adult↗
PubMed1991

[5-year follow-up study of brain function in the healthy aged--study of the relationship between environmental factors and results of psychiatric examinations].

In order to investigate the relationship between environmental factors and results of psychiatric examinations, a questionnaire survey studying these factors and neurophysiological examinations (electroncephalography (EEG), somatosensory evoked response (SER) and contingent negative variation (CNV)), as well as clinical neuropsychiatric examinations and intelligence scale (Hasegawa's dementia rating scale (HDRS) and Kohs's blocking design test (KBDT)), were performed on 41 healthy aged (61-80 years old) who were participants in programs of Osaka Prefectural Center for the elderly. Initial examinations were conducted in 1983 and the second in 1988 on the same subjects for the purpose of measuring the aging process over 5 years with regard to brain function. A total of 29 subjects, for a participation rate of 82.9% (excluding deceased and those who moved away from the area), attended the second examination. The results are summarized as follows. 1. When environmental factors were compared for 1983 and 1988, a reduction in participation in social activity was observed in some of the aged in 1988, although differences in their daily living situations were unchanged. 2. The mean scores of HDRS and KBDT were 31.9, 98.6 in 1983 and 30.2, 94.6 in 1988 respectively, with only 2 subjects showing considerable decline of intelligence. 3. With regard to the neurophysiological examinations, the number of subjects with peak latencies of SER that were abnormally prolonged increased in 1988, while there was little difference in their EEGs between 1983 and 1988. 4. From these results, it appears that the relation between declines in brain function and environmental factors, involves multiple factors that will require further study.

Age Factors↗
PubMed2003

EEG responses to visual erotic stimuli in men with normal and paraphilic interests.

Contingent negative variation and evoked potentials to visual erotic stimuli were recorded from 8 brain sites in a sample of 62 right-handed men aged 20-50, half of whom declared paraphilic interests and half claimed "normal" heterosexual interests. To quantify erotic preferences, a "variance quotient" (VQ) was calculated from scores on the Wilson Sex Fantasy Questionnaire using the formula VQ = Impersonal + Sadomasochistic fantasies/Intimate + Exploratory fantasies. Stimuli consisted of 57 paraphilic slides (depicting fetishistic and sadomasochistic themes), 57 heterosexual erotic slides (explicit pictures of nude women, coitus, and oral sex), and 57 neutral slides (landscapes and street scenes). The P600 response appeared to be the best indicator of erotic preferences, butthe locus of maximum arousal was different for paraphilic and heterosexual stimuli. The primary brain site for heterosexual arousal was P4 (right parietal), where there was a -.34 (p < .01) correlation between VQ and P600 (i.e., nonvariant males showed greater responses to normal erotic stimuli at this location). For paraphilic stimuli, there was a correlation of .26 (p < .05) between the VQ and P600 response at the F3 (left frontal) site (i.e., paraphilic men showed greater responses to paraphilic stimuli than normal men at this brain location). Dividing the sample into groups of 23 paraphilics and 23 heterosexual controls on the basis of their VQs showed that "normals" differentiated between stimulus types more at the P4 than paraphilics. Theoretical and clinical implications of these findings are discussed.

Adult↗
PubMed2004

Influence of sympathetic autonomic arousal on cortical arousal: implications for a therapeutic behavioural intervention in epilepsy.

Negative amplitude shifts of cortical potential are related to seizure activity in epilepsy. Regulation of the cortical potential with biofeedback has been successfully used to reduce the frequency of some patients' seizures. Although such behavioural treatments are increasingly popular as an alternative to pharmacotherapy, there has been no investigation of the mechanisms that might bridge the behavioural index of peripheral autonomic activity and the central regulation of arousal. Galvanic Skin Response (GSR) is a sensitive measurement of autonomic arousal and physiological state which reflects one's behaviour. Thus we investigated the effect of peripheral autonomic modulation on cortical arousal with the future intention of using GSR biofeedback as a therapeutic treatment for epilepsy. The cortical negative potential was induced using the paradigm called Contingent Negative Variation (CNV) and measured in different physiological states. A high skin resistance state (reflecting a state of relaxation) and a low skin resistance state (reflecting a state of arousal), were engendered by two opposing procedures of GSR biofeedback. The CNV negative potential, acting as an index of cortical excitation, was significantly greater in amplitude at high levels of skin resistance (relaxed state) than at low levels of skin resistance (aroused state). Our results suggest an inverse relationship between a peripheral measure of autonomic arousal and an index of cortical arousal, the CNV. Moreover, we demonstrate modulation of this arousal-related potential by a behavioural intervention, indicating a potential therapeutic use of arousal biofeedback using GSR in the management of treatment-resistant epilepsy.

Adrenergic Fibers↗
PubMedDate not supplied

How the brain anticipates an attack: a study of neurophysiological periodicity in migraine.

We investigated cortical excitability and the pattern of arousal in migraine patients using contingent negative variation (CNV) and EEG power spectrum analysis performed before and after a migraine attack. Twenty females suffering from migraine without aura and 12 healthy controls were enrolled in the study. In the group of patients, the CNV, EEG power spectrum and hemispheric asymmetry analyses were performed 1-4 days before the first day of an attack and 4 days following the last day with migraine. The recordings in healthy subjects were carried out on a day chosen by the participants. The comparisons were made using non-parametric procedures. After an attack no difference was found between patients and controls in EEG power spectrum, hemispheric asymmetry or CNV components (with the exception of the beta 1 power, which was more pronounced in patients). Before an attack, however, a significant increase in the power of delta and theta frequency bands, in the alpha asymmetry, and in early CNV amplitude were observed. The patients differed from controls both in the extent of cortical excitability and in the arousal pattern found. In such a way migraine is characterized by periodic CNV and EEG power spectrum changes during the pain-free interval. The abnormalities in cortical excitability and arousal were only observed before an attack, and could be used to predict the next migraine episode. We assume that these changes reflect the increased susceptibility of the migrainous brain to precipitating factors and the neurophysiological readiness to generate an attack. The time duration since the last attack must be taken into account when performing studies in the field of migraine research.

Adult↗
PubMed2002

Assessing cerebral dysfunction with probe-evoked potentials in a CNV task -- a study in alcoholics.

OBJECTIVES: Contrary to event-related potential (ERP) components N1, N2 and P3, slow ERPs have rarely been used in assessing cerebral dysfunction in mental disorders. Focussing on slow waves (SWs) and on patients with mild cerebral dysfunction, we recorded ERPs in alcoholics using a dual task design. METHODS: ERPs to auditory probes presented either 1s before the warning or 1s before the imperative stimulus of a visual contingent negative variation (CNV) paradigm were recorded from 33 scalp electrodes in 27 alcoholics following detoxification and 12 healthy controls. Independent component analysis (ICA) was used to separate potentially overlapping spatial components. RESULTS: In alcoholics compared to controls, probe ERPs showed increased N2, decreased P3 and increased negative SWs of two types appearing pre- and post-P3, respectively. Both negative SWs significantly correlated with neuropsychological indices reflecting verbal intelligence and memory functions. The increase in probe-evoked N1 and P3 potentials during CNV, putatively associated with enhanced cortical excitability, significantly correlated with clinical features of protracted alcohol withdrawal syndrome in alcoholics. CONCLUSIONS: Our experimental approach revealed two types of negative SWs which strongly correlated with neuropsychological deficits of mildly impaired patients. It is suggested that our methods might enhance diagnostic efficiency of ERPs. An electrophysiological measure of protracted alcohol withdrawal might be useful for managing central nervous system dysfunction in alcoholics.

Adult↗