Topography of CNV and PINV in schizotypal personality

The topography of the postimperative negative variation (PINV) was analyzed in participants with high and low scores on the German version of the Schizotypal Personality Questionnaire. Scalp amplitude and Laplacian maps of the terminal contingent negative variation (tCNV) and PINV and the time course of the PINV were compared between the two groups. CNV and PINV were induced with a delayed matching-to-sample task, in which the pattern of the imperative stimulus was either clearly or ambiguous matched to one of the two diamonds simultaneously presented as a warning stimulus 4.0 s earlier. Electroencephalograms were recorded with a DC amplifier (32 channels). Negativity increased from tCNV to PINV, especially at frontal sites, and the PINV was larger under ambiguous than under clear matching conditions. Low-scoring participants showed a right-sided predominance of the PINV, which was absent in high-scoring participants. These results resemble differences in the topography of the PINV between healthy control participants and those with schizophrenia under identical experimental conditions and suggest functional differences between tCNV and PINV.     

老年性抑郁症患者的伴随负电位变异研究

目的：探讨老年性抑郁症患者的伴随负电位（CNV）变异。方法：记录21例老年性抑郁症患者的事件相关电位CNV，并与33例正常对照者和39例非老年期的抑郁症患者的CNV进行比较。结果：老年性抑郁症患者的CNV变化与非老年期的抑郁症患者的CNV变异基本类似，但CV波幅降低更明显、命令后伴随负电位（PINV）出现率更高，反应时间进一步延长。结论：CNV可以作为评定老年性抑郁症患者大脑综合功能的辅助方法之一。     

A STUDY ON CNV OF PATIENTS WITH MENTAL RETARDATION

Objective:To investigate the variations of contingent negative variation(CNV)of petientswith mental retardation.Methods:The CNV was recorded in 16 children with mental retardation(MR)and 14healthly age-matched controls.And CNV retest was carried out in 11 children with MR after one yeat treatment ofPiracetam.Results:Compared with the normal control,the CNV of MR group showed prolonged postimperativenegative variation(PINV)duration(P<0.01)and total A-C duration(P<0.01),decreased amplitude B(P<0.01),and reduced preimperative A-S2 area(P<0.01).A comparison of the CNV of MR group was made be-tween before and after one year treatment of Piracetam and no significant difference was found.Conclusions:The significant CNV variations were found in children with MR and these abnormal changes presisted throughoutthe Piracetam treatment.     

Cognitive Determinants of the Postimperative Negative Variation

This study examined cognitive determinants of the postimperative negative variation (PINV), a slow brain potential observable after the onset of an imperative stimulus in a forewarned reaction time task. Controllability of the aversive imperative stimulus by a motor reaction and predictability of the contingency were varied in a factorial design. The exogenous portion of the slow negative wave was assessed in a passive listening condition using tones of the same quality as the imperative stimuli, but presented without forewarning. Results show that PINV not only occurs when control is absent but also during unpredictably gained control. Similarly, unpredictable lack of control yields a more negative potential than continual helplessness. Negativity elicited by the aversive tone alone was not significantly different from PINV during predictable lack of control. The order of conditions, which was manipulated between groups, did not affect amplitudes. It was concluded that contingency change is a crucial cognitive determinant of the PINV, whereas the effect of lack of control is difficult to differentiate from the sensory influence of the acoustic stimulation.     

CORTICAL SLOW POTENTIAL CHANGES IN MAN RELATED TO INTERSTIMULUS INTERVAL AND TO PRE TRIAL PREDICTION OF INTERSTIMULUS INTERVAL

Two experiments were performed to explore further the relationship between the cortical slow potential change known as the “contingent negative variation” (CNV) and the concept of “expectancy.” In Experiment I, 24 male Ss were presented click pairs, with inter-click intervals of 800, 1600 and 4800 msec (2 blocks of 10 trials each, counterbalanced between Ss for order), and instructed to press a key after the second click. Interval by order by trials analysis of variance showed interval to be the only significant factor: CNVs were lower and RTs longer as interval increased. In Experiment II, 8 female Ss given 60 pairs of clicks, 30 each with separations of 1200 and 2400 msec, were instructed to respond as in Experiment I, and were asked to make a pretrial prediction of the interval they would next receive. Analysis of variance of RTs showed that Ss responded slower when the interval was other than that predicted. Prediction by reception by subjects analysis of variance of CNV amplitude at the 1200 msec point gave a significant F only for prediction, mean amplitude for short being higher than for long. A similar design applied to CNV amplitudes at both the 1200 and 2400 msec points when Ss received the long interval yielded a significant measurement point by interval predicted interaction; at the 1200 msec point, short predictions were followed by higher CNVs than were long predictions; at 2400 msec, the opposite was found. These data combine with those already in the literature to indicate that the relationship between “expectancy” and the CNV is far from simple, and that cognitive and motivational factors play a significant role in determining CNV amplitude.     

军人心理创伤后应激障碍患者与健康军人事件相关电位的对照研究

目的　探讨军人心理创伤后应激障碍 ( PTSD)患者 3种事件相关电位 ( ERP)的变异。方法　应用美国 Nicolet Bravo脑诱发电位仪 ,采用光和声成对刺激、反应时间以及听觉靶 -非靶刺激序列技术 ,检测 66例 PTSD和 3 6名正常人 ( NC)的关联性负变 ( CNV)、P30 0 、以及失配性负波 ( MMN)。结果　 1 CNV:M1 潜伏期 PTSD组 [( 5 0 3 .4± 1 3 9.2 ) ms]长于 NC组[( 4 2 0 .1± 1 2 3 .6) ms;P<0 .0 1 ],M2 波幅 PTSD组 [( 1 8.9± 7.9) μv]高于 NC组 [( 1 1 .7± 5 .8) μv;P<0 .0 1 ],指令信号后负变化 ( PINV)的出现率 PTSD组 ( 3 9% )高于 NC组 ( 3 % ;P<0 .0 1 )。 2 P30 0 :在靶刺激中 ,Cz脑区的 P3潜伏期 PTSD组[( 3 1 5 .4± 1 7.8) ms]短于 NC组 [( 3 3 6.7± 1 5 .5 ) ms;P<0 .0 1 ],Pz脑区的 N2 潜伏期 PTSD组 [( 2 78.5± 2 1 .8) ms]长于 NC组 [( 2 63 .4± 1 4.2 ) ms;P<0 .0 1 ],Pz脑区的 P3波幅 PTSD组 [( 3 .4± 1 .8) μv]低于 NC组 [( 5 .9± 2 .4) μv;P<0 .0 1 ]。在非靶刺激中 ,Cz脑区的 P2 波幅 PTSD组 [( 2 .5± 1 .4) μv]低于 NC组 [( 3 .4± 0 .1 ) μv;P<0 .0 1 ]。 3 MMN:潜伏期 PTSD组[( 2 1 4.2± 2 5 .7) ms]长于 NC组 [( 1 93 .7± 2 2 .6) ms;P<0 .0 1 ],波幅 PTSD组 [( 8.5     

Some Interrelations Between the Contingent Negative Variation and the Evoked Potential

The purpose of this study was to compare the evoked potential (EP) to the “imperative stimulus” (S2) in the contingent negative variation (CNV) paradigm with the EP to a comparable stimulus nut associated with a CNV. Twelve subjects performed a task that required reporting an occasional change in frequency of a tone. In one condition each change was paired with a warning Hash, thus generating a CNV. In another condition tone changes were only occasionally preceded by a flash and no CNV was observed. Three differences were noted in the vertex EP associated with a CNV: 1) all components after approximately 60 msec were shifted in a more positive direction, 2) negative components Nl and N2 were shorter in latency, and 3) negative components N1, N2, and N3 were attenuated in amplitude. Possible interpretations of these results are discussed. Conclusions are drawn concerning the methodological and theoretical importance of this interaction between the CNV and EP.     

Influence of Total Sleep Deprivation on Event-Related Potentials in Man

The contingent negative variation (CNV) can be spontaneously followed in psychiatric patients by a postimperative negative variation (PINV), and also in normal subjects who have undergone sufficiently intense interference during the CNV paradigm. Our hypothesis was that sleep deprivation could facilitate the induction of a spontaneous PINV which would reflect a transient psychophysiological perturbation. The present experiment investigates the influence of total sleep deprivation on event-related potentials (PINV, CNV, auditory evoked potential), behavioral performance (reaction time), and autonomic response (heart rate). Nineteen subjects participated in the experiment. The subjects were studied before and after 2 consecutive nights of total sleep deprivation. The event-related potentials resulted from the summation of 16 trials. The warning stimulus (tone burst) was followed 1.5 sec later by an imperative stimulus (continuous tone) which was stopped by the subject. After the deprivation, 6 subjects underwent the CNV paradigm with interference. None of the subjects showed a PINV after sleep deprivation either spontaneously or with an interference which had induced it under non-deprived conditions. The CNV and auditory evoked potential (AEP) amplitudes were reduced after the deprivation whereas AEP latencies increased. The unobtainable PINV after sleep deprivation and the low CNV amplitude could suggest a common neurophysiological origin for these two slow potentials.     

Exposure to uncontrollable stress and the postimperative negative variation (PINV): prior control matters

The main goal of this study was to assess cortical functioning as indexed by the postimperative negative variation (PINV) induced by uncontrollable stress. Sixty-six persons were randomly assigned to three groups who underwent different sequences of stressor controllability. Within an S1-S2 paradigm, one group had initial control over aversive stimulation followed by loss of control and restitution of control. The other groups initially experienced either uncontrollability or controllability followed by a condition of control. Uncontrollable stress significantly enhanced PINV magnitudes independent of preceding control. However, control over aversive stimulation prior to loss of control normalized PINVs during restitution of control. Persons not experiencing prior control showed enhanced PINVs, longer reaction times, and more errors during restitution of control. We conclude that cortical activation changes are linked to the evaluation of instrumental contingencies. However, the exact determination of brain regions involved in the processing of uncontrollable stress needs further investigation.     

Subjective and Response-Related Determinants of CNV Amplitude

The effect on contingent negative variation (CNV) of varying the difficulty of obtaining reaction time (RT) feedback and the relationship of CNV and RT were studied. Subjects (Ss) were run in a reaction-time-foreperiod experiment with 4 conditions of varying RT feedback duration. Subjective reactions to the experiment were recorded by Ss on a questionnaire and were divided by the experimenters into two highly significant sets of mean CNVs based on the most “positive’ and most “negative’ responses to the conditions. CNVs and their associated RTs were analyzed, and a significant rank order correlation over all Ss showed there was a trend for individuals with faster RTs to have larger CNVs. Individual correlations were low and highly variable. Only the very slowest RTs were associated with small CNVs. The failure of explicit RT feedback to have any effect upon CNV amplitude is in agreement with previous studies, and the significant association of CNV amplitude with written reactions of Ss might prove a useful tool for further CNV analysis. The RT data indicated that CNVs and RTs reflect relatively independent functions and that very slow RTs may reflect qualitative changes in S's psychological state which affect both RT and CNV; and such trials might appropriately be eliminated from CNV data analysis.     

Correlates of cerebral event-related slow potentials and psychopathology

The study explored associations between the cerebral event-related slow potentials (ERSP) and psychiatric symptoms and syndromes as reflected by the Present State Examination (PSE) in 36 randomly selected psychiatric in-patients. Independent raters measured the readiness potential (RP), contingent negative variation (CNV) and post-imperative negative variation (PINV) in terms of their amplitude and duration. The 360 individual PSE items were grouped into units of analysis (UA) and further collapsed into groups of units of analysis (GUA). Canonical correlations were computed between two sets of variables (psychological and electrophysiological). Kendall's rank-order correlation was used as the main statistical approach. Some psychotic signs were associated with increased PINV amplitude. Obsessive thoughts, ideas of reference and verbal hallucinations correlated with longer PINV duration. Hopelessness and suicidal thoughts (affect-laden thoughts) as well as first-rank Schneiderian symptoms (FRS) were negatively correlated with CNV amplitude. The results support the hypothesis that CNV and PINV, alone or in combination, can be used to indicate the presence or absence of identifiable psychiatric symptoms and syndromes. The implications of electrophysiological correlates of psychopathology for psychiatric nosology and for the validity of psychiatric symptoms and syndromes were discussed.     

Slow Cortical Potentials Under Conditions of Uncontrollability

The present experiment investigates the influence of an unexpected change from an escape paradigm to uncontrollability on slow cortical potentials (SCPs) and autonomic responses (heart rate, skin conductance, and EMG). Two groups of 10 male students each participated in a reaction time experiment; subjects heard one of two warning stimuli (WS) of 6 sec duration, which signaled one of two imperative stimuli (IS), an aversive noise or a neutral tone. Subjects in the experimental group could escape the IS by pressing a microswitch within 300 msec after the onset of the IS. This possibility to escape was interrupted after an experimental period of 40 trials for another period of 40 trials, during which the IS lasted for 5 sec irrespective of the actual motor response of the subject. Yoked control subjects received WS and IS in the same sequence and length as the matched experimental partner but without having any experience of control of the IS. During the WS-interval all subjects showed a two-component negative shift of SCPs. In response to the uncontrollable aversive IS during the second experimental period, experimental subjects showed a marked postimperative negative variation (PINV). No comparable PINV was found in response to the neutral IS or in the yoked control subjects. The PINV was, furthermore, more pronounced in subjects who showed a larger differentiation in the late component of the negative shift between the aversive and the neutral WS during the first 40 trials.     

INTERACTION OF ELECTRO-OCULAR POTENTIALS WITH THE CONTINGENT NEGATIVE VARIATION

The contingent negative variation (CNV) was recorded from the vertex in forty-five subjects during a two-stimulus expectancy paradigm under varying conditions of eye closure and fixation. Simultaneously averaged electro-oculograms (EOG) were recorded as a measure of eye movement. The amplitude of both CNV and EOG responses was significantly greater for the eyes closed and eyes open unfixated conditions as compared to the eyes fixated condition. CNV and EOG responses were often highly similar in terms of waveform. For the eyes fixated condition three patterns of CNV–EOG interaction were observed. Eighteen subjects demonstrated a CNV response of low amplitude in the absence of detectable EOG responses. Twenty-three subjects showed a predominant pattern in which CNV responses of high amplitude and EOG responses were present. Four subjects failed to show either a CNV or EOG response. There was considerable within subject variability in the pattern of response with replicated blocks of trials. Thus contamination of the CNV by EOG potentials is reduced by eye fixation but not eliminated because of subject variability in control of eye movement.     

Slow Cortical Potentials in Subjects With High or Low Scores on a Questionnaire Measuring Physical Anhedonia and Body Image Distortion

Slow cortical potentials, response speed, and peripheral physiological responses were investigated in two experiments with four groups of male subjects. Experiment 1 examined constant foreperiod reaction time in a sound-light-button press sequence with an interstimulus interval of 2 sec. Experiment 2 investigated constant foreperiod reaction time conditions with a sudden change from controllable to uncontrollable offset of an aversive imperative stimulus. There were two visual warning stimuli of 6-sec duration followed by an aversive or neutral imperative stimulus to be terminated by button press within 1 sec. Forty trials of this contingency were followed by 40 trials with 5-sec duration of imperative stimuli irrespective of response speed. Subjects were selected by high or low scores on two questionnaire scales measuring physical anhedonia (PA) and body image distortion (BI). In the first paradigm subjects with high PA scores as compared to low-scoring subjects showed less resolution of left precentral CNV after S2, i.e., a more pronounced postimperative negative component. In the second paradigm a postimperative negative variation (PINV) developed in all groups, but was more pronounced in frontal recordings and in subjects with high PA and BI scores. Results are discussed in the context of electrocortical phenomena observed in psychopathological groups.     

On the relation of movement-related potentials to the go/no-go effect on P3

According to Simson et al. [Simson, R., Vaughan, H.G., Jr., Ritter, W., 1977. The scalp topography of potentials in auditory and visual go/nogo tasks. Electroencephalography and Clinical Neurophysiology 43, 864-875], the difference between no-go P3 and go-P3 (the go/no-go effect) is due to overlap of P3 onto the return of the preceding contingent negative variation (CNV) in no-go trials and onto the continuing CNV in go trials. Similarly, according to Kok [Kok, A., 1986. Effects of degradation of visual stimuli on components of the event-related potential (ERP) in go/nogo reaction tasks. Biological Psychology 23, 21-38], the go/no-go effect is due to movement-related negative potentials, in particular contralateral negativity, adding with P3 in go trials. To investigate these notions, we studied how CNV, go-P3 and no-go P3 are lateralized at fronto-central sites when the side of the response varies across trials, comparing these effects between hand movements and eye movements and delineating them more precisely for hand movements with multichannel recordings. The go/no-go effect was larger and contralaterally lateralized with hand movements than with eye movements. Dipole analysis dissected its components into a large contribution of the medial cingulate gyrus, into activity of motor areas contralateral to the cued hand and a left-frontal source. Motor-related portions of the effect seemed to build upon and extend motor-related components included in CNV. Results provide support for the notion that the go/no-go effect is related to movement-related potentials. We suggest that go-P3 and no-go P3 are characterized by addition and reduction of motor-related activation to the core P3.     

Reduced cortical activity due to chronic low blood pressure: an EEG study

Alterations in cortical activation processes due to chronic low blood pressure were investigated. In 40 hypotensive subjects and 40 normotensive controls, the contingent negative variation (CNV), induced by a constant foreperiod reaction time task, was assessed at nine scalp sites (F3, Fz, F4, C3, Cz, C4, P3, Pz, P4). Additionally, spontaneous EEG was recorded at resting conditions. In hypotensives, a reduced amplitude of both the early and the late component of the CNV were found at Cz. At Fz the early CNV was reduced. Hypotensives exhibited longer reaction times, and the reaction time was negatively correlated with the CNV amplitude. Resting alpha power correlated negatively with blood pressure. The findings can be related to cognitive deficits due to hypotension found in earlier studies. The effects of hypotension on cortical activity are discussed to be mediated by afferents from the cardiovascular system to the prefrontal cortex as well as by reduced cerebral blood flow.     

The contingent negative variation in an odor labeling paradigm

Fifteen subjects participated in an experiment designed to assess the contingent negative variation (CNV) during the labeling of odors and shapes. Odors or shapes were presented (SI) and followed 3 s later by a lexical label (A, B, or C) (S2). In 75% of the trials, the S2 was the correct label for the odor or shape. In the remaining trials, the S2 was an incorrect label. Subjects' olfactory performance was correlated with both the CNV during in the S1/S2 interval and also the P300 following the S2 stimulus. The CNV over the left frontal area was significantly larger in the olfactory phase of the experiment. CNV activity also correlated with olfactory performance such that subjects with the largest odor-related CNVs had the best olfactory performance. Although P300 differed as a function of label matches versus mismatches, no odor-specific effects or correlations were found.     

Cortical evoked potentials and clinical rating scales as measures of depressive illness

Relationships between clinical ratings and cortical evoked potentials were examined before and during antidepressant drug treatment in 32 patients with major depressive disorder (DSM-III). Clinical rating scales included Hamilton Rating Scale for Depression, Beck Depression Inventory, Present State Examination (PSE) and Newcastle Scale. Evoked potentials included contingent negative variation (CNV), post-imperative negative variation (PINV) and auditory evoked potential (AEP) There were close correlations between all rating scales, and factor analysis produced only one component, suggesting that the common variance between them related to severity of depression. CNV magnitude before treatment correlated negatively with severity of depression regardless of diagnostic category. Depressed patients had a prominent PINV which persisted during antidepressant treatment. The amplitude of late components (N1P2) of the AEP was reduced strikingly in patients with a history of suicide attempts.     

Movement-related potentials associated with self-paced,cued and imagined arm movements

Self-paced movements, movement to a cue and imagined movement have all been reported to be preceded by a prolonged negativity on averaged electroencephalograph (EEG) recordings. Considerable evidence supports an important contribution from the supplementary motor area (SMA) to this potential and all three types of movement have been shown to be associated with SMA activation. This study was designed to compare the premovement component of these movement-related potentials (MRPs) in a group of subjects who performed each of these three types of movement. In addition, in view of the greater SMA activation in association with proximal arm movements, we studied movements at multiple joints in the right arm. All the potentials were largest at Cz. Self-paced movements were preceded by a negativity (mean onset 1.2 s prior to electromyographic activity) with two distinct phases – an early slow increase (early BP, Bereitschaftspotential) and a later, steeper phase (NS', negative slope). Proximal movements were associated with a larger peak amplitude (mean peak amplitude for shoulder 11.6 μV, finger movement 9.0 μV at Cz, n=14) due to a bigger NS' phase. Movements to a regular cue, but not to a randomly timed cue, were also preceded by a long duration negativity, but the NS' phase began earlier and was less distinct than for self-paced movements (mean peak amplitude for shoulder movement 9.1 μV, finger 8.2 μV at Cz, n=12). Imagining the movements to a regular cue was associated with a slow negativity, with no clear NS' phase (mean peak amplitude for shoulder movement 6.5 μV, finger 6.2 μV at Cz). Our results indicate that the MRPs prior to the three types of movement have distinct characteristics, most notably for the NS' phase. The MRP associated with movement to a regular cue may be analogous to the S2-related negativity of the contingent negative variation (CNV). We discuss the findings in the light of current evidence from functional imaging as to the cortical areas activated in similar movements. Electronic Publication     

Preparing for (valenced) action: The role of differential effort in the orthogonalized go/no‐go task

Associating reward to task performance has been shown to benefit scores of cognitive functions. Importantly, this typically entails associating reward to the execution of a response, hence intertwining action‐related processes with motivational ones. However, recently, preparatory action requirements (go/no‐go) and outcome valence (reward/punishment) were elegantly separated using a cued orthogonalized go/no‐go task. Functional magnetic resonance imaging results from this task showed that typical areas of the “reward network,” like the dopaminergic midbrain and the striatum, predominantly encode action rather than valence, displaying enhanced activity when preparing for action (go) compared to inaction (no‐go). In the current study, we used ERPs to probe for differences in preparatory state related to cognitive effort in this task, which has similarly been linked to reward‐network activity. Importantly, the contingent negative variation, which is linked to effortful cognitive preparation processes during cue‐target intervals, was clearly observed in go trials but not in no‐go trials. Moreover, target‐locked ERP results (N1 and P3) suggested that attention to the target was enhanced when an action had to be performed (go trials), and typical inhibition‐related ERP components were not observed in no‐go trials, suggesting a lack of active response inhibition. Finally, feedback‐related P3 results could suggest that correct feedback was valued more in motivated go trials, again implying that more effort was required to correctly perform the task. Together, these results indicate that the anticipation of action compared to inaction simultaneously entails differences in mental effort, highlighting the need for further dissociation of these concepts.