Involvement Of Cingulate Cortex Research Articles

Vestibular receptors contribute to cortical auditory evoked potentials

Acoustic sensitivity of the vestibular apparatus is well-established, but the contribution of vestibular receptors to the late auditory evoked potentials of cortical origin is unknown. Evoked potentials from 500 Hz tone pips were recorded using 70 channel EEG at several intensities below and above the vestibular acoustic threshold, as determined by vestibular evoked myogenic potentials (VEMPs). In healthy subjects both auditory mid- and long-latency auditory evoked potentials (AEPs), consisting of Na, Pa, N1 and P2 waves, were observed in the sub-threshold conditions. However, in passing through the vestibular threshold, systematic changes were observed in the morphology of the potentials and in the intensity dependence of their amplitude and latency. These changes were absent in a patient without functioning vestibular receptors. In particular, for the healthy subjects there was a fronto-central negativity, which appeared at about 42 ms, referred to as an N42, prior to the AEP N1. Source analysis of both the N42 and N1 indicated involvement of cingulate cortex, as well as bilateral superior temporal cortex. Our findings are best explained by vestibular receptors contributing to what were hitherto considered as purely auditory evoked potentials and in addition tentatively identify a new component that appears to be primarily of vestibular origin.

Anterior cingulate cortex involvement in subclinical social anxiety

We demonstrated differential activation in the anterior cingulate cortex (ACC) between subjects with high and low social anxiety in response to angry versus neutral faces. Activation in the ACC distinguished between facial expressions in the low, but not the high, anxious group. The ACC's role in threat processing is discussed.

To Cross or Not To Cross

Different theoretical accounts have attempted to integrate anterior cingulate cortex involvement in relation to conflict detection, error-likelihood predictions, and error monitoring. Regarding the latter, event-related potential studies have identified the feedback-related negativity (FRN) component in relation to processing feedback which indicates that a particular outcome was worse than expected. According to the conflict-monitoring theory the stimulus-locked N2 reflects pre-response conflict. Assumptions of these theories have been made on the basis of relatively simple response-mapping tasks, rather than more complex decision-making processes associated with everyday situations. The question remains whether expectancies and conflicts induced by everyday knowledge similarly affect decision-making processes. To answer this question, electroencephalogram and behavioral measurements were obtained while participants performed a simulated traffic task that varied high and low ambiguous situations at an intersection by presenting multiple varying traffic light combinations. Although feedback was kept constant for the different conditions, the tendency to cross was more pronounced for traffic light combinations that in reallife are associated with proceeding, as opposed to more ambiguous traffic light combinations not uniquely associated with a specific response. On a neurophysiological level, the stimulus-locked N2 was enhanced on trials that induced experience-based conflict and the FRN was more pronounced for negative as compared to positive feedback, but did not differ as a function of everyday expectancies related to traffic rules. The current study shows that well-learned everyday rules may influence decision-making processes in situations that are associated with the application of these rules, even if responding accordingly does not lead to the intended outcomes.

Involvement of Cingulate Cortex in the Formation of Defensive Behavior in Rats

Changes in behavior patterns in rats during electric stimulation of the ventromedial hypothalamus (the center of defensive behavior) and cingulate cortex were studied. Electric stimulation of the frontomedial cingulate cortex reduced the latency for anxiety and escape reactions during electric stimulation of the ventromedial hypothalamus. Electrolytic destruction of the frontomedial cingulate cortex substantially increased the threshold of escape behavior during stimulation of the ventromedial hypothalamus. These findings demonstrate the involvement of the frontomedial cingulate cortex into the development of defensive (anxiety and escape) behavior in rats.

The involvement of cingulate cortex in Bipolar disorder: a systematic review of existing data

Background Bipolar disorder (BD) is a complex and chronic mental disorder and synthesis of different theoretical frameworks and empirical data concerning its etiopathology, is difficult. Most models include among other structures the anterior cingulate cortex (ACC). The current paper is a review of the literature on the involvement of the cingulate cortex (CC) in the development and course of BD.

Caudal cingulate cortex involvement in pain processing: an inter-individual laser evoked potential source localisation study using realistic head models

Electrophysiological studies have revealed a source of laser pain evoked potentials (LEPs) in cingulate cortex. However, few studies have used realistically shaped head models in the source analysis, which account for individual differences in anatomy and allow detailed anatomical localisation of sources. The aim of the current study was to accurately localise the cingulate source of LEPs in a group of healthy volunteers, using realistic head models, and to assess the inter-individual variability in anatomical location. LEPs, elicited by painful CO 2 laser stimulation of the right forearm, were recorded from 62 electrodes in five healthy subjects. Dipole source localisation (CURRY 4.0) was performed on the most prominent (P2) peak of each LEP data set, using head models derived from each subject's structural magnetic resonance image (MRI). For all subjects, the P2 LEP peak was best explained by a dipole whose origin was in cingulate cortex (mean residual variance was 3.9±2.4 %) . For four out of five subjects, it was located at the border of the caudal division of left anterior cingulate cortex (area 24/32′) with left posterior cingulate cortex (area 23/31). For the fifth subject the dipole was centred in right posterior cingulate cortex (area 31). This study demonstrates that the location of the cingulate source of LEPs is highly consistent across subjects, when analysed in this way, and supports the involvement of caudal cingulate regions in pain processing.

Evidence for Anterior Cingulate Cortex Involvement in Monitoring Preparatory Attentional Set

An important cognitive function underlying unified, voluntary behavior is attentional control. Two frontal regions, anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC), appear to be particularly involved in attentional control and monitoring. In this study, we investigated whether ACC is involved in monitoring the preparatory allocation of attention during task switching, or whether ACC is active only when subjects are processing target stimuli and selecting a response, via a cued-attention design. Event-related BOLD fMRI activity was examined using a cue–target paradigm in which subjects performed task switches that selectively required reallocation of attention when tasks changed. There were three cue conditions: informative switch, informative repeat, and neutral. There were four target conditions: informatively cued switch, informatively cued repeat, neutrally cued switch, and neutrally cued repeat. Significant ACC activity was observed following both informative switch and informative repeat cues, but not after neutral cues. No significant ACC activity was observed following any of the target conditions. Significant DLPFC activity was observed following all three cue conditions and following neutrally cued switch targets. Overall, our results suggest that ACC is involved in monitoring the preparatory allocation of attention for conflict at the level of activation of competing attentional sets. The results also support the role of DLPFC in holding cognitive goals in working memory and allocating attention to the appropriate processing systems to meet those goals.

Evidence for Anterior Cingulate Cortex Involvement in Monitoring Preparatory Attentional Set

Evidence for Anterior Cingulate Cortex Involvement in Monitoring Preparatory Attentional Set

PET study of voluntary saccadic eye movements in humans: basal ganglia-thalamocortical system and cingulate cortex involvement

1. The purpose of this work was to explore the cortical and subcortical mechanisms underlying the execution of voluntary saccadic eye movements in humans. 2. Normalized regional cerebral blood flow (NrCBF) was measured using positron emission tomography (PET) and H2(15O) bolus intravenous injections in four right-handed healthy volunteers at rest and while performing self-paced voluntary horizontal saccadic eye movements in total darkness. 3. Magnetic resonance imaging of each subject's brain was matched to PET images, allowing the detection of activation in individually defined anatomic regions of interest. Cortical regions were drawn according to gyri limits; subcortical structures were also defined. 4. Self-paced saccadic eye movements elicited bilateral NrCBF increases in the lenticular nuclei, including putamen and globus pallidus, and in the thalamus. At the cortical level, we found bilateral NrCBF increases in the precentral gyrus, the superior part of the median frontal gyrus that corresponds to the supplementary motor area. There was also a significant NrCBF increase in the cerebellar vermis. 5. Right fusiform and lingual gyri, right insula, and left cingulate gyrus were also activated during the execution of saccades. 6. These results indicate that the classical basal ganglia-thalamocortical motor loop previously described for skeletal movements may also be involved in simple saccadic eye movements in humans.