P300-like Potentials Research Articles

Disentangling the effects of reward value and probability on anticipatory event-related potentials

Optimal decision-making requires humans to predict the value and probability of prospective (rewarding) outcomes. The aim of the present study was to evaluate and dissociate the cortical mechanisms activated by information on an upcoming potentially rewarded target stimulus with varying probabilities. Electro-cortical activity was recorded during a cued Go/NoGo experiment, during which cue letters signaled upcoming target letters to which participants had to respond. The probability of target letter appearance after the cue letter and the amount of money that could be won for correct and fast responses were orthogonally manipulated across four task blocks. As expected, reward availability affected a prefrontally distributed reward-related positivity, and a centrally distributed P300-like event-related potential (ERP). Moreover, a late prefrontally distributed ERP was affected by probability information. These results show that information on value and probability, respectively, activates separate mechanisms in the cortex. These results contribute to a further understanding of the neural underpinnings of normal and abnormal reward processing.

Cholinergic Mechanisms of Target Oddball Stimuli Detection: The Late "P300-Like" Event-Related Potential in Rats.

Event-related potentials (ERPs) and oscillations (EROs) provide powerful tools for studying the brain's synaptic function underlying information processing. The P300 component of ERPs indexing attention and working memory shows abnormal amplitude and latency in neurological and psychiatric diseases that are sensitive to pharmacological agents. In the active auditory oddball discriminant paradigm, behavior and auditory-evoked potentials (AEPs) were simultaneously recorded in awake rats to investigate whether P300-like potentials generated in rats responding to rare target oddball tones are sensitive to subcutaneous modulation of the cholinergic tone by donepezil (1 mg/kg) and scopolamine (0.64 mg/kg). After operant training, rats consistently discriminate rare target auditory stimuli from frequent irrelevant nontarget auditory stimuli by a higher level of correct lever presses (i.e., accuracy) in target trials associated with a food reward. Donepezil attenuated the disruptive effect of scopolamine on the level of accuracy and premature responses in target trials. Larger P300-like peaks with early and late components were revealed in correct rare target stimuli trials as compared to frequent tones. Donepezil enhanced the peak amplitude of the P300-like component to target stimuli and evoked slow theta and gamma oscillations, whereas scopolamine altered the amplitude of the P300-like component and EROs to target stimuli. Pretreatment with donepezil attenuated effects of scopolamine on the peak amplitude of the P300-like component and on EROs. This study provides evidence that AEP P300-like responses can be elicited by rats engaged in attentive and memory processing of target stimuli and outline the relevance of the cholinergic system in stimulus discrimination processing. The findings highlight the sensitivity of this translational index for investigating brain circuits and/or novel pharmacological agents, which modulate cholinergic transmission associated with increased allocation of attentional resources.

Multisensory integration of speech sounds with letters vs. visual speech: only visual speech induces the mismatch negativity

Numerous studies have demonstrated that the vision of lip movements can alter the perception of auditory speech syllables (McGurk effect). While there is ample evidence for integration of text and auditory speech, there are only a few studies on the orthographic equivalent of the McGurk effect. Here, we examined whether written text, like visual speech, can induce an illusory change in the perception of speech sounds on both the behavioural and neural levels. In a sound categorization task, we found that both text and visual speech changed the identity of speech sounds from an /aba/‐/ada/ continuum, but the size of this audiovisual effect was considerably smaller for text than visual speech. To examine at which level in the information processing hierarchy these multisensory interactions occur, we recorded electroencephalography in an audiovisual mismatch negativity (MMN, a component of the event‐related potential reflecting preattentive auditory change detection) paradigm in which deviant text or visual speech was used to induce an illusory change in a sequence of ambiguous sounds halfway between /aba/ and /ada/. We found that only deviant visual speech induced an MMN, but not deviant text, which induced a late P3‐like positive potential. These results demonstrate that text has much weaker effects on sound processing than visual speech does, possibly because text has different biological roots than visual speech.

Functional Dissociation of Latency-Variable, Stimulus- and Response-Locked Target P3 Sub-components in Task-Switching.

Cognitive control warrants efficient task performance in dynamic and changing environments through adjustments in executive attention, stimulus and response selection. The well-known P300 component of the human event-related potential (ERP) has long been proposed to index “context-updating”—critical for cognitive control—in simple target detection tasks. However, task switching ERP studies have revealed both target P3 (300–350 ms) and later sustained P3-like potentials (400–1,200 ms) to first targets ensuing transition cues, although it remains unclear whether these target P3-like potentials also reflect context updating operations. To address this question, we applied novel single-trial EEG analyses—residue iteration decomposition (RIDE)—in order to disentangle target P3 sub-components in a sample of 22 young adults while they either repeated or switched (updated) task rules. The rationale was to revise the context updating hypothesis of P300 elicitation in the light of new evidence suggesting that “the context” consists of not only the sensory units of stimulation, but also associated motor units, and intermediate low- and high-order sensorimotor units, all of which may need to be dynamically updated on a trial by trial basis. The results showed functionally distinct target P3-like potentials in stimulus-locked, response-locked, and intermediate RIDE component clusters overlying parietal and frontal regions, implying multiple functionally distinct, though temporarily overlapping context updating operations. These findings support a reformulated version of the context updating hypothesis, and reveal a rich family of distinct target P3-like sub-components during the reactive control of target detection in task-switching, plausibly indexing the complex and dynamic workings of frontoparietal cortical networks subserving cognitive control.

An information theory account of late frontoparietal ERP positivities in cognitive control.

ERP research on task switching has revealed distinct transient and sustained positive waveforms (latency circa 300-900 ms) while shifting task rules or stimulus-response (S-R) mappings. However, it remains unclear whether such switch-related positivities show similar scalp topography and index context-updating mechanisms akin to those posed for domain-general (i.e., classic P300) positivities in many task domains. To examine this question, ERPs were recorded from 31 young adults (18-30 years) while they were intermittently cued to switch or repeat their perceptual categorization of Gabor gratings varying in color and thickness (switch task), or else they performed two visually identical control tasks (go/no-go and oddball). Our task cueing paradigm examined two temporarily distinct stages of proactive rule updating and reactive rule execution. A simple information theory model helped us gauge cognitive demands under distinct temporal and task contexts in terms of low-level S-R pathways and higher-order rule updating operations. Task demands modulated domain-general (indexed by classic oddball P3) and switch positivities-indexed by both a cue-locked late positive complex and a sustained positivity ensuing task transitions. Topographic scalp analyses confirmed subtle yet significant split-second changes in the configuration of neural sources for both domain-general P3s and switch positivities as a function of both the temporal and task context. These findings partly meet predictions from information estimates, and are compatible with a family of P3-like potentials indexing functionally distinct neural operations within a common frontoparietal "multiple demand" system during the preparation and execution of simple task rules.

Adapted wavelet transform improves time-frequency representations: a study of auditory elicited P300-like event-related potentials in rats

Objective. Active auditory oddball paradigms are simple tone discrimination tasks used to study the P300 deflection of event-related potentials (ERPs). These ERPs may be quantified by time-frequency analysis. As auditory stimuli cause early high frequency and late low frequency ERP oscillations, the continuous wavelet transform (CWT) is often chosen for decomposition due to its multi-resolution properties. However, as the conventional CWT traditionally applies only one mother wavelet to represent the entire spectrum, the time-frequency resolution is not optimal across all scales. To account for this, we developed and validated a novel method specifically refined to analyse P300-like ERPs in rats. Approach. An adapted CWT (aCWT) was implemented to preserve high time-frequency resolution across all scales by commissioning of multiple wavelets operating at different scales. First, decomposition of simulated ERPs was illustrated using the classical CWT and the aCWT. Next, the two methods were applied to EEG recordings obtained from prefrontal cortex in rats performing a two-tone auditory discrimination task. Main results. While only early ERP frequency changes between responses to target and non-target tones were detected by the CWT, both early and late changes were successfully described with strong accuracy by the aCWT in rat ERPs. Increased frontal gamma power and phase synchrony was observed particularly within theta and gamma frequency bands during deviant tones. Significance. The study suggests superior performance of the aCWT over the CWT in terms of detailed quantification of time-frequency properties of ERPs. Our methodological investigation indicates that accurate and complete assessment of time-frequency components of short-time neural signals is feasible with the novel analysis approach which may be advantageous for characterisation of several types of evoked potentials in particularly rodents.

ID 389 – Studies of neuronal circuits underlying information processing through late P300 event-related potentials in rats

Cognitive event related potentials (ERPs) and oscillations synchrony (EROS) provide a powerful tool for studying brain’s synaptic function underlying information processing. The P300 component of ERPs indexing attention and working memory is altered in neurologic and psychiatric diseases, and is sensitive to pharmacological agents. Here, we investigated whether the P300-like potentials can be generated in rats performing an active auditory discriminant task, and to what extent this response is sensitive to modulation of the cholinergic neurotransmission. In the active oddball paradigm, behavior and auditory evoked potentials (AEPs) were simultaneously recorded in rats as they were presented with frequent non-target and rare target tones during baseline conditions and following the administration of donepezil and scopolamine. Rats that consistently discriminate target tones showed P300 peaks with early and late components. Donepezil enhanced P300 amplitude and evoked theta/gamma oscillations to target tones and attenuated scopolamine-induced deficits in behavioral and AEPs/EROS. We demonstrate that P300-like response can be elicited by rats engaged in stimulus discrimination processing and outline the relevance of the cholinergic system in this response. The AEP P300 paradigm is valuable for characterizing targets and/or drugs that may contribute to facilitation and/or suppression of synaptic responses underlying early and late P300 components.

The Role of Anterior Nuclei of the Thalamus: A Subcortical Gate in Memory Processing: An Intracerebral Recording Study.

ObjectiveTo study the involvement of the anterior nuclei of the thalamus (ANT) as compared to the involvement of the hippocampus in the processes of encoding and recognition during visual and verbal memory tasks.MethodsWe studied intracerebral recordings in patients with pharmacoresistent epilepsy who underwent deep brain stimulation (DBS) of the ANT with depth electrodes implanted bilaterally in the ANT and compared the results with epilepsy surgery candidates with depth electrodes implanted bilaterally in the hippocampus. We recorded the event-related potentials (ERPs) elicited by the visual and verbal memory encoding and recognition tasks.ResultsP300-like potentials were recorded in the hippocampus by visual and verbal memory encoding and recognition tasks and in the ANT by the visual encoding and visual and verbal recognition tasks. No significant ERPs were recorded during the verbal encoding task in the ANT. In the visual and verbal recognition tasks, the P300-like potentials in the ANT preceded the P300-like potentials in the hippocampus.ConclusionsThe ANT is a structure in the memory pathway that processes memory information before the hippocampus. We suggest that the ANT has a specific role in memory processes, especially memory recognition, and that memory disturbance should be considered in patients with ANT-DBS and in patients with ANT lesions.ANT is well positioned to serve as a subcortical gate for memory processing in cortical structures.

An Accessory Agonist Binding Site Promotes Activation of α4β2* Nicotinic Acetylcholine Receptors

Neuronal nicotinic acetylcholine receptors containing α4, β2, and sometimes other subunits (α4β2* nAChRs) regulate addictive and other behavioral effects of nicotine. These nAChRs exist in several stoichiometries, typically with two high affinity acetylcholine (ACh) binding sites at the interface of α4 and β2 subunits and a fifth accessory subunit. A third low affinity ACh binding site is formed when this accessory subunit is α4 but not if it is β2. Agonists selective for the accessory ACh site, such as 3-[3-(3-pyridyl)-1,2,4-oxadiazol-5-yl]benzonitrile (NS9283), cannot alone activate a nAChR but can facilitate more efficient activation in combination with agonists at the canonical α4β2 sites. We therefore suggest categorizing agonists according to their site selectivity. NS9283 binds to the accessory ACh binding site; thus it is termed an accessory site-selective agonist. We expressed (α4β2)2 concatamers in Xenopus oocytes with free accessory subunits to obtain defined nAChR stoichiometries and α4/accessory subunit interfaces. We show that α2, α3, α4, and α6 accessory subunits can form binding sites for ACh and NS9283 at interfaces with α4 subunits, but β2 and β4 accessory subunits cannot. To permit selective blockage of the accessory site, α4 threonine 126 located on the minus side of α4 that contributes to the accessory site, but not the α4β2 sites, was mutated to cysteine. Alkylation of this cysteine with a thioreactive reagent blocked activity of ACh and NS9283 at the accessory site. Accessory agonist binding sites are promising drug targets.

Neuropharmacological modulation of the P3-like event-related potential in a rat two-tone auditory discrimination task with modafinil and NS9283, a positive allosteric modulator of α4β2 nAChRs

The P300 (P3) event-related potential (ERP) is a neurophysiological signal believed to reflect cognitive processing of salient cues, and is thus used as a measure of attention and working memory. Additionally, P3 amplitude and latency is altered in neurological diseases and can be pharmacologically modulated. As P3-like ERPs can be recorded in rodents, it may serve as a potential translational biomarker of value for drug discovery.Here we investigated whether a positive allosteric modulator of α4β2 nicotinic acetylcholine receptors, NS9283, and the psychostimulant modafinil could modulate P3-like ERPs in healthy adult rats performing an auditory oddball discrimination task. ERPs were recorded with electroencephalography electrodes implanted into mediodorsal (MD) thalamus, medial prefrontal cortex, hippocampus and auditory cortex (AC).P3-like ERPs were detected in all brain regions, displaying larger amplitudes in target trials compared to non-target trials. Administration of modafinil (64 mg/kg) decreased P3-like ERP latency in MD thalamus and AC, whereas NS9283 augmented P3-like ERP amplitude in MD thalamus at 0.3 mg/kg and in AC at 3.0 mg/kg. Additionally, N1 pre-attention peak amplitude in MD thalamus was increased with 0.3 mg/kg NS9283. Neither of the compounds enhanced task performance. Rather, modafinil lowered correct rejections in non-target trials.In summary, our findings reveal pharmacological modulation of the rat P3-like ERP in cortical and subcortical regions by modafinil and NS9283. These findings encourage further exploration of the rat P3-like ERP in order to promote the understanding of its meaning within cognition, as well as its applicability as a translatable biomarker in drug development.

Preservation of Auditory P300-Like Potentials in Cortical Deafness

The phenomenon of blindsight has been largely studied and refers to residual abilities of blind patients without an acknowledged visual awareness. Similarly, “deaf hearing” might represent a further example of dissociation between detection and perception of sounds.Here we report the rare case of a patient with a persistent and complete cortical deafness caused by damage to the bilateral temporo-parietal lobes who occasionally showed unexpected reactions to environmental sounds despite she denied hearing. We applied for the first time electrophysiological techniques to better understand auditory processing and perceptual awareness of the patient. While auditory brainstem responses were within normal limits, no middle- and long-latency waveforms could be identified. However, event-related potentials showed conflicting results. While the Mismatch Negativity could not be evoked, robust P3-like waveforms were surprisingly found in the latency range of 600–700 ms. The generation of P3-like potentials, despite extensive destruction of the auditory cortex, might imply the integrity of independent circuits necessary to process auditory stimuli even in the absence of consciousness of sound. Our results support the reverse hierarchy theory that asserts that the higher levels of the hierarchy are immediately available for perception, while low-level information requires more specific conditions. The accurate characterization in terms of anatomy and neurophysiology of the auditory lesions might facilitate understanding of the neural substrates involved in deaf-hearing.

Reversibility in Chinese word formation influences target identification

We recorded event-related brain potentials during the processing of visually presented compound words in Mandarin Chinese. We capitalized on a particular characteristic of Chinese word formation, where two constituents can be combined in two different orders (A + B or B + A), yielding distinct meanings—so-called “reversible words”. By investigating the impact of structural reversibility on the processing of compounds in Chinese during a lexical decision task, the present study revealed a pronounced difference between reversible and non-reversible words. Analyses revealed a more enhanced negativity (N400) for reversible words, reflecting demands during semantic processing, followed by a P300-like deflection for non-reversible words, which we interpret with respect to the ease of target identification due to target discriminability. The findings indicate that both character combinations (A + B, B + A) as well as access to the individual constituent meanings result in interference during the processing of reversible and non-reversible words. They reveal that combinatorial processes are affected by demands arising from competing representations (N400), and more importantly, that this impacts the task-relevant cognitive processes required in the current word/non-word identification task (P300). The observed P300-like potential suggests that the allocation of attentional resources is intertwined with combinatorial operations.

Modulation of neural activity by motivational and spatial biases

Motivational biases and spatial attention both modulate neural activity and influence behavioural performance. The time course of motivational bias effects, as well as the relationship between motivation and attention across the time course of information processing, however, are relatively unknown. In the present study, event-related potentials (ERPs) were recorded whilst individuals performed a modified Posner task, in which cue stimuli indicated the reward stakes of a given trial and the probable spatial location of a subsequent target stimulus. Reaction times (RTs) were sensitive to motivation and to attention, with faster responses produced on valid and on rewarded trials. In addition, motivation modulated neural activity from the visual analysis of stimuli, with an earlier N1 peak for rewarded compared with non-rewarded stimuli. Effects of motivation were relatively independent from those of attention until late cognitive processing and response production, where motivation and attention interacted to enhance P300-like potentials and the lateralised readiness potential (LRP). The results suggest that multiple sources of modulatory influences may exist, with motivation and attention exerting independent influences over early stimulus and cognitive processing, followed by a late interaction allowing the construction of a comprehensive stimulus representation that contains information pertaining to both motivational and spatial expectations.

The Executive Functions in Frontal and Temporal Lobes: A Flanker Task Intracerebral Recording Study

The occurrence of the local generators of P3-like potentials elicited by a noise-compatibility flanker test was used to study the processing of executive functions, particularly in the frontal and temporal cortices. The test performed with arrows comprised a simpler congruent and a more difficult incongruent task. The two tasks activated the attention and several particular executive functions, i.e., working memory, time perception, initiation, and motor control of executed task. The incongruent task increased demand on executive functions, and besides the functions common for both tasks, an inhibition of automatic responses, the reversal of incorrect response tendency, the internal ordering of the correct response, and the initiation of the target-induced correct response were involved. In seven epilepsy surgery candidates (four men and three women), ranging in age from 26 to 38 years, multicontact depth electrodes were implanted in 590 cortical sites. In the two tasks, the P3-like potential sources were displayed in the mesial temporal structures, the lateral temporal neocortex, the anterior and posterior cingulate, the orbitofrontal cortex, and dorsolateral prefrontal cortex. The P3-like potentials occurred more frequently with the incongruent than with congruent stimuli in all these areas. This more frequent occurrence of P3 sources elicited by the incongruent task appeared significant in temporal lateral neocortex and orbitofrontal cortex. The executive functions are processed in a widespread frontotemporal neurocognitive network. This study confirms the involvement of the temporal neocortex in the executive functions.

Role of the subthalamic nucleus (STN) in modulation of cognitive functions: recordings via deep brain stimulation electrodes (DBS)

Event Abstract Back to Event Role of the subthalamic nucleus (STN) in modulation of cognitive functions: recordings via deep brain stimulation electrodes (DBS) Ivan Rektor1* 1 Masaryk University, Germany Neuropsychiatric disturbances after DBS indicate the STN involvement in cognitive functions. We report the STN recordings via DBS electrodes in cognitive tasks (Baláž et al., 2008; Rektor et al., 2009; Baláž et al., 2010; Bočková et al., 2011). The STN is implicated in tasks with increased cognitive loads. A dual task but not the simple oddball task evoked local field of P3-like potentials (Baláž et al., 2008). Oscillations in STN were modulated by writing other letter than that which appeared on a screen, but not by simple letter copying (Bočková, in Rektor et al., 2009). In the three stimulus paradigm, the distracter stimulus evoked an early potential (latency 200 ms), not known from the scalp recordings (Bočková et al., 2011). The rTMS of the inferior frontal cortex but not of the dorsolateral prefrontal cortex increased the speed of processing the dual task (Baláž et al., 2010). The STN (1) is implicated in modulation, rather than in a direct regulation, of cognitive functions; (2) there is a spatial overlap of sites regulating various functions, the STN might modulate cognitive activities via contextual modulation of certain cortical areas; (3) implicated in the non-motor activities in some way other than the well-known organisation of the basal ganglia-thalamocortical circuits; direct cortex-STN connexions may play an important role; (4) the modulation of cognitive functions is selective, probably determined by involvement of cortical neuronal population that are interconnected with the STN. Keywords: DBS, Neuropsychiatry Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Poster Presentation Topic: Poster Sessions: Neuropsychiatric Applications Citation: Rektor I (2011). Role of the subthalamic nucleus (STN) in modulation of cognitive functions: recordings via deep brain stimulation electrodes (DBS). Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00111 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 16 Nov 2011; Published Online: 25 Nov 2011. * Correspondence: Dr. Ivan Rektor, Masaryk University, Brno, Germany, irektor@med.muni.cz Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Ivan Rektor Google Ivan Rektor Google Scholar Ivan Rektor PubMed Ivan Rektor Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

P5-14 Time-frequency and spectral analysis of auditory executive event-related potentials in subthalamic nucleus

In our present work we have noted clear 8-10 Hz activity related to auditory ERPs. It is important to observe whether such an activity can be replicated in higher number of patients. We have not observed such an activity recorded from the globus pallidum internum in a patient with generalised dystonia (we do not report these results here). We also observed the major activation in frequency of 20 Hz and more in direct relation to P3-like potentials. Here, the correspondent changes were present in latencies of P3 potentials in standard and modified protocols.

Identification of rat P3-like processes in the anterior cingulate cortex and hippocampus

The purpose of this study was to investigate whether the rat P3-like potential reflects “attention processes” rather than “arousal level”. After controlling for arousal levels, event-related potentials (ERPs) of the rat were recorded at the anterior cingulate cortex and hippocampal CA1 during active and passive oddball paradigms. The arousal level of the passive group was equivalent to that of the active group, while the amplitude of the P3-like potential during the active paradigm was greater than that during the passive paradigm for both sites. These results provide evidence that the rat P3-like component reflects “attention processes”, which is also the case for the human P3 component. Rats can provide a useful model for investigation of the neural mechanisms of the P3 in humans.

Cognitive activities in the subthalamic nucleus. Invasive studies

According to our studies, based on intracerebral recordings of cognitive Event Related Potentials (ERP), the cognitive activities in the the Basal Ganglia (BG) are organized in some way other than the well-known organization of the cortico-BG-thalamocortical circuits. The cognitive role of the subthalamic nucleus (STN) has been largely unknown. Direct connections with the cortex that bypass the circuitries might underlie the processing of specific cognitive functions in the STN. STN seems to be specifically involved in the processing of some cognitive activities, e.g. of the executive functions. A modified protocol with a dual task elicited local field ERP within the STN. Impact of cortical 1 Hz rTMS on STN was tested. ERD/S in was tested in visuomotor tasks with single letters writing. No generators of ERP (P3-like potentials) were elicited by the standard oddball protocol in the STN (at variance with recordings from the putamen, caudate and pallidum). rTMS over the right inferior frontal cortex caused a shortening of latencies of ERP in standard and dual protocols. No changes were observable after the rTMS over the dorzolateral prefrontal cortex and sham stimulation. In the STN, only the tasks with an increased demand on executive functions produced the alpha and beta ERD/S (event-related desynchronization/synchronization). Our results indicate a specific, task-related involvement of the STN in the cognitive activities. Cognitive processing in the STN is possibly processed via hyperdirect cortico-STN pathway. Certain effects of DBS surgery on cognitive performance could be explained by a direct effect on 'cognitive' parts of the STN.

The cognitive event related potentials in the basal ganglia

Event Abstract Back to Event The cognitive event related potentials in the basal ganglia Ivan Rektor1* 1 Masaryk University, St. Anne’s Hospital, Czechia In this lecture we will discuss our recordings of ERP in the basal ganglia and their relationship to the cortical ERP. We studied potentials related to a variety of cognitive activities (attentional, decisional, motor preparation, sensory processing, etc.) in brain structures that participate in cortico-basal ganglia-thalamocortical loops. We chose relatively simple and well-known protocols that had been consecutively tested. The occurrence of several cognitive potentials has partially been published in previous studies. Patients with pharmacoresistant epilepsy and with advanced Parkinson’s disease were tested. Using intracerebrally inserted electrodes (in one patient, also subdural strip electrodes) ERP recordings were obtained from 32 patients, all of whom were candidates for epilepsy surgery. Fifteen patients (12 men and 3 women; the mean age 28.5 years), had diagonal electrodes targeted in the amygdalo-hippocampal complex, with one or several contacts in the basal ganglia; in putamen, caudate and in pallidum. Ten patients with idiopathic Parkinson’s disease had ERP potentials recorded from externalised deep brain electrodes implanted in the subthalamic nucleus (STN) or in its immediate vicinity. In four other patients with Parkinson’s disease the ERP in the STN were modulated by cortical rTMS. We will present: 1. Recordings of the P3-like potentials in the basal ganglia (putamen, caudate and pallidum) and in the cortex 1.1. The distribution of P3-like potentials in the basal ganglia 1.2. The relationship between the P3-like potentials in the basal ganglia and the cortical targets of the cortico-basal ganglia-thalamocortical circuits 2. P3-like potentials in the subthalamic nucleus 3. General discussion CONCLUSION: The basal ganglia represent a very complex system with large volumes of grey matter. The role of the basal ganglia in cognitive processing is largely unknown. According to our studies, based mainly on direct intracerebral recordings of cognitive event related potentials, the cognitive activities in the basal ganglia are organized in some way other than the well-known organization of the cortico-basal ganglia-thalamocortical circuits. An integrative role of the basal ganglia, with subsequent modulation of cortical cognitive processing, is suggested. In some cases, direct connections with the cortex that bypass the circuitries might underlie the processing of specific cognitive functions. This might be the case of STN. In this nucleus, the standard oddball ERP are not generated. This result differs from all other explored basal ganglia. STN seems to be specifically involved in the processing of some cognitive activities, e.g. of the executive functions. Acknowledgement: Supported by research program MŠ ČR 112801. Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Oral Presentation Topic: Abstracts Citation: Rektor I (2008). The cognitive event related potentials in the basal ganglia. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.025 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Nov 2008; Published Online: 27 Nov 2008. * Correspondence: Ivan Rektor, Masaryk University, St. Anne’s Hospital, Brno, Czechia, ivan.rektor@fnusa.cz Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Ivan Rektor Google Ivan Rektor Google Scholar Ivan Rektor PubMed Ivan Rektor Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Modifications of cognitive and motor tasks affect the occurrence of event‐related potentials in the human cortex

This study concerns the question of how task modification affects the frequency occurrence of event-related potentials (ERP) inside the active cortical areas. In 13 candidates for epilepsy surgery, 156 sites in the temporal (74), frontal (73), and parietal (9) cortices were recorded by means of depth and subdural electrodes. Four modifications of the somatosensory evoked P3-like potentials were performed; (i) an oddball paradigm with silent counting of target stimuli (P3c); (ii) an oddball paradigm with a hand movement in response to target stimuli (P3m); (iii) an S1-S2 paradigm, ERP in the P300 time window after the S2 stimulus, with silent counting of target stimuli (S2c), and (iv) an S1-S2 paradigm with a hand movement in response to target stimuli (S2m). In comparing the oddball paradigms with the S1-S2 (contingent negative variation, CNV) paradigms, four regions emerge that are significantly linked with the oddball P3; the prefrontal cortex, the cingulate, the amygdalo-hippocampal complex, and the lateral temporal cortex. A prominent role of the cingulate and the fronto-orbital cortex in the cognitive processing of movement was supported when tasks with identical cognitive loads but different required responses were compared. Even relatively simple cognitive tasks activate many cortical regions. The investigated areas were activated in all tests; however, small regions in each field were active or inactive in relation to the nature of the task. The study indicates a variable and task-dependent internal organization of a highly complex and widely distributed system of active cortical areas.