An infrequent change to an otherwise repetitive sequence of stimuli leads to the generation of mismatch negativity (MMN), even in the absence of attention. This evoked negative response occurs in the scalp-recorded electroencephalogram (EEG) over the temporal and frontal cortices, 100-250 ms after onset of the deviant stimulus. The MMN is used to detect sensory information processing. The aim of our study was to investigate whether MMN can be recorded in the subthalamic nuclei (STN) as evidence of auditory information processing on an unconscious level within this structure. To our knowledge, MMN has never been recorded in the human STN. We recorded intracerebral EEG using a MMN paradigm in five patients with Parkinson's disease (PD) who were implanted with depth electrodes in the subthalamic nuclei (STN). We found far-field MMN when intracerebral contacts were connected to an extracranial reference electrode. In all five PD patients (and nine of ten intracerebral electrodes), we also found near-field MMN-like potentials when intracerebral contacts were referenced to one another, and in some electrodes, we observed phase reversals in these potentials. The mean time-to-peak latency of the intracerebral MMN-like potentials was 214 ± 38 ms (median 219 ms). We reveal MMN-like potentials in bilateral STN. This finding provides evidence that STN receives sensory (auditory) information from other structures. The question for further research is whether STN receives such signals through a previously described hyperdirect pathway between STN and frontal cortex (a known generator of the MMN potential) and if the STN contributes to sensorimotor integration.

• MeSH
• Acoustic Stimulation MeSH
• Electroencephalography MeSH
• Functional Laterality MeSH
• Contingent Negative Variation physiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Neuropsychological Tests MeSH
• Subthalamic Nucleus physiopathology   MeSH
• Parkinson Disease complications   pathology   MeSH
• Reaction Time physiology   MeSH
• Aged MeSH
• Evoked Potentials, Auditory physiology   MeSH
• Severity of Illness Index MeSH
• Tomography Scanners, X-Ray Computed MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

The objective is to study the involvement of the posterior medial cortex (PMC) in encoding and retrieval by visual and auditory memory processing. Intracerebral recordings were studied in two epilepsy-surgery candidates with depth electrodes implanted in the retrosplenial cingulate, precuneus, cuneus, lingual gyrus and hippocampus. We recorded the event-related potentials (ERP) evoked by visual and auditory memory encoding-retrieval tasks. In the hippocampus, ERP were elicited in the encoding and retrieval phases in the two modalities. In the PMC, ERP were recorded in both the encoding and the retrieval visual tasks; in the auditory modality, they were recorded in the retrieval task, but not in the encoding task. In conclusion, the PMC is modality dependent in memory processing. ERP is elicited by memory retrieval, but it is not elicited by auditory encoding memory processing in the PMC. The PMC appears to be involved not only in higher-order top-down cognitive activities but also in more basic, rather than bottom-up activities.

• MeSH
• Acoustic Stimulation MeSH
• Adult MeSH
• Electroencephalography methods   MeSH
• Epilepsy physiopathology   MeSH
• Electrodes, Implanted MeSH
• Humans MeSH
• Brain physiology   MeSH
• Memory physiology   MeSH
• Signal Processing, Computer-Assisted MeSH
• Evoked Potentials, Auditory physiology   MeSH
• Photic Stimulation MeSH
• Evoked Potentials, Visual physiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

We studied the appearance of cognitive event-related potentials (ERPs) and event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and globus pallidus internus (GPi). We particularly focused on the rare non-target (distractor) stimuli processing. ERPs and ERD/S in the alpha and beta frequency range were analyzed in seven Parkinson's disease patients and one primary dystonia patient with implanted deep brain stimulation (DBS) electrodes. A visual three-stimulus protocol was used (frequent stimulus, target stimulus, and distractor). The non-target and distractor-related waveforms manifested similar shapes. A specific positive ERP peak around 200 ms and a low alpha frequency ERS were detected from the STN as a response to the distractor stimuli in six of the patients with Parkinson's disease and also in the primary dystonia patient's GPi. This positivity probably reflects an attentional orienting response to the distractor stimuli. The STN and GPi are probably involved in attentional cerebral networks.

• MeSH
• Electroencephalography methods   MeSH
• Evoked Potentials physiology   MeSH
• Globus Pallidus physiology   MeSH
• Deep Brain Stimulation instrumentation   methods   MeSH
• Electrodes, Implanted MeSH
• Middle Aged MeSH
• Humans MeSH
• Subthalamic Nucleus physiology   MeSH
• Parkinson Disease physiopathology   therapy   MeSH
• Attention physiology   MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

We studied whether the cognitive event-related potentials (ERP) in the subthalamic nucleus (STN) are modified by the modulation of the inferior frontal cortex (IFC) and the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS). Eighteen patients with Parkinson's disease who had been implanted with a deep brain stimulation (DBS) electrode were included in the study. The ERPs were recorded from the DBS electrode before and after the rTMS (1 Hz, 600 pulses) over either the right IFC (10 patients) or the right DLPFC (8 patients). The ERPs were generated by auditory stimuli. rTMS over the right IFC led to a shortening of ERP latencies from 277 +/- 14 ms (SD) to 252 +/- 19 ms in the standard protocol and from 296 +/- 17 ms to 270 +/- 20 ms in the protocol modified by a higher load of executive functions (both P < 0.01). The application of rTMS over the DLPFC and the sham stimulation over the IFC showed no significant changes. The shortening of ERP latency after rTMS over the right IFC reflected the increase in the speed of the cognitive process. The rTMS modulation of activity of the DLPFC did not influence the ERP. Connections (the IFC-STN hyperdirect pathway) with the cortex that bypass the BG-thalamocortical circuitries could explain the position of the STN in the processing of executive functions.

• MeSH
• Acoustic Stimulation MeSH
• Analysis of Variance MeSH
• Frontal Lobe physiopathology   MeSH
• Electroencephalography MeSH
• Evoked Potentials physiology   MeSH
• Executive Function physiology   MeSH
• Electrodes, Implanted MeSH
• Middle Aged MeSH
• Humans MeSH
• Brain Mapping MeSH
• Neural Pathways physiopathology   MeSH
• Subthalamic Nucleus physiopathology   MeSH
• Parkinson Disease physiopathology   MeSH
• Signal Processing, Computer-Assisted MeSH
• Psychomotor Performance physiology   MeSH
• Reaction Time MeSH
• Auditory Perception physiology   MeSH
• Transcranial Magnetic Stimulation methods   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

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.

• MeSH
• Acoustic Stimulation MeSH
• Basal Ganglia physiology   MeSH
• Frontal Lobe physiology   MeSH
• Gyrus Cinguli physiology   MeSH
• Adult MeSH
• Evoked Potentials physiology   MeSH
• Cognition physiology   MeSH
• Contingent Negative Variation physiology   MeSH
• Humans MeSH
• Brain Mapping MeSH
• Adolescent MeSH
• Motor Cortex physiology   MeSH
• Neural Pathways physiology   MeSH
• Movement physiology   MeSH
• Prefrontal Cortex physiology   MeSH
• Putamen physiology   MeSH
• Reaction Time physiology   MeSH
• Auditory Perception physiology   MeSH
• Evoked Potentials, Auditory physiology   MeSH
• Visual Perception physiology   MeSH
• Evoked Potentials, Visual physiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH