Theta-band Oscillations Research Articles

Seizure activity classification based on bimodal Gaussian modeling of the gamma and theta band IMFs of EEG signals

In this manuscript, EEG signals of seizure and non-seizure activities have been discussed and classified into five groups on the basis of seizure onset, seizure action and brain signal recording location. EEG signals consisting of gamma-band (40–80 Hz) and theta-band (4–8 Hz) oscillations have been captured for performing empirical mode decomposition (EMD). Dominant intrinsic mode functions (IMFs) have been selected from the consequences of EMD and a statistical model is employed upon the IMFs to summarize the information on those. Bimodal Gaussian statistical model has been found most effective to prepare feature set taking the modeling parameters of its probability density function (PDF). Plotting together bimodal Gaussian PDF and empirical PDF for pictorial scrutiny; cumulative distribution function (CDF) in probability–probability (p–p) plot and goodness of fit K–S test result justified the effectiveness of proposed bimodal Gaussian statistical model. Hence, aforementioned statistical modeling parameters have been sent to numerous classifiers and rationalization of goodness of features has been shown through inter-class separability and intra-class compactness parameters. Extensive varieties of simulations are performed using a well-established dataset. The suggested strategy reveals the capability of making higher values of sensitivity, specificity and accuracy compared to that made by some cutting-edge methods utilizing the same EEG dataset.

Mediofrontal theta-band oscillations reflect top-down influence in the ventriloquist illusion.

In the ventriloquist illusion, spatially disparate visual signals can influence the perceived location of simultaneous sounds. Previous studies have shown asymmetrical responses in auditory cortical regions following perceived peripheral sound shifts. Moreover, higher‐order cortical areas perform inferences on the sources of disparate audiovisual signals. Recent studies have also highlighted top‐down influence in the ventriloquist illusion and postulated a governing function of neural oscillations for crossmodal processing. In this EEG study, we analyzed source‐reconstructed neural oscillations to address the question of whether perceived sound shifts affect the laterality of auditory responses. Moreover, we investigated the modulation of neural oscillations related to the occurrence of the illusion more generally. With respect to the first question, we did not find evidence for significant changes in the laterality of auditory responses due to perceived sound shifts. However, we found a sustained reduction of mediofrontal theta‐band power starting prior to stimulus onset when participants perceived the illusion compared to when they did not perceive the illusion. We suggest that this effect reflects a state of diminished cognitive control, leading to reliance on more readily discriminable visual information and increased crossmodal influence. We conclude that mediofrontal theta‐band oscillations serve as a neural mechanism underlying top‐down modulation of crossmodal processing in the ventriloquist illusion.

Theta band (4~8 Hz) oscillations reflect syllables processing in Chinese spoken word production

Theta band (4~8 Hz) oscillations reflect syllables processing in Chinese spoken word production

Altered gamma and theta oscillations during multistable perception in schizophrenia

ObjectiveCoherent object perception in patients with schizophrenia is known to be impaired. Oscillatory brain dynamics constitute a fundamental mechanism for the coordinated communication of neural circuits. Such dynamics have been proposed to reflect impaired spatio-temporal integration of sensory and cognitive processes during object perception in schizophrenia. MethodEEG recordings of patients with schizophrenia (n = 23) and control participants (n = 23) were examined. Presented were either an ambiguous (multistable) stimulus, endogenously inducing switching between two perceptual alternatives, or a slightly modified unambiguous control stimulus, during which perceptual reversals were triggered by a minor change in the stimulus configuration. Event-related amplitude modulation induced by perceptual reversals was analyzed for theta (3–8 Hz) and gamma band oscillations (28–48 Hz). ResultsPatients displayed increased reaction times and more errors when indicating unambiguous reversals. The patients´ amplitude enhancement of theta oscillations was diminished in both task conditions. During the control task were gamma amplitudes larger in patients than in healthy participants. ConclusionThe results indicate that impairments in generating coherent percepts are reflected in alterations of multiple frequency bands and time windows. Changes in gamma band oscillations may reflect the patients' impairments in perceptuo-cognitive integration processes. Diminished theta amplitude modulation in patients further emphasize diminished top-down cognitive control during perceptual reversals. SignificanceThis study provides insight into how theta and gamma oscillations underlie changes in object perception, and thereby possibly the generation of core symptoms, in schizophrenia.This paper is dedicated to Prof. Dr. Erol Başar, a pioneer in research on oscillatory braindynamics. He was tireless in his effort to understand brain functions and integratedphilosophy, physics, biology and psychology in his research. His vision on how informationis coded in brain networks inspired many researchers in the last 40 years. With him, we not only lose an exceptional researcher, but also a supportive academic teacher and mentor with a persistent, prolific enthusiasm for international and collaborative projects.

Reorganization of theta phase-locking in the orbitofrontal cortex drives cocaine choice under the influence

Cortical theta oscillations of neuronal activity are a fundamental mechanism driving goal-directed behavior. We previously identified in the rat orbitofrontal cortex (OFC) a neuronal correlate of individual preferences between cocaine use and an alternative nondrug reward (i.e. saccharin). Whether theta oscillations are also associated with choice behavior between a drug and a nondrug reward remains unknown. Here we investigated the temporal structure between single unit activity and theta band oscillations (4–12 Hz) in the OFC of rats choosing between cocaine and saccharin. First, we found that the relative amplitude of theta oscillations is associated with subjective value and preference between two rewards. Second, OFC phase-locked neurons fired on opposite phase of the theta oscillation during saccharin and cocaine rewards, suggesting the existence of two separable neuronal assemblies. Finally, the pharmacological influence of cocaine at the moment of choice altered both theta band power and theta phase-locking in the OFC. That is, this drug influence shifted spike-phase relative to theta cycle and decreased the synchronization of OFC neurons relative to the theta oscillation. Overall, this study indicates that the reorganization of theta phase-locking under the influence of cocaine biases OFC neuronal assemblies in favor of cocaine choice and at the expense of a normally preferred alternative, a neuronal change that may contribute to drug preference in cocaine addiction.

Coupled CP Decomposition of Simultaneous MEG-EEG Signals for Differentiating Oscillators During Photic Driving.

Magnetoencephalography (MEG) and electroencephalography (EEG) are contemporary methods to investigate the function and organization of the brain. Simultaneously acquired MEG-EEG data are inherently multi-dimensional and exhibit coupling. This study uses a coupled tensor decomposition to extract the signal sources from MEG-EEG during intermittent photic stimulation (IPS). We employ the Coupled Semi-Algebraic framework for approximate CP decomposition via SImultaneous matrix diagonalization (C-SECSI). After comparing its performance with alternative methods using simulated benchmark data, we apply it to MEG-EEG recordings of 12 participants during IPS with fractions of the individual alpha frequency between 0.4 and 1.3. In the benchmark tests, C-SECSI is more accurate than SECSI and alternative methods, especially in ill-conditioned scenarios, e.g., involving collinear factors or noise sources with different variances. The component field-maps allow us to separate physiologically meaningful oscillations of visually evoked brain activity from background signals. The frequency signatures of the components identify either an entrainment to the respective stimulation frequency or its first harmonic, or an oscillation in the individual alpha band or theta band. In the group analysis of both, MEG and EEG data, we observe a reciprocal relationship between alpha and theta band oscillations. The coupled tensor decomposition using C-SECSI is a robust, powerful method for the extraction of physiologically meaningful sources from multidimensional biomedical data. Unsupervised signal source extraction is an essential solution for rendering advanced multi-modal signal acquisition technology accessible to clinical diagnostics, pre-surgical planning, and brain computer interface applications.

A Facilitatory Effect of Perceptual Incongruity on Target-Source Matching in Pictorial Metaphors of Chinese Advertising: EEG Evidence.

Using evoked response potentials, we investigated the implicit detection of incongruity during target-source matching in pictorial metaphors of Chinese advertising. Participants saw an image of a product (the target in a visual metaphorical relationship), and then made a same-different judgment in response to a second image (the source in a visual metaphorical relationship) which was (in)congruous to the first image in terms of shape and/or function. We collected behavioral (button-press reaction time and accuracy), and neural (N270, delta and theta band activity) measures. The time-frequency analysis showed faster processing of incongruous visual information. Moreover, shape and conceptual incongruity were associated with increased N270 amplitude as well as delta (1-3 Hz) and theta (4-8 Hz) band power. Noticeably, compared with conceptual incongruity, shape incongruity evoked a larger N270 amplitude and stronger delta and theta band oscillation. In addition, the average topographical analysis revealed a frontal and central distribution of the power activity. The analysis of attitudes towards the advertising metaphor pictures also proved the supportive role played by incongruity. In conclusion, incongruity facilitates target-source matching in pictorial metaphors of Chinese advertising. The findings obtained from the study are important to metaphor designs of advertising pictures.

Time estimation exposure modifies cognitive aspects and cortical activity of attention deficit hyperactivity disorder adults

Aim This study investigated whether time-estimation task exposure influences the severity of Attention Deficit Hyperactivity Disorder (ADHD), as well as theta band activity in the dorsolateral prefrontal cortex and ventrolateral prefrontal cortex. Material and methods Twenty-two patients with ADHD participated in a crossover experiment with a visual time-estimation task under control conditions (without exposure to time estimation tasks) and experimental (thirty days exposure to time-estimation tasks) in association with electroencephalographic analysis of theta band. Results ADHD patients with thirty days of time-estimation task exposure presented a worse performance of the time-estimation task, as revealed by the measurements of the absolute error and relative error (p ≤ 0.05). However, our findings show the improvement of self-reported symptoms of attention, impulsivity, and emotional control in patients after the time-estimation task exposure (p = 0.0001). Moreover, the theta band oscillations in the right dorsolateral prefrontal cortex and in the ventrolateral prefrontal increased with thirty days of time-estimation task exposure (p ≤ 0.05). Conclusion We propose that the decrease in EEG theta power may indicate an efficient accumulation of temporal pulses, which could be responsible for the improvement in the patient cognitive aspects as demonstrated by the current study. Time-estimation task improves ADHD cognitive symptoms, with a substantial increase in cortical areas activity related to attention and memory, suggesting its use as a tool for cognitive timing function management and non-invasive therapeutic aid in ADHD.

Effect of upright standing postures on cortical oscillation spectral power modulations

Introduction Amplitude modulation of cortical oscillations are associated to various movement parameters. Recently, theta-band cortical oscillations were shown to be involved in maintaining upright posture. However, the function of delta-, alpha-, beta-, and gamma-band cortical oscillatory components still needs to be clarified. To provide further understanding of the function of cortical oscillations in controlling balance, we investigated the effect of different upright standing postures on the modulation of cortical oscillations. Materials and methods Brain activity and ground reaction forces of 13 participants were recorded using 64 electroencephalographic electrodes and a force platform. Participants stood upright in four conditions: with regular and narrow stance widths and on firm and foam surfaces. To obtain modulation of cortical oscillations, brain activity was also recorded while sitting on a chair. Modulation of cortical oscillation spectral power and the confidence ellipse area of the center of pressure displacement were compared between stance widths and surfaces using a linear mixed model. Results Confidence ellipse area significantly increased during the narrow and the foam conditions. Delta-band synchronization significantly increased in the central region during foam and narrow conditions. In all conditions, alpha- and beta-band showed desynchronization in the central region. Additionally, alpha-band showed desynchronization in frontal and occipital regions, which was significantly greater during narrow stance conditions. Finally, gamma-band synchronization significantly increased in the right temporoparietal junction during narrow and foam conditions. Discussion/conclusion Alpha- and beta-band desynchronization as well as delta- and gamma-band synchronization and their modulations during unstable postural conditions highlight the involvement of these cortical oscillatory components in balance control.

Co-localization of theta-band activity and hemodynamic responses during face perception: simultaneous electroencephalography and functional near-infrared spectroscopy recordings.

.Face-specific neural processes in the human brain have been localized to multiple anatomical structures and associated with diverse and dynamic social functions. The question of how various face-related systems and functions may be bound together remains an active area of investigation. We hypothesize that face processing may be associated with specific frequency band oscillations that serve to integrate distributed face processing systems. Using a multimodal imaging approach, including electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS), simultaneous signals were acquired during face and object picture viewing. As expected for face processing, hemodynamic activity in the right occipital face area (OFA) increased during face viewing compared to object viewing, and in a subset of participants, the expected N170 EEG response was observed for faces. Based on recently reported associations between the theta band and visual processing, we hypothesized that increased hemodynamic activity in a face processing area would also be associated with greater theta-band activity originating in the same area. Consistent with our hypothesis, theta-band oscillations were also localized to the right OFA for faces, whereas alpha- and beta-band oscillations were not. Together, these findings suggest that theta-band oscillations originating in the OFA may be part of the distributed face-specific processing mechanism.

Subthalamic nucleus oscillations correlate with vulnerability to freezing of gait in patients with Parkinson's disease

Freezing of gait (FOG) is a disabling clinical phenomenon often found in patients with advanced Parkinson's disease (PD). FOG impairs motor function, causes falls and leads to loss of independence. Whereas dual tasking that distracts patients' attention precipitates FOG, auditory or visual cues ameliorate this phenomenon. The pathophysiology of FOG remains unclear. Previous studies suggest that the basal ganglia are involved in the generation of FOG. Investigation of the modulation of neuronal activities within basal ganglia structures during walking is warranted. To this end, we recorded local field potentials (LFP) from the subthalamic nucleus (STN) while PD patients performed single-task gait (ST) or walked while dual-tasking (DT). An index of FOG (iFOG) derived from trunk accelerometry was used as an objective measure to differentiate FOG-vulnerable gait from normal gait. Two spectral activities recorded from the STN region were associated with vulnerability to freezing. Greater LFP power in the low beta (15–21 Hz) and theta (5–8 Hz) bands were noted during periods of vulnerable gait in both ST and DT states. Whereas the elevation of low beta activities was distributed across STN, the increase in theta activity was focal and found in ventral STN and/or substantia nigra (SNr) in ST. The results demonstrate that low beta and theta band oscillations within the STN area occur during gait susceptible to freezing in PD. They also add to the evidence that narrow band ~18 Hz activity may be linked to FOG.

Speech-specific audiovisual integration modulates induced theta-band oscillations.

Speech perception is influenced by vision through a process of audiovisual integration. This is demonstrated by the McGurk illusion where visual speech (for example /ga/) dubbed with incongruent auditory speech (such as /ba/) leads to a modified auditory percept (/da/). Recent studies have indicated that perception of the incongruent speech stimuli used in McGurk paradigms involves mechanisms of both general and audiovisual speech specific mismatch processing and that general mismatch processing modulates induced theta-band (4–8 Hz) oscillations. Here, we investigated whether the theta modulation merely reflects mismatch processing or, alternatively, audiovisual integration of speech. We used electroencephalographic recordings from two previously published studies using audiovisual sine-wave speech (SWS), a spectrally degraded speech signal sounding nonsensical to naïve perceivers but perceived as speech by informed subjects. Earlier studies have shown that informed, but not naïve subjects integrate SWS phonetically with visual speech. In an N1/P2 event-related potential paradigm, we found a significant difference in theta-band activity between informed and naïve perceivers of audiovisual speech, suggesting that audiovisual integration modulates induced theta-band oscillations. In a McGurk mismatch negativity paradigm (MMN) where infrequent McGurk stimuli were embedded in a sequence of frequent audio-visually congruent stimuli we found no difference between congruent and McGurk stimuli. The infrequent stimuli in this paradigm are violating both the general prediction of stimulus content, and that of audiovisual congruence. Hence, we found no support for the hypothesis that audiovisual mismatch modulates induced theta-band oscillations. We also did not find any effects of audiovisual integration in the MMN paradigm, possibly due to the experimental design.

The lasting effects of 1Hz repetitive transcranial magnetic stimulation on resting state EEG in healthy subjects.

Repetitive Transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation technique that able to influence cortical excitability. Low-frequency rTMS (stimulation frequency ≤1Hz) induces long-lasting inhibitory effects on cortical excitability. In order to study the effects of 1Hz rTMS of the motor cortex on neuronal activity, 20 healthy subjects were recruited to receive rTMS, and electroencephalography (EEG) in resting condition with eye open were recorded before rTMS, at 0min, 20min, 40min, 60min after rTMS. In multiple frequency bands, power values on each channel were calculated, and functional connectivity between two channels was assessed using phase synchronization. We found an increase in power of theta-band oscillations in the frontal and the central brain areas immediately after rTMS. And alpha resting power in the central-parietal brain area did not change immediately after rTMS, but increased at 20min after rTMS. Moreover, there is a widespread increase in functional connectivity after rTMS in the theta band, whereas widespread decreases in the functional connectivity were found in the alpha band after rTMS. At the same time, there was no significant recovery on power and functional connectivity at 60min after rTMS. These results provide an evidence for a transient reorganization of neuronal activity after 1Hz rTMS over the motor cortex. In addition, low-frequency rTMS produces widespread long-lasting alterations in cortical functional connectivity.

Theta band high definition transcranial alternating current stimulation, but not transcranial direct current stimulation, improves associative memory performance

Associative memory (AM) deficits are common in neurodegenerative disease and novel therapies aimed at improving these faculties are needed. Theta band oscillations within AM networks have been shown to be important for successful memory encoding and modulating these rhythms represents a promising strategy for cognitive enhancement. Transcranial alternating current stimulation (TACS) has been hypothesized to entrain and increase power of endogenous brain rhythms. For this reason, we hypothesized that focal delivery of theta band electrical current, using high-definition TACS, would result in improved AM performance compared to sham stimulation or transcranial direct current stimulation (TDCS). In this pilot study, 60 healthy subjects were randomized to receive high definition TACS, high definition TDCS, or sham stimulation delivered to the right fusiform cortex during encoding of visual associations. Consistent with our hypothesis, improved AM performance was observed in the TACS group, while TDCS had no effect. However, TACS also resulted in improved correct rejection of never seen items, reduced false memory, and reduced forgetting, suggesting the effect may not be specific for AM processes. Overall, this work informs strategies for improving associative memory and suggests alternating current is more effective than direct current stimulation in some contexts.

Phase-amplitude coupling between theta and gamma oscillations adapts to speech rate.

Low‐ and high‐frequency cortical oscillations play an important role in speech processing. Low‐frequency neural oscillations in the delta (<4 Hz) and theta (4–8 Hz) bands entrain to the prosodic and syllabic rates of speech, respectively. Theta band neural oscillations modulate high‐frequency neural oscillations in the gamma band (28−40 Hz), which have been hypothesized to be crucial for processing phonemes in natural speech. Since speech rate is known to vary considerably, both between and within talkers, it has yet to be determined whether this nested gamma response reflects an externally induced rhythm sensitive to the rate of the fine‐grained structure of the input or a speech rate−independent endogenous response. Here, we recorded magnetoencephalography responses from participants listening to a speech delivered at different rates: decelerated, normal, and accelerated. We found that the phase of theta band oscillations in left and right auditory regions adjusts to speech rate variations. Importantly, we showed that the peak of the gamma response—coupled to the phase of theta—follows the speech rate. This indicates that gamma activity in auditory regions synchronizes with the fine‐grain properties of speech, possibly reflecting detailed acoustic analysis of the input.

Theta and alpha band oscillations during value-directed strategic processing

Strategic processing allows for value-based preferential encoding of information. Event-related spectral perturbations can provide insights into neural processes linked to the different aspects of strategic processing. This study examined theta and alpha band power differences linked to processing of high- versus low-value information. Thirty-three young adults (17 F; mean age: 21.2 ± 1.5 years) completed a value-directed word list learning task. The task consisted of five word lists that each contained a unique set of high- and low-value words that were visually presented one at a time and EEG corresponding to these words were examined. To encourage strategic processing, participants were informed that after each list they would be asked to recall as many words as possible with their goal being to maximize their score. Overall, participants recalled more high-value words for each of the five lists as compared to low-value words, which supports that participants engaged in strategic processing. Frontal theta band power showed greater positivity during processing of low- compared to high-value words, whereas parietal alpha band power showed greater negativity during processing of high- compared to low-value words. These findings suggest that theta and alpha bands index different aspects of strategic processing, namely inhibition and selective attention, and have future applications for understanding the effects of aging and brain diseases/disorders.

Reading Shakespearean tropes in a foreign tongue: Age of L2 acquisition modulates neural responses to functional shifts

Functional shifts (FSs) – morphosyntactically marked words evoking coherent but novel meanings – are ubiquitous in English and, specially, in Shakespearean literature. While their neural signatures have been explored in native speakers, no study has targeted foreign-language users, let alone comparing early and late bilinguals. Here, we administered a validated FS paradigm to subjects from both populations and evaluated time-frequency modulations evoked by FS and control sentences. Early bilinguals exhibited greater sensitivity towards FSs, indexed by reduced fronto-posterior theta-band oscillations across semantic- and structural-integration windows. Such oscillatory modulations may represent a key marker of age-of-acquisition effects during foreign-language wordplay processing.

Eltoprazine prevents levodopa-induced dyskinesias by reducing causal interactions for theta oscillations in the dorsolateral striatum and substantia nigra pars reticulate

Oscillatory activities within basal ganglia (BG) circuitry in L-DOPA induced dyskinesia (LID), a condition that occurs in patients with Parkinson disease (PD), are not well understood. The aims of this study were firstly to investigate oscillations in main BG input and output structures—the dorsolateral striatum (dStr) and substantia nigra pars reticulata (SNr), respectively— including the direction of oscillation information flow, and secondly to investigate the effects of 5-HT1A/B receptor agonism with eltoprazine on oscillatory activities and abnormal involuntary movements (AIMs) characteristic. To this end, we conducted local field potential (LFP) electrophysiology in the dStr and SNr of LID rats simultaneous with AIM scoring. The LFP data were submitted to power spectral density, coherence, and partial Granger causality analyses. AIM data were analyzed relative to simultaneous oscillatory activities, with and without eltoprazine. We obtained four major findings. 1) Theta band (5–8 Hz) oscillations were enhanced in the dStr and SNr of LID rats. 2) Theta power correlated with AIM scores in the 180-min period after the last LID-inducing L-DOPA injection, but not with daily summed AIM scores during LID development. 3) Oscillatory information flowed from the dStr to the SNr. 4) Chronic eltoprazine reduced BG theta activity in LID rats and normalized information flow directionality, relative to that in LID rats not given eltoprazine. These results indicate that dStr activity plays a determinative role in the causal interactions of theta oscillations and that serotonergic inhibition may suppress dyskinesia by reducing dStr-SNr theta activity and restoring theta network information flow.

Neural signatures of reactive and intentional inhibitions: An ERP study

Humans can inhibit an action based on external instruction (i.e., reactive inhibition) or internal decision (i.e., intentional inhibition). Although some functional magnetic resonance imaging (fMRI) studies have documented the relationship between reactive and intentional inhibitions, they could not provide pertinent temporal dynamics information due to fMRI’s low temporal resolution. Therefore, in the current study, we explored this issue by extracting the time-domain dynamics and oscillatory-power dynamics from electroencephalographic (EEG) data while participants performed a modified Go/NoGo/Choose task, in which free choices trials were integrated with conventional go/nogo trials. Participants were asked to decide for themselves to either inhibit or execute an action for free choices trials, and to respond properly according to go/nogo signal for conventional go/nogo trials. Two important results were obtained. First, for the reactive condition, nogo trials elicited greater N2 and P3 amplitudes and induced more pronounced delta, theta, and beta band oscillations than go trials, while for the intentional condition, nogo trials only elicited greater P3 amplitudes and triggered pronounced beta band oscillations compared to go trials. Second, while the P3/delta, theta, and beta oscillations were larger for reactive nogo trials than for intentional go/nogo trials, the P3/delta and theta oscillations were larger for intentional go/nogo trials than for reactive go trials. Together, these results suggest that there are both similarities and differences in oscillatory dynamics between reactive and intentional inhibitions. This study is the first to investigate the relationship between reactive and intentional inhibitions at the time-frequency domain, and the current results expand our understanding about different inhibitions.

Electroacupuncture Treatment Alleviates the Remifentanil-Induced Hyperalgesia by Regulating the Activities of the Ventral Posterior Lateral Nucleus of the Thalamus Neurons in Rats.

Mechanisms underlying remifentanil- (RF-) induced hyperalgesia, a phenomenon that is generally named as opioid-induced hyperalgesia (OIH), still remain elusive. The ventral posterior lateral nucleus (VPL) of the thalamus, a key relay station for the transmission of nociceptive information to the cerebral cortex, is activated by RF infusion. Electroacupuncture (EA) is an effective method for the treatment of pain. This study aimed to explore the role of VPL in the development of OIH and the effect of EA treatment on OIH in rats. RF was administered to rats via the tail vein for OIH induction. Paw withdrawal threshold (PWT) in response to mechanical stimuli and paw withdrawal latency (PWL) to thermal stimulation were tested in rats for the assessment of mechanical allodynia and thermal hyperalgesia, respectively. Spontaneous neuronal activity and local field potential (LFP) in VPL were recorded in freely moving rats using the in vivo multichannel recording technique. EA at 2 Hz frequency (pulse width 0.6 ms, 1–3 mA) was applied to the bilateral acupoints “Zusanli” (ST.36) and “Sanyinjiao” (SP.6) in rats. The results showed that both the PWT and PWL were significantly decreased after RF infusion to rats. Meanwhile, both the spontaneous neuronal firing rate and the theta band oscillation in VPL LFP were increased on day 3 post-RF infusion, indicating that the VPL may promote the development of RF-induced hyperalgesia by regulating the pain-related cortical activity. Moreover, 2 Hz-EA reversed the RF-induced decrease both in PWT and PWL of rats and also abrogated the RF-induced augmentation of the spontaneous neuronal activity and the power spectral density (PSD) of the theta band oscillation in VPL LFP. These results suggested that 2 Hz-EA attenuates the remifentanil-induced hyperalgesia via reducing the excitability of VPL neurons and the low-frequency (theta band) oscillation in VPL LFP.