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Papers by Gerald Tramontano

Research paper thumbnail of Connectivity changes following transcranial alternating current stimulation at 5-Hz: an EEG study

Research Square (Research Square), Jun 18, 2024

Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can alleviate... more Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can alleviate anxiety symptoms. This study aimed to explore the connectivity changes following the treatment. We collected electroencephalography (EEG) data from 24 participants with anxiety disorders before and after the tACS treatment during a single session. Electric stimulation was applied over the right hemisphere, with 1.0 mA at F4, 1.0 mA at P4, and 2.0 mA at T8, following the 10-10 EEG convention. With eLORETA, the scalp signals were transformed into the cortex's current source density. We assessed the connectivity changes at theta frequency between the centers of Brodmann area (BA) 6/8 (frontal), BA 39/40 (parietal), and BA 21 (middle temporal). Functional connectivity was indicated by lagged coherences and lagged phase synchronization. Paired t-tests were used to quantify the differences statistically. We observed enhanced lagged phase synchronization at theta frequency between the frontal and parietal regions (P = 0.002) and between the parietal and temporal regions (P = 0.005), after Bonferroni correction. Applying tACS 5-Hz over the right hemisphere enhanced inter-regional interaction, which was spectrumspeci c and mainly mediated by phase, rather than power, synchrony. The potential neural mechanisms are discussed.

Research paper thumbnail of Attention improvement to transcranial alternating current stimulation at gamma frequency over the right frontoparietal network: a preliminary report

Attention improvement to transcranial alternating current stimulation at gamma frequency over the right frontoparietal network: a preliminary report

Research paper thumbnail of Negative relationship between inter-regional interaction and regional power: a resting fMRI study

bioRxiv (Cold Spring Harbor Laboratory), Feb 2, 2024

Background: Regional neural response and network property used to be treated separately. However,... more Background: Regional neural response and network property used to be treated separately. However, evidence has suggested an intimate relationship between the regional and inter-regional profiles. This research aimed to investigate the influence of functional connectivity on regional spontaneous activity. Methods: Thirty-six and sixty datasets of structural magnetic resonance imaging (sMRI) and resting state functional MRI (rsfMRI) were selected from the NKI and CAN-BIND database, respectively. The cerebral cortex in rsfMRI was parcellated by MOSI (modular analysis and similarity measurements), which enables multi-resolution exploration. For each parcellated cluster, the mean amplitude of low-frequency fluctuation (ALFF) and its average functional connectivity strength with the remaining cortical analogs were computed. Correlation analyses were exploited to examine their relationship. Supplementary analysis was applied to CAN-BIND EEG data (1 to 30 Hz). Results: Negative correlation coefficients between inter-regional interaction and regional power were noticed in both MRI datasets. One-sample t-tests revealed robust statistics across different analytic resolutions yielded by MOSI, with individual P values at the level 10^-4 to 10^-5. The results suggested that the more intense crosstalk a neural node is embedded in, the less regional power it manifests, and vice (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission.

Research paper thumbnail of Connectivity changes following transcranial alternating current stimulation at 5-Hz: an EEG study

medRxiv (Cold Spring Harbor Laboratory), Oct 13, 2023

Research paper thumbnail of Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: An EEG study

Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: An EEG study

Biosystems, Dec 31, 2023

Research paper thumbnail of Neural consequences of 5-Hz transcranial alternating current stimulation over right hemisphere: an eLORETA EEG study

Introduction: Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere... more Introduction: Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can effectively alleviate symptoms of anxiety. The objective of this study was to explore the neural mechanisms that drive the therapeutic benefits. Methods: We collected electroencephalography (EEG) data from 24 participants with anxiety disorders both before and after the tACS treatment during a single session. We applied the stimulation over the right hemisphere, with 1.0 mA at F4, 1.0 mA at P4, and 2.0 mA at T8, following the 10-10 EEG convention. With eLORETA, we transformed the scalp signals into the current source density in the cortex. We then assessed the differences between post- and pre-treatment brain maps across multiple spectra (delta to low gamma) with non-parametric statistics. Results: We observed a trend of heightened power in alpha and reduced power in mid-to-high beta and low gamma, in accord with the EEG markers of anxiolytic effects reported in previous studies. Ad...

Research paper thumbnail of Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: an EEG study

Introduction: Despite its complexity, deciphering nodal interaction is imperative to understandin... more Introduction: Despite its complexity, deciphering nodal interaction is imperative to understanding a neural network. Network interaction is an even more complicated topic that must be addressed. This study aimed to examine the relationship between the brain waves of two canonical brain structures, i.e., the frontoparietal and limbic compartments, during a resting state. Methods: Electroencephalography (EEG) of 51 subjects in eye-closed condition was analyzed, and the eLORETA method was applied to convert the signals from the scalp to the brain. By way of community detection, representative neural nodes and the associated mean activities were retrieved. Total and lagged coherences were computed to indicate functional connectivity between those neural nodes. Two global network properties were elucidated based on the connectivity measures, i.e., global efficiency and mean functional connectivity strength. The temporal correlation of the global network indices between the two studied ne...

Research paper thumbnail of Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Acta Neuropsychiatrica, May 30, 2022

Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given ... more Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given that there is an increase in treatment options and that early intervention could modify the disease course, it is desirable to devise biological indices that may differentiate AD and nonAD at mild cognitive impairment (MCI) stage.Methods:Based on two well-acknowledged observations of background slowing (attenuation in alpha power and enhancement in theta and delta powers) and early involvement of posterior cingulate cortex (PCC, a neural hub of default-mode network), this study devised novel neural markers, namely, spectral ratios of alpha1 to delta and alpha1 to theta in the PCC.Results:We analysed 46 MCI patients, with 22 ADMCI and 24 nonADMCI who were matched in age, education, and global cognitive capability. Concordant with the prediction, the regional spectral ratios were lower in the ADMCI group, suggesting its clinical application potential.Conclusion:Previous research has verified that neural markers derived from clinical electroencephalography may be informative in differentiating AD from other neurological conditions. We believe that the spectral ratios in the neural hubs that show early pathological changes can enrich the instrumental assessment of brain dysfunctions at the MCI (or pre-clinical) stage.

Research paper thumbnail of Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Acta Neuropsychiatrica

Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given ... more Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given that there is an increase in treatment options and that early intervention could modify the disease course, it is desirable to devise biological indices that may differentiate AD and nonAD at mild cognitive impairment (MCI) stage.Methods:Based on two well-acknowledged observations of background slowing (attenuation in alpha power and enhancement in theta and delta powers) and early involvement of posterior cingulate cortex (PCC, a neural hub of default-mode network), this study devised novel neural markers, namely, spectral ratios of alpha1 to delta and alpha1 to theta in the PCC.Results:We analysed 46 MCI patients, with 22 ADMCI and 24 nonADMCI who were matched in age, education, and global cognitive capability. Concordant with the prediction, the regional spectral ratios were lower in the ADMCI group, suggesting its clinical application potential.Conclusion:Previous research has verifi...

Research paper thumbnail of QEEG Testing Can Discern Reason for Cognitive Disorder : Digital EEG Recordings of Brainwaves Can Determine TBI Etiology

QEEG Testing Can Discern Reason for Cognitive Disorder : Digital EEG Recordings of Brainwaves Can Determine TBI Etiology

Research paper thumbnail of Automatic parcellation of resting-state cortical dynamics by iterative community detection and similarity measurements

Automatic parcellation of resting-state cortical dynamics by iterative community detection and similarity measurements

AIMS Neuroscience, 2021

To investigate the properties of a large-scale brain network, it is a common practice to reduce t... more To investigate the properties of a large-scale brain network, it is a common practice to reduce the dimension of resting state functional magnetic resonance imaging (rs-fMRI) data to tens to hundreds of nodes. This study presents an analytic streamline that incorporates modular analysis and similarity measurements (MOSI) to fulfill functional parcellation (FP) of the cortex. MOSI is carried out by iteratively dividing a module into sub-modules (via the Louvain community detection method) and unifying similar neighboring sub-modules into a new module (adjacent sub-modules with a similarity index <0.05) until the brain modular structures of successive runs become constant. By adjusting the gamma value, a parameter in the Louvain algorithm, MOSI may segment the cortex with different resolutions. rs-fMRI scans of 33 healthy subjects were selected from the dataset of the Rockland sample. MOSI was applied to the rs-fMRI data after standardized pre-processing steps. The results indicate...

Research paper thumbnail of Integrating Various Neural Features Based on Mechanism of Intricate Balance and Ongoing Activity: Unified Neural Account Underlying and Correspondent to Mental Phenomena

World Journal of Neuroscience, 2021

In recent decades, brain science has been enriched from both empirical and computational approach... more In recent decades, brain science has been enriched from both empirical and computational approaches. Interesting emerging neural features include power-law distribution, chaotic behavior, self-organized criticality, variance approach, neuronal avalanches, difference-based and sparse coding, optimized information transfer, maximized dynamic range for information processing, and reproducibility of evoked spatio-temporal motifs in spontaneous activities, and so on. These intriguing findings can be largely categorized into two classes: complexity and regularity. This article would like to highlight that the above-mentioned properties although look diverse and unrelated, but actually may be rooted in a common foundation-excitatory and inhibitory balance (EIB) and ongoing activities (OA). To be clear, description and observation of neural features are phenomena or epiphenomena, while EIB-OA is the underlying mechanism. The EIB is maintained in a dynamic manner and may possess regional specificity, and importantly, EIB is organized along the boundary of phase transition which has been called criticality, bifurcation or edge of chaos. OA is composed of spontaneous organized activity, physiological noise, non-physiological noise and the interacting effect between OA and evoked activities. Based on EIB-OA, the brain may accommodate the property of chaos and regularity. We propose "virtual brain space" to bridge brain dynamics and mental space, and "code driving complexity hypothesis" to integrate regularity and complexity. The functional implication of oscillation and energy consumption of the brain are discussed.

Research paper thumbnail of Speed of Information Processing in Traumatic Brain Injury: Modality-Specific Factors

Speed of Information Processing in Traumatic Brain Injury: Modality-Specific Factors

Journal of Head Trauma Rehabilitation, 2000

To assess speed of information processing by two serial addition tests (one visual, one auditory)... more To assess speed of information processing by two serial addition tests (one visual, one auditory) in individuals with moderate-to-severe traumatic brain injuries (TBIs) and in a healthy, normal control group (NC). The tasks were designed to equate and control for accuracy of performance across the TBI and NC groups, thus allowing for quantification of information processing speed. Performance across groups and tasks were compared using 2 x 2 repeated measure analyses of variance (ANOVAs). In addition, each individual&#39;s processing speed was used to adjust rate of stimulus presentation on a subsequent &quot;rehabilitation&quot; trial to determine further whether this adjustment equated accuracy of performance. Rehabilitation hospital. 22 outpatients with moderate-to-severe TBI (6 women, 16 men; mean age = 34.6 years; duration of loss of consciousness = 22.6 days) and 20 age- and education-matched healthy controls. Processing speed was slower in TBI subjects, relative to controls and was significantly related to measures of executive functioning for those with TBI. Relative to controls, speed of processing in the TBI group was disproportionately slower when information was presented in the auditory, relative to the visual, modality. Speed of information processing is a major impairment in those with TBI when unconfounded by performance accuracy. The modality-specific impairment observed in the TBI group may, in part, be due to a greater within-modality interference effect created by the auditory version of the task. By manipulating information at a pace customized for an individual through compensatory strategies and environmental modifications, information-processing performance of TBI participants can be enhanced significantly.

Research paper thumbnail of Tripod transcranial alternating current stimulation at 5-Hz to alleviate anxiety symptoms: a preliminary report

ABSTRACTIntroductionOne of the most common applications of transcranial electrical stimulation (t... more ABSTRACTIntroductionOne of the most common applications of transcranial electrical stimulation (tES) at low current intensity is to induce a relaxed state or reduce anxiety. With technical advancement, different waveforms, montages, and parameters can be incorporated into the treatment regimen. We developed a novel protocol to treat individuals with anxiety disorders by transcranial alternating current stimulation (tACS).MethodsA total of 27 individuals with anxiety disorders underwent tACS treatment for 12 sessions, with each session lasting 25 minutes. tACS at 5 Hz was applied to F4 (1.0 mA), P4 (1.0 mA), and T8 (2.0 mA) EEG lead positions (tripod), with sinewave oscillation between T8 and F4/P4. We evaluated the primary and secondary outcomes using the Beck Anxiety Inventory (BAI) and neuropsychological assessments.ResultsOf the 27 patients, 19 (70.4%) experienced a reduction in symptom severity greater than 50%, with an average reduction of BAI 58.5%. All reported side effects w...

Research paper thumbnail of Connectivity changes following transcranial alternating current stimulation at 5-Hz: an EEG study

Research Square (Research Square), Jun 18, 2024

Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can alleviate... more Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can alleviate anxiety symptoms. This study aimed to explore the connectivity changes following the treatment. We collected electroencephalography (EEG) data from 24 participants with anxiety disorders before and after the tACS treatment during a single session. Electric stimulation was applied over the right hemisphere, with 1.0 mA at F4, 1.0 mA at P4, and 2.0 mA at T8, following the 10-10 EEG convention. With eLORETA, the scalp signals were transformed into the cortex's current source density. We assessed the connectivity changes at theta frequency between the centers of Brodmann area (BA) 6/8 (frontal), BA 39/40 (parietal), and BA 21 (middle temporal). Functional connectivity was indicated by lagged coherences and lagged phase synchronization. Paired t-tests were used to quantify the differences statistically. We observed enhanced lagged phase synchronization at theta frequency between the frontal and parietal regions (P = 0.002) and between the parietal and temporal regions (P = 0.005), after Bonferroni correction. Applying tACS 5-Hz over the right hemisphere enhanced inter-regional interaction, which was spectrumspeci c and mainly mediated by phase, rather than power, synchrony. The potential neural mechanisms are discussed.

Research paper thumbnail of Attention improvement to transcranial alternating current stimulation at gamma frequency over the right frontoparietal network: a preliminary report

Attention improvement to transcranial alternating current stimulation at gamma frequency over the right frontoparietal network: a preliminary report

Research paper thumbnail of Negative relationship between inter-regional interaction and regional power: a resting fMRI study

bioRxiv (Cold Spring Harbor Laboratory), Feb 2, 2024

Background: Regional neural response and network property used to be treated separately. However,... more Background: Regional neural response and network property used to be treated separately. However, evidence has suggested an intimate relationship between the regional and inter-regional profiles. This research aimed to investigate the influence of functional connectivity on regional spontaneous activity. Methods: Thirty-six and sixty datasets of structural magnetic resonance imaging (sMRI) and resting state functional MRI (rsfMRI) were selected from the NKI and CAN-BIND database, respectively. The cerebral cortex in rsfMRI was parcellated by MOSI (modular analysis and similarity measurements), which enables multi-resolution exploration. For each parcellated cluster, the mean amplitude of low-frequency fluctuation (ALFF) and its average functional connectivity strength with the remaining cortical analogs were computed. Correlation analyses were exploited to examine their relationship. Supplementary analysis was applied to CAN-BIND EEG data (1 to 30 Hz). Results: Negative correlation coefficients between inter-regional interaction and regional power were noticed in both MRI datasets. One-sample t-tests revealed robust statistics across different analytic resolutions yielded by MOSI, with individual P values at the level 10^-4 to 10^-5. The results suggested that the more intense crosstalk a neural node is embedded in, the less regional power it manifests, and vice (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission.

Research paper thumbnail of Connectivity changes following transcranial alternating current stimulation at 5-Hz: an EEG study

medRxiv (Cold Spring Harbor Laboratory), Oct 13, 2023

Research paper thumbnail of Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: An EEG study

Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: An EEG study

Biosystems, Dec 31, 2023

Research paper thumbnail of Neural consequences of 5-Hz transcranial alternating current stimulation over right hemisphere: an eLORETA EEG study

Introduction: Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere... more Introduction: Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can effectively alleviate symptoms of anxiety. The objective of this study was to explore the neural mechanisms that drive the therapeutic benefits. Methods: We collected electroencephalography (EEG) data from 24 participants with anxiety disorders both before and after the tACS treatment during a single session. We applied the stimulation over the right hemisphere, with 1.0 mA at F4, 1.0 mA at P4, and 2.0 mA at T8, following the 10-10 EEG convention. With eLORETA, we transformed the scalp signals into the current source density in the cortex. We then assessed the differences between post- and pre-treatment brain maps across multiple spectra (delta to low gamma) with non-parametric statistics. Results: We observed a trend of heightened power in alpha and reduced power in mid-to-high beta and low gamma, in accord with the EEG markers of anxiolytic effects reported in previous studies. Ad...

Research paper thumbnail of Concordant dynamic changes of global network properties in the frontoparietal and limbic compartments: an EEG study

Introduction: Despite its complexity, deciphering nodal interaction is imperative to understandin... more Introduction: Despite its complexity, deciphering nodal interaction is imperative to understanding a neural network. Network interaction is an even more complicated topic that must be addressed. This study aimed to examine the relationship between the brain waves of two canonical brain structures, i.e., the frontoparietal and limbic compartments, during a resting state. Methods: Electroencephalography (EEG) of 51 subjects in eye-closed condition was analyzed, and the eLORETA method was applied to convert the signals from the scalp to the brain. By way of community detection, representative neural nodes and the associated mean activities were retrieved. Total and lagged coherences were computed to indicate functional connectivity between those neural nodes. Two global network properties were elucidated based on the connectivity measures, i.e., global efficiency and mean functional connectivity strength. The temporal correlation of the global network indices between the two studied ne...

Research paper thumbnail of Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Acta Neuropsychiatrica, May 30, 2022

Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given ... more Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given that there is an increase in treatment options and that early intervention could modify the disease course, it is desirable to devise biological indices that may differentiate AD and nonAD at mild cognitive impairment (MCI) stage.Methods:Based on two well-acknowledged observations of background slowing (attenuation in alpha power and enhancement in theta and delta powers) and early involvement of posterior cingulate cortex (PCC, a neural hub of default-mode network), this study devised novel neural markers, namely, spectral ratios of alpha1 to delta and alpha1 to theta in the PCC.Results:We analysed 46 MCI patients, with 22 ADMCI and 24 nonADMCI who were matched in age, education, and global cognitive capability. Concordant with the prediction, the regional spectral ratios were lower in the ADMCI group, suggesting its clinical application potential.Conclusion:Previous research has verified that neural markers derived from clinical electroencephalography may be informative in differentiating AD from other neurological conditions. We believe that the spectral ratios in the neural hubs that show early pathological changes can enrich the instrumental assessment of brain dysfunctions at the MCI (or pre-clinical) stage.

Research paper thumbnail of Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Regional spectral ratios as potential neural markers to identify mild cognitive impairment related to Alzheimer’s disease

Acta Neuropsychiatrica

Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given ... more Objective:Alzheimer’s disease (AD) has prolonged asymptomatic or mild symptomatic periods. Given that there is an increase in treatment options and that early intervention could modify the disease course, it is desirable to devise biological indices that may differentiate AD and nonAD at mild cognitive impairment (MCI) stage.Methods:Based on two well-acknowledged observations of background slowing (attenuation in alpha power and enhancement in theta and delta powers) and early involvement of posterior cingulate cortex (PCC, a neural hub of default-mode network), this study devised novel neural markers, namely, spectral ratios of alpha1 to delta and alpha1 to theta in the PCC.Results:We analysed 46 MCI patients, with 22 ADMCI and 24 nonADMCI who were matched in age, education, and global cognitive capability. Concordant with the prediction, the regional spectral ratios were lower in the ADMCI group, suggesting its clinical application potential.Conclusion:Previous research has verifi...

Research paper thumbnail of QEEG Testing Can Discern Reason for Cognitive Disorder : Digital EEG Recordings of Brainwaves Can Determine TBI Etiology

QEEG Testing Can Discern Reason for Cognitive Disorder : Digital EEG Recordings of Brainwaves Can Determine TBI Etiology

Research paper thumbnail of Automatic parcellation of resting-state cortical dynamics by iterative community detection and similarity measurements

Automatic parcellation of resting-state cortical dynamics by iterative community detection and similarity measurements

AIMS Neuroscience, 2021

To investigate the properties of a large-scale brain network, it is a common practice to reduce t... more To investigate the properties of a large-scale brain network, it is a common practice to reduce the dimension of resting state functional magnetic resonance imaging (rs-fMRI) data to tens to hundreds of nodes. This study presents an analytic streamline that incorporates modular analysis and similarity measurements (MOSI) to fulfill functional parcellation (FP) of the cortex. MOSI is carried out by iteratively dividing a module into sub-modules (via the Louvain community detection method) and unifying similar neighboring sub-modules into a new module (adjacent sub-modules with a similarity index <0.05) until the brain modular structures of successive runs become constant. By adjusting the gamma value, a parameter in the Louvain algorithm, MOSI may segment the cortex with different resolutions. rs-fMRI scans of 33 healthy subjects were selected from the dataset of the Rockland sample. MOSI was applied to the rs-fMRI data after standardized pre-processing steps. The results indicate...

Research paper thumbnail of Integrating Various Neural Features Based on Mechanism of Intricate Balance and Ongoing Activity: Unified Neural Account Underlying and Correspondent to Mental Phenomena

World Journal of Neuroscience, 2021

In recent decades, brain science has been enriched from both empirical and computational approach... more In recent decades, brain science has been enriched from both empirical and computational approaches. Interesting emerging neural features include power-law distribution, chaotic behavior, self-organized criticality, variance approach, neuronal avalanches, difference-based and sparse coding, optimized information transfer, maximized dynamic range for information processing, and reproducibility of evoked spatio-temporal motifs in spontaneous activities, and so on. These intriguing findings can be largely categorized into two classes: complexity and regularity. This article would like to highlight that the above-mentioned properties although look diverse and unrelated, but actually may be rooted in a common foundation-excitatory and inhibitory balance (EIB) and ongoing activities (OA). To be clear, description and observation of neural features are phenomena or epiphenomena, while EIB-OA is the underlying mechanism. The EIB is maintained in a dynamic manner and may possess regional specificity, and importantly, EIB is organized along the boundary of phase transition which has been called criticality, bifurcation or edge of chaos. OA is composed of spontaneous organized activity, physiological noise, non-physiological noise and the interacting effect between OA and evoked activities. Based on EIB-OA, the brain may accommodate the property of chaos and regularity. We propose "virtual brain space" to bridge brain dynamics and mental space, and "code driving complexity hypothesis" to integrate regularity and complexity. The functional implication of oscillation and energy consumption of the brain are discussed.

Research paper thumbnail of Speed of Information Processing in Traumatic Brain Injury: Modality-Specific Factors

Speed of Information Processing in Traumatic Brain Injury: Modality-Specific Factors

Journal of Head Trauma Rehabilitation, 2000

To assess speed of information processing by two serial addition tests (one visual, one auditory)... more To assess speed of information processing by two serial addition tests (one visual, one auditory) in individuals with moderate-to-severe traumatic brain injuries (TBIs) and in a healthy, normal control group (NC). The tasks were designed to equate and control for accuracy of performance across the TBI and NC groups, thus allowing for quantification of information processing speed. Performance across groups and tasks were compared using 2 x 2 repeated measure analyses of variance (ANOVAs). In addition, each individual&#39;s processing speed was used to adjust rate of stimulus presentation on a subsequent &quot;rehabilitation&quot; trial to determine further whether this adjustment equated accuracy of performance. Rehabilitation hospital. 22 outpatients with moderate-to-severe TBI (6 women, 16 men; mean age = 34.6 years; duration of loss of consciousness = 22.6 days) and 20 age- and education-matched healthy controls. Processing speed was slower in TBI subjects, relative to controls and was significantly related to measures of executive functioning for those with TBI. Relative to controls, speed of processing in the TBI group was disproportionately slower when information was presented in the auditory, relative to the visual, modality. Speed of information processing is a major impairment in those with TBI when unconfounded by performance accuracy. The modality-specific impairment observed in the TBI group may, in part, be due to a greater within-modality interference effect created by the auditory version of the task. By manipulating information at a pace customized for an individual through compensatory strategies and environmental modifications, information-processing performance of TBI participants can be enhanced significantly.

Research paper thumbnail of Tripod transcranial alternating current stimulation at 5-Hz to alleviate anxiety symptoms: a preliminary report

ABSTRACTIntroductionOne of the most common applications of transcranial electrical stimulation (t... more ABSTRACTIntroductionOne of the most common applications of transcranial electrical stimulation (tES) at low current intensity is to induce a relaxed state or reduce anxiety. With technical advancement, different waveforms, montages, and parameters can be incorporated into the treatment regimen. We developed a novel protocol to treat individuals with anxiety disorders by transcranial alternating current stimulation (tACS).MethodsA total of 27 individuals with anxiety disorders underwent tACS treatment for 12 sessions, with each session lasting 25 minutes. tACS at 5 Hz was applied to F4 (1.0 mA), P4 (1.0 mA), and T8 (2.0 mA) EEG lead positions (tripod), with sinewave oscillation between T8 and F4/P4. We evaluated the primary and secondary outcomes using the Beck Anxiety Inventory (BAI) and neuropsychological assessments.ResultsOf the 27 patients, 19 (70.4%) experienced a reduction in symptom severity greater than 50%, with an average reduction of BAI 58.5%. All reported side effects w...