Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as ... more Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. Event-related oscillations (EROs) have been used to effectively measure brain (dys)function during cognitive tasks in individuals with alcoholism and related disorders and in those at risk to develop these disorders. The current study examines ERO theta power during reward processing as well as impulsivity in adolescent and young adult subjects at high risk for alcoholism. EROs were recorded during a monetary gambling task (MGT) in 12-25 years old participants (N = 1821; males = 48%) from high risk alcoholic families (HR, N = 1534) and comparison low risk community families (LR, N = 287) from the Collaborative Study on the Genetics of Alcoholism (COGA). Impulsivity scores and prevalence of externalizing diagnoses were also compared between LR and HR groups. HR offspring showed lower theta power and decreased current source density (CSD) activity than LR offspring d...
Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2016
Higher impulsivity observed in alcoholics is thought to be due to neurocognitive functional defic... more Higher impulsivity observed in alcoholics is thought to be due to neurocognitive functional deficits involving impaired inhibition in several brain regions and/or neuronal circuits. Event-related Oscillations (EROs) offer time-frequency measure of brain rhythms during perceptual and cognitive processing, which provide a detailed view of neuroelectric oscillatory responses to external/internal events. The present study examines evoked power (temporally locked to events) of oscillatory brain signals in alcoholics during an equal probability Go/NoGo task, assessing their functional relevance in execution and inhibition of a motor response. The current study hypothesized that increases in the power of slow frequency bands and their topographical distribution is associated with tasks that have increased cognitive demands, such as the execution and inhibition of a motor response. Therefore, it is hypothesized that alcoholics would show lower spectral power in their topographical densities compared to controls. The sample consisted of 20 right-handed abstinent alcoholic males and 20 age and gender-matched healthy controls. Evoked delta (1.0-3.5Hz; 200-600ms), theta (4.0-7.5Hz; 200-400ms), slow alpha (8.0-9.5Hz; 200-300ms), and fast alpha (10.0-12.5Hz; 100-200ms) ERO power were compared across group and task conditions. Compared to controls, alcoholics had higher impulsiveness scores on the Barrett Impulsiveness Scale (BIS-11) and made more errors on Go trials. Alcoholics showed significantly lower evoked delta, theta, and slow alpha power compared to controls for both Go and NoGo task conditions, and lower evoked fast alpha power compared to controls for only the NoGo condition. The results confirm previous findings and are suggestive of neurocognitive deficits while executing and suppressing a motor response. Based on findings in the alpha frequency ranges, it is further suggested that the inhibitory processing impairments in alcoholics may arise from inadequate early attentional processing with respect to the stimulus related aspects/semantic memory processes, which may be reflected in lower posterio-temporal evoked fast alpha power. It can thus be concluded that alcoholics show neurocognitive deficits in both execution and suppression of a motor response and inadequate early attentional processing with respect to the semantic memory/stimulus related aspects while suppressing a motor response.
Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as ... more Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. The goal of the present study is to elucidate reward processing deficits, externalizing disorders, and impulsivity as elicited by electrophysiological, clinical and behavioral measures in subjects at high risk for alcoholism from families densely affected by alcoholism in the context of brain maturation across age groups and gender. Event-related potentials (ERPs) and current source density (CSD) during a monetary gambling task (MGT) were measured in 12-25year old offspring (N=1864) of families in the Collaborative Study on the Genetics of Alcoholism (COGA) Prospective study; the high risk (HR, N=1569) subjects were from families densely affected with alcoholism and the low risk (LR, N=295) subjects were from community families. Externalizing disorders and impulsivity scores were also compared between LR and HR groups. HR offspring from older (16-25years) male and younger (12-15years) female subgroups showed lower P3 amplitude than LR subjects. The amplitude decrement was most prominent in HR males during the loss condition. Overall, P3 amplitude increase at anterior sites and decrease at posterior areas were seen in older compared to younger subjects, suggesting frontalization during brain maturation. The HR subgroups also exhibited hypofrontality manifested as weaker CSD activity during both loss and gain conditions at frontal regions. Further, the HR subjects had higher impulsivity scores and increased prevalence of externalizing disorders. P3 amplitudes during the gain condition were negatively correlated with impulsivity scores. Older male and younger female HR offspring, compared to their LR counterparts, manifested reward processing deficits as indexed by lower P3 amplitude and weaker CSD activity, along with higher prevalence of externalizing disorders and higher impulsivity scores. Reward related P3 is a valuable measure reflecting neurocognitive dysfunction in subjects at risk for alcoholism, as well as to characterize reward processing and brain maturation across gender and age group.
OBJECTIVE: Impulsivity is an important characteristic of many psychiatric disorders, including su... more OBJECTIVE: Impulsivity is an important characteristic of many psychiatric disorders, including substance-related disorders. These disinhibitory disorders have a similar underlying genetic diathesis, with each disorder representing a different expression of the same underlying genetic liability. This study assessed whether there is a relationship between impulsivity and alcohol dependence, and their correlations with P3 (P300) amplitude, a proposed endophenotype of alcoholism. METHODS: Healthy control subjects (n=58) and subjects with DSM-IV diagnosis of alcohol dependence (n=57) were assessed with a visual oddball task. Event-Related Potentials (ERPs) were recorded from 61 scalp electrodes and P3 amplitudes measured. Barratt Impulsiveness Scale (BIS), version 11, was used to evaluate impulsivity. Source localization of P3 was computed using low-resolution brain electromagnetic tomography (LORETA). RESULTS: Alcoholic subjects manifested reductions in target P3 amplitudes (p<0.0001...
Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, wi... more Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, with impulsivity being an important characteristic. Event-related potentials (ERPs) have been used as effective tools to study cognitive deficits related alcoholism and risk. Previous studies have reported low P3 amplitudes of the ERP and high impulsivity in alcoholics as well as in offspring who are at high risk (HR) to develop alcoholism. Our objective in the present study was to investigate the P3 component of the ERP as well as impulsivity in high risk subjects with a heavy loading of family history of alcoholism using an auditory oddball paradigm. Current source density (CSD) was also computed in each group to examine brain topography of P3 in these risk groups. Methods: Offspring in an adolescent age range (12-17 years) from HR families (N = 396) from the multi-site Collaborative Study on the Genetics of Alcoholism (COGA) and offspring from low risk (LR) control families (N = 79) wer...
Event-related oscillations (EROs) have served as a powerful tool to measure neurocognitive proces... more Event-related oscillations (EROs) have served as a powerful tool to measure neurocognitive processing in normal and clinical populations including those with Alcohol Use Disorders (AUDs). Studies have reported reduced theta EROs during reward processing in alcoholics and individuals at risk for AUDs. Theta EROs to targets during a visual oddball task have been found to be significantly associated with several single nucleotide polymorphisms (SNPs) in KCNJ6 at genome-wide significant levels in a family genome-wide association study (GWAS). The KCNJ6 gene encodes GIRK2, a G-protein inward rectifying potassium channel that is important in regulating the excitability of neuronal networks, and has been shown to be involved in the pharmacokinetics of alcohol. The goal of the present study is to examine the effects of a synonymous KCNJ6 SNP (rs702859) on theta EROs during reward processing in a monetary gambling task. The sample included 1,601 individuals (800 males and 801 females) betwee...
The outcome related negativity (ORN), an event-related potential (ERP) component around 200-250 m... more The outcome related negativity (ORN), an event-related potential (ERP) component around 200-250 ms, has been suggested to be an electrophysiological brain signature for the processing of loss and gain. This component has been suggested to involve theta band oscillations as a primary feature. The aim of the current study is to examine oscillatory activity and functional connectivity between frontal and parietal regions during the processing of monetary loss and gain. The sample consisted of 36 healthy individuals with the age range of 18-35 years. A 64-channel EEG was recorded continuously while the subjects were performing a gambling task that prompted the subject to select one of two amounts, 10 and 50. Loss (-50) and Gain (+50) conditions were analyzed using a Wavelet coherence method for frontal (FZ) and parietal (PZ) regions. Time-Frequency representation and Power and Coherence were plotted and compared between loss and gain conditions. Loss condition had more power at FZ while...
Neurocognitive correlates of impulsivity have been thought to underlie several of externalizing/d... more Neurocognitive correlates of impulsivity have been thought to underlie several of externalizing/disinhibitory disorders including alcoholism. The current study examines the aspects of impulsivity in terms of behavioral measures as well as event-related oscillations (EROs) while performing a gambling task that involves monetary gain and loss. Behavioral measures of impulsivity were analyzed and brain oscillations were decomposed into time-frequency-amplitude data using the S-Transform algorithm. The mean amplitude in the outcome-related negativity (ORN) time window (225-275 ms) in each frequency band was statistically analyzed in both groups across four outcomes that involved valence (loss or gain) and magnitude (50 or 10 cents). Alcoholics showed higher impulsivity as measured in Barratt Impulsivity Scale (BIS) and in other task-related impulsivity responses. Further, alcoholics showed significantly decreased amplitude in delta (1-3 Hz) and theta (4-7 Hz) band during the ORN time wi...
The developmental trajectories of theta band (4-7Hz) event-related oscillations (EROs), a key neu... more The developmental trajectories of theta band (4-7Hz) event-related oscillations (EROs), a key neurophysiological constituent of the P3 response, were assessed in 2170 adolescents and young adults ages 12 to 25. The theta EROs occurring in the P3 response, important indicators of neurocognitive function, were elicited during the evaluation of task-relevant target stimuli in visual and auditory oddball tasks. These tasks call upon attentional and working memory resources. Large differences in developmental rates between males and females were found; scalp location and task modality (visual or auditory) differences within males and females were small compared to gender differences. Trajectories of interregional and intermodal correlations between ERO power values exhibited increases with age in both genders, but showed a divergence in development between auditory and visual systems during ages 16 to 21. These results are consistent with previous electrophysiological and imaging studies...
Background: Electrophysiological anomalies in individuals at risk for alcoholism have been previo... more Background: Electrophysiological anomalies in individuals at risk for alcoholism have been previously reported using several tasks, including gambling paradigms. Studies have also identified deficits in reward processing as a key cognitive component in alcoholism and as well as in predicting the risk to develop alcoholism. While reward processing deficits in alcoholics have been reported earlier, such anomalies in highrisk individuals have not been frequently studied. The goal of the present study is to elucidate patterns of current density activations during reward processing in individuals at high risk for developing alcoholism. Method: The sample comprised both male and female offspring from families in the Collaborative Study on the Genetics of Alcoholism (COGA) within the age range of 12-25 years; 742 high risk (HR) subjects who had at least one parent who was alcohol dependent and 428 low risk (LR) individuals without any parental history of alcohol dependence were included. S...
Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, wi... more Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, with impulsivity being an important characteristic. Previous studies have shown a correlation between impulsivity and cognitive deficits in alcoholics and in offspring who are at high risk (HR) to develop alcoholism. Event- related potentials (ERPs) have been used as an effective tool to study cognitive deficits in these populations. Our objective in the present study was to investigate the P300 component of the ERP as well as impulsivity in high risk subjects with a heavy loading of family history of alcoholism using an auditory oddball paradigm. Methods: Offspring from HR families (N=1785) from the multi-site Collaborative Study on the Genetics of Alcoholism (COGA) and offspring of low risk (LR) control families (N=152) were assessed with an Auditory Oddball Paradigm; P3 amplitudes to target stimuli were measured at midline frontal (Fz), central (Cz), parietal (Pz) and occipital (Oz) reg...
To examine the topographic relationship of P3(00) between the visual and auditory modalities, esp... more To examine the topographic relationship of P3(00) between the visual and auditory modalities, especially to examine whether there are any modality-specific hemispheric differences of P3 in normal adults. The P3s were recorded from the same 41 normal right-handed males between the ages of 20 and 33 in both a typical auditory oddball task and a visual oddball paradigm with novel stimuli, with an extensive set of 61 scalp electrodes. In addition to the visual comparison and quantitative assessment of current source density (CSD) maps between the two modalities, canonical correlation analyses on the P3 raw amplitudes and examination of interaction effects of modality x location on both raw and normalized P3 data were performed. The canonical correlation between modalities was generally high, especially at the left parietal brain region. There were no significant hemispheric effects in anterior brain but significant left-greater-than-right hemispheric effects in posterior brain regions i...
An event-related potential (ERP) correlate of visual short-term memory (VMP) has been identified ... more An event-related potential (ERP) correlate of visual short-term memory (VMP) has been identified in our laboratory. This study aims to determine how stimulus load modulates recognition processing of digits. ERPs were recorded from 117 healthy right-handed subjects during a delayed matching-to-sample paradigm, using number stimuli that were either low load (three digits long) or high load (five digits long). The bootstrap method [R. Srebro, A bootstrap method to compare the shapes of two scalp fields, Electroenceph. Clin. Neurophysiol. 100 (1996) 25-32.] was employed to evaluate the topographic features of the VMP revealed in the current source density (CSD) maps. Response times were significantly shorter for matching stimuli than for non-matching stimuli only for low loads; longer response times were related to higher loads compared to low loads only for matching stimuli. The high loads were related to larger ERP responses. The ERP was significantly smaller for matching than for non...
Electroencephalography and clinical neurophysiology, 1998
The P3 event-related brain potential (ERP) is a positive-going voltage change of scalp-recorded e... more The P3 event-related brain potential (ERP) is a positive-going voltage change of scalp-recorded electroencephalographic activity that occurs between 300-500 ms after stimulus onset. It is elicited when a stimulus is perceived, memory operations are engaged, and attentional resources are allocated toward its processing. Because this ERP component reflects fundamental cognitive processing, it has found wide utility as an assessment of human mental function in basic and clinical studies. In particular, P3 attributes are heritable and have demonstrated considerable promise as a means to identify individuals at genetic risk for alcoholism. We have conducted a quantitative linkage analysis on a large sample from families with a high density of affected individuals. The analyses suggest that several regions of the human genome contain genetic loci related to the generation of the P3 component of the ERP, which are possible candidate loci underlying the functional organization of human neur...
Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as ... more Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. Event-related oscillations (EROs) have been used to effectively measure brain (dys)function during cognitive tasks in individuals with alcoholism and related disorders and in those at risk to develop these disorders. The current study examines ERO theta power during reward processing as well as impulsivity in adolescent and young adult subjects at high risk for alcoholism. EROs were recorded during a monetary gambling task (MGT) in 12-25 years old participants (N = 1821; males = 48%) from high risk alcoholic families (HR, N = 1534) and comparison low risk community families (LR, N = 287) from the Collaborative Study on the Genetics of Alcoholism (COGA). Impulsivity scores and prevalence of externalizing diagnoses were also compared between LR and HR groups. HR offspring showed lower theta power and decreased current source density (CSD) activity than LR offspring d...
Progress in Neuro-Psychopharmacology and Biological Psychiatry, 2016
Higher impulsivity observed in alcoholics is thought to be due to neurocognitive functional defic... more Higher impulsivity observed in alcoholics is thought to be due to neurocognitive functional deficits involving impaired inhibition in several brain regions and/or neuronal circuits. Event-related Oscillations (EROs) offer time-frequency measure of brain rhythms during perceptual and cognitive processing, which provide a detailed view of neuroelectric oscillatory responses to external/internal events. The present study examines evoked power (temporally locked to events) of oscillatory brain signals in alcoholics during an equal probability Go/NoGo task, assessing their functional relevance in execution and inhibition of a motor response. The current study hypothesized that increases in the power of slow frequency bands and their topographical distribution is associated with tasks that have increased cognitive demands, such as the execution and inhibition of a motor response. Therefore, it is hypothesized that alcoholics would show lower spectral power in their topographical densities compared to controls. The sample consisted of 20 right-handed abstinent alcoholic males and 20 age and gender-matched healthy controls. Evoked delta (1.0-3.5Hz; 200-600ms), theta (4.0-7.5Hz; 200-400ms), slow alpha (8.0-9.5Hz; 200-300ms), and fast alpha (10.0-12.5Hz; 100-200ms) ERO power were compared across group and task conditions. Compared to controls, alcoholics had higher impulsiveness scores on the Barrett Impulsiveness Scale (BIS-11) and made more errors on Go trials. Alcoholics showed significantly lower evoked delta, theta, and slow alpha power compared to controls for both Go and NoGo task conditions, and lower evoked fast alpha power compared to controls for only the NoGo condition. The results confirm previous findings and are suggestive of neurocognitive deficits while executing and suppressing a motor response. Based on findings in the alpha frequency ranges, it is further suggested that the inhibitory processing impairments in alcoholics may arise from inadequate early attentional processing with respect to the stimulus related aspects/semantic memory processes, which may be reflected in lower posterio-temporal evoked fast alpha power. It can thus be concluded that alcoholics show neurocognitive deficits in both execution and suppression of a motor response and inadequate early attentional processing with respect to the semantic memory/stimulus related aspects while suppressing a motor response.
Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as ... more Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. The goal of the present study is to elucidate reward processing deficits, externalizing disorders, and impulsivity as elicited by electrophysiological, clinical and behavioral measures in subjects at high risk for alcoholism from families densely affected by alcoholism in the context of brain maturation across age groups and gender. Event-related potentials (ERPs) and current source density (CSD) during a monetary gambling task (MGT) were measured in 12-25year old offspring (N=1864) of families in the Collaborative Study on the Genetics of Alcoholism (COGA) Prospective study; the high risk (HR, N=1569) subjects were from families densely affected with alcoholism and the low risk (LR, N=295) subjects were from community families. Externalizing disorders and impulsivity scores were also compared between LR and HR groups. HR offspring from older (16-25years) male and younger (12-15years) female subgroups showed lower P3 amplitude than LR subjects. The amplitude decrement was most prominent in HR males during the loss condition. Overall, P3 amplitude increase at anterior sites and decrease at posterior areas were seen in older compared to younger subjects, suggesting frontalization during brain maturation. The HR subgroups also exhibited hypofrontality manifested as weaker CSD activity during both loss and gain conditions at frontal regions. Further, the HR subjects had higher impulsivity scores and increased prevalence of externalizing disorders. P3 amplitudes during the gain condition were negatively correlated with impulsivity scores. Older male and younger female HR offspring, compared to their LR counterparts, manifested reward processing deficits as indexed by lower P3 amplitude and weaker CSD activity, along with higher prevalence of externalizing disorders and higher impulsivity scores. Reward related P3 is a valuable measure reflecting neurocognitive dysfunction in subjects at risk for alcoholism, as well as to characterize reward processing and brain maturation across gender and age group.
OBJECTIVE: Impulsivity is an important characteristic of many psychiatric disorders, including su... more OBJECTIVE: Impulsivity is an important characteristic of many psychiatric disorders, including substance-related disorders. These disinhibitory disorders have a similar underlying genetic diathesis, with each disorder representing a different expression of the same underlying genetic liability. This study assessed whether there is a relationship between impulsivity and alcohol dependence, and their correlations with P3 (P300) amplitude, a proposed endophenotype of alcoholism. METHODS: Healthy control subjects (n=58) and subjects with DSM-IV diagnosis of alcohol dependence (n=57) were assessed with a visual oddball task. Event-Related Potentials (ERPs) were recorded from 61 scalp electrodes and P3 amplitudes measured. Barratt Impulsiveness Scale (BIS), version 11, was used to evaluate impulsivity. Source localization of P3 was computed using low-resolution brain electromagnetic tomography (LORETA). RESULTS: Alcoholic subjects manifested reductions in target P3 amplitudes (p<0.0001...
Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, wi... more Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, with impulsivity being an important characteristic. Event-related potentials (ERPs) have been used as effective tools to study cognitive deficits related alcoholism and risk. Previous studies have reported low P3 amplitudes of the ERP and high impulsivity in alcoholics as well as in offspring who are at high risk (HR) to develop alcoholism. Our objective in the present study was to investigate the P3 component of the ERP as well as impulsivity in high risk subjects with a heavy loading of family history of alcoholism using an auditory oddball paradigm. Current source density (CSD) was also computed in each group to examine brain topography of P3 in these risk groups. Methods: Offspring in an adolescent age range (12-17 years) from HR families (N = 396) from the multi-site Collaborative Study on the Genetics of Alcoholism (COGA) and offspring from low risk (LR) control families (N = 79) wer...
Event-related oscillations (EROs) have served as a powerful tool to measure neurocognitive proces... more Event-related oscillations (EROs) have served as a powerful tool to measure neurocognitive processing in normal and clinical populations including those with Alcohol Use Disorders (AUDs). Studies have reported reduced theta EROs during reward processing in alcoholics and individuals at risk for AUDs. Theta EROs to targets during a visual oddball task have been found to be significantly associated with several single nucleotide polymorphisms (SNPs) in KCNJ6 at genome-wide significant levels in a family genome-wide association study (GWAS). The KCNJ6 gene encodes GIRK2, a G-protein inward rectifying potassium channel that is important in regulating the excitability of neuronal networks, and has been shown to be involved in the pharmacokinetics of alcohol. The goal of the present study is to examine the effects of a synonymous KCNJ6 SNP (rs702859) on theta EROs during reward processing in a monetary gambling task. The sample included 1,601 individuals (800 males and 801 females) betwee...
The outcome related negativity (ORN), an event-related potential (ERP) component around 200-250 m... more The outcome related negativity (ORN), an event-related potential (ERP) component around 200-250 ms, has been suggested to be an electrophysiological brain signature for the processing of loss and gain. This component has been suggested to involve theta band oscillations as a primary feature. The aim of the current study is to examine oscillatory activity and functional connectivity between frontal and parietal regions during the processing of monetary loss and gain. The sample consisted of 36 healthy individuals with the age range of 18-35 years. A 64-channel EEG was recorded continuously while the subjects were performing a gambling task that prompted the subject to select one of two amounts, 10 and 50. Loss (-50) and Gain (+50) conditions were analyzed using a Wavelet coherence method for frontal (FZ) and parietal (PZ) regions. Time-Frequency representation and Power and Coherence were plotted and compared between loss and gain conditions. Loss condition had more power at FZ while...
Neurocognitive correlates of impulsivity have been thought to underlie several of externalizing/d... more Neurocognitive correlates of impulsivity have been thought to underlie several of externalizing/disinhibitory disorders including alcoholism. The current study examines the aspects of impulsivity in terms of behavioral measures as well as event-related oscillations (EROs) while performing a gambling task that involves monetary gain and loss. Behavioral measures of impulsivity were analyzed and brain oscillations were decomposed into time-frequency-amplitude data using the S-Transform algorithm. The mean amplitude in the outcome-related negativity (ORN) time window (225-275 ms) in each frequency band was statistically analyzed in both groups across four outcomes that involved valence (loss or gain) and magnitude (50 or 10 cents). Alcoholics showed higher impulsivity as measured in Barratt Impulsivity Scale (BIS) and in other task-related impulsivity responses. Further, alcoholics showed significantly decreased amplitude in delta (1-3 Hz) and theta (4-7 Hz) band during the ORN time wi...
The developmental trajectories of theta band (4-7Hz) event-related oscillations (EROs), a key neu... more The developmental trajectories of theta band (4-7Hz) event-related oscillations (EROs), a key neurophysiological constituent of the P3 response, were assessed in 2170 adolescents and young adults ages 12 to 25. The theta EROs occurring in the P3 response, important indicators of neurocognitive function, were elicited during the evaluation of task-relevant target stimuli in visual and auditory oddball tasks. These tasks call upon attentional and working memory resources. Large differences in developmental rates between males and females were found; scalp location and task modality (visual or auditory) differences within males and females were small compared to gender differences. Trajectories of interregional and intermodal correlations between ERO power values exhibited increases with age in both genders, but showed a divergence in development between auditory and visual systems during ages 16 to 21. These results are consistent with previous electrophysiological and imaging studies...
Background: Electrophysiological anomalies in individuals at risk for alcoholism have been previo... more Background: Electrophysiological anomalies in individuals at risk for alcoholism have been previously reported using several tasks, including gambling paradigms. Studies have also identified deficits in reward processing as a key cognitive component in alcoholism and as well as in predicting the risk to develop alcoholism. While reward processing deficits in alcoholics have been reported earlier, such anomalies in highrisk individuals have not been frequently studied. The goal of the present study is to elucidate patterns of current density activations during reward processing in individuals at high risk for developing alcoholism. Method: The sample comprised both male and female offspring from families in the Collaborative Study on the Genetics of Alcoholism (COGA) within the age range of 12-25 years; 742 high risk (HR) subjects who had at least one parent who was alcohol dependent and 428 low risk (LR) individuals without any parental history of alcohol dependence were included. S...
Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, wi... more Objective: Alcoholism has been considered to be part of a spectrum of disinhibitory disorders, with impulsivity being an important characteristic. Previous studies have shown a correlation between impulsivity and cognitive deficits in alcoholics and in offspring who are at high risk (HR) to develop alcoholism. Event- related potentials (ERPs) have been used as an effective tool to study cognitive deficits in these populations. Our objective in the present study was to investigate the P300 component of the ERP as well as impulsivity in high risk subjects with a heavy loading of family history of alcoholism using an auditory oddball paradigm. Methods: Offspring from HR families (N=1785) from the multi-site Collaborative Study on the Genetics of Alcoholism (COGA) and offspring of low risk (LR) control families (N=152) were assessed with an Auditory Oddball Paradigm; P3 amplitudes to target stimuli were measured at midline frontal (Fz), central (Cz), parietal (Pz) and occipital (Oz) reg...
To examine the topographic relationship of P3(00) between the visual and auditory modalities, esp... more To examine the topographic relationship of P3(00) between the visual and auditory modalities, especially to examine whether there are any modality-specific hemispheric differences of P3 in normal adults. The P3s were recorded from the same 41 normal right-handed males between the ages of 20 and 33 in both a typical auditory oddball task and a visual oddball paradigm with novel stimuli, with an extensive set of 61 scalp electrodes. In addition to the visual comparison and quantitative assessment of current source density (CSD) maps between the two modalities, canonical correlation analyses on the P3 raw amplitudes and examination of interaction effects of modality x location on both raw and normalized P3 data were performed. The canonical correlation between modalities was generally high, especially at the left parietal brain region. There were no significant hemispheric effects in anterior brain but significant left-greater-than-right hemispheric effects in posterior brain regions i...
An event-related potential (ERP) correlate of visual short-term memory (VMP) has been identified ... more An event-related potential (ERP) correlate of visual short-term memory (VMP) has been identified in our laboratory. This study aims to determine how stimulus load modulates recognition processing of digits. ERPs were recorded from 117 healthy right-handed subjects during a delayed matching-to-sample paradigm, using number stimuli that were either low load (three digits long) or high load (five digits long). The bootstrap method [R. Srebro, A bootstrap method to compare the shapes of two scalp fields, Electroenceph. Clin. Neurophysiol. 100 (1996) 25-32.] was employed to evaluate the topographic features of the VMP revealed in the current source density (CSD) maps. Response times were significantly shorter for matching stimuli than for non-matching stimuli only for low loads; longer response times were related to higher loads compared to low loads only for matching stimuli. The high loads were related to larger ERP responses. The ERP was significantly smaller for matching than for non...
Electroencephalography and clinical neurophysiology, 1998
The P3 event-related brain potential (ERP) is a positive-going voltage change of scalp-recorded e... more The P3 event-related brain potential (ERP) is a positive-going voltage change of scalp-recorded electroencephalographic activity that occurs between 300-500 ms after stimulus onset. It is elicited when a stimulus is perceived, memory operations are engaged, and attentional resources are allocated toward its processing. Because this ERP component reflects fundamental cognitive processing, it has found wide utility as an assessment of human mental function in basic and clinical studies. In particular, P3 attributes are heritable and have demonstrated considerable promise as a means to identify individuals at genetic risk for alcoholism. We have conducted a quantitative linkage analysis on a large sample from families with a high density of affected individuals. The analyses suggest that several regions of the human genome contain genetic loci related to the generation of the P3 component of the ERP, which are possible candidate loci underlying the functional organization of human neur...
Uploads
Papers by David Chorlian