Decreased event-related theta power and phase-synchrony in young binge drinkers during target detection: An anatomically-constrained MEG approach.

BACKGROUND: The prevalence of binge drinking has risen in recent years. It is associated with a range of neurocognitive deficits among adolescents and young emerging adults who are especially vulnerable to alcohol use. Attention is an essential dimension of executive functioning and attentional disturbances may be associated with hazardous drinking. The aim of the study was to examine the oscillatory neural dynamics of attentional control during visual target detection in emerging young adults as a function of binge drinking. METHOD: In total, 51 first-year university students (18 ± 0.6 years) were assigned to light drinking ( n = 26), and binge drinking ( n = 25) groups based on their alcohol consumption patterns. A high-density magnetoencephalography signal was combined with structural magnetic resonance imaging in an anatomically constrained magnetoencephalography model to estimate event-related source power in a theta (4-7 Hz) frequency band. Phase-locked co-oscillations were further estimated between the principally activated regions during task performance. RESULTS: Overall, the greatest event-related theta power was elicited by targets in the right inferior frontal cortex and it correlated with performance accuracy and selective attention scores. Binge drinkers exhibited lower theta power and dysregulated oscillatory synchrony to targets in the right inferior frontal cortex, which correlated with higher levels of alcohol consumption. CONCLUSIONS: These results confirm that a highly interactive network in the right inferior frontal cortex subserves attentional control, revealing the importance of theta oscillations and neural synchrony for attentional capture and contextual maintenance. Attenuation of theta power and synchronous interactions in binge drinkers may indicate early stages of suboptimal integrative processing in young, highly functioning binge drinkers.

Working memory over a six-year period in young binge drinkers.

Adolescence and early adulthood are periods of particular vulnerability to the neurotoxic effects of alcohol. Young people with alcohol-use disorders display deficits in working memory (WM). This function is supported by the prefrontal cortex, a late-maturing brain region. However, little is known about the progression of cognitive dysfunctions associated with a binge-drinking (BD) pattern of alcohol consumption among non-clinical adolescents. The objective of this study was to analyze the relationship between BD trajectory and WM in university students. An initial sample of 155 male and female first-year university students was followed prospectively over 6 years. The participants were classified as stable non-BDs, stable BDs, and ex-BDs, according to the third item of the Alcohol Use Disorders Identification Test (AUDIT). WM was assessed using the Self-Ordered Pointing Task. Generalized linear mixed models were applied. The results showed that stable BDs committed more total perseverative errors and showed a lower WM span in the difficult blocks than stable non-BDs. Difficulties in WM span showed some improvement, whereas perseveration errors remained constant throughout the follow-ups in the stable BDs. There were no significant differences between ex-BDs and non-BDs. In conclusion, stable BD is associated with WM deficits, particularly perseverations and low WM span in demanding trials, when compensatory mechanisms may no longer be successful. The partial improvement in WM span may support the notion of a neuromaturational delay, whereas the temporal stability of perseveration deficits may reflect either neurotoxic effects of alcohol or premorbid characteristics. Abandoning the BD pattern of alcohol consumption may lead to partial recovery.

Functional and structural brain connectivity of young binge drinkers: a follow-up study.

Adolescence is a period of ongoing brain maturation characterized by hierarchical changes in the functional and structural networks. For this reason, the young brain is particularly vulnerable to the toxic effects of alcohol. Nowadays, binge drinking is a pattern of alcohol consumption increasingly prevalent among adolescents. The aim of the present study is to evaluate the evolution of the functional and anatomical connectivity of the Default Mode Network (DMN) in young binge drinkers along two years. Magnetoencephalography signal during eyes closed resting state as well as Diffusion Tensor Imaging (DTI) were acquired twice within a 2-year interval from 39 undergraduate students (22 controls, 17 binge drinkers) with neither personal nor family history of alcoholism. The group comparison showed that, after maintaining a binge drinking pattern along at least two years, binge drinkers displayed an increased brain connectivity of the DMN in comparison with the control group. On the other hand, the structural connectivity did not show significant differences neither between groups nor over the time. These findings point out that a continued pattern of binge drinking leads to functional alterations in the normal brain maturation process, even before anatomical changes can be detected.

Exploratory Analysis of Power Spectrum and Functional Connectivity During Resting State in Young Binge Drinkers: A MEG Study.

Binge Drinking (BD) is a pattern of intermittent intensive alcohol intake which has spread among young adults over the last decades. Adolescence constitutes a critical neuromaturation period in which the brain is particularly sensitive to the effects of alcohol. However, little is known about how BD affects the brain activity. This study aimed to characterize the brain's functional organization in BD and non-BD young population by means of analyzing functional connectivity (FC) and relative power spectra (PS) profiles measured with magnetoencephalography (MEG) during eyes-closed resting state. Our sample composed 73 first-year university students (35 BDs and 38 controls). Results showed that the BD subjects displayed a decreased alpha FC in frontal-parietal regions, and conversely, an enhanced FC in the delta, theta and beta bands in fronto-temporal networks. Besides the FC differences, the BD group showed a decreased PS within alpha range and an increased PS within theta range in the brain's occipital region. These differences in FC and PS measurements provide new evidence of the neurophysiological alterations related to the alcohol neurotoxicity and could represent an initial sign of an anomalous neural activity caused by a BD pattern of alcohol consumption during youth.

Impact of alcohol use on inhibitory control (and vice versa) during adolescence and young adulthood: a review.

AIMS: Adolescence is usually the time when individuals first drink alcohol and this has been associated with relatively weak or immature inhibitory control. This review examines the changes on brain development and inhibitory function that take place during adolescence and youth as well as the relationship between inhibitory control and alcohol use at this early age. METHODS: Narrative review of the chief studies related to (a) the development of inhibitory control during adolescence, (b) the deficits in the inhibitory ability in alcohol use disorders and (c) the effects of acute alcohol intake and binge drinking on inhibitory control in adolescents and young adults. RESULTS: Inhibitory control processes are developing during adolescence and youth. Poor inhibitory functions may predispose the individual to alcohol misuse. Likewise, acute and binge alcohol drinking may impair the inhibitory control and compromise the ability to prevent or stop behaviour related to alcohol use. CONCLUSION: Poor inhibitory control can be both the cause and the consequence of excessive alcohol use. Adolescence and young adulthood may be a particularly vulnerable period due to (a) the weak or immature inhibitory functioning typical of this stage may contribute to the inability of the individual to control alcohol use and (b) alcohol consumption per se may alter or interrupt the proper development of inhibitory control leading to a reduced ability to regulate alcohol intake. Further longitudinal research is needed to evaluate the interaction between inhibitory control dysfunction and alcohol use in both situations.

The time course of the effects of central and peripheral cues on visual processing: an event-related potentials study.

OBJECTIVE: The varying results of visual event-related potential (ERP) studies of central and peripheral cueing suggest that these types of cue may modulate stimuli processing with different time courses. The aim of this study was to investigate differences in the time course of facilitatory effects on the visual processing induced by peripheral and central cues. METHODS: ERPs were recorded for visual target stimuli that were preceded by informative-central, informative-peripheral or uninformative-peripheral cues with stimulus onset asynchronies (SOAs) of 100, 300, 500 or 700 ms. RESULTS: Validly cued stimuli elicited an enhanced P1 component with peripheral cueing at 100 ms SOA. P1 amplitude in valid trials was reduced at 300, 500 and 700 ms SOAs with uninformative-peripheral cueing, but only at 500 ms SOA with informative-peripheral cueing. With informative-central cueing, there was no validity effect on P1. CONCLUSIONS: These results suggest that the automatic attraction of attention by a peripheral cue results in improved sensory processing at the cued location. This facilitation is replaced by an inhibitory effect when SOA increases, although cue informativeness may modulate this effect. Central cueing does not affect sensory processing at the P1 level.

Middle-latency auditory evoked potentials in children at high risk for alcoholism.

PURPOSE: In the course of a high-risk study for alcoholism, the middle-latency auditory evoked potentials (MAEPs) of children of alcoholics were explored. MATERIAL AND METHODS: A series of auditory clicks (0.1 ms, 60 dB SL, 1.1/s) were used to record the Pa and Pb peaks of the MAEPs in 15 children of alcoholics with a multigenerational family history of alcoholism, and 17 control subjects, ranging from 10 to 14 years of age. RESULTS: The latency of Pb was shorter in the high-risk than in the control group, and there was also a significant risk group by age interaction on Pa latency. The amplitude of Pa was smaller in the children of alcoholics. CONCLUSIONS: The characteristics of the MAEPs of the high-risk subjects did not match the pattern of abnormalities previously observed in chronic alcoholics, which are supposed to be a consequence of the neurotoxic effects of ethanol. Nonetheless, the results showed significant differences in MAEPs between children of alcoholics and controls, pointing to an anomalous pattern of information transmission from thalamus to cortex that should be further analyzed using larger samples in a broader age range.

The effects of stimulus intensity and age on visual-evoked potentials (VEPs) in normal children.

In this study, we explored the effects of flash intensity and age on visual-evoked potentials (VEPs) in a sample of 85 children aged 8-15 years. Results of previous studies are discrepant regarding the extent to which children show an evoked potential augmenting tendency at vertex, which has been reported to be a characteristic of an immature inhibitory control system. In the present study, VEPs to light flashes of four different intensities were recorded at Cz. The results confirmed that P1N1 and N1P2 at Cz were positively related to increases in stimulus intensity, whereas N1 was not related reliably to intensity. This difference between peak-peak and baseline-peak amplitude findings at Cz relative to evoked potential augmenting and reducing may help to explain discrepant results among earlier studies. Developmental changes were found for our sample of children that were independent of stimulus intensity: N1 amplitude increased significantly with age, whereas N1 latency showed a small (nonsignificant) age-related decrease.

Event-related potentials elicited by a visual continuous performance task in children of alcoholics.

Event-related potentials (ERPs) were recorded from a group of young children of alcoholics (HR; n = 17, 7 females) with a high-density family-history of alcoholism and from a control group (CN; n = 19, 10 females), ages 7-15 years old, during a visual continuous performance task. The P3 peak amplitude and the mean amplitude at five latency windows (300-800 ms) were measured at frontal (F3-Fz-F4), central (C3-Cz-C4) and parietal (P3-Pz-P4) electrodes. Data were analyzed using a mixed-model risk-group by stimulus-type (matching vs. nonmatching) by Electrode ANCOVA, with age as a covariate, for each of the scalp regions. The risk-group by stimulus-type interactions were significant at the parietal region for the P3 peak amplitude and for the 300-400 ms mean amplitude, although there were no risk-group main differences. The HR group manifested smaller differences between the amplitude of the matching and nonmatching condition than the CN group. These results suggest a deficient electrophysiological differentiation between relevant and irrelevant information and are discussed in relation to previous reports and to the characteristics of the sample.

Visual P3a in male subjects at high risk for alcoholism.

BACKGROUND: Voltage of the P300 component of event-related potentials (ERPs) has been proposed as a phenotypic marker of risk for alcoholism. P3a elicited by intrusive events is important in the context of deficits in inhibition found during psychophysiological and behavioral evaluations in children of alcoholics. METHODS: ERPs were recorded from a group of adult children of alcoholics (n = 26) and controls (n = 23) with a three-stimulus visual oddball paradigm. The task required a difficult perceptual discrimination between a frequent (.80) vertical line and an infrequent (.10) 2 degrees tilted line (target). An easily discriminable nontarget infrequent horizontal line also occurred (.10). Subjects were required to press a button to the target. P3a was compared using mixed-model ANCOVAs at 31 sites organized in 5 scalp regions. Current source density (CSD) maps were also analyzed. RESULTS: High-risk (HR) subjects manifested reduced P3a amplitudes compared to controls at frontal, central, parietal, and temporal electrodes. CSD analyses supported these findings with group differences found for all the scalp regions. CONCLUSIONS: The results are discussed in relation to previous HR studies. P3a reductions may be related to deficits in neuronal inhibition during stimulus processing. These results suggest that P3a amplitude may be important as a marker for vulnerability to alcoholism.

Visual P3a in male alcoholics and controls.

The goal of this study was to assess the P3a component of event-related potentials in a population of abstinent, chronic alcoholics. A three-stimulus visual oddball paradigm was used to elicit robust P3a components in a large group of well-characterized male alcoholics (n = 44) and controls (n = 28). The task required subjects to make a difficult perceptual discrimination between randomly presented, frequently occurring vertical lines (.80) and infrequent target lines that were tilted 2 degrees to the right of vertical (.10) by only responding with a button press to the target stimuli. A nontarget infrequent horizontal line occurred (.10) randomly to which no response was made. The target stimulus elicited robust late P3b components with a parietal maximum amplitude, and the nontarget stimulus elicited reliable P3a components with a fronto-central maximum amplitude distribution. Group differences in P3a were assessed using repeated measures ANCOVA analyses in five scalp regions. Alcoholic subjects produced smaller P3a amplitudes over the central, parietal, temporal, and occipital areas compared with controls. Current source density analyses supported these findings with extension of the differences between the groups to the frontal region. The results suggest that the P3a may be important in the evaluation of alcoholism and its heritability. Theoretical implications are discussed.

Mismatch negativity in young children of alcoholics from high-density families.

The mismatch negativity (MMN) component of event-related potentials was recorded from a group of young children of alcoholics (n = 19, 8 females) with a high-density family history of alcoholism and from a control group (n = 23, 12 females), between 8 and 15 years of age. A dichotic listening task was used, and subjects had to pay attention to an oddball paradigm in one ear and ignore the stimuli in the other ear. The event-related potentials elicited by the standard unattended tones were subtracted from those elicited by the infrequent deviant unattended tones, and the MMN was measured at 10 frontal and central electrodes. No group differences were observed in peak latency, peak amplitude, and mean amplitude of the MMN. These results indicated that preattentive mechanisms of mismatch detection were not impaired in young subjects at high risk for alcoholism. Results are discussed in relation to differences in electrophysiological indexes of automatic versus controlled information processing and in relation to the characteristics of the sample.

Event-related potentials elicited by infrequent non-target stimuli in young children of alcoholics: family history and gender differences.

This article analyses the visual and auditory event-related potentials (ERPs) elicited by infrequent non-target stimuli in young children with alcoholic fathers. The aim was to study the characteristics of the ERP waves specifically evoked by stimuli which capture the attention of the subject in young ones at risk for alcoholism, and to assess the effect of sample factors which can modulate these characteristics, namely family history of alcoholism and gender. There were no differences related to risk for alcoholism on the auditory ERPs. However, males and females with a multigenerational family history of alcoholism showed significant differences on visual ERP latencies, although different waves were affected for each gender. Females showed a larger latency of the visual frontal negative wave, Nc, and males showed a larger latency of the visual parietocentral P300 wave.

Visual and auditory event-related potentials in young children of alcoholics from high- and low-density families.

Event-related potentials (ERPs), particularly the P3 wave, have been proposed as biological markers of genetic risk for alcoholism. The present study assesses the ERPs from 102 boys and girls (7 to 15 years old) divided into three groups: two groups of sons and daughters of alcoholic fathers, with and without other first- or second-degree relatives affected, and a control group of children of nonalcoholics. Both visual and auditory discrimination tasks with three stimuli (standard, target, and infrequent nontarget) were used. P3 amplitudes did not reach significant reduction for the high-risk males and were complex for females. There were significant differences among females in P3 visual latency elicited by targets; delays in this variable were associated with multigenerational familial alcoholism. Results are discussed in light of the tasks used for eliciting the ERPs and the characteristics of the selected sample.

Reversibility of brain-stem evoked potential abnormalities in abstinent chronic alcoholics: one year follow-up.

Brain-stem auditory evoked potentials (BAEPs) were studied in 34 chronic alcoholics who had been abstinent for 1 year, and in age- and sex-matched control subjects. The patients were examined 3 times, at 1 month, 5 months and 1 year after the start of the abstinence treatment. At 1 month of abstinence the alcoholics showed differences with respect to controls in the peak V latency (P < 0.01), and in the III-V (P < 0.01) and I-V (P < 0.01) intervals. After 1 year of abstinence a significant improvement in the V (P < 0.01), III-V (P < 0.01) and I-V (P < 0.01) parameters was recorded. The most notable development was in the 5-12 month period, with shortening in V latency (P < 0.01) and in the I-V interval (P < 0.01); in the first 5 months there was only shortening in the III-V interval (P < 0.01). This improvement was also indicated by a decrease in the number of patients with BAEP parameter abnormalities. The recovery of the functions impaired by chronic alcohol consumption after 1 year of abstinence was incomplete, although the tendency was towards normalization.

Field dependence-independence and brain organization: the confluence of two different ways of describing general forms of cognitive functioning? A theoretical review.

We reviewed a total of 67 studies of the relationship between the cognitive style dimension of field dependence-independence and brain organization. To date, such studies have followed three basic lines of approach: (1) cerebral localization of processes involved in field dependence-independence; (2) evaluation of the relationship between field dependence-independence and hemisphericity; (3) evaluation of the relationship between field dependence-independence and hemispheric differentiation. The results of all three types of study are largely coherent with the differentiation theory formulated by Witkin and his coworkers. In addition, findings to date are of interest in that they suggest new directions for more detailed investigation of the relationship between field dependence-independence and brain organization. These directions appear very promising for improving our understanding of both the nature of cognitive styles and the functioning of the brain in general.