Greater Activation in Left Hemisphere Language-Related Regions During Simple Judgment Tasks Among Substance-Dependent Patients in Treatment for Alcoholism

Laboratory of Clinical and Translational Studies, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892, USA.
Alcoholism Clinical and Experimental Research (Impact Factor: 3.21). 11/2009; 34(2):331-41. DOI: 10.1111/j.1530-0277.2009.01095.x
Source: PubMed


Alcoholism is often associated with impaired emotional control. Alcoholics have also been found to have deficits in frontal lobe executive functions. Recent functional imaging studies have suggested that alcoholics show greater activation than nonalcoholics in circuits involving frontal lobes, as well as more posterior brain regions, when engaged in executive-type tasks. In this study, we compared brain activations of alcohol-dependent patients and healthy nonalcoholics while they performed 2 simple judgment tasks designed to activate frontal circuits involved in a basic form of decision making. Participants completed 1 judgment task that required an emotional judgment and 1 task that did not, which enabled us to study whether alcoholics had greater brain activation while performing executive tasks, and to determine if emotional tasks elicited even greater activation than nonemotional tasks.
We performed functional magnetic resonance imaging scans while alcoholic patients and nonalcoholic controls viewed pictures from the International Affective Picture System. In 3 separate runs, participants viewed the images without making a judgment, determined whether the images were indoor or outdoor scenes, or decided if they liked or disliked the images.
There was little difference in brain activation between alcoholics and controls when no judgment was required. When participants made judgments about either the location or whether they liked or disliked an image, however, we observed significantly increased activation in frontal, limbic, and temporal regions in the patients relative to the controls. Increases were particularly robust in the frontal lobe and in areas of the brain associated with language. When we compared the emotional to the nonemotional judgment, the alcoholics, but not the controls, showed greater activation in the ventral mesial frontal cortex.
Alcoholic patients appear to use brain language areas more than nonalcoholics while making judgments about the setting or liking of emotionally arousing visual images. This increased activation may reflect a compensatory recruitment of brain regions to perform simple decision-making tasks.

Download full-text


Available from: Daniel W Hommer, Oct 05, 2015
27 Reads
  • Source
    • "Studies examining a variety of cognitive tasks in ADP have shown differences in neural responses despite intact behavior in laboratory tasks [e.g. working memory (Pfefferbaum et al. 2001; Desmond et al. 2003), emotional processing (Gilman, Davis & Hommer 2010) and language processing (Chanraud-Guillermo et al. 2009)]. This striatal reactivity may be a signature of an effective response to cumulative instrumental gains that could bias behavior in more obscure or real-world contexts. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Substance use disorder is characterized by a transition from volitional to compulsive responding for drug reward. A possible explanation for this transition may be that alcohol-dependent patients (ADP) show a general propensity for a history of rewarded instrumental responses, and these rewarded responses may boost the activation of motivational neurocircuitry for additional reward. Brain imaging studies of decision-making have demonstrated that ADP relative to controls (CON) often show altered neural activation in response to anticipating and receiving rewards, but the majority of studies have not investigated how past performance affects activation. A potential exists for ADP to show increased sensitivity to reward as a function of reward delivery history. In the current study, we used functional magnetic resonance imaging to investigate the neural correlates of risky decision-making in ADP (n = 18) and CON (n = 18) while they played a two-choice monetary risk-taking game. In addition to investigating general neural recruitment by risky decision-making, we also modeled each participant's running total of monetary earnings in order to determine areas of activation that correlated with cumulative reward. We found that ADP and CON showed few differences in behavior or in mesolimbic activation by choice for, and receipt of, risky gains. However, when including a cumulative-earnings covariate, ADP exhibited heightened striatal activation that correlated with total earnings during the choice event in the task. The heightened contextual sensitivity of striatal responses to cumulative earnings in ADP may represent a general neurobiological affective substrate for development of automatized instrumental behavior.
    Addiction Biology 05/2014; 20(3). DOI:10.1111/adb.12147 · 5.36 Impact Factor
  • Source
    • "Kim and colleagues [33,34] reasoned that this finding was in congruence with previous studies indirectly suggesting left hemisphere dysfunction in comparison to observed right hemisphere dominance in PTSD [53–55]. Accordingly, given the more right-sided deficits observed in alcoholism [5,13,19], these two competing right-sided effects in a combined ALC+PTSD population may average out, resulting in no observable difference between ALC and ALC+PTSD. This may also be an explanation for why no differences were seen between control subjects and alcohol dependent subjects, at least in the right dorsal cingulum bundle. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Many brain imaging studies have demonstrated reductions in gray and white matter volumes in alcoholism, with fewer investigators using diffusion tensor imaging (DTI) to examine the integrity of white matter pathways. Among various medical conditions, alcoholism and post-traumatic stress disorder (PTSD) are two comorbid diseases that have similar degenerative effects on the white matter integrity. Therefore, understanding and differentiating these effects would be very important in characterizing alcoholism and PTSD. Alcoholics are known to have neurocognitive deficits in decision-making, particularly in decisions related to emotionally-motivated behavior, while individuals with PTSD have deficits in emotional regulation and enhanced fear response. It is widely believed that these types of abnormalities in both alcoholism and PTSD are related to fronto-limbic dysfunction. In addition, previous studies have shown cortico-limbic fiber degradation through fiber tracking in alcoholism. DTI was used to measure white matter fractional anisotropy (FA), which provides information about tissue microstructure, possibly indicating white matter integrity. We quantitatively investigated the microstructure of white matter through whole brain DTI analysis in healthy volunteers (HV) and alcohol dependent subjects without PTSD (ALC) and with PTSD (ALC+PTSD). These data show significant differences in FA between alcoholics and non-alcoholic HVs, with no significant differences in FA between ALC and ALC+PTSD in any white matter structure. We performed a post-hoc region of interest analysis that allowed us to incorporate multiple covariates into the analysis and found similar results. HV had higher FA in several areas implicated in the reward circuit, emotion, and executive functioning, suggesting that there may be microstructural abnormalities in white matter pathways that contribute to neurocognitive and executive functioning deficits observed in alcoholics. Furthermore, our data do not reveal any differences between ALC and ALC+PTSD, suggesting that the effect of alcohol on white matter microstructure may be more significant than any effect caused by PTSD.
    PLoS ONE 11/2013; 8(11):e80952. DOI:10.1371/journal.pone.0080952 · 3.23 Impact Factor
  • Source
    • "While not rigorously comparable, we see that this analysis shows similar regions of BOLD response to those seen in the original temporal-based group analysis of this data. This can best be summed up by quoting from the conclusion of the original paper by Gilman et al. [40], " Alcoholic patients appear to use brain language areas more than non-alcoholics while making judgments about the setting or liking of emotionally arousing visual images. This increased activation may reflect a compensatory recruitment of brain regions to perform simple decision-making tasks. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A linear time-invariant model based on statistical time series analysis in the Fourier domain for single subjects is further developed and applied to functional MRI (fMRI) blood-oxygen level-dependent (BOLD) multivariate data. This methodology was originally developed to analyze multiple stimulus input evoked response BOLD data. However, to analyze clinical data generated using a repeated measures experimental design, the model has been extended to handle multivariate time series data and demonstrated on control and alcoholic subjects taken from data previously analyzed in the temporal domain. Analysis of BOLD data is typically carried out in the time domain where the data has a high temporal correlation. These analyses generally employ parametric models of the hemodynamic response function (HRF) where prewhitening of the data is attempted using autoregressive (AR) models for the noise. However, this data can be analyzed in the Fourier domain. Here, assumptions made on the noise structure are less restrictive, and hypothesis tests can be constructed based on voxel-specific nonparametric estimates of the hemodynamic transfer function (HRF in the Fourier domain). This is especially important for experimental designs involving multiple states (either stimulus or drug induced) that may alter the form of the response function.
    Computational and Mathematical Methods in Medicine 06/2013; 2013(4):645043. DOI:10.1155/2013/645043 · 0.77 Impact Factor
Show more