Dual Tasking and Working Memory in Alcoholism: Relation to Frontocerebellar Circuitry

Abstract

Controversy exists regarding the role of cerebellar systems in cognition and whether working memory compromise commonly marking alcoholism can be explained by compromise of nodes of corticocerebellar circuitry. We tested 17 alcoholics and 31 age-matched controls with dual-task, working memory paradigms. Interference tasks competed with verbal and spatial working memory tasks using low (three item) or high (six item) memory loads. Participants also underwent structural MRI to obtain volumes of nodes of the frontocerebellar system. On the verbal working memory task, both groups performed equally. On the spatial working memory with the high-load task, the alcoholic group was disproportionately more affected by the arithmetic distractor than were controls. In alcoholics, volumes of the left thalamus and left cerebellar Crus I volumes were more robust predictors of performance in the spatial working memory task with the arithmetic distractor than the left frontal superior cortex. In controls, volumes of the right middle frontal gyrus and right cerebellar Crus I were independent predictors over the left cerebellar Crus I, left thalamus, right superior parietal cortex, or left middle frontal gyrus of spatial working memory performance with tracking interference. The brain–behavior correlations suggest that alcoholics and controls relied on the integrity of certain nodes of corticocerebellar systems to perform these verbal and spatial working memory tasks, but that the specific pattern of relationships differed by group. The resulting brain structure–function patterns provide correlational support that components of this corticocerebellar system not typically related to normal performance in dual-task conditions may be available to augment otherwise dampened performance by alcoholics.

Profiles of impaired, spared, and recovered neuropsychologic processes in alcoholism

“…Some researchers have suggested that the lack of detectable deficits in these seemingly spared domains could be due to compensatory recruitment of alternative brain regions to facilitate cognitive processes (Sullivan and Pfefferbaum, 2005; Oscar-Berman and Marinkovic, 2007; Chanraud et al, 2013). In support of this notion, fMRI studies have demonstrated altered patterns of neural activation among alcoholics, with reduced activity in some regions (Chanraud et al, 2010; Chanraud et al, 2011), but simultaneous increases in activity in others (Pfefferbaum et al, 2001a; Desmond et al, 2003; Chanraud-Guillermo et al, 2009; Chanraud et al, 2013). As such, it can be difficult to distinguish between functions that have been truly spared and those that appear unimpaired due to compensatory mechanisms or other recovery of function.…”

Volumetric Differences in Cerebellar Lobes in Individuals from Multiplex Alcohol Dependence Families and Controls: Their Relationship to Externalizing and Internalizing Disorders and Working Memory

“…Additionally, there is data to suggest a functional topography of the cerebellum, with posterior regions preferentially involved in cognitive processes whereas anterior portions of the cerebellum support motor functions [56]. Previous work comparing 17 alcohol-dependent individuals and 31 controls has revealed performance deficits in visuospatial working memory tasks that are related to structural differences in left cerebellar Crus I, though differences in verbal working memory functioning did not appear to be impaired in alcohol-dependent individuals [9]. In a study of 15 patients with spinocerebellar ataxia, verbal working memory deficits were found using the WAIS subtests (Forward and Backward Digit Span and Letter Number Sequencing) [10].…”

“…Lesion studies have demonstrated that individuals with posterior cerebellar lesions consistently display working memory deficits [4, 7, 8], whereas damage to other cerebellar regions does not appear to affect working memory [7]. Positive correlations between posterior cerebellar lobe volume and working memory performance have been reported [9–11] along with greater BOLD activation during working memory task performance [12–14]. …”

“…Furthermore, aberrant cerebellar volume has been found to correlate with motor deficits among alcoholics, including abnormal postural sway [17, 19] as well as impaired cognitive performance, including poorer executive function, visuospatial ability [17], and spatial working memory performance [9]. …”

Daño cerebral relacionado con el alcohol. Situación actual y llamada a la acción

“…For instance, when compared to controls in task performance, alcoholic patients have shown spontaneous, compensatory recruitment of additional brain networks like fronto-cerebellar and others (Chanraud, Pitel, Rohlfing, Pfefferbaum & Sullivan, 2010;Chanraud, Pitel, Pfefferbaum & Sullivan, 2011;Parks et al, 2012;Camchong, Stenger & Fein 2012;Chanraud, Pitel, Muller-Ohering, Pfefferbaum & Sullivan, 2013). Some of these compensatory strategies have been linked to the ability to sustain abstinence .…”