Decreased neural activity in reward circuitry during personal reference in abstinent alcoholics—A fMRI study

Abstract

Two of the most striking features in alcoholism are the irresistible craving for alcohol and the proceeding neglect of other activities and pleasures that were formerly relevant. Craving has been investigated extensively and is commonly due to a dysfunctional reward system. The neural basis of the neglect of self-relevant interests, which can be described as altered personal reference, and its association to the reward system, however, remains unclear. Using fMRI, we investigated neural activity during a paradigm that tested for both reward and personal reference with regard to the same stimuli, i.e., alcoholic and nonalcoholic pictures, in healthy subjects and abstinent alcoholic patients. Alcoholic patients showed slightly reduced signal changes in the brain stem adjacent to ventral tegmental area (VTA) and in the ventromedial prefrontal cortex (VMPFC) during the reward task, while we found no alterations in the right and left ventral striatum (VS). The same regions (VS, VTA, and VMPFC), however, showed reduced signal changes during personal reference with lack of neural differentiation between high and low referenced stimuli in alcoholic patients. In summary, we demonstrate for the first time neurophysiological alterations in reward circuitry during personal reference in alcoholic patients. Our results underline the important role of the reward circuitry during personal reference in the pathophysiology of alcohol addiction.

Resting state glutamate predicts elevated pre-stimulus alpha during self-relatedness: A combined EEG-MRS study on “rest-self overlap”

“…Nevertheless, we remained unable to control for other possible factors like reward. High self-related stimuli may exhibit a higher degree of reward than those that exhibit low self-relatedness because self appears to be related to distinctive activity levels in the reward system (de Greck et al, 2008(de Greck et al, , 2009(de Greck et al, , 2010. Hence, future EEG and MRS studies may be necessary in order to directly compare self-relatedness and reward, as well as to determine how these are modulated by glutamate.…”

Decreased neuronal activity in reward circuitry of pathological gamblers during processing of personal relevant stimuli

“…In a preliminary study by our group, tasks of high personal relevance induced neuronal activity in exactly the regions implicated in reward function in healthy subjects [de Greck et al, 2008]. Recently, our group also found that alcoholic patients showed decreased neuronal activity in reward circuitry (i.e., left and right NACC/VS, VTA, VMPFC) during the evaluation of stimuli with a high personal relevance as compared to healthy controls [de Greck et al, 2009] showing that the apparent changes in behavior stem from a lack of activation in reward circuitry during the evaluation of stimuli of high personal relevance.…”

“…Patients are increasingly preoccupied by gambling and so begin to neglect other formerly self-relevant stimuli and behaviors. Psychologically, the evaluation of personal relevance or self-relatedness, as previous studies have called it [de Greck et al, 2008[de Greck et al, , 2009Kelley et al, 2002;Northoff and Bermpohl, 2004;Northoff et al, 2006;Phan et al, 2004], describes how important and how close to themselves subjects experience specific stimuli. Neurobiologically, tasks that engage the notion of self-relatedness, and hence personal relevance have implicated regions from reward circuitry such as the NACC, VTA, and the VMPFC [de Greck et al, 2008;Northoff et al, 2006;Northoff et al, 2007;Phan et al, 2004].…”

How Is Our Self Altered in Psychiatric Disorders? A Neurophenomenal Approach to Psychopathological Symptoms

“…This will be the focus in the following. Reasons of space will prevent me from giving a more general overview of the psychopathology of the self in other psychiatric disorders such as in addiction (see for instance de Greck et al [6,7]) and personality disorders (see Doering et al [8]).…”