Gambling and Brain Frontal-Striatum Connections

For the remainder of 2015, Brain Posts will focus on pathological gambling and also highlight the top-viewed posts for the year.

Functional connectivity is a relatively recent brain imaging technique that provides a new look at brain circuitry at rest and with tasks.

Resting state connectivity using fMRI provides a snapshot of brain connections in each individual. There is increasing study of resting connectivity in individuals with disorders in neuroscience medicine compared to control populations.

Saskia Koehler and colleagues in Germany recently published a study of resting fMRI connectivity in a group of problem gamblers and controls.

Problem gamblers (PG) in this study were recruited via advertisement on the internet and posted notices in casinos. PB was assigned based on a questionnaire for problem gambling that included DSM-IV and ICD-10 diagnostic criteria.

The key findings in the PG compared to the controls included:

• Increased connectivity in PG between the right middle frontal gyrus and the right striatum
• Decreased connectivity in the PG between the right middle frontal gyrus and other prefrontal regions
• The right ventral striatum region showed enhanced connectivity to the right middle and superior frontal gyrus and the left cerebellum

The striatum is a brain region known to be linked to the reward system. The authors note in the introduction:

"Immediate reward seeking behavior has been linked to regions of the mesolimbic system, since subcortical areas such as the ventral striatum (including the nucleus accumbens) are highly active during reward processing."

It makes sense that individuals with PG show hyperactivity between brain executive decision-making regions (frontal cortex) and the brain reward regions of the striatum. The fact that these increased hard-wiring effects can be seen at rest supports the strength of the brain connectivity finding. 

The study also found correlations between the frontal-striatum hyperactivity and two psychometric measures assessed in the study: nonplanning impulsivity and gambling craving subscores.

The increased connectivity between the right frontal cortex and the striatum have been previously demonstrated in substance abuse. In the current study, alcohol intake and cigarette use were match in PG and control to address potential confounding addiction variable effects.

The authors note their study supports research into therapies (psychotherapy and drugs) that target frontal-striatum connectivity in developing innovative interventions in PG.

Readers with more interest in this study can access the free full-text manuscript by clicking on the PMID link in the citation below.

Figure in this post is an original photo with impressionism filter from the author's files. Photo may be reproduced with link to the site.

Follow the author on Twitter: WRY999 

Koehler S, Ovadia-Caro S, van der Meer E, Villringer A, Heinz A, Romanczuk-Seiferth N, & Margulies DS (2013). Increased functional connectivity between prefrontal cortex and reward system in pathological gambling. PloS one, 8 (12) PMID: 24367675