Finger tapping shows that alcoholics may recruit other brain regions for simple tasks

November 15, 2011, Alcoholism: Clinical & Experimental Research

Chronic drinking is associated with neurocognitive deficits due to neuropathological changes in the structure, metabolism, and function of the brain. One of the consequences of neuropathological brain abnormalities in the cerebellum of alcoholics has been impairment of motor functioning. A new study using functional magnetic resonance imaging (fMRI) during a finger-tapping exercise has found a weakened relationship between frontal lobe and cerebellar activity in alcoholic individuals.

Results will be published in the February 2012 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.

"Chronic exposure most commonly causes deficits in visuospatial skills and problem solving, while problems with learning and memory can also be observed," said Baxter P. Rogers, research assistant professor at the Vanderbilt University Institute of Imaging Science and corresponding author for the study. "But a commonly unappreciated deficit is in motor functions: for instance, balance when standing can be affected by dysfunction of the as can the ability to perform rhythmic movements."

Rogers and his colleagues used to examine 10 uncomplicated chronic alcoholic patients after five to seven days of abstinence and once signs of withdrawal had lessened, as well as 10 matched healthy controls. "We used fMRI during a finger-tapping to examine functional connectivity between cerebellar and cortical brain regions because fMRI measures the function of the entire brain painlessly and non-invasively, and functional MRI can identify specific brain regions that are involved in tasks, and that are affected in disease," explained Rogers.

Although it may seem an unsophisticated movement, finger tapping is a simple, rhythmic movement that can be used to study the function of the parts of the brain that are often damaged by chronic drinking, such as the cerebellum and the frontal lobes. "Finger tapping is also a very convenient task for the MRI environment, and output from the task is easily described by counting the number of taps in a given amount of time," said Rogers.

"In addition, finger tapping recruits portions of both the cerebellum and frontal cortex," he added. "Previous research strongly suggested that both are affected in alcoholism, especially the cerebellum." The study authors focused on the prefrontal, frontal, temporal, and parietal cortex regions of the brain.

"The key finding was that the relationship between and cerebellar activity was weaker in alcoholic people, even a week after they had stopped drinking," said Rogers. "The weaker relationship between these regions in alcoholics might reflect direct injury to one or both of these parts of the brain, disruption of frontal-cerebellar neural pathways that connect these regions, or some sort of compensation for injuries elsewhere in the brain. It could even be that a weakened relationship between these brain regions was present prior to when a person started drinking which actually predisposes people to alcoholism in the first place."

Rogers explained that while they found that the alcoholic patients could produce the same number of finger taps per minute as did the normal controls, they employed different parts of the brain to do so. This suggested that alcoholics needed to compensate for their brain injury. "That is, they may need to expend more effort, or at least a different brain response, to produce a normal outcome on simple tasks because they are unable to utilize the brain regions needed in an integrated fashion," he said. "However, if the task becomes more complex, we predict that performance may break down and alcoholics may seem impaired when tested. This is the big advantage of studying simple tasks that alcoholics can perform at normal levels: we can identify the 'brain strategy' – the that are activated – to perform the task. fMRI allows us to go below the surface, so to speak."

While this study supports other research showing problems in the frontal-cerebellar brain circuits in alcoholic patients, Rogers said its major contribution is related to studying the simple tasks that alcoholics apparently perform quite "normally."

"In many studies, the focus has been on the focus was on neuropsychological testing of alcoholics," said Rogers. "Researchers focused on examining complex tasks – such as memory and problem solving – that alcoholics cannot perform as well as normal controls to determine what parts of their brain were dysfunctional. Now that we have fMRI available to help us determine the areas of the brain that are activated in the performance of tasks, the study of simple tasks may also be very informative. Complex tasks clearly show abnormalities in fMRI, but it becomes impossible to determine whether the fMRI differences observed are due to the impaired performance or brain differences that account for the impaired performance. Our study allows us to infer that changes in strategies are employed in performance of the task, which may lead to new approaches to rehabilitation."

Explore further: Damaged gait and balance can recover with long-term abstinence from alcohol

Related Stories

Damaged gait and balance can recover with long-term abstinence from alcohol

September 15, 2011
Chronic alcoholism is often associated with a disturbed gait and balance, likely caused by alcohol damage to neural systems. While some studies have suggested that abstinence can lead to partial recovery of gait and balance ...

Researchers link alcohol-dependence impulsivity to brain anomalies

April 15, 2011
Researchers already know that alcohol dependence (AD) is strongly associated with impaired impulse control or, more precisely, the inability to choose large, delayed rewards rather than smaller but more immediate rewards. ...

Recommended for you

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.