Some Alcohol Effects Last Long Into Sobriety

Visual Tasks More Difficult for Alcoholics

Confused Woman
Some Deficits Last Long Into Sobriety. © Getty Images

People with severe alcohol use disorders can experience cognitive deficits due to the damage that drinking too much alcohol for a long period of time can cause within the brain.

Fortunately, much of the damage that alcohol does to the brain begins to reverse when alcoholics stop drinking. But, there are some problems with brain function that linger long after the drinker quits.

Studies have found that alcoholics who have remained abstinent, even for a prolonged period of time, can display visuospatial and visuoperception deficits.

Visuospatial skills include the ability to see an object or image as a set of parts and then be able to construct a replica of the original from the parts. For example, visuospatial construction includes putting together furniture that comes unassembled, constructing models, or even making a bed or buttoning shirts.

Visuoperceptual ability is being able to recognize objects based on their form, pattern, and color. Simply put, visual perception is the brain's ability to make sense of what the eyes see.

Important Basic, Every Day Skills

These cognitive skills are important for many basic everyday tasks such as reading, writing, completing math problems, or even getting dressed. For example, someone with visual perception deficits might have a problem reading a map.

If someone has visuospatial or visuoperceptual deficits it can impair their ability to accurately assess distance and spatial relations between objects, which could cause problems in trying to drive a vehicle, for example.

A deficit of the ability to use visual-spatial cues, to detect changes and consistencies, and subtle visual discriminations can affect the ability to accomplish everyday tasks like pushing a cart through a grocery store or recognizing your child in a group of similarly dressed children.

Less Efficient Use of Brain Functions

Researchers have found that even with long-term sobriety, alcoholics can continue to display deficits in visuoperception and frontal executive functioning of the brain.

Additionally, because of the damage alcohol has done to their brains, alcoholics have to use a more complex higher-order cognitive system, frontal executive functions, to perform the same tasks that others without a history of alcoholism perform, researchers have found.

In one study, researchers at the Stanford University School of Medicine gave a picture fragment identification test to 51 recently detoxified alcoholic men and 63 control men. They also tested executive function and explicit declarative memory.

Using 'Perceptual Closure' Skills

The picture-fragment test measured how quickly the men could identify line drawings of common objects or animals when only partially visible.

People who have visuoperceptual impairments require a more complete rendition of these drawings before they are able to identify them compared to unaffected subjects.

Unaffected individuals can use a process known as "perceptual closure" to imagine or "fill in" parts of the image that are not actually visible.

Ability to Learn Measured

To measure the ability to learn, the drawings were shown to the men in the study again after a delay.

If they were able to identify the object the second time in a more fragmented rendition, then learning occurred, the researchers said.

The study found that the alcoholic men displayed deficits in visuoperception and frontal executive function compare to the control group.

The researchers also found that although the alcoholic group was able to learn visuoperceptual tasks at the same level of the controls, how they performed the task was very different from how the controls performed it.

More Complex Processing Needed

The alcoholics used different underlying component processes to execute the task.

"Unable to invoke normal visuoperceptual abilities, alcoholics relied on a more complex cognitive system to perform the visuoperceptual learning task than required by controls," said Stanford professor said Edith Sullivan. "The potential problem with this is that if that same system - frontal executive functions - is needed for a competing task, alcoholics may be at a disadvantage because that system would otherwise be engaged."

The researchers concluded that the necessity of having to use frontal executive functions to complete visuoperceptual tasks could affect the performance of recovering alcoholics in driving a vehicle or performing in the workplace.

Could Affect Workplace Performance

It would be more difficult for alcoholics to complete tasks that required sequencing, judgment, and decision-making, or complex tasks that required organization or planning. Jobs that required visuospatial skills, like operating heavy equipment or dentistry, could also be impaired, the researchers said.

"Use of more demanding cognitive systems by the alcoholics may be less efficient and more costly to processing capacity than those invoked by controls," the authors wrote.

Souces:

Fama, R, et al. "Perceptual Learning in Detoxified Alcoholic Men: Contributions From Explicit Memory, Executive Function, and Age." Alcoholism: Clinical & Experimental Research November 2004

Irani, F. "Visuoperceptual." Encyclopedia of Clinical Neuropsychology 2011

Mervis, CB, et al. "Visuospatial Construction." American Journal of Human Genetics Oct. 1999

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