Investigators at the Georgetown University Medical Center, led by psychology PhD student Katherine R. Gamble, found that a very simple dot test can be used to successfully measure the amount of dopamine loss that occurs in the brains of seniors suffering from Parkinson’s disease.
Gamble, who is also the lead author of the new study, worked closely with psychiatrists and neurologists at the university to create the new tests. The sequential learning task has been called the Triplets Learning Task (TLT), PsychCentral reports.
One of the reasons why this work is so important is that it is currently very difficult to determine exactly how much dopamine the human brain loses when it becomes afflicted with this degenerative neurological condition.
The research group says that physicians can start using the TLT right away, but it underlines the fact that more work needs to be conducted in order to fully understand the test's utility and applications.
Gamble explains that this task is used to gage a type of learning called implicit learning, which occurs without intent or awareness. In other words, the test cannot be cheated, but it can still provide accurate data on the brain of the patient taking it.
The team adds that implicit learning is centered in an area of the brain called the caudate nucleus, which tends to be adversely affected by reduced dopamine levels. Dopamine is an essential neurotransmitter that plays a role in underlying reward-motivated behavior and motor control.
The test will be easy to apply on people already suffering from Parkinson's because it does not require complex motor skills. Researchers have already tested its performance in a study on patients suffering from this condition, and compared the results to those of a test group.
Patients' performances “began to decline toward the end of training, suggesting that people with Parkinson’s disease lack the neural resources in the caudate, such as dopamine, to complete the learning task,” Gamble explains.
“This work is important in that it may be a non-invasive way to evaluate the level of dopamine deficiency in PD patients, and which may lead to future ways to improve clinical treatment of PD patients,” concludes GU associate professor of neurology Steven E. Lo, a coauthor of the new study.