How disrupted brain activity affects cognitive function in Parkinson's patients

Researchers from the Indian Institute of Technology IIT Bombay have in a new study unravelled how disrupted brain activity impacts cognitive functions in Parkinsonrsquos patientsThe study focussed on altered reward processing in Parkinsonrsquos patients to decode why Parkinsonrsquos patients lack motivation and have impaired decisionmakingParkinsonrsquos disease is a neurodegenerative disorder mainly causing shaky limbs muscle stiffness and slow movements However some Parkinsonrsquos patients also manifest symptoms such as a lack of motivation or disability in experiencing pleasure attributed to a lack of dopamine hormoneCommonly known as the lsquofeelgoodrsquo hormone dopamine is generally produced when performing a pleasurable task or receiving a rewardLack of dopamine in individuals with Parkinsonrsquos leads to altered brain activity and impaired reward processing the brains ability to recognise value and respond to rewarding stimuliTo investigate reward processing in individuals with Parkinsonrsquos the team used brain signalsThe results showed that reward positivity was weaker in Parkinsonrsquos patients indicating that their brains do not process rewards effectively Reward positivity is essential for cognitive processes like attention learning and emotional responsesFurther dopamine medication failed to restore the reward positivityldquoNormally the brain releases dopamine as short bursts following a reward but in Parkinsonrsquos these bursts are weaker Although dopamine medication replenishes the dopamine levels in the brain it does not produce burstlike signals that mimic the natural process This could be the reason why dopamine is able to improve motor symptoms but not cognitive functions like reward processingrdquo said Prof Nivethida Thirugnanasambandam from the Human Motor Neurophysiology and Neuromodulation Lab Department of Biosciences and Bioengineering who led the studyldquoHence adjunct treatment strategies may be required to restore cognitive impairments in Parkinsonrsquosrdquo she addedThe team analysed electroencephalography EEG data recorded from 28 Parkinsonrsquos patients and 28 healthy individuals while they performed a rewardbased learning taskEEG was recorded from Parkinsonrsquos patients both before and after taking dopamine medication ON condition Comparing these conditions allowed researchers to understand the influence of dopamine medication on reward processingFurther the analysis indicates that Parkinsonrsquos patients have weaker thetagamma synchronisation resulting in poor communication between brain regions that process reward information and use it for learning goaldirected behaviour This could be the reason behind the lack of motivation and impaired decisionmaking in Parkinsonrsquos patients the researchers explainedThetagamma coupling or synchronisation is crucial for cognitive functions such as reward processing and goaloriented behaviourDopamine medication was able to partially restore thetagamma synchronisation This finding highlights thetagamma coupling as a potential biomarker to identify the impairment of reward mechanisms in Parkinsonrsquos patients the researchers saidThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoeveratOptionskeyd0ddb8ef8f1a62a8cdd22fac27fc5ea7formatiframeheight90width728params