Fast changes in dopamine levels may impact human behaviour: Study

Scientists are studying dopamine to understand decisionmaking and human behaviourDopamine is a neurotransmitter produced in the brain that serves as a chemical messenger facilitating communication between nerve cells in the brain and the bodyIt is involved in functions such as movement cognition and learning While dopamine is most known for its association with positive emotions scientists are also exploring its role in negative experiencesThe new study published in the journal Science Advances shows that dopamine release in the human brain plays a crucial role in encoding both reward and punishment prediction errorsThis means that dopamine is involved in the process of learning from both positive and negative experiences allowing the brain to adjust and adapt its behaviour based on the outcomes of these experiencesPreviously research has shown that dopamine plays an important role in how animals learn from rewarding and possibly punishing experiences But little work has been done to directly assess what dopamine does on fast timescales in the human brain said Kenneth T Kishida Associate Professor of physiology and pharmacology and neurosurgery at Wake Forest University School of Medicine in the USThis is the first study in humans to examine how dopamine encodes rewards and punishments and whether dopamine reflects an optimal teaching signal that is used in todays most advanced artificial intelligence research Kishida saidFor the study the team utilised fastscan cyclic voltammetry an electrochemical technique paired with machine learning to detect and measure dopamine levels in realtime ie 10 measurements per secondHowever this method is challenging and can only be performed during invasive procedures such as deepbrain stimulation DBS brain surgeryDBS is commonly employed to treat conditions such as Parkinsons disease essential tremor obsessivecompulsive disorder and epilepsyThe team inserted a carbon fibre microelectrode deep into the brain of three participants who were scheduled to receive DBS to treat essential tremorWhile the participants were awake in the operating room they played a simple computer game As they played the game dopamine measurements were taken in the striatum a part of the brain that is important for cognition decisionmaking and coordinated movementsDuring the game participants choices were either rewarded or punished with real monetary gains or losses The game was divided into three stages in which participants learned from positive or negative feedback to make choices that maximised rewards and minimised penaltiesKishida said the study showed that dopamine not only plays a role in signalling both positive and negative experiences in the brain but it seems to do so in a way that is optimal when trying to learn from those outcomesWhat was also interesting is that it seems like there may be independent pathways in the brain that separately engage the dopamine system for rewarding versus punishing experiencesOur results reveal a surprising result that these two pathways may encode rewarding and punishing experiences on slightly shifted timescales separated by only 200 to 400 milliseconds in time Kishida 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 whatsoever