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Findings from Drexel University Broaden Understanding of Substantia Nigra (Microstimulation of the Human Substantia Nigra Alters Reinforcement...

July 11, 2014

Findings from Drexel University Broaden Understanding of Substantia Nigra (Microstimulation of the Human Substantia Nigra Alters Reinforcement Learning)

By a News Reporter-Staff News Editor at Health & Medicine Week -- Research findings on Central Nervous System are discussed in a new report. According to news reporting originating in Philadelphia, Pennsylvania, by NewsRx journalists, research stated, "Animal studies have shown that substantia nigra (SN) dopaminergic (DA) neurons strengthen action-reward associations during reinforcement learning, but their role in human learning is not known. Here, we applied microstimulation in the SN of 11 patients undergoing deep brain stimulation surgery for the treatment of Parkinson's disease as they performed a two-alternative probability learning task in which rewards were contingent on stimuli, rather than actions."

The news reporters obtained a quote from the research from Drexel University, "Subjects demonstrated decreased learning from reward trials that were accompanied by phasic SN microstimulation compared with reward trials without stimulation. Subjects who showed large decreases in learning also showed an increased bias toward repeating actions after stimulation trials; therefore, stimulation may have decreased learning by strengthening action-reward associations rather than stimulus-reward associations."

According to the news reporters, the research concluded: "Our findings build on previous studies implicating SN DA neurons in preferentially strengthening action-reward associations during reinforcement learning."

For more information on this research see: Microstimulation of the Human Substantia Nigra Alters Reinforcement Learning. Journal of Neuroscience, 2014;34(20):6887-6895. Journal of Neuroscience can be contacted at: Soc Neuroscience, 11 Dupont Circle, NW, Ste 500, Washington, DC 20036, USA. (Society for Neuroscience -; Journal of Neuroscience -

Our news correspondents report that additional information may be obtained by contacting A.G. Ramayya, Drexel University, Sch Biomed Engn Sci & Hlth Syst, Philadelphia, PA 19103, United States. Additional authors for this research include A. Misra, G.H. Baltuch and M.J. Kahana (see also Central Nervous System).

Keywords for this news article include: Brain Stem, Philadelphia, Pennsylvania, United States, Machine Learning, Substantia Nigra, Emerging Technologies, Central Nervous System, Reinforcement Learning, Tegmentum Mesencephali, North and Central America

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC

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Source: Health & Medicine Week

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