UNIVERSITY OF HERTFORDSHIRE
    	     COMPUTER SCIENCE RESEARCH COLLOQUIUM

	     		        presents


      "To go, or not to go: behavioural models and the basal ganglia
                  neurophysiology of stopping"



		             Dr. Robert Schmidt

	   (Department of Psychology, University of Sheffield)

		           10th April 2019 (Wednesday)

			            12:00 - 13:00


		        Hatfield, College Lane Campus
		             Seminar Room C214

	    	    Everyone is welcome to attend

	     	    Refreshments will be available

Abstract:
For decades cognitive psychologists have described action cancellation
as a race between a "Go" and a "Stop" process. However, it was entirely
unclear whether these actually reflect neural processes. We found
evidence that in the basal ganglia there is a literal race between
excitatory inputs from the subthalamic nucleus (acting as a Stop
process) and inhibitory inputs from the striatum (acting as a Go
process; Schmidt et al., 2013). In current work we expand on these
results and find that there are multiple circuits in the basal ganglia
that work in concert for stopping actions: a fast, but unspecific
process that buys time for a slower, but more specific stop process to
suppress the action on the level of the striatum (Mallet et al., 2016).
Thereby, we provide the first precisely-defined behavioral function of
so-called arkypallidal neurons, a newly characterized subtype of basal
ganglia cells which has been proposed to play a key role in Parkinson's
disease. We recently synthesized these findings into a novel model of
stopping actions through multiple interacting pathways (Schmidt and
Berke, 2017).

References:

R. Schmidt and J.D. Berke (2017). A Pause-then-Cancel model of Stopping:
Evidence from Basal Ganglia Neurophysiology. Philosophical Transactions
of the Royal Society B 372: 20160202.

N.M. Mallet, R. Schmidt, D. Leventhal, F. Chen, N. Amer, T. Boraud and
J.D. Berke (2016). Arkypallidal cells send a stop signal to striatum.
Neuron 89:1-9.

R. Schmidt, D.K. Leventhal, N. Mallet, F. Chen and J.D. Berke (2013):
Canceling actions involves a race between basal ganglia pathways. Nature
Neuroscience 16: 1118-1124.