Fig. 1: Experimental setup and healthy behavioral performance. | Nature Communications

Fig. 1: Experimental setup and healthy behavioral performance.

From: Basal ganglia deep brain stimulation restores cognitive flexibility and exploration-exploitation balance disrupted by NMDA-R antagonism

Fig. 1

a Top - MRI of the non-human primates’ (NHPs) brain and recording chamber. The red arrow points to the dorsolateral prefrontal cortex (DLPFC). Middle, extracellular recordings of DLPFC exemplary neuron (left) and 100 randomly chosen superimposed spike waveforms of the recorded cell (right). Bottom, Raster display and a post-stimulus time histogram (PSTH) of the neuron’s firing during 60 trials around choice selection (two seconds before and two seconds after). Bottom—The same as the top image, but for the external segment of the globus pallidus (GPe). b Top—Task design. NHPs had to identify the hidden association change and learn the new association. The first line represents an association change trial (AC) in which the NHP is unaware of the change of the new association and, therefore, chooses the wrong cue. The second line represents the next trial in the block in which the NHP changes its choice to another incorrect choice. In the third line, the NHP changes again, this time receiving a reward. The fourth line represents the following block, where the association changes without the NHPs’ knowledge. The NHP then chooses the same stimulus as before, but this time receives no reward. Bottom—A table showing the amount (and proportion) of recorded trial types for both brain regions. Rows indicate what happened in the previous trial (trial n) and columns indicate the current trial (n + 1). Text color coding indicates the fraction of recorded cells within each category of the total sum. For example, our neural data set of perseveration trials consists of 389 DLPFC and 700 GPe recordings, constituting 28% and 24% of all neural-recorded trials following an unsuccessful trial, respectively, and 4% and 5% of all neural-recorded trials following same-choice trials. c Top—The learning curve, i.e., the NHPs’ probability of choosing successfully. ‘AC’ indicates the association change trial; trials prior/post to the AC trial are of negative/positive sign, respectively. Middle—The learning slope (i.e., the derivative of the learning curve). Inset—the learning slope across the AC trial. Bottom—Switch probability.

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