Intermittent rate coding and cue-specific neuronal ensembles support working memory

Persistent, memorandum-specific neuronal spiking activity has long been hypothesized to underlie working memory. However, emerging evidence suggests a possible role for ‘activity-silent’, synaptic mechanisms. This issue remains controversial because evidence for either view has largely relied on datasets that fail to capture single-trial population dynamics or on indirect measures of neuronal spiking. We addressed this by examining the dynamics of mnemonic information on single trials obtained from large, local populations of lateral prefrontal neurons recorded simultaneously in monkeys performing a working memory task.  Here, we show that mnemonic information does not persist in the spiking activity of neuronal populations during memory delays, but instead alternates between coordinated ‘On’ and ‘Off’ states. At the level of single neurons, Off states are driven both by a loss of selectivity for memoranda and a return of firing rates to spontaneous levels. Further exploiting the large-..., Subjects
Three adult male rhesus monkeys (Macaca mulatta) participated in the experiment. Monkey A, H, and J weighed 11, 14, and 12 kg, respectively. All surgical and experimental procedures were approved by the Stanford University Institutional Animal Care and Use Committee and were in accordance with the policies and procedures of the National Institutes of Health.
Behavioral task                         
Stimuli were presented on a VIEWPixx3D monitor positioned at a viewing distance of 60 cm using Psychtoolbox and MATLAB (MathWorks). Eye position was monitored at 1kHz using an Eyelink 1000 eye-tracking system (SR Research). On each trial, the animals were presented with a cue at one of 8 possible locations and reported this location after a brief memory delay to receive a fluid reward. Cues were square frames (green for Monkey A, black for Monkey H, white for Monkey J) measuring 1 degree of visual angle on a side and presented at 5-7 degrees of eccentricity (depending on the session)..., , # Intermittent rate coding and cue-specific neuronal ensembles support working memory

### Overview

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This dataset consists of neural recordings from the lateral prefrontal cortex of rhesus macaques performing a spatial working memory task. The data are organized by *session*, a single ~1-3 hour experiment during which the animal performed the task while we measured neuronal and behavioral responses. 10 sessions were recorded from monkey A, 8 from monkey H, 7 from monkey J. For more details, see the associated paper, [Panichello, Jonikaitis, Oh, Zhu, Trepka, & Moore (2023)](https://www.biorxiv.org/content/10.1101/2023.10.06.561121v1).

### Format

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The data for each session is saved as a set of variables in a MAT-file (*yymmdd*.mat). The variables are:

* **spks**. *nTrials* x *nTimebins* x *nUnits boolean*. Spike rasters for each single- and multi-unit identified via spike sorting, aligned to cue onset on each trial. Spikes were binned with 1 ms resolution, from 500 ms befo...