scholarly journals Canonical goal-selective representations are absent from prefrontal cortex in a spatial working memory task requiring behavioral flexibility

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Claudia Böhm ◽  
Albert K Lee
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Behavioral Flexibility ◽  
Task Structure ◽  
Specific Memory ◽  
Multiple Routes ◽  
Task Features

The prefrontal cortex (PFC)’s functions are thought to include working memory, as its activity can reflect information that must be temporarily maintained to realize the current goal. We designed a flexible spatial working memory task that required rats to navigate – after distractions and a delay – to multiple possible goal locations from different starting points and via multiple routes. This made the current goal location the key variable to remember, instead of a particular direction or route to the goal. However, across a broad population of PFC neurons, we found no evidence of current-goal-specific memory in any previously reported form – that is differences in the rate, sequence, phase, or covariance of firing. This suggests that such patterns do not hold working memory in the PFC when information must be employed flexibly. Instead, the PFC grouped locations representing behaviorally equivalent task features together, consistent with a role in encoding long-term knowledge of task structure.

scholarly journals Canonical goal-selective representations are absent from prefrontal cortex in a spatial working memory task requiring behavioral flexibility

2020 ◽  
Author(s):  
Claudia Böhm ◽  
Albert K. Lee
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Behavioral Flexibility ◽  
Task Structure ◽  
Specific Memory ◽  
Multiple Routes ◽  
Task Features

AbstractThe prefrontal cortex (PFC)’s functions are thought to include working memory, as its activity can reflect information that must be temporarily maintained to realize the current goal. We designed a flexible spatial working memory task that required rats to navigate - after distractions and a delay - to multiple possible goal locations from different starting points and via multiple routes. This made the current goal location the key variable to remember, instead of a particular direction or route to the goal. However, across a broad population of PFC neurons, we found no evidence of current-goal-specific memory in any previously reported form - i.e. differences in the rate, sequence, phase or covariance of firing. This suggests such patterns do not hold working memory in the PFC when information must be employed flexibly. Instead, the PFC grouped locations representing behaviorally equivalent task features together, consistent with a role in encoding long-term knowledge of task structure.

scholarly journals Cerebellar Purkinje cell simple spike activity in awake mice represents phase differences between oscillations in medial prefrontal cortex and hippocampus

2017 ◽  
Author(s):  
Samuel S. McAfee ◽  
Yu Liu ◽  
Roy V. Sillitoe ◽  
Detlef H. Heck
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Spike Activity ◽  
Spatial Working Memory ◽  
Memory Task ◽  
Temporal Coordination ◽  
Frequency Bands ◽  
Simple Spike ◽  
Phase Differences

AbstractThe cerebellum has long been recognized for its role in tasks involving precise timing, particularly the temporal coordination of movements. Here we asked whether cerebellar might be involved in the temporal coordination of the phases of neuronal oscillations in the medial prefrontal cortex (mPFC) and dorsal hippocampus CA1 region (CA1). These two structures and the cerebellum are jointly involved in spatial working memory. The phases of oscillations in the mPFC and CA1 have been shown to reach a stable alignment (coherence) during the decision making process in a spatial working memory task. Here we report that PC simple spike activity in the cerebellar lobulus simplex in awake, head-fixed mice represents specific phase differences between oscillations in the mPFC and CA1. Most PCs represented phase differences in more than one the conventional frequency bands (delta, theta, beta and gamma). Between the 32 PCs analyzed here, phase differences in all frequency bands were represented. PCs representing phase differences in the theta and low gamma bands showed significant population preference for mPFC phase leading CA1 phase. These findings support the possibility of a cerebellar involvement in the temporal coordination of phase relationships between oscillations in the mPFC and CA1.

Prefrontal Cortex Activity Associated with Source Monitoring in a Working Memory Task

2004 ◽  
Vol 16 (6) ◽  
pp. 921-934 ◽  
Author(s):  
Karen J. Mitchell ◽  
Marcia K. Johnson ◽  
Carol L. Raye ◽  
Erich J. Greene
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Source Monitoring ◽  
Memory Task ◽  
Long Term Memory ◽  
Source Information ◽  
Related Activity ◽  
Specific Source ◽  
Evaluative Processes

Using functional magnetic resonance imaging (fMRI), we investigated prefrontal cortex (PFC) activity during remembering specific source information (format, location judgments) versus remembering that could be based on undifferentiated information, such as familiarity (old/new recognition [ON], recency judgments). A working memory (WM) paradigm with an immediate test yielded greater activation in the lateral PFC for format and location source memory (SM) tasks than ON recognition; this SM-related activity was left lateralized. The same regions of PFC were recruited in Experiment 2 when information was tested immediately and after a filled delay. Substituting recency for location judgments (Experiment 3) resulted in an overall shift in task context that produced greater right PFC activity associated with ON and recency tasks compared to the format task, in addition to left SM-related activity. These data extend to WM previous findings from long-term memory (LTM) indicating that the left and right PFC may be differentially involved in memory attributions depending on the specificity of information evaluated. The findings also provide evidence for the continuity of evaluative processes recruited in WM and LTM.

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