PMC

(a) The principal angles between the working memory subspace and the motor preparation subspace are shown in the magenta lines in ascending order. The black boxplots illustrate the distribution of principal angles between two random subspaces with the same dimensions as the working memory and motor preparation subspaces. The borders of the box represented the 25^th and the 95^th percentile of the distribution, while the whiskers represent the 5^th and the 95^th percentiles. (b) Decoding performance in the working memory subspace. M stands for unmixed single-trial working memory activity; proj_MSub(M), decoding of the unmixed single-trial working memory activity projected into the working memory subspace; proj_MSub(M+P), decoding of the single-trial Delay 2 activity projected into the working memory subspace; proj_MSub(M_E), decoding of the unmixed single-trial working memory activity in error trials projected into the working memory subspace using a classifier built on unmixed single-trial working memory activity in correct trials projected into the working memory subspace; (c) Decoding performance in the motor preparation subspace. P stands for unmixed single-trial motor preparation activity. Same conventions as in a, but for unmixed single-trial motor preparation activity and the motor preparation subspace. We verified that the drop in performance in error trials was specific to the two subspaces, and not due to a non-specific increase in noise in the population (see Materials and methods). (d) Inter-to-Intra cluster ratio of unmixed single-trial working memory activity projected into the working memory subspace (proj_MSub(M)), and of single-trial full-space activity projected into the working memory subspace (proj_MSub(M+P)). (e) Same conventions as in d, but for unmixed single-trial motor preparation activity and motor preparation subspace.

Egocentric working memory correlates with regional variations in caudate volumes and allocentric working memory with regional variations in hippocampal volumes. A. Caudate regions that correlate with egocentric working memory accuracy. B. Hippocampal regions that correlate with allocentric working memory accuracy. C. Scatterplot of the correlation between egocentric working memory accuracy and the combined caudate regional volumes that significantly correlated with performance (shown in A). D. Scatterplot of the correlation between allocentric working memory accuracy and the combined hippocampal regional volumes that significantly correlated with performance (shown in B). E. Correlation of each caudate region with egocentric working memory accuracy. F. Correlation of each hippocampus region with allocentric working memory. Abbreviations: CN=caudate nucleus, HPC=hippocampus, EWM=egocentric working memory, AWM = allocentric working memory.

A) Exposure to cannabis smoke had no effect on working memory accuracy in male rats. B) Exposure to cannabis smoke enhanced working memory accuracy in female rats compared to no-exposure control conditions C) Exposure to cannabis smoke enhanced working memory performance in the worse performing subgroup of female rats. D) Exposure to cannabis smoke had no effect on working memory accuracy in the better performing subgroup of female rats. E) Exposure to cannabis smoke enhanced working memory performance in the worst performing subgroup of male rats.

Visually dependent and tactilely dependent testing paradigms used to assess obstacle working memory. (A) Schematic depicting the visual obstacle working memory test where each animal would see and step over an 8.7 cm high obstacle with their forelegs to reach food placed on an elevated platform. As the animal ate, the obstacle was covertly lowered becoming flush with the walkway. Following a variable delay period, the food was moved forwards to encourage the animal to resume walking. Hindleg stepping was measured to assess working memory of the obstacle. Horizontal blue and red bars (i–iv) represent variations in cooling onset (blue) and offset (red) used to examine overall parietal cortex contributions to the working memory task as a whole (i), or to distinct phases of working memory acquisition (ii) and working memory maintenance (iii–iv). (B) Schematic depicting the tactile obstacle working memory test where each animal would approach the food platform in the absence of the obstacle. As the animal ate, it could not see that the obstacle was covertly raised beneath the food platform. By moving the food forward, the forelegs would contact the obstacle before stepping over it. During the subsequent delay period, the obstacle was lowered becoming flush with the walkway. As in the visual obstacle working memory paradigm, hindleg stepping when walking resumed was examined to assess obstacle working memory. Horizontal blue and red bars (i–iii) represent variations in cooling onset (blue) and offset (red) used to examine overall parietal cortex contributions to the working memory task as a whole (i), or to distinct phases of working memory acquisition (ii) and working memory maintenance (iii).