Lesion studies have elucidated the distinct roles played by different areas in the prefrontal cortex (PFC) in guiding behaviour according to abstract rules, as observed in a macaque-adapted version of the Wisconsin Card Sorting Test (WCST). Nevertheless, we do not fully understand how these functional specialisations relate to the underlying neuronal activity across these different prefrontal regions. In this study, we present novel insights derived from our multi-area multi-electrode recording in non-human primates (NHPs). We chronically implanted Utah arrays in dorsolateral PFC, ventrolateral PFC, orbitofrontal cortex, and frontopolar cortex (FPC) of two macaques, allowing us to simultaneously record single and multiunit activity, and local field potentials (LFP), from all regions while the monkey performs the WCST analog. Our analysis of the spiking data shows that rule-related neuronal activity was widespread in all areas recorded but it differed in degree and in timing (task-epoch) between different areas. Our analysis on the level of LFP coherence between areas across different task epochs indicate that inter-area coherence is generally higher in the beta frequency when the sample appears and when the choice is made, whereas the coherence between frontal areas decreases when all options appear on the screen and the period before the choice is made. Furthermore, our preliminary spectral Granger causality analysis reveals the directionality of information flow across the different prefrontal areas at theta and beta frequencies. Our results are starting to provide a better picture of the dynamic contributions and interactions of the different PFC regions to support rule-guided behaviour.