Efficiency and robustness in three cortical areas: frontal pole cortex, dorsolateral prefrontal cortex and...

Area of Science:

• Neuroscience
• Evolutionary Biology
• Primate Cognition

Background:

• The prefrontal cortex (PFC) in primates displays a varied evolutionary trajectory.
• Granular regions of the orbital prefrontal cortex (PFo) are evolutionarily older, while dorsolateral (PFdl) and polar (PFp) regions evolved later in anthropoids.

Purpose of the Study:

• To investigate functional distinctions between PFp, PFdl, and PFo in macaques.
• To compare the neural coding mechanisms, specifically efficiency and robustness, across these PFC regions.

Main Methods:

• Quantified coding efficiency using 'contrast entropy' (normalized neuronal spiking activity entropy).
• Assessed coding robustness via neuronal activity synchrony within each area.
• Compared these metrics across PFp, PFdl, and PFo in macaque monkeys.

Main Results:

• PFp and PFdl demonstrated higher information capacity, indicating more efficient neural coding than PFo.
• PFo exhibited greater robustness, suggesting reduced reliability in neural signaling.
• A trade-off between coding efficiency and robustness was observed, correlating with evolutionary stages.

Conclusions:

• Later-evolving granular PFC regions (PFp, PFdl) utilize a more efficient neural code.
• This enhanced efficiency in PFp and PFdl comes at the cost of reduced robustness or reliability.
• Findings support an evolutionary trade-off between neural code efficiency and robustness in the primate prefrontal cortex.