Auditory sequence processing reveals evolutionarily conserved regions of frontal cortex in macaques and humans

Area of Science:

• Neuroscience
• Evolutionary Biology
• Comparative Cognition

Background:

• Understanding human language evolution requires distinguishing unique neurocognitive processes from conserved, domain-general ones found in primates.
• Comparative neuroimaging across species can identify homologous brain regions supporting conserved functions versus distinct substrates for human-specific traits.

Purpose of the Study:

• To investigate the neural basis of processing rule-based sequences in auditory stimuli across species.
• To determine if brain regions involved in human syntactic processing have functional counterparts in non-human primates.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed in Rhesus macaques and humans.
• Participants processed auditory nonsense words presented in rule-based sequences.

Main Results:

• Key regions in the human ventral frontal and opercular cortex showed functional similarities to corresponding areas in the monkey brain.
• These homologous regions are implicated in the initial stages of syntactic processing in humans.

Conclusions:

• The findings suggest that ventral frontal neural systems crucial for human language may have evolved from ancestral domain-general sequence processing abilities.
• This provides a potential evolutionary pathway for the development of complex language functions from more basic cognitive skills.