… which only makes the gap harder to account for. (“See All together now, one, two, three—what separates us from other animals?”)
From ScienceDaily:
The research concerns the ventrolateral frontal cortex, a region of the brain known for more than 150 years to be important for cognitive processes including language, cognitive flexibility, and decision-making. “It has been argued that to develop these abilities, humans had to evolve a completely new neural apparatus; however others have suggested precursors to these specialized brain systems might have existed in other primates,” explains lead author Dr. Franz-Xaver Neubert of the University of Oxford, in the UK.
By using non-invasive MRI techniques in 25 people and 25 macaques, Dr. Neubert and his team compared ventrolateral frontal cortex connectivity and architecture in humans and monkeys. The investigators were surprised to find many similarities in the connectivity of these regions. This suggests that some uniquely human cognitive traits may rely on an evolutionarily conserved neural apparatus that initially supported different functions. Additional research may reveal how slight changes in connectivity accompanied or facilitated the development of distinctly human abilities.
The researchers also noted some key differences between monkeys and humans. For example, ventrolateral frontal cortex circuits in the two species differ in the way that they interact with brain areas involved with hearing.
Actually, neural circuits tend to grow and decrease with use, so most likely the difference between using one’s ventrolateral frontal cortex for practising a speech vs. screeching makes at least some difference in organization.