A new study has revealed that the brain structures which enable humans to recognize language are in fact shared with certain primates. While this doesn’t mean we’re all going to be able to talk to animals like Dr. Dolittle, it does shed light on the evolutionary origins of our linguistic prowess.
Publishing their findings in the journal Nature Communications, a team of researchers from Newcastle University used functional magnetic resonance imaging (fMRI) to study the neurological activities of rhesus macaques when presented with ordered sequences of sounds. They discovered that the same regions of the brain associated with linguistic operations in humans became active when the monkeys processed these sequences.
To conduct the experiment, the researchers invented an artificial grammar – or fake language – that contained rules and patterns simple enough for the macaques to learn. The monkeys then listened to a number of sequences, some of which adhered to these rules while others violated them. Scans of their brains were then taken as they processed both the “legal” and “illegal” phrases, in order to determine which brain regions were involved in detecting sequence ordering violations.
The epicenter of this activity was found to be the ventral frontal and opercular cortex (vFOC), the same area of the brain associated with syntactic ordering and processing in humans. This was confirmed by subjecting a sample of 12 human subjects to the same tests, which showed activation patterns within the vFOC were similar in both test subjects when violations in the ordering of the artificial grammar were presented.
Data obtained from the study builds upon previous work which had suggested that the ability to recognize language sequences may not be unique to humans. For instance, a study published earlier this year by the same authors examined the eye movements of macaques while processing an artificial grammar, indicating that they may be sensitive to violations of linguistic rules.
However, the latest study is the first to indicate that this process is controlled by the same brain regions in both humans and macaques, suggesting that sequence processing functions are in fact “evolutionary conserved.” The authors therefore propose that the vFOC may have originally evolved in a common ancestor in order to support these particular abilities.
Aside from revealing new information about the evolutionary development of our language-processing capabilities, the researchers hope that the study could have future implications for treating conditions such as aphasia, which often occurs after strokes and involves the loss of linguistic functionality.