Theface recognitionit is a fundamental tool for social interactions between human beings. Without the ability to read other faces and their expressions, it would be difficult to tell friends from strangers at first glance, and we couldn’t tell a sad person from a happy one. Now, American neuroscientists coordinated by researchers at the California Institute of Technology (Caltech) have discovered a novel response to human faces by looking at neural recordings from the brain of neurosurgical patients.
The finding, echoed by the magazineCurrent Biology, offers the first description ofa series of neurons that respond intensely when the patient sees a full face, but whoseresponse is weaker to a face in which a very small region has been erased.
“Our interpretation of this effect, initially disconcerting, is that the brain is concerned with the representation of a complete face, and is very sensitive to any anomaly of the faces, such as the lack of a part,” explains Ralph Adolphs, co-lead author of the study. “This is probably an important mechanism to avoid mistaking one person for another,” he adds.
The neurons studied are found in a region of the brain calledamygdala, known for its importance for the processing of emotions. However, the study results strengthen the theory that the amygdala also has a more general role inprocessing and learning of social stimuli, such as face recognition.
The team plans to study, in the future, how these same neurons respond to emotional stimuli. This work, together with the results of the current study, could be very valuable in understanding different psychiatric illnesses, such as mood disorders and autism.
