Familiarity fires when faced with those we know
Scientists have learned a little bit more about the physical process of remembering.
An international team of scientists has shown how individual neurons in the human brain react to faces, and revealed a new interaction between our memories and our senses.
For the study, researchers used images of celebrities, such as Angelina Jolie and Halle Berry, morphed together to create an ambiguous face which test subjects were asked to identify.
The study found that for the same ambiguous images, the neurons fired according to the subjective perception by the subjects, rather than the actual visual stimulus.
For example, a neuron that fired to a picture of Whoopi Goldberg also fired to a morph image between Goldberg and Bob Marley, but only when the subject actually identified the morphed image as Goldberg.
Researchers said their findings indicated that neurons fire in line with conscious recognition of images rather than just the image itself.
Furthermore, in most cases the neuron's responses to morphed pictures were the same as when shown the pictures without morphing.
“We indeed see the face of a friend rather than the combination of visual features that compose the person's face. The neurons we report in this article fire exactly to this, to the subjective perception by the subjects, not to the features of the faces they were seeing,” Leicester University’s Rodrigo Quian Quiroga said.
“In a sense, the interpretation of this result goes way back to British Empiricism and even to Aristotle. As Aristotle put it, we create images of the external world and use these images rather than the sensory stimulus itself for our thoughts. These neurons encode exactly that.”
“This result supports the view that these neurons are play a key role in the formation of memory.”
A new paper, 'Single-Cell Responses to Face Adaptation in the Human Medial Temporal Lobe', has now been published in Neuron.