Neuroscientists were puzzled by the brain’s visual cortex preferential response to specific types of input, such as faces or objects. But now they found an answer by adapting an MRI scanner.
Studying brain functions is possible with the MRI (magnetic resonance imaging) technology, but it represents a challenge when it comes to trying to scan babies brains, especially while they are awake.
Rebecca Saxe, a professor of brain and cognitive sciences and member of MITs McGovern Institute for Brain Research, and her colleagues took on the challenge and adapted their MRI scanner to make it easier to scan infants brains as the babies watch movies featuring different types of visual input.
According to an MIT press release, the researchers showed the babies videos of either smiling children or outdoor scenes such as a suburban street seen from a moving car, since distinguishing social scenes from the physical environment is one of the main high-level divisions that human brains make when interpreting the world.
The scans revealed that many regions of the babies visual cortex showed the same preferences for scenes or faces seen in adult brains. This suggests that these preferences form within the first few months of life and refutes the hypothesis that it takes years of experience interpreting the world for the brain to develop the responses that it shows in adulthood.
The researchers also found some differences in the way that babies brains respond to visual stimuli. One is that they do not seem to have regions found in the adult brain that are highly selective, meaning these regions prefer features such as human faces over any other kind of input, including human bodies or the faces of other animals.
The babies also showed some differences in their responses when shown examples from four different categories not just faces and scenes but also bodies and objects.
Researchers at MIT now hope to try to scan more babies between the ages of 3 and 8 months so they can get a better idea of how these vision-processing regions change over the first several months of life. Also, Saxe and her colleagues want to study even younger babies to help them discover when these distinctive brain responses first appear.