Neurons for Recognition

Professor Earl Miller explains that neurons in the prefrontal cortex respond to recognize very specific categories of object such as 'dog' or 'cat'.

We decided to study how the brain represents categories because we thought that categories are important for high level complex intelligent thought. Because categories provide us with the basic knowledge of how the world works. Our basic understanding of the world when we look around us, we see things like tables and chairs and motor vehicles and tools. Our brain labeling these things gives us our understanding of the meaning of the things around us and that's important baseline knowledge for any sort of complex intelligent thought that uses this information. We decided to study a particular part of the brain called the prefrontal cortex and its role in representing categories because the prefrontal cortex, in many ways, is the part of the brain most associated with high level intelligence, executive types of brain functions. It needs to have that type of knowledge about the world in order to do its job. We studied neurons in the prefrontal cortex as monkeys categorize objects and found there were many neurons that explicitly represented the category the monkey needed to solve a particular problem. That is, a neuron might be activated whenever the monkey is looking at, maybe dogs, in regards to what the dog exactly looked like. Or a neuron is activated by the concept of cat regardless of the individual cat. And it's important that there be this explicit representation in the brain of these concepts per se divorced from all these details of what exactly the thing looks like because otherwise we'd clutter our high level intelligent thoughts with lots of useless details. So it's a way of streamlining thoughts to make it more generalized and intelligent.