14 DAY TRIAL // According to the conclusions of a new study by experts at Brown University, it would appear that two types of neurons in a region of the brain called the inferior temporal cortex are involved in the complex mental process of recognizing objects.
Even though we do this automatically, without conscious processing, the ability relies on a series of intricate neural pathways. The team at Brown was very interested in finding out how the latter work.
One of the things that fascinate researchers about this ability is its malleability. After we see an object a small number of times, we can start recognizing it right way. This means that it loses its novelty value, experts explain.
Details of the new research effort were published in the latest advanced online issue of the esteemed scientific journal Neuron. The team set out to investigate this ability from the inferior temporal cortex (ITC), a brain area that was known to be involved in visual recognition of familiar items.
What experts did not know is how the ITC allowed the brain to move from a feeling of novelty to one of familiarity with new objects. This process is known among experts as plasticity. “We know little about that because of the level at which this plasticity is taking place,” David Sheinberg explains.
“The inner workings made up of individual neurons make it very hard to actually track what’s going on at that level,” adds the scientist, who was the senior author of the research. He holds an appointment as a professor of neuroscience and a member of the Brown Institute for Brain Science.
In a series of experiments conducted at the university, scientist had two monkeys watch 125 new and 125 unfamiliar objects, as their ITC were being monitored using implanted microelectrodes. It was immediately made clear that excitatory and inhibitory neurons reacted differently to the photos.
Seeing familiar objects made excitatory neurons light up immediately. Interestingly, scientists found that each nerve cell had a preferred image, of the 125 the monkey saw. When the animals saw unfamiliar images, inhibitory neurons were the most active.
“When a familiar object has been recognized, that’s a positive signal and that can cause the system to move on,” Sheinberg explains.
“In the absence of that signal, that means the object isn’t familiar. What we think is going on is that the ongoing inhibitory activity actually promotes a learning process. It can be a signal to learn,” he concludes.