Thursday, December 1, 2011

Brain processes visual information unconsciously

Scientists have shown that the brain does not always need to make use of our consciousness to process visual information. For visual input we are accustomed to perceiving, it takes longer before our awareness is being notified. However, if our visual systems process something unusual, our consciousness is called in much earlier. It shows that we do not necessarily need to be aware of things to assess the impact of visual information. And this may hold true for other sensory input as well, raising the question of how much we actually consciously process from the world that surrounds us.

At the University of Jerusalem, participants were shown pictures of natural scenes, which is something most people would not find peculiar or weird. In one of the examples, people are playing basketball. However, in this case the basketball was replaced by a watermelon, a situation we find quite unusual. These pictures were viewed by only one eye. At the same time, the participant's attention was drawn by rapidly flickering colour patterns that were shown to the second eye. The scientists then assessed how long it took before a picture shown to the first eye captured their attention.

In their experiments, the researchers from the University of Jerusalem found that pictures with unusual content, such as the basketball players with a watermelon drew attention quicker than pictures that did not have anything unusual on them. That highlights the brain is processing information unconsciously, and decides later on whether brain areas that are involved with awareness should come into play. We have a fully automated processing system that does not require our attention, even though we would think that we are always aware of our surroundings when we have our eyes open.

Using awareness
When we see something we are accustomed to, we do not need the immediate attention of our consciousness. Instead, the scientists think the brain processes the visual information from the picture even before the participant is aware that a picture exists. When a picture contains something unusual, our awareness is called in to make sense of what we are seeing. It shows that the awareness level is a tool to help us interpret our surroundings, but it is not needed to accurately process visual information.

The conscious brain
It is known that we are not aware of most of the sensory input we receive. For example, when looking at a specific object, we are not consciously processing the information around that object. However, when something happens in the surroundings which is out of the ordinary, then the awareness layer of our brain comes into play. Letting most sensory information fly by without being aware of it is not a flaw in our brain. If we were to process everything consciously, our brain would be overloaded with information and we could not determine what the most important thing to focus on is. The current system makes sure we do focus on what is important. However, when something unusual happens we have the capability to drive our awareness towards it to process and deal with the situation accordingly.
The pathway of processing visual information.

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