Past experiences do come in handy when people have to make complex decisions based on uncertain or confusing information, according to a study.
Funded by the Biotechnology and Biological Sciences Research Council (BBSRC), the study has shown that learning from experience actually changes the circuitry in the brain, and so a person can quickly categorise what he/she is seeing and make a decision or carry out appropriate actions.
"What we have found is that learning from past experience actually rewires our brains so that we can categorise the things we are looking at, and respond appropriately to them in any context," said lead researcher Dr. Zoe Kourtzi, from the University of Birmingham.
"We have shown that this learning process is not just a matter of learning the structure of the physical world - when I look at something I'm not just playing a game of 'snap' in my head where I try to match images to each other. In fact, areas in our brains are actually trained to learn the rules that determine the way we interpret sensory information," the researcher added.
Kourtzi's team wanted to find out about the human brain mechanisms that mediate flexible decision making through learning, which have so far not been well understood, despite it being fairly clear that successful decisions benefit from previous experience.
The researchers combined measurements of behaviour and brain signals to study how volunteers learnt to discriminate between highly similar visual patterns and to assign them in different categories.
They used two different rules to assign visual patterns into categories, and, consequently, patterns belonging to the same category based on one of the rules could be members of different categories based on the alternate rule.
"This flexible learning paradigm allowed us to test for brain changes related to the perceived rather than the physical similarity between visual patterns. Our use of brain imaging in combination with mathematical techniques enabled us to extract sensitive information about brain signals that reflected the participant's choice," said Kourtzi.
"What we've shown is that we don't just get better at the task of picking out a familiar face amongst a crowd, for example. Our results tell us that previous experience can train circuits in our brains to recognise perceived categories rather than simply the physical similarity between visual patterns.
"Based on what we found, we propose that learned information about categories is actually retained in brain circuits in the posterior areas of the brain. From there we think it is fed through to circuits in frontal areas that translate this information into flexible decisions and appropriate actions depending on the requirements and context of the task," added Kourtzi.
Dr Janet Allen, Director of Research, BBSRC said: "We have to be able to understand how healthy brains work before we can see what has gone wrong when a person's brain is affected by disease. This work also shows that the complex human brain has evolved an incredibly effective mechanism for making good decisions that lead to successful everyday actions - something that has surely been a significant evolutionary advantage."
The study has been reported in the journal Neuron.