Does a bigger brain make you smarter?

Increasing the size of neural circuits in the brain can boost learning performance, but this increased connectivity also has the potential to impede learning, new research has revealed.

Cambridge neuroscientists predict that there is an "ideal" brain circuit size suited to carrying out particular tasks. The study, published in the journal PNAS, looked at how neural circuits can use additional connectivity to achieve faster and more precise learning.

The research showed that adding apparently "redundant" neurons (cells that make your brain work) and synaptic connections (that enable information to flow from one neuron to another) to a network is, in fact, a double-edged sword. On the one hand an increase in connectivity can make a task easier to learn. On the other hand, due to inherent noisiness in signal-carrying connections, increased connectivity will eventually hinder both learning and task performance once a circuit exceeds a certain size.

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