IISc Study Unlocks Brain SecretsThe Neuroscience of Rewards: IISc Unlocks Attention-Decision Link.
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Why do we instinctively pick the ripest fruit or go for the most rewarding option in life? A new study by researchers at the Indian Institute of Science (IISc) reveals how the brain handles such choices – and the findings could reshape how we understand attention, decision-making, and even addictive behaviours.
Led by Sridharan Devarajan, Associate Professor at IISc, and PhD student Ankita Sengupta, the study (published in PLOS Biology) shows that reward expectation influences two different brain processes – sensitivity and bias – and that these are controlled by distinct neural mechanisms.
In carefully designed cognitive experiments, 24 participants were shown visual patterns and offered variable rewards based on their ability to detect changes (sensitivity) or their choice to act (bias). Eye-tracking and EEG scans revealed striking differences:
- When reward influenced sensitivity, participants focused their attention more sharply, and brain activity lit up in regions linked to sensory processing.
- When reward influenced bias, participants leaned toward choosing the more rewarding option, but without any signs of enhanced attention in their brain scans.
This separation of mechanisms suggests that the brain uses different circuits for noticing things versus deciding to act on them – both shaped by expected rewards.
The study could inform better understanding of risk-taking, impulsive behaviour, and conditions like gambling addiction. By separating attention from decision-making at the neural level, it opens pathways for future research in psychology, neuroscience, and behavioural therapies.
