The Impact of Reward Expectations on Attention and Decision-Making in Humans

Recent research by scientists at the Indian Institute of Science has provided novel insights into how reward expectations influence attention and decision-making processes in the human brain. Led by Associate Professor Sridharan Devarajan and Ph.D. student Ankita Sengupta, the study explores how anticipation of rewards modulates two key aspects of attention: sensitivity (the ability to detect subtle changes) and bias (the tendency to favor certain choices). Published in PLOS Biology, the research utilized behavioral tasks paired with electroencephalography (EEG) recordings to dissect these mechanisms.

In the experiments, participants engaged in a task where they observed two Gabor patches and reported orientation changes. The reward structure was manipulated such that one side offered fixed points, while the other varied, prompting participants to focus more on the higher-rewarded side. The findings revealed that reward anticipation enhances sensory sensitivity, leading participants to pay more attention to stimuli associated with higher rewards. Interestingly, this modulation was specific to sensitivity, with no significant impact on decisional bias.

Further analysis showed that neural signatures linked to attentional processing were heightened during sensitivity tasks, indicating increased sensory focus. However, when the task measured bias, participants’ gaze and brain activity patterns did not align with known attention centers, suggesting that bias operates through different neural pathways. This dissociation underscores that sensitivity and bias are governed by separate neural mechanisms, each differentially influenced by reward expectation.

These discoveries have meaningful implications for understanding how humans learn and make decisions under uncertainty. They also pave the way for potential interventions in conditions like addiction and gambling, where reward processing and impulsive choices play crucial roles. Overall, the study emphasizes the distinct neural pathways through which reward influences perceptual sensitivity and decision-making biases, offering a comprehensive view of motivation-driven attention.

Source: https://medicalxpress.com/news/2025-08-reward-modulates-attention-humans.html