Neuroscience Talk: "Temporal dynamics of probabilistic decision"

Join us for a talk by Midd Alum, Nuttida Rungratsameetaweemana ‘14, UC San Diego, 
Prior expectations about likely stimulus features or motor responses play an important role in shaping behavior. Classic theoretical frameworks posit that expectations about sensory regularities modulate information processing by biasing late stages of decision making including the selection and execution of motor response. Challenging this framework, recent studies suggest that expectations enhance the encoding and accumulation of sensory evidence during decision-making. However, it is possible that these findings reflect well documented attention modulations in visual cortex. Here we examine the effect of expectation about sensory features and motor responses on a set of electroencephalography (EEG) markers that index early sensory processing and later post-perceptual processing. We show that, counter to recent empirical results, expectations have little effect on early sensory processing but instead primarily influence decisions by modulating post-perceptual stages of information processing.