Primacy biases endure the addition of frequency variability

Attention is required for canonical brain signature of prediction error despite early encoding of the stimuli

“…Doing so seems to us to undermine one of the most frequently cited evolutionary purposes of prediction error: to monitor one’s immense sensory input preattentively and to select only those that elicit prediction errors. We have no dispute with the notion that endogenous attention serves to increase the precision of prediction errors, as Smout and colleagues and others have argued [ 16 , 17 , 27 ], thereby engaging the vMMN mechanism. The neural mechanism is via regulation of the postsynaptic gain of error units undertaking the top down-sensory comparison and production of prediction errors.…”

“…Friston [7,[13][14][15] described the theory based on energy conservation and free-energy principles: It is that the brain uses past, bottom-up, sensory information, along with top-down information (such as prior probabilities, expectations, and attention) to generate predictive models of sensory input at various levels of the sensory pathway, linked by feedforward and feedback connections. To ensure good predictions, precision of predictions from previous bottom-up and top-down influences and from the success of previous predictions affect whether, or the degree to which, the model is updated [16][17][18][19]. For example, a prediction error for a small irregularity after high-precision predictions should prompt updating of the model, whereas the same irregularity after low-precision predictions may not [16].…”