Prior Expectation Modulates the Interaction between Sensory and Prefrontal Regions in the Human Brain

Abstract

How do expectations about the identity of a forthcoming visual stimulus influence the neural mechanisms of perceptual decision making in the human brain? Previous investigations into this issue have mostly involved changing the subjects' attentional focus or the behavioral relevance of certain targets but rarely manipulated subjects' prior expectation about the likely identity of the stimulus. Also, because perceptual decisions were often paired with specific motor responses, it has been difficult to dissociate neural activity that reflects perceptual decisions from motor preparatory activity. Here we designed a task in which we induced prior expectations about the direction of a moving-dot pattern and withheld the stimulus-response mapping until the subjects were prompted to respond. In line with current models of perceptual decision making, we found that subjects' performance was influenced by their expectation about upcoming motion direction. The integration of such information into the decision process was reflected by heightened activity in the dorsolateral prefrontal cortex. Activity in this area reflected the degree to which subjects adjusted their decisions based on the prior expectation cue. Furthermore, there was increased effective connectivity between sensory regions (motion-sensitive medial temporal area MTϩ) and dorsolateral prefrontal cortex when subjects had a prior expectation about the upcoming motion direction. Dynamic causal modeling suggested that stimulus expectation modulated both the feedforward and feedback connectivity between MTϩ and prefrontal cortex. These results provide a mechanism of how prior expectations may affect perceptual decision making, namely by changing neural activity in, and sensory drive to, prefrontal areas.

The contribution of surprise to the prediction based modulation of fMRI responses

“…On other hand, if the classifier performance is lower for both surprising and neutral events, then one can assume that there is an additional ɛ unit activity reduction, driven by correct predictions. Rahnev et al, (2011) also confirms this result when inducing expectations regarding the direction of a moving-dot pattern. Authors found a neural response enhancement for invalidly cued (therefore surprising) events when compared to expected and neutral events (with the expected cued activations falling in between the other two) in the dorsolateral prefrontal cortex and in the intraparietal sulcus.…”

“…These were corresponding to a previously suggested neutral or unpredicted condition (Rahnev et al, 2011;Kovács & Vogels, 2014) in which the probability of repeated (Rep) and alternated (Alt) trials was identical. The other four conditions were identical to those of Grotheer & Kovács (2015).…”

Does Expectation of Abnormality Affect the Search Pattern of Radiologists When Looking for Pulmonary Nodules?

“…Perceptions are greatly influenced by expectations [20]. Previous research has demonstrated how prior expectation might bias perceptual decisions [21,22]. We investigated whether an expectation of abnormality affects visual search by altering clinical information when looking for pulmonary nodules in adult chest radiographs.…”

Is there a common oscillatory brain mechanism for producing and predicting language?

“…EEG recordings, however, do not offer comparable evidence concerning the underlying brain regions involved in specific computations. To better evaluate the reliability of the prediction/production parallel (Pickering & Garrod, 2007), it is important to identify the brain source of beta-band effects, that both production (Klein et al, 2014) and prediction studies (Rahnev et al, 2011) would identify in frontal brain regions.…”

“…Frontal regions would constitute a critical hub collecting abstract information preliminary to production/prediction. Previous studies (Bastos et al, 2015;Rahnev et al, 2011) in fact show that pre-frontal brain regions would drive the recruitment of source information to develop Forward Models and Sensory Predictions, i.e., pre-activation of lowlevel information (in peripheral sensory regions) related to the physical properties of the predicted stimulus. Enhanced expectations could thus modulate visual attention and the perception of an incoming stimulus (for a discussion of the relation between expectation and attention see Summerfield & Egner, 2009).…”