Fig. 6.

Simulated behavioural responses during reading: upper panel. This shows the trajectory of eye movements over four transitions at the second level that entail one or two saccadic eye movements at the first. In this trial, the subject looks at the first quadrant of the first word and sees a cat. She therefore knows immediately that the first word is flee. She then turns to the first quadrant of the second word and sees nothing. To resolve uncertainty she then looks at the fourth quadrant and again finds nothing, which means this word must be wait (because the second word of each sentence is either flee or wait – and the current word cannot be flee because the cat cannot be next to the bird). The next two saccades, on the subsequent word confirm the word feed (with the seed next to the bird sampled on the first saccade). Finally, the subject turns to the final word and discloses seeds after the second saccade. At this point, uncertainty about the sentence (sentence one versus sentence four) is resolved and the subject makes a correct categorisation – a happy story. Lower panel: this panel shows expected outcomes at the end of sampling each word. The upper row shows the final beliefs about the words under (correct) expectations about the sentence at the second level. This (first) sentence was “flee, wait, feed and wait”. At the first level, expectations about the letters under posterior beliefs about the words are shown in terms of mixtures of icons.