Figure 5

The pupil local and global effects in a phonemic version of the task Results of Experiments 3 and 4. Grand-averages of the variation of both pupil diameters (in mm) are plotted over time (in milliseconds) both for the local (upper panels) and global (lower panels) effects, with explicit counting instructions (Experiment 3, left panels) or without instruction (Experiment 4, right panels). While the event-related pupil response was undistinguishable between local standard (green curves) and local deviant (red curves) trials, a global effect was observed: a significant (black horizontal segments) pupil dilation was observed in response to global deviant trials. With explicit instructions, this effect began around 500 ms after the onset of the last syllable (time 0), peaked around 1.5 second and was sustained during more than 3 seconds. The effect was shorter and weaker without instructions, and only observed for those participants who were aware of the global regularity. The vertical dotted line indicates the beginning of the baseline period. The vertical solid line indicates the end of the baseline period, which corresponds to the temporal onset of the last syllable of each trial (time 0).