University of Padova


Eye-tracking movements

This research focuses on eye behaviour during imagery phase. There is still a controversial debate about the role of eye movements during mental imagery tasks (Thoms, 1999).
We developed two experiments to verify if eye movements are epiphenomenal or not during a mental imagery task.

EXPERIMENT 1

In the first experiment subjects viewed an abstract picture with six different objects insert in a grind of 9 areas of interest (Fig.1). Subsequently were asked to the subjects to form a mental image of these stimuli while keeping their eyes open. The feedback is provided between each session of the game and the following one. In this experiment, we will focus only on a modality of communication among players, i.e. dyadic communication (one-to-one). Further research will study global (all-to-all) verbal interaction.

Example of stimulus
Fig.1 Example of stimulus

Similar to Laeng and Teodorescu’s study (2002), there were two different perceptual conditions: in the first one subjects were free to watch the picture, in the other one they had to watch the picture fixing the center of the screen. Differently in this research imagery phase consisted just in an empty white page, without any recall object as the grid used in Laeng and Teodorescu’s study.
Results confirmed in part Laeng and Teodorescu’s conclusion: the time spent fixating specific location during perception was correlated with the time spent on the same location during imagery, but we also found a top-down effect that draw attention on some specific areas (5 and 2), when subjects were free to move their eyes, and this effect influenced also the order of first fixations.

EXPERIMENT 2

In the second experiment the perceptual phase consisted of finding a specific object, using the same kind of stimulus of experiment 1. Afterward were presented two imagery tasks. In the first one we asked to form a mental image of the total picture, in the second one to think where the object was placed.
Confirming the first results, we found that subjects replace the same eye behaviour learned during perceptual condition also when the imagery task was different (Fig. 2).

Hot spot plots of experiment 2, this output represents the fixations time spent by all the subject during percepual phase find the red sun Hot spot plots of experiment 2, this output represents the fixations time spent by all the subject during percepual phase form a mental image of the total picture
Fig.2: Hot spot plots of experiment 2, this output represents the fixations time spent by all the subject during percepual phase ‘find the red sun’ (a.) and corrispondent imagery phase ‘form a mental image of the total picture’ (b.)
CONCLUSION

These results confirm that eye movements during imagery are not epiphenomenous but assist the process of image genaration. Althought we did not find a strong relationship between the scanpaths of the two phases, eyes behaviour during imagery reflects that people learn even if there is no recall object during perceptual phase and also if the imagery task is different.

BIBLIOGRAPHY

– Thomas, N. J. T. (1999). Are theories of imagery theories of imagination? An active perception approach to conscious mental content. Cognitive Science, 23, 207-245.
– Laeng, B., & Teodorescu, D. S. (2002). Eye scanpaths during visual imagery reenact those of perception of the same visual scene. Cognitive Science, 26, 207-231.


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