Eye scanpaths during visual imagery reenact those of perception of the same visual scene

Abstract

Eye movements during mental imagery are not epiphenomenal but assist the process of image generation. Commands to the eyes for each fixation are stored along with the visual representation and are used as spatial index in a motor-based coordinate system for the proper arrangement of parts of an image. In two experiments, subjects viewed an irregular checkerboard or color pictures of fish and were subsequently asked to form mental images of these stimuli while keeping their eyes open. During the perceptual phase, a group of subjects was requested to maintain fixation onto the screen's center, whereas another group was free to inspect the stimuli. During the imagery phase, all of these subjects were free to move their eyes. A third group of subjects (in Experiment 2) was free to explore the pattern but was requested to maintain central fixation during imagery. For subjects free to explore the pattern, the percentage of time spent fixating a specific location during perception was highly correlated with the time spent on the same (empty) locations during imagery. The order of scanning of these locations during imagery was correlated to the original order during perception. The strength of relatedness of these scanpaths and the vividness of each image predicted performance accuracy. Subjects who fixed their gaze centrally during perception did the same spontaneously during imagery. Subjects free to explore during perception, but maintaining central fixation during imagery, showed decreased ability to recall the pattern. We conclude that the eye scanpaths during visual imagery reenact those of perception of the same visual scene and that they play a functional role.

Pictures and Spoken Descriptions Elicit Similar Eye Movements During Mental Imagery, Both in Light and in Complete Darkness

“…Brandt and Stark (1997) and Laeng and Teodorescu (2002) showed that spontaneous eye movements occur in participants asked to do visual imagery and that these eye movements closely reflect the content and spatial relations of the original picture or scene. A similar eye movement effect has also been found for spatial relations that are verbally described.…”

“…Although it appears that similar eye movements occur when visualizing verbal descriptions as when visualizing previously seen pictures, it is still not known whether the effect is equally strong. Brandt and Stark (1997) and Laeng and Teodorescu (2002) interpreted their results as eye movements that reflect an internal image (Finke, 1989;Kosslyn, 1994) that is used to remember and visualize the locations and spatiality of the imagined scene. The existence of internal images is, however, an issue of debate.…”

Using space to represent categories: insights from gaze position

“…In previous studies while recalling from memory the image of an animal (e.g., a dog) that was encoded in a defined area (e.g., upper-left area of the screen), participants spent more time in the same area of interest although the screen was blank (e.g., Laeng & Teodorescu, 2002). Despite many studies have replicated the above finding, it remains unclear whether eye movements during memory/imagery are only related to the recollection of a previous episode with its specific element (e.g., a dog) or can also be generalized to other items in the same category (e.g., other mammals or four-legged animals).…”

“…Running Head: Mental Imagery and Visual Memory 5 However, the results of other experiments in which eye position was manipulated (e.g., Johansson & Johansson, 2014;Laeng & Teodorescu, 2002;Scholz et al, 2016) suggest that the location in space may be encoded by default. If locations are stored and integrated into the memory trace, then eye movements may play a critical role in many cognitive tasks.…”

Exploring the numerical mind by eye-tracking: a special issue

“…The principal function of eye movements is to bring details of our visual environment into focus, allowing for conscious perception. However, our eyes do not only move to extract information from the visual world: previous studies already showed that inspecting a mental image in the mind's eye (e.g., inspecting an imagined house from the bottom to the top) leads to corresponding eye movements in the physical world (Laeng & Teodorescu, 2002;Spivey & Geng, 2001), and eye movement patterns during memory retrieval resemble those during real-time exploration (Johansson, Holsanova, Dewhurst, & Holmqvist, 2012;Johansson & Johansson, 2014;Martarelli & Mast, 2013;Micic, Ehrlichman, & Chen, 2010). The studies reported here suggest that the eyes also ''inspect'' abstract concepts such as a mental number line, and that they ''act out'' spatial relations of our thoughts.…”