Limits...
Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.

Marlow CA, Viskontas IV, Matlin A, Boydston C, Boxer A, Taylor RP - PLoS ONE (2015)

Bottom Line: We find H is robust regardless of the spatial complexity generated by the fractal images.The value we find for H of 0.57 shows that the gaze dynamics during free viewing of fractal images are consistent with a random walk process with persistent movements.Our research suggests the human visual system may have a common strategy that drives the dynamics of human gaze during exploration.

View Article: PubMed Central - PubMed

Affiliation: Keck Center for Integrative Neuroscience, University of California, San Francisco, California, 94143-044, United States of America; Physics Department, California Polytechnic State University, San Luis Obispo, California, 93407, United States of America.

ABSTRACT
We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher order visual processes due to neural degeneration. The value we find for H of 0.57 shows that the gaze dynamics during free viewing of fractal images are consistent with a random walk process with persistent movements. Our research suggests the human visual system may have a common strategy that drives the dynamics of human gaze during exploration.

No MeSH data available.


Related in: MedlinePlus

Examples of different fractal image stimuli which vary in spatial complexity from low (C = 0.1) to high (C = 0.9), along with examples of non-fractal images used (C = 0).Also shown in the lower left is the image viewing protocol, where participants focus on the screen center for one second between images. The lower right has two examples of natural landscape images used.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4589360&req=5

pone.0139379.g001: Examples of different fractal image stimuli which vary in spatial complexity from low (C = 0.1) to high (C = 0.9), along with examples of non-fractal images used (C = 0).Also shown in the lower left is the image viewing protocol, where participants focus on the screen center for one second between images. The lower right has two examples of natural landscape images used.

Mentions: Each participant viewed from 9 to 93 images including at least one complete set of fractal images of varying complexity (Fig 1). The images, along with versions of the image where the black and white regions were inverted, were presented in random order. Each image was viewed for 5 seconds and a fixation screen was viewed for 1 second between each image (to re-center the gaze). The viewing protocol is shown in the lower left section of Fig 1. To increase the likelihood the participant remained engaged throughout the entire viewing time, participants were asked to answer (recorded with a press of key on a keyboard) whether or not they found the image aesthetically appealing as compared to previous images. The x and y positions of the participant’s left pupil’s gaze were recorded at 120 Hz using an ASL infrared eye tracker (504HS).


Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.

Marlow CA, Viskontas IV, Matlin A, Boydston C, Boxer A, Taylor RP - PLoS ONE (2015)

Examples of different fractal image stimuli which vary in spatial complexity from low (C = 0.1) to high (C = 0.9), along with examples of non-fractal images used (C = 0).Also shown in the lower left is the image viewing protocol, where participants focus on the screen center for one second between images. The lower right has two examples of natural landscape images used.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4589360&req=5

pone.0139379.g001: Examples of different fractal image stimuli which vary in spatial complexity from low (C = 0.1) to high (C = 0.9), along with examples of non-fractal images used (C = 0).Also shown in the lower left is the image viewing protocol, where participants focus on the screen center for one second between images. The lower right has two examples of natural landscape images used.
Mentions: Each participant viewed from 9 to 93 images including at least one complete set of fractal images of varying complexity (Fig 1). The images, along with versions of the image where the black and white regions were inverted, were presented in random order. Each image was viewed for 5 seconds and a fixation screen was viewed for 1 second between each image (to re-center the gaze). The viewing protocol is shown in the lower left section of Fig 1. To increase the likelihood the participant remained engaged throughout the entire viewing time, participants were asked to answer (recorded with a press of key on a keyboard) whether or not they found the image aesthetically appealing as compared to previous images. The x and y positions of the participant’s left pupil’s gaze were recorded at 120 Hz using an ASL infrared eye tracker (504HS).

Bottom Line: We find H is robust regardless of the spatial complexity generated by the fractal images.The value we find for H of 0.57 shows that the gaze dynamics during free viewing of fractal images are consistent with a random walk process with persistent movements.Our research suggests the human visual system may have a common strategy that drives the dynamics of human gaze during exploration.

View Article: PubMed Central - PubMed

Affiliation: Keck Center for Integrative Neuroscience, University of California, San Francisco, California, 94143-044, United States of America; Physics Department, California Polytechnic State University, San Luis Obispo, California, 93407, United States of America.

ABSTRACT
We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher order visual processes due to neural degeneration. The value we find for H of 0.57 shows that the gaze dynamics during free viewing of fractal images are consistent with a random walk process with persistent movements. Our research suggests the human visual system may have a common strategy that drives the dynamics of human gaze during exploration.

No MeSH data available.


Related in: MedlinePlus