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.

#### Subject and Trial Image data

Xcel spreadsheet which lists subject’s age, sex, diagnosis and trial. Also listed are the images (along with image complexity value) for each trial associated with a particular xdat value.

SubjectTrialImageDetails.xlsx

#### Y1Files

Matlab Struct array of data for subject Y1. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y3Files

Matlab Struct array of data for subject Y3. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y6Files

Matlab Struct array of data for subject Y6. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y7Files

Matlab Struct array of data for subject Y7. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y8Files

Matlab Struct array of data for subject Y8. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### C2Files

Matlab Struct array of data for subject C2. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### FTD1Files

Matlab Struct array of data for subject FTD1. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### FTD3Files

Matlab Struct array of data for subject FTD3. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### AD2Files

Matlab Struct array of data for subject AD2. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### AD3Files

Matlab Struct array of data for subject AD3. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y2Files

Matlab Struct array of data for subject Y2. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y4Files

Matlab Struct array of data for subject Y4. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### Y5Files

Matlab Struct array of data for subject Y5. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### C1Files

Matlab Struct array of data for subject C1. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### C3Files

Matlab Struct array of data for subject C3. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### FTD2Files

Matlab Struct array of data for subject FTD2. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### FTD4Files

Matlab Struct array of data for subject FTD4. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### FTD5Files

Matlab Struct array of data for subject FTD5. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### PSP1Files

Matlab Struct array of data for subject PSP1. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.

#### AD1Files

Matlab Struct array of data for subject AD1. Contains raweyedata which is of the form [time pupilrecognition xposition(pix) yposition(pix)] , xdat which is the value associated with the image and trial which gives the trial letter for the given data.