Oculomotor function in frontotemporal lobar degeneration, related disorders and Alzheimer's disease

Frontotemporal lobar degeneration (FTLD) often overlaps clinically with corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP), both of which have prominent eye movement abnormalities. To investigate the ability of oculomotor performance to differentiate between FTLD, Alzheimer's disease, CBS and PSP, saccades and smooth pursuit were measured in three FTLD subtypes, including 24 individuals with frontotemporal dementia (FTD), 19 with semantic dementia (SD) and six with progressive non-fluent aphasia (PA), as compared to 28 individuals with Alzheimer's disease, 15 with CBS, 10 with PSP and 27 control subjects. Different combinations of oculomotor abnormalities were identified in all clinical syndromes except for SD, which had oculomotor performance that was indistinguishable from age-matched controls. Only PSP patients displayed abnormalities in saccade velocity, whereas abnormalities in saccade gain were observed in PSP > CBS > Alzheimer's disease subjects. All patient groups except those with SD were impaired on the anti-saccade task, however only the FTLD subjects and not Alzheimer's disease, CBS or PSP groups, were able to spontaneously self-correct anti-saccade errors as well as controls. Receiver operating characteristic statistics demonstrated that oculomotor findings were superior to neuropsychological tests in differentiating PSP from other disorders, and comparable to neuropsychological tests in differentiating the other patient groups. These data suggest that oculomotor assessment may aid in the diagnosis of FTLD and related disorders

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

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

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

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

Data from: Temporal structure of human gaze dynamics is invariant during free viewing

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

Data from: Temporal structure of human gaze dynamics is invariant during free viewing

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

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

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

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