Capturing and Analysing Data

A two-channel data acquisition system is required to capture the separate horizontal and vertical eye position signals. An application such as National Instrument's LabVIEW, or a user-provided program can be used to display and process the signal. Alternatively, the vsgEyetrace software for the ViSaGe provides an integrated data acquisition and visual stimulator solution for common ocular-motor tasks. The scanner should be programmed to provide a TTL-compatible pulse at the beginning of each volume acquisition to synchronize both the stimulation and the acquisition programs. This is required to later classify the brain areas based on the processed eye position signals.

Example Data

In this example, the subject fixated at a point (FP) in the centre of the display (position 0/0). After one second the FP disappeared and a target (T) was turned on at position x/y, for 1.5 s duration. The subject performed a saccade from FP to T.

The stimulus was generated using a VSG2/5 and back projected using an LCD projector onto a transluminent screen.

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