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| To track head movements volunteers need to have 4 small coils attached to ther head. 2 will be on the forehead and 2 behind the ears. In addition we normally also attach 5 electrodes to the face to measure eye movements |
To track head movements volunteers need to have 4 small HPI (Head Position Indicator) coils attached to their head: 2 on the forehead and 2 behind the ears. In addition we normally attach 5 electrodes to the face as well to measure eye movements |
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| The location of the coils needs to be measured with a 3D digitiser. We also measure 4 landmarks and a number of additional points on the head to indicate headshape and enable easier matching to an MRI structural scan. |
The location of the coils needs to be recorded with a 3D digitiser. We also measure 3 landmarks and a number of additional points on the head to indicate headshape and enable easier matching to an MRI structural scan. The digitiser has a pen-like sensor that will record the location of its tip when the button is pressed. |
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| attachment: | [[ImageLink(jason_subject.jpg,//CbuMeg, height=400)]] |
Subject Preparation
Subjects need to be free of magnetic materials, like coins, watches and other metal items. Underwired bras can be a problem, and even dyes in clothing or hairdye can cause interference.
To track head movements volunteers need to have 4 small HPI (Head Position Indicator) coils attached to their head: 2 on the forehead and 2 behind the ears. In addition we normally attach 5 electrodes to the face as well to measure eye movements and blinks.
The location of the coils needs to be recorded with a 3D digitiser. We also measure 3 landmarks and a number of additional points on the head to indicate headshape and enable easier matching to an MRI structural scan. The digitiser has a pen-like sensor that will record the location of its tip when the button is pressed.
