experiment seven: spike referencing
DESCRIPTION
Experiment Seven: Spike Referencing. Voltage is the difference in electrical potential between two points (like your hair and the comb)…. a nd like the difference between electrical environment around recording electrode and reference electrode . - PowerPoint PPT PresentationTRANSCRIPT
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Experiment Seven: Spike Referencing
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Voltage is the difference in electrical potential between two points (like your hair and the comb)….
![Page 3: Experiment Seven: Spike Referencing](https://reader035.vdocuments.us/reader035/viewer/2022062410/56816413550346895dd5c36c/html5/thumbnails/3.jpg)
and like the difference between electrical environment around recording electrode and reference electrode
![Page 4: Experiment Seven: Spike Referencing](https://reader035.vdocuments.us/reader035/viewer/2022062410/56816413550346895dd5c36c/html5/thumbnails/4.jpg)
Differential recordings: voltage = difference between recording and ground electrode.
If “perfect ground”, voltage = potential at recording electrode.
However…
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In biology, there is no such thing as the perfect ground!
http://tinyurl.com/7qcz5ks http://tinyurl.com/73lwcbu
Everywhere in your body there’s an electrical signal of some sort, so care must be taken choosing your ground to minimize this.
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Procedure: put recording electrode in femur and ground electrode in coxa
When you touch the barbs on the leg, make note of the level of “background activity” vs. individual spikes.
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Procedure: Move ground electrode from coxa to the femur
When you touch the barbs on the leg, is there a difference in the ratio of “background activity” vs. individual spikes?
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Procedure: Move both electrodes to coxa
What do you notice this time?