Project: Anschutz (112 OPM sensors)
Subject: OA
Subject ID: AS28
Date: December 20, 2021
Paradigm: Auditory

AUDITORY Paradigm / Tonotopy
Template: TONOTOPY
frequencies: 250, 1000, 4000 Hz in separate files
Tested hearing threshold at each frequency to compensate for both human hearing differences and (more importantly) variable frequency response of the delivery system 
Set the sound level a certain value (??? Which one) above the hearing threshold
Left ear
ISI: 2 sec (random 500 ms component, so it can be a low as 1.75 sec or as high as 2.25 seconds)
5 minutes per frequency

Hearing threshold 1000 Hz:  38 dB
Hearing threshold 250 Hz:  38 dB
Hearing threshold 4000 Hz:  38 dB
Sound levels: 250 Hz 102 db SPL, for 1 kHz 92 db SPL, and for 4 kHz 83 db SPL

Triggers
Channel 00:00        HPI
Channel 01:00        BNC 0 (box)
Channel 03:00        BNC 1 (box)
Channel 04:00        BNC 2 (box)
Channel 05:00        Sensor localization (Tyler’s box)
Channel 06:00        BNC 3 (box)

Sensor positions
If a location is 00 for x, y, and z, it is a bad channel

Coregistration
Before and after measurement day
HPI coils 1-5, one measurement per file 
43 Hz sine wave
100  Ohm resistor
10 sec measured at two amplitudes: 0.05 V and 0.5V

Two Polhemus files:
Polhemus head shape measurement outside the helmet and inside the helmet
Five point Polhemus file has fiducially, HPI coils, and 5 points on the OPM helmet
	LPA, RPA, Nasion are the fiducials
	Cz, Inion are the coil positions taped to the eyebrow/temple region
	Coil1=LPA coil
	Coil2=RPA coil
	Coil3=Nasion coil
	Coil4=Cz coil around left eyebrow
	Coil5=Inion around right eyebrow
	OPM1-5 are the following reference points on the helmet
	OPM1=Point 1
	OPM2=Point 4
	OPM3=Point 2
	OPM4=Point 3
	OPM5=Point 5
The coordinates in the sensor frame are:

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