Can an EEG be re-sampled to fix a poor voltage resolution? I’ve made quite a bad mistake in ca. 14 EEG recordings – I recorded at 10uV resolution @ 5000 Hz instead of 0.1 uV @ 500 Hz. I’m conducting an ERP experiment, and the signals of interest are on the order of ~5 uV. I’m wondering if there is any way to up-sample the voltage given I have way more time series data points than I need..? Some sort of interpolation?

I’ve seen a number of posts on up-sampling from say 500 hz to 1000 hz, but not sure if the principal is the same?

Is there a way to trade off the sample rate against the poor resolution? Maybe by means of interpolation, or an averaging method to apply directly to the raw data**

This represents about 42 hours of recording time and I’m anxious to know if I can recover any usable data from these recordings, or if I have to try to get participants back in (there is a treatment enrollment deadline which means I can’t simply acquire more data).
The bit depth basically indicates how accurately your analog-to-digital converter records and reproduces the signal (Fig. 1). A higher bit depth means that more subtle fluctuations in the waveform are more faithfully reproduced in the digitized signal (source: Presonus)

As the answer from Bryan alludes to, data cannot be generated de novo, unfortunately. Data can be processed, yes, but data acquired at a certain resolution cannot be enhanced. Of course, as Strongbad indicates, you can generate an indefinite number of steps by upsampling, that's not an issue, but that will simply leave you with an estimate of possible intervening values; the real values are simply not there and are lost. Look at Fig. 1. If we would upsample the data, the points between successive samples would be interpolated, seemingly increasing your voltage steps, but the resulting trace will not be any better than it was before (only bigger :-).

Note that the resolution in the time-domain (sample rate) will not help you in any way. The amplitude (y) step size in Fig. 1 will not change, even if you has used an infinitely high sample rate. 


Fig. 1. Illustration of bit depth. source: Presonus