Sampling Rate

[LWill]

Hello (me again ). I have another question regarding recordings.

I have been recording my data at a low sampling rate, but have now changed this to 'constant'. However, am I still able to get this kind of data for the recordings done so far? Or have they been recorded/stored only in the lower sampling rate?

Thanks in advance.

[James]

No. There is 256 times less data, when you record at the default one second recording interval. There's no way to make up that data after the fact.

[LWill]

Thank you for your reply, James.

I thought this may be the case. If we would switch to 256Hz now, would it be possible to calculate the 1Hz data from the 256Hz data? Are the 1Hz data usable at all?

[James]

The 1Hz data is a once per second snapshot of the 256Hz data. So, if you drop 255 data points out of the data, this will match the 1Hz data.
I would point out that you only need full 256Hz data if you're using the RAW EEG to do your own FFT calculations.
The Absolute brainwave values are only ever 10Hz at their maximum data rate and if you are (like most people) looking at 30 minutes of data, then having an absolute brainwave data point every second, that is usually plenty.

[LWill]

Thanks very much for your help, James