I have a question regarding the calculation of spontaneous firing rates using the ecephys_session tutorial. In the instructions it is stated: ‘The gray period stimulus (just a blank gray screen) never gets a block.’ Yet, when I filter for the ‘spontaneous’ epochs, it looks like multiple epochs of gray screen are acquired throughout the session but the stimulus block value is set to ‘null’ for all blocks.
I tried using the tutorial to calculate the firing rates but for ‘spontaneous’ the firing rates go off the charts compared to ‘drifting grating’ etc. I assume that this is due to the fact that all spontaneous epochs have the same Stimulus_ID across the ‘null’ blocks, which is set to 0. While the stimulus_presentation_id seems to be unique across the different spontaneous epochs, the stimulus_condition_id is actually 0 for all entries. I would appreciate any feedback on whether it is possible to use the ‘spontaneous’ epoch as a filter due the stimulus ID as it’s done for ‘drifting gratings’ in the tutorial. Is there a specific reason that all spontaneous’ epochs have been assigned a ‘null’ value for the blocks?