Hi,
I’ve been doing some work that uses the stimulus table dataframe for reconstructing the exact stimulus presented. I’m a bit uncertain as to what units are being used in this dataframe, particularly for the temporal_frequency, because in the whitepaper, the gabor/receptive field mapping describes the following.
All experiments began with a receptive field mapping stimulus consisting of 2 Hz, 0.04 cycles per degree drifting gratings with a 20º circular mask. These Gabor patches randomly appeared at one of 81 locations on the screen (9 x 9 grid) for 250 ms at a time, with no blank interval. The receptive field mapping stimulus was followed by a series of dark or light fullfield flashes, lasting 250 ms each and separated by a 2 second inter-trial interval.
However the dataframe shows a temporal frequency of 4
| Column 1 | Column 2 | Column 3 | Column 4 | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| stimulus_presentation_id | stimulus_block | start_time | stop_time | contrast | mask | temporal_frequency | opacity | x_position | y_position | size | stimulus_name | orientation | frame | spatial_frequency | units | color | phase | color_triplet | duration | stimulus_condition_id |
| 1 | 0.0 | 84.49618798636119 | 84.72970394503696 | 0.8 | circle | 4.0 | True | 40.0 | 30.0 | [20.0, 20.0] | gabors | 45.0 | null | 0.08 | deg | null | [3644.93333333, 3644.93333333] | [1.0, 1.0, 1.0] | 0.2335159586757669 | 1 |
Could you please clarify what the units being used here are? Apologies in advance if some of this is self evident to the vision field.