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MSchnei / pyprf_feature

Population receptive field estimation with feature weights.
GNU General Public License v3.0
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Correspondence of stimuli in psychopy & PNG log files #3

Closed ingo-m closed 6 years ago

ingo-m commented 7 years ago

During testing, it became apparent that under some conditions the stimuli as presented in psychopy & the PNG logs (created with ~/py_pRF_motion/prePro/pRF_createPNGs.py) do not correspond exactly. For the mskBar stimulus, an upside-down flip was apparent. The commit 523997c solves this issue for the mskBar stimulus (correspondence of psychopy display & PNGs tested on several runs).

However, the issue remains unresolved for mskCircleBar stimuli.

MSchnei commented 6 years ago

This issue was solved with pull request #11

Solving this issue required a two-step approach:

First, since psychopy displays apertures in a manner which flips images along the y-axis (top to bottom on computer screen), it is essential to swap aperture masks before using pyprf_feauture. The script prepro_get_spat_info.py provided in the /analysis/prepro folder achieves this by indexing: arySptExpInf = arySptExpInf[::-1, :, :].

Second, the trick was to turn the apertures by 90 degrees such that indexing with x and y in python is equivalent to 'intuitive' visual coordinate indexing where the x-axis axis runs from left to right on the monitor (i.e. width) and the y-axis from top to bottom (i.e. height).