Hand Grasp Task

Quick psychopy implementaiton using the lncdtask wrapper.

• ./grasp_trcount.py - specify number of TRs per block
• ./grasp_task.py - specify duration of blocks

Outputs

subj_info/
└── sub-AAA
    └── ses-01
        └── 20260205_grasp
            ├── grasp_tr1-0.576_tr2-0.448-1770315169.csv
            └── log
                └── grasp-1770315164.log

Completed runs have a csv file like subj_info/sub-*/ses-*/{YYYYMMDD}_grasp/grasp_tr1-*_tr2-*-{epochtime}.csv useful for GLM timing input. File name also includes 2 observed TRs (likely BOLD and VASO).

cat subj_info/sub-AAA/ses-01//20260205_grasp/grasp_tr1-0.576_tr2-0.448-1770315169.csv

,onset,event_name,onset0
0,5.190117120742798,Relax,0.034680843353271484
0,6.690381765365601,Grasp,1.5349454879760742

All runs save a log like subj_info/sub-*/ses-*/{yyymmdd}_grasp/log/grasp-{epochtime}.log. Format is lines containing "marks": epoch seconds at observation and description of the observations

cat subj_info/sub-AAA/ses-01//20260205_grasp/log/grasp-1770315164.log

1770315164.44887 STARTING: recieved first TR pulse 5.155436277389526
1770315164.48355 Relax
1770315164.89645 Pulse 1 for block 0 recieved 5.603025197982788
1770315164.89650 TR 1 is 0.4475889205932617
1770315165.47247 Pulse 2 for block 0 recieved 6.179050922393799
1770315165.47251 TR 0 is 0.5760257244110107
1770315165.95255 Pulse 3 for block 0 recieved 6.659131288528442
1770315165.98382 Grasp
1770315166.43254 Pulse 0 for block 0 recieved 7.139124631881714
1770315166.92853 Pulse 1 for block 0 recieved 7.635113000869751
1770315167.42454 Pulse 2 for block 0 recieved 8.131099939346313
1770315167.93649 Pulse 3 for block 0 recieved 8.64306116104126

Note

This example task log is from interactive testing: pushing "=" instead of recieving it from the scanner. However, START to first relax is TR independent. Ideally would be 0 seconds but here is 346.8 ms (1770315164.48355 - 1770315164.44887)! This is the time from when the scanner starts collecting the first volume to when the screen actually shows the task start

Usage

To run offline (on windows), install psychopy and copy the lncdtask repo as directory within this project.

Development

Run with uv to avoid manual venv managment.

uv run --script ./grasp_trcount.py --instructions --ntr 4 --ntrials 1 --subjid AAA