Spatiotemporal dynamics of responses to biological motion in the human brain

The code in this repo was used for the generation and presentation of biological motion stimuli for the following work: Chang, D. H. F., Troje, N. F., Ikegaya, Y., Fujita, I., & Ban, H. (in press). Spatiotemporal dynamics of responses to biological motion in the human brain. Cortex. [full doi will be updated once available]

Getting Started and Usage

The top-level function is BMdirection(subjectname, runnum, runtype)

e.g., BMdirection('TEST', 1, 1) subjectname looks for a subject-string identifier runnum looks for a digit, denoting run iteration runtype looks for a digit, here fixed as 1. This was simply used internally to separate this code from a variation that was earlier piloted.

Dependencies

Portions of this script tap on functions available in Psychtoolbox. Instructions for installation of PTB can be found at http://psychtoolbox.org/.

File list

BMdirection.m \top-level function to initiate experiment

CreateDataFile.m \self explanatory...finalizes data structure, stamps date, and saves

GenerateBlocks.m \defines stimulus type based on block ID, shuffles, outputs trial order.

CreateTrials.m \called by GenerateBlocks -- defines single trial parameters

PresentStimulus.m \presents...the stimulus.

RunOneTrial.m \runs a single trial

RunTrials.m \runs full trial loop

create_windows.m \opens PTB windows

get_key.m \prompts response pickup

getdatatypes.m \called by RunTrials -- checks type of walker/stimulus data fed in. Fourier series? Time series data?

mdComputePositions.m \computes the array of dots to draw at current frame.

mdPhaseScramble.m \called by mdprepare_single -- when called, this script takes time series data and phase-shuffles them.

mdSpatialScramble.m \called by mdprepare_single -- when called, this script takes an intact walker and performs a spatial reordering of walker point-lights

mdprepare_single.m \applies inversion, size, azimuth, 2D projection, centering, and scrambling as necessary

shuffle.m \for trial order randomization

walkerdata.mat \data structure containing time-series data for each of the three main walker types

Authors

• Dorita CHANG, Hiroshi BAN

Acknowledgments

• Parts of this code are attributed to the BioMotionLab, biomotionlab.ca