characterize_plaid

This analysis creates direction tuning curves and computes indices for pattern and component motion selectivity based on a set of drifting plaid and drifting sinusoidal grating stimuli. The plaid must be the sum of two gratings varying by 120 degrees in their direction of motion.

A partial correlation analysis is used to compute the pattern index and component index (Gizzi et al., 1985 - note that the equation for partical correlation may be incorrect in the published literature).

Any conditions in the .nda file will be included after the automatically built conditions that are used to select trials for Pattern and Component analyses.

Note: This analysis is designed to work with the specific sets of stimulus parameters found in stimulus files known as plaid120 from the Movshon lab and the Bair lab. More explanation is needed here and changes to the analysis code need to be made to make it more general.

The analysis works for continuous data (starting Feb 2019) in addition to spike channels.

Options:

• plot - plot the following tuning curves in the outfile (xplot format):
  • pred_Pat - the predicted pattern cell response (this is the sinewave tuning curve, shifted if necessary to account for the direction of the plaid).
  • pred_Comp - the predicted component cell response (this is the sum of two shifted copies of the sinewave tuning curve).
  • [infile]_pat - the direction tuning curve for plaids
  • [infile]_comp - the direction tuning curve for gratings
  and write the following parameters to the statistics file (listed by column number):
  1. name - input file name given on command line
  2. r_Component - component index
  3. r_Pattern - pattern index
  4. z_Component - Fisher-Z for r_Pattern
  5. z_Pattern - Fisher-Z for r_Component

Parameter definitions:

• ori_pname - ['oria'] Name of parameter that specifies direction of motion (e.g., 'direction' or 'ori')
• ampl1_pname - ['ampla'] Name of parameter specifying contrast of component 1 of the plaid (e.g., 'contrast1' or 'ampla')
• ampl2_pname - ['amplb'] Name of parameter specifying contrast of component 2 of the plaid (e.g., 'contrast2' or 'amplb')
• stat_filename - [outfile] Name of output file to be appended with statistics.
• multi_win - [1] Use multiple analysis windows, if > 1.
• multi_increment - [-1] see source code.
• multi_cumulative - [0] see source code.
• fix_prediction - [1] see source code.

Example:

#
#  For plaid120.stm
#
characterize_plaid
group 0
plot

start 30
period 2000

stat_filename zzz_plaid120.stat

ori_pname   direction
ampl1_pname contrast1
ampl2_pname contrast2