######  PercLearn\PLExp2\README-2008-02-22.txt

README for the PLExp2 folder, release 1.1.1, 22 Feb 2008.

This folder contains the raw data for the no-feedback perceptual
learning experiment described in:
  Petrov, A., Dosher, B, and Lu, Z.-L. (2006).
  Perceptual Learning Without Feedback in Non-Stationary Contexts:
  Data and model.  Vision Research, 46, 3177-3197.
  Reprint available at http://alexpetrov.com/pub/plfeedbk/
See also the original publication:
  Petrov, A., Dosher, B, and Lu, Z.-L. (2005).
  The dynamics of perceptual learning: An incremental reweighting model.
  Psychological Review, 112 (4), 715-743.
  Reprint available at http://alexpetrov.com/pub/perclearn/
  

The PLExp2 folder contains the following subfolders(**) and files(--):
  ** programs -- MATLAB software that administered the experiment
      It uses PsychToolbox (http://psychtoolbox.org/) on Matlab 5.2 
      running on Mac OS 9. Also uses files from  work\utils
      Some particularly important files are:
    -- PLExp2_params.m -- definition of the stimuli, trial sequence, etc.
    -- PLExp2.m -- main file. It carries out "phase 1" of the experiment,
         which comprises days 1-9 and is the only phase reported in the
         Vision Research mansucript cited above.  See the documentation
         in this file for the format of the raw data files.
    -- PLExp2a.m and PLExp2b.m -- files implementing "phase 2" (days 10-11)
         and "phase 3" (day 12) of the experiment. Phase 2 involved
         turning stimuli by 90 degrees and changing retinal positions to
         test for specificity. Phase 2 tested a day in mixed contexts.
         None of them is reported in the Vision Research manuscript.
  ** cache -- empty folder intended to store the filtered-noise caches 
         generated by programs\cache_PLE2_backgr.m. During the actual data
         collection there were 36 caches in context L and 36 caches in 
         context R. They were stored on a separate CD-ROM and were read in 
         during before each block. Contact Alex to obtain the noise caches
         underlying the behavioral data (e.g., if you want to calculate
         classification images). Alternatively, you can simply generate
         new ones. See cache_PLE2_backgr for details.
  -- raw_data.dat -- a massive ASCII file containing all data from the 18 "good"
         participants in the feedback experiment. See programs\PLExp2.m for
         the data format. Generally, there is one row per trial and many 
         columns specifying the Gabor orientation, contrast, context direction,
         as well as the response and RT of the subject.  The data were collected 
         at Professor Dosher's lab at UCI (SSL 340) between Sep and Nov 2003.
         Each participant took 12 sessions, although only the first 9 are
         reported in the Vision Research paper cited above.
  -- D.mat -- A saved MATLAB structure D generated from the raw data by 
         programs\import_PLE2_data.m  This structure contains all 
         data and is used for all subsequent analyses.
         [D.mat is not stored in the .zip archive but is regenerated from
          raw_data.dat by the ..\PercLean_install script.]
  ** modelfits -- notes taken while fitting the multi-channel reweighting model
         to the no-feedback (and feedback) data.
  ** fig -- MATLAB figure files for some of the empirical figures in the Vision
         Research manuscript. See work\PLPaper2\fig for the final figures.
  -- README-2008-02-22.txt -- this file
All this software (possibly in newer versions) is available for download from 
http://alexpetrov.com/proj/plearn/
In the (unlikely) event that the web site has moved, just Google search for "Alex Petrov".

See ..\PLReadme2008-02-22.txt and PercLearn_install for installation instructions.
See also:
work\PLExp1 for the earlier experiment with feedback, 
work\PLModel1 for various versions of the multi-channel reweighting model, 
work\utils for files such as gabor.m, PlayMovieStruct.m, and paramsearch.m.

If something doesn't work or some relevant files are missing, please do not 
hesitate to contact me. Thank you for your interest in this work. Good luck!

  -- Alex

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Alexander A. Petrov:  apetrov [at] alexpetrov [dot] com

Assistant Professor, Department of Psychology
Ohio State University, Columbus, OH 43210
http://alexpetrov.com

It is better to light one candle than to curse the darkness.
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