Just downloaded psignifit for Matlab (I'm using a PC),
here is the error I get when I try to run the test_psignifit:
>> test_psignifit
testing 2afc setting
MapEstimate
Error using MapEstimate (line 156)
Error: Unexpected MATLAB expression.
Error in test_psignifit (line 9)
mapest = MapEstimate ( data2afc, priors );