Data Downloads
Hillis, J. M. & Brainard, D. H. (under review), Do common mechanisms of adaptation
mediate color discrimination and appearance? Contrast adaptation.
The data available on this web site were originally published in summary form in Hillis &
Brainard (under review). This paper investigated the effect of background luminance
and chromatic contrast on color appearance and discriminability. There are two types
of data files available on this web page. One type is discrimination data from
a 2-interval forced choice (2-IFC). The other data are from an asymmetric matching
task. Data are formatted in the downloadable
text files below or in a complete archive here.
(Back to main supplemental figure page)
| L_bg | M_bg | S_bg | L_ped | M_ped | S_ped | L_test | M_test | S_test | #Correct | #Trials |
These data are available in 3 formats. To compute the Smith-Porkorny cone coordinates,
cone spectral sensitivities were normalized to one and cone coordinates were
computed for the light reaching the cornea. Isomerization rates and totals are
computed for the light reaching the photoreceptors (i.e. light losses due to
optical factors in the eye are accounted for. Left click on the links below
to open data in web browser or right click to download (email Jamie, j.hillis@psy.gla.ac.uk,
if you have any problems obtaining the data).
(1) LMS Smith-Porkorny
JMH: LM cone data, S cone Data
QRS: LM cone data, S cone data
(2) LMS Isomerization rates
JMH: LM cone data, S cone Data
QRS: LM cone data, S cone data
(3) LMS Isomerization totals.
JMH: LM cone data, S cone Data
QRS: LM cone data, S cone data
Matching
Data
Similar to the discrimination data,
there were 2 adapting conditions for LM-cone isolating
tests (Gray and LM-cone noise) and 3 adapting conditions for S-cone isolating tests (Gray, S-cone Noise and LM-cone noise). Each data file contains 13 columns of
tab delimited text. The first 6 columns provide L, M, S coordinates the background
againts which the fixed test was presented. This was always the noise condition. The cone values for the noise background values are the background cone coordinates are written as the difference between the maximum and minimum absorption rates in the noise patterns (i.e. the LM cone values are zero for the S-cone noise condition and the S-cone values are zero for the LM-cone noise condition). The next 6 columns provide
L, M, S coordinates the background againts which the adjustable match was presented
and the observer's settings for those matches. The last column is the rating
(between 0 ans 3) the observer gave to the quality of the match they set. Thus
the column organization is as follows:
| L_test_bg | M_test_bg | S_test_bg | L_test | M_test | S_test | L_match_bg | M_match_bg | S_match_bg | L_match | M_match | S_match | Rating |
Note that there is variation in the test values because the numbers reported here are values measured from the display. That is, after each block of trials a Photo Research 650 spectra-radiometer was used to measure the spectral density function of the test and match. The values of the test and match contained in the data tables are these measured values. These data are also available in 3 formats (left click to open data in web browser, right click to download):
(1) LMS Smith-Porkorny
JMH: LM cone data, S cone Data
QRS: LM cone data, S cone data
(2) LMS Isomerization rates
JMH: LM cone data, S cone Data
QRS: LM cone data, S cone data
(3) LMS Isomerization totals.
JMH: LM cone data, S cone Data
QRS: LM cone data, S cone data