Color naming, lens aging, and grue: what the optics of the aging eye can teach us about color language.

Many languages without separate terms for green and blue are or were spoken in locations receiving above-average exposure to ultraviolet-B (UV-B) radiation. It has been proposed that this correlation is caused by premature lens aging. This conclusion was supported by an experiment in which younger observers used the term "blue" less often when they described simulated paint chips filtered through the equivalent of an older observer's lens-removing much short-wavelength light-than when they described the unfiltered versions of the same paint chips. Some stimuli that were called "blue" without simulated aging were called "green" when filtered. However, in the experiment reported here, we found that the proportion of "blue" color-name responses did not differ between younger subjects and older observers with known ocular media optical densities. Color naming for stimuli that were nominally green, blue-green, or blue was virtually identical for older and younger observers who viewed the same (unfiltered) stimuli. Our results are inconsistent with the lens-brunescence hypothesis.

Separating sensitivity from response bias: implications of comparisons of yes-no and forced-choice tests for models and measures of recognition memory.

A fundamental challenge to psychological research is the measurement of cognitive processes uncontaminated by response strategies resulting from different testing procedures. Test-free estimates of ability are vital when comparing the performance of different groups or different conditions. The current study applied several sets of measurement models to both forced-choice and yes-no recognition memory tests and concluded that the traditional signal-detection model resulted in distorted estimates of accuracy. Two-factor models were necessary to separate memory sensitivity from response bias. These models indicated that (a) memory accuracy did not differ across the tests and (b) the tests relied on the same underlying memory processes. The results illustrate the pitfalls of using a single-component model to measure accuracy in tasks that reflect 2 or more underlying processes.