This was not the case for the WGTA
- instead, industry members were personally invited by DG Enterprise.
(1995) used the WGTA
with typically developing children ages 5 to 7 years old.
McClearn and Harlow (1954) used stimuli separations of 0, 1, 2, and 4 inches using a modified WGTA. Two color blocks were the stimuli throughout the experiments, and white was always the correct stimulus.
In WGTA tasks, the monkeys touched spatially discontiguous response loci with the hand.
However, if performance remains high with such spatial discontiguity, this may indicate that the computerized apparatus frees the monkeys from the constraints of cue and response loci typically found with the WGTA.
When responding manually to presented stimuli using an apparatus like the WGTA, rhesus monkeys have great difficulty in correctly selecting response loci spatially removed from the stimuli to be discriminated.
Although the typical WGTA tray does not appear to be visually noisy, perhaps it is to the monkey.
The WGTA consists of a wooden box bisected with a guillotine door.
Saunders and Williams (1998) describe several advantages of the WGTA. These include the prevention of facial cues during the preparation and presentation of trials, the delivery of reinforcement "at a uniform time with respect to the response" and "the ease with which three-dimensional stimuli can be used" (p.
First, the likelihood of the experimenter cuing with a tabletop procedure is reduced in the same manner as seen with the WGTA by arranging a freestanding divide between the subject and experimenter.
Second, while the WGTA facilitates uniformity in reinforcer deliveries, uniformity across trials may not always be accomplished.
Finally, although the WGTA lends itself well to investigations involving three-dimensional stimuli, such stimuli can be incorporated into other nonautomated procedures as well.