Duration comparison: relative stimulus differences stimulus age, and stimulus predictiveness.
Under a psychophysical trials procedure, pigeons were presented with a red light of one duration followed by a green light of a second duration. Eight geometrically spaced base durations were paired with one of four shorter and four longer durations as the alternate member of a duration pair, with different pairs randomly intermixed. One choice was reinforced if red had lasted longer than green, and a second choice was reinforced if green had lasted longer. Performance was compared when all the base durations and their pair members were included (entire-range condition) or when only the four longest base durations and their comparison durations (restricted-range condition) were used. Discrimination sensitivity decreased for longer duration pairs under both conditions, supporting a memory-based account. Sensitivity was lower under the restricted-range condition. Under both conditions, a bias to report "green as longer" increased as the second green duration increased. Bias changed as a matching function of the green-duration predictiveness of the correct choice. The results are related to a quantitative model of timing and remembering proposed by Staddon.
Stubbs
D A
DA
Psychology Department, University of Maine, Orono 04469-5742.
Dreyfus
L R
LR
Fetterman
J G
JG
Boynton
D M
DM
Locklin
N
N
Smith
L D
LD
D000818:Animals; D001522:Behavior, Animal; D010856:Columbidae; D004193:Discrimination Learning; D008568:Memory; D012055:Reinforcement Schedule; D017603:Signal Detection, Psychological; D013997:Time Factors; D013998:Time Perception