Sargisson & White, K.G. (2007).
Timing, remembering, and discrimination.
Journal of the Experimental Analysis of Behavior, 87, 25-37.
Four pigeons were first trained in a timing procedure. In one condition, each trial began with the presentation
of an X on the center key, followed by a delay (short or long), after which two side keys were lit. If the delay
was short, pecks to the red side key were reinforced. If the delay was long, pecks to the green side key were
reinforced. In a second condition, the opposite contingencies applied following presentation of a square on the
center key. Choice responses were then tested at 10 time intervals ranging from short to long (1 to 4 s and 4
to 7 s in different conditions). The two timing conditions were combined to create a remembering condition in
which correct responding depended upon discrimination of both the sample stimulus (X or square) and the delay
interval (short or long). Choices varied systematically across delay in timing conditions, but in remembering
conditions, accurate choice at the training delays did not initially generalize to intermediate delays. However,
with prolonged training in the remembering task, the response pattern began to resemble that of the timing
conditions. Generalization gradients were asymmetrical, in accordance with Weber’s Law, in that greater
generalization occurred with longer delays than with shorter delays.
Key words: remembering, timing, discrimination, generalization, delayed-symbolic-matching to sample,
key peck, pigeon