Sargisson, R. J. & White, K. G. (2003).
On the form of the forgetting function: The effects of
arithmetic and logarithmic distributions of delays.
Journal of Experimental Analysis of Behavior,
80, 295-309.
Forgetting functions with 18 delay intervals were generated for
delayed matching-to-sample performance in pigeons. Delay interval
variation was achieved by arranging five different sets of five
delays across daily sessions. In different conditions, the delays
were distributed in arithmetic or logarithmic series. There was no
convincing evidence for different effects on discriminability of the
distributions of different delays. The mean data were better fitted
by some mathematical functions than by others, but the best-fitting
functions depended on the distribution of delays. In further
conditions with a fixed set of five delays, discriminability was
higher with a logarithmic distribution of delays than with an
arithmetic distribution. This result is consistent with the
treatment of the forgetting function in terms of generalization decrement.
Key words: forgetting functions, multiple delays, delay
interval distribution, delayed matching to sample, pigeon