Effect of proactive inhibition upon the postdiscrimination generalization gradient.

Proactive interference in the retention of “attentional sets” in pigeons

“…Experiment 1 examined this hypothesis, and was concerned with another matter as well. While the Burr and Thomas (1972) study compared the gradients of groups exposed to Task 1 and Task 2 with those exposed only to Task 2, in the present study all subjects received a single-stimulus pretraining experience as Task I, but they differed in the relationship of the pretraining stimulus to the stimuli used in Task 2 interdimensional training. It was expected that this factor would affect the amount of PI observed.…”

“…15 00904996/82/010015-07$00.95/0 gradients, Burr and Thomas (1972) predicted that forgetting resulting from conflicting memories would have a similar effect. Interference theory (cf.…”

“…An immediate generalization test would presumably reflect the attentional set produced by the most recent training, just as Burr and Thomas (1972) found that an immediate test reflected only Task 2 learning in their study. With the passage of time before testing, however, the attentional set produced by Task 1 training might increase in relative strength and be reflected in an appropriate change in generalization slope.…”

“…Experiment 1 in this paper is an extension of the Burr and Thomas (1972) study. It was designed to extend the range of habits that might be considered "conflicting" from the perspective of interference theory.…”

“…It is also possible that massed practice on the second task is conducive to the demonstration of PI because it leads to less effective learning of Task 2, rendering it more subject to interference. The study by Burr and Thomas (1972) included the massing, or spacing, of training on Task 2 as an independent variable in addition to the presence or absence of (spaced) Task I learning, and immediate vs. delayed generalization testing. The two habits, Task I and Task 2, were directly conflicting, that is, Task 1 was a successive discrimination with responding to a light of 570 nm reinforced and responding to 550 nm extinguished; Task 2 was the reversal of this problem, that is, 550 nm was S+ and 570 nm was S-.…”