Studies of Interference in Serial Verbal Reactions

INTRODUCTION

Interference or inhibition (the terms seem to have been used almost indiscriminately) has been given a large place in experimental literature. The investigation was begun by the physiologists prior to 1890 (Bowditch and Warren, J. W., 1890) and has been continued to the present, principally by psychologists (Lester, 1932). Of the numerous studies that have been published during this period only a limited number of the most relevant reports demand our attention here.

Münsterberg (1892) studied the inhibiting effects of changes in common daily habits such as opening the door of his room, dipping his pen in ink, and taking his watch out of his pocket. He concluded that a given association can function automatically even though some effect of a previous contrary association remains.

Müller and Schumann (1894) discovered that more time [p. 644] was necessary to relearn a series of nonsense syllables if the stimulus syllables had been associated with other syllables in the meantime. From their results they deduced the law of associative inhibition which is quoted by Kline (1921, p. 270) as follows: "If a is already connected with b, then it is difficult to connect it with k, b gets in the way." Nonsense syllables were also used by Shepard and Fogelsonger (1913) in a series of experiments in association and inhibition. Only three subjects were used in any experiment and the changes introduced to produce the inhibition were so great in many cases as to present novel situations. This latter fact was shown by the introspections. The results showed an increase in time for the response which corresponded roughly to the increase in the complexity of the situation. The only conclusion was stated thus: "We have found then that in acquiring associations there is involved an inhibitory process which is not a mere result of divided paths but has some deeper basis yet unknown" (p. 311).

Kline (1921) used 'meaningful' material (states and capitals, counties and county seats, and books and authors) in a study of interference effects of associations. He found that if the first associative bond had a recall power of 10 percent or less it facilitated the second association, if it had a recall power of 15 percent to 40 percent the inhibitory power was small, if it had a recall power of 45 percent to 70 percent the inhibiting strength approached a maximum, if the recall power was 70 percent to 100 percent the inhibition was of medium strength and in some cases might disappear or even facilitate the learning of a new associaiton.

In card sorting Bergström (1893 and 1894), Brown (1914), Bair (1902), and Culler (1912) found that changing the arrangement of compartments into which cards were being sorted produced interference effects. Bergström (1894, p. 441) concluded that "the interference effect of an association bears a constant relation to the practice