PSEUDO-PRIMACY EFFECTS IN FREE RECALL

Abstract

Summary.-Shiffrin (1970) has suggested that the primacy effect in the serial position curve is the result of the temporal distinctiveness of the initial items in the list. Given this assumption a pseudo-primacy effect should be observed in other parts of the list if distinctive cues are provided. The present experiments tested this prediction. The distinctive cues presented were a change from a male to a female reader (or vice versa) and a short pause in list presentation. Pseudo-primacy effects were produced and the shape of the serial position curve was changed to a significant degree. A number of recent models of memory have emphasized the role of the context in which information is given for memorization as an important factor in the memorization process (e.g., Norman & Rumelhart, 1970; Shiffrin, 1970). These models propose that one does not store the literal meaning of the stimu111s or its nature since this information is already stored before the experiment begins. Rather, memorization proceeds by the establishing of an association between pre-existing representarions of the stimuli (including their characteristics or attributes) and the experimental context in which they are given. According to Norman and Rumelhart (1970), recall then proceeds by retrieving all those attributes which have the proper contextual association and reconstructing the stimulus or item. Shiffrin (1970) conceives of all the icerns possessing [he contextual association as defining a search set. The probability of retrieving an item from the search set depends, in part, on its size. The larger the search set the lower the probability of recall. Any search restricted to a cercain part of the list should result in a higher probability of recall for the items in that part. In this way, Shiffrin (1970) can account for the primacy effect in the serial position curve without making a rehearsal assumption. The beginning of the list provides a natural and distinctive cue upon which to define a smaller search set, one for beginning items. Since at some point in recall the search process is restricted to this smaller part of the list, the probability of recall from this portion of the list is greater. It is essentially the von Restorff effect at work at the beginning of the list. It should be noted that this explanation of the primacy effect differs considerably from the more commonly cited explanation proposed by Glanzer and Cunitz (1966). They propose that recall is higher for the initial list items because they are retrieved from long-term storage. 'The present research was adapted from a doctoral dissertation done under the direction of Dr. John A. Robinson, and submitted to the Department of Psychology, University of