Serial learning, interitem associations, phrasing cues, interference, overshadowing, chunking, memory, and extinction

Abstract

Two experiments indicated that two approaches to serial learning are too extreme-the classical view that it consists only of interitem associations and various recent views that it involves no interitem associations. The novel assumption introduced here was that phrasing cues, normally conceptualized as merely segregating long series into smaller units or chunks, may also enter into associations with items, thereby reducing interitem interference and facilitating serial learning. It was found that one item could become a signal for another item, an interitem association, or be overshadowed by a phrasing cue, such as a brightness and temporal cue, also signaling that item. The items were ,045-g pellets. Rats traversed a runway for items arranged in ordered series, 14-7-3-1-0 pellets (Experiment 1) or 10-2-0-10 (Experiment 2), Complete tracking of, for example, the 10-2-0-10 series would consist of fastest running to 10 pellets and slowest running to 0 pellets. In both investigations, the interitem association overshadowed was that between 0 pellets and the subsequent rewarded item, 0-14 (Experiment 1) or 0-10 (Experiment 2). Either repetitions of the 14·7·3-1-0 subpattem (Experiment 1) or merely the terminall0·pellet item (Experiment 2) were phrased, both methods producing identical results. Overshadowing the O-pellet item produced superior serial learning, more rapid extinction, and, in Experiment 1, considerable elevation of responding when the brightness phrasing cue was introduced in extinction, an effect said to be conceptually identical to spontaneous recovery and one demonstrating directly that phrasing cues are in reality overshadowing cues. It was suggested that many effects attributed to forgetting may be due to unrecognized overshadowing of memory cues by phrasing cues, giving rise to exaggerated estimates of forgetting.

Number, But Not Rhythmicity, of Temporal Cues Determines Phrasing Effects in Rat Serial-Pattern Learning

“…Furthermore, many of the finer details of the results could be accounted for by the additional assumption that phrasing cues overshadowed interitem associations (Stempowski et al, 1999). Stempowski et al's (1999) results, along with those of Capaldi et al (1984), clearly showed that discriminability and overshadowing are important factors mediating phrasing cue effects. On the other hand, evidence in both the rat and human literatures suggests that the correspondence between phrasing cues and sequential element organization may also be important determinants of chunking and phrasing effects.…”

“…Stated another way, rhythmic patterning facilitated sequence recall under conditions of ''good rhythmicity'' defined as phrasing that highlighted boundaries between chunks of equal length (numeric balance) and structured content (structural subgroup-level equivalence, symmetry, and other relations). Capaldi et al (1984) also studied the effects of different phrasing conditions applied to the same pattern of sequential elements. They replicated the effects of spatial cues reported by Fountain et al (1984), but argued that phrasing effects, like other aspects of serial-pattern learning, should be explained by appealing to traditional discrimination learning rather than rulelearning processes.…”

“…In recent years, animal cognition researchers have investigated a number of factors thought fundamental to how animals encode sequences of events (Capaldi, 2000;Capaldi, Verry, Nawrocki, & Miller, 1984;Fountain, 1990;Fountain, Henne, & Hulse, 1984;Fountain & Rowan, 1995a;Fountain, Wallace, Rowan, & Stempowski, 2000;Swartz, Chen, & Terrace, 1991;Terrace, 1987Terrace, , 1991Terrace, , 2000Terrace & Chen, 1991a, 1991b. Work on experimental manipulations that affect chunking has shown that cues inserted into a sequence, termed ''phrasing cues,'' can affect acquisition and performance under a variety of conditions.…”

Serial-Pattern Learning in Mice: Pattern Structure and Phrasing

“…One prominent view of phrasing developed in the rat and pigeon learning and memory literature is that phrasing cues facilitate learning by acting as discriminative cues to facilitate anticipating specific stimuli, responses, or sequences of stimuli or responses (Capaldi, Verry, Nawrocki , & Miller, 1984;Terrace, 1987). According to this view, phrasing cues facilitate learning by reducing interference in memory for items in sequence (Capaldi et aI., 1984) or by signaling specific events (Capaldi et aI.…”

“…One might hypothesize that phrasing cues could serve at least two roles: They could signal the termination of a chunk, perhaps through overshadowing as suggested by Capaldi et aL (1984), and they could also signal the proper response on the forthcoming trial, namely, the first element of the chunk to come. For mice, it was observed that phrasing cues reduced overextension errors-as if mice knew to discontinue using the within-chunk "+1" or "move-one-to-the-right" response rule.…”