Inhibition of associates and activation of synonyms in the rare-word paradigm: Further evidence for a center-surround mechanism

Abstract

Two experiments investigated semantic priming effects in a modified version of the Dagenbach, Carr, and Barnhardt (1990) rare-word paradigm. After learning a list of rare words to a criterion of 50%recall, subjects participated in a lexical decision task in which the rare words served as primes. Whenthe targets were associatively related to the primes, lexical decision responses were facilitated following recalled definitions and inhibited following unrecalled definitions. When the targets were synonyms of the rare words, facilitation occurred following both recalled and unrecalled definitions. The results were interpreted as supporting a center-surround model of attentional retrieval that may serve an adaptive role in new learning.Knowledge concerning the meanings of words has usually been attributed to a functionally distinct system known variously as lexical memory (Oldfield, 1966), generic memory (Hintzman, 1978), or semantic memory (Tulving, 1972). Access to a word's meaning on the basis of its orthographic or phonological code appears to occur rapidly and automatically, and appears also to activate the representations of semantically related words. This latter phenomenon, known as semantic priming (see, e.g., Meyer & Schvaneveldt, 1971), has been studied extensively and has prompted a number of theoretical formulations concerning the organizational structure ofand processes associated with the semantic memory system (see Neely, 1991, for review).In the standard semantic priming paradigm (Neely, 1977), subjects are required to make a lexical decision to the second of two consecutive letter strings. When both strings are words, subjects are faster to respond when the words are semantically related than when they are not. Such semantic priming effects have usually been interpreted within a spreading activation model of semantic memory (Collins & Loftus, 1975). According to this model, concepts are connected by pathways that vary in length according to their degree of semantic relatedness: Highly related concepts are close in semantic space and unrelated concepts are far apart. When any particular concept is activated, activation spreads along the pathways to related nodes such that concepts close in space benefit more than distant concepts. In the semantic priming paradigm, activation spreads from the prime to the related target node, which can then be accessed more quickly so that lexical decisions are speeded. This spread of activation appears to occur automatically. Snyder (1975a, 1975b) proposed, however, that in addition to an automatic spreading activation mechanism, strategic or attentional processes that reflect the expectations or intentions of the subject may also be involved in semantic priming. These theoretical ideas received empirical support in a series of studies by Neely (1977) in which he manipulated the expectations of the subjects and the prime-target stimulus onset asynchronies (SOAs). At short SOAs (i.e., 250 msec), expectations concerning the type of targets had no effect on the stand...

Rethinking interference theory: Executive control and the mechanisms of forgetting

“…Parallel findings have been observed in episodic memory experiments using homographs, which establish that inhibitory effects are recall specific, consistent with properties of retrieval-induced forgetting more generally (Shivde & Anderson, 2001). Finally, research using the rare-word paradigm has found that difficult semantic retrievals recruit inhibitory processes: When subjects struggle to recall the meaning of an unusual, infrequently encountered word that is weakly represented in memory, related concepts appear to be impaired (Barnhardt, Glisky, Polster, & Elam, 1996;Dagenbach, Carr, & Barnhardt, 1990; see also Thompson-Schill, 1997 for an interesting discussion of the role of the left prefrontal cortex in controlling selective retrieval from semantic memory). Taken together, these results argue that retrieval induced forgetting is not limited to episodic retrieval, or to taxonomic categories; rather, it is a general consequence arising whenever inhibitory mechanisms are recruited to guide selection in the face of competition from distracting memories.…”

Repeated Masked Category Primes Interfere With Related Exemplars: New Evidence for Negative Semantic Priming.

“…Thus, an a priori hypothesis for our experiments would have been to assume negative effects, especially for highdominant exemplars. However, adapting an argument provided by Kahan to account for results of Barnhardt et al (1996), we could speculate that possibly, if low-dЈ participants are shown a lowdominant target, they will make a long partial match between the related prime and the target, slowing responses to the target compared with the unrelated prime condition. If the target is a highdominant exemplar, low-dЈ participants will quickly make a complete match between the related prime and target before responding to the target.…”

Similarity and inhibition in long-term memory: Evidence for a two-factor theory.

“…If a competitor substantially overlaps the target in semantic space, enough of its representation may be in the attentional center so as to create facilitation rather than inhibition. This implication was tested recently by Barnhardt, Glisky, Polster, and Elam (1996), who showed that a very difficult retrieval of the meaning of an uncommon word on a prime trial actually facilitated a subsequent lexical decision for a direct synonym of the prime, even though it slowed lexical decision times to semantically similar nonsynonyms. Barnhardt et al argued that the facilitation of synonyms provides strong support for the centersurround theory because synonyms should occupy a region in semantic space that overlaps with the target, preventing them from being suppressed.…”

“…In particular, the reduction in retrieval-induced forgetting associated with target-competitor similarity in Experiment 1 may be produced by mechanisms similar to those thought to be at work in the study of Barnhardt et al (1996). If we assume that encoding target-competitor similarities brings a target and a competitor closer together in semantic space, some portion of the unpracticed competitor's representation might fall within the attentional center of the item being recalled during retrieval practice.…”