The concept of activation is a critical component of many models of cognition. A key characteristic of activation is that recent experience with a concept or stimulus increases the accessibility of the corresponding representation. The extent to which increases in accessibility occur as a result of experiences outside of laboratory settings has not been extensively explored. In the present study, we presented lexical stimuli associated with different holidays and festivities over the course of a year in a lexical decision task. When stimulus meaning and time of testing were congruent (e.g., leprechaun in March), response times were faster and accuracy greater than when meaning and time of test were incongruent (e.g., leprechaun in November). Congruency also benefited performance on a surprise free recall task of the items presented earlier in the lexical decision task. The discussion focuses on potential theoretical accounts of this heightened accessibility of time-of-the-year-relevant concepts.
Activation is a fundamental construct in many classic models of cognition (e.g., Anderson, 1983; Collins & Loftus, 1975; Dell, 1986). In its simplest instantiation, a concept or mental representation is activated directly, through the presentation of an eliciting stimulus, or indirectly, through the presentation of a similar or related stimulus. An activated representation results in shorter response times (RTs) and greater accuracy relative to a representation that is not activated above its baseline level. For example, in semantic and repetition priming experiments, a target (e.g., dog) preceded either by itself (dog) or a related prime (cat) produces facilitation relative to when it is preceded by an unrelated prime (chair). Activation, as it is conceptualized by most models, is assumed to be short-lived, such that representations return quickly to baseline, through rapid decay or because of a more active dampening process (e.g., Anderson, 1983; Dell, 1986). Some degree of attention to the stimulus is required to keep it activated in order to avoid the overload of countless sources of activation, at least in rich linguistic contexts (e.g., Balota & Lorch, 1986; Bowers, 2000). However, there is also evidence that conscious processing of stimuli is not necessary for representations to become active (e.g., Bodner & Masson, 1997), although, for masked stimuli, the activation is often very short-lived.
An alternative account proposes that, instead of activation of abstract mental representations, priming effects are the result of retrieval processes (Tenpenny, 1995; Whittlesea & Jacoby, 1990). Recent experience with a stimulus produces a memory trace, which is retrieved to facilitate processing on a subsequent encounter with the same or a similar stimulus (see Hintzman, 1986). Over time, the traces decay. A key difference between the activation and retrieval accounts is in the nature of the representations: Whereas activation accounts assume the existence of stored, relatively abstract representations that are susceptible to changes in accessibility over time, retrieval accounts do not necessarily posit the existence of abstract representations but assume that episodically laid memory traces become more accessible following recent or frequent experience (see Neely, 1991, for a discussion of these theoretical perspectives).
Given the amount of stimuli that an individual is exposed to on a daily basis, it seems plausible that not every stimulus would undergo a measurable change in activation or accessibility, but only those stimuli that are relevant to current processing would yield measurable changes in activation that extend across situational contexts. To our knowledge, the question of how naturalistic experience with a stimulus (i.e., exposure outside of an experimental setting) influences accessibility has received relatively little empirical attention in the literature. Furthermore, the extent to which a concept's accessibility changes over time and persists across different contextually defined experiences has been somewhat unexplored. …