نشانه تفسیری و ابهام در اختلال اضطراب فراگیر

The current study investigated whether generalized anxiety disorder (GAD) individuals rely on antecedent information to interpret ambiguity and whether reliance on such preceding cues persists in the absence of potential threat. Twenty-six GAD and 23 nonanxious control college students performed a lexical decision task, using homographs (i.e. words with multiple meanings) as ambiguous primes. In half the trials, a homograph prime that possessed both threat-related, as well as neutral meanings was followed by a target word related to one of these two meanings. In addition, each ambiguous prime was immediately preceded by a series of four antecedent words that were either: (a) associated with the threatening meaning of the prime; (b) associated with the neutral meaning of the prime; or (c) unrelated to either meaning of the homograph, as well as the target. Homographs for which both meanings were neutral in valence comprised the other half of the trials. Effect size statistics suggest that GAD participants utilized the antecedent words to interpret the homograph primes with threat-related meanings, unlike their nonanxious counterparts (p<0.06). When both meanings of the homograph prime were neutral in valence, the GAD group appeared deficient in the use of preceding information to interpret the ambiguous prime.

Anxious individuals are more likely than nonanxious individuals to interpret ambiguous stimuli as threatening. In a comprehensive recent review of this literature, MacLeod (in press) described several studies finding evidence for an interpretive threat bias among GAD samples. However, methodological limitations including experimenter demand characteristics, reliance on participant self-report, potential response selection biases, and possible memory biases were identified. Experimentally rigorous investigations of trait-anxious participants have addressed these concerns, but interpretive biases of GAD individuals have not been explored with these superior methods (MacLeod, in press; Aikins & Craske, 2001). In one such trait-anxiety study, Richards and French (1992) utilized homographs as ambiguous stimuli in a lexical decision task. In this experimental paradigm, words with both threat-related and neutral meanings (threat/neutral homographs) were presented on a computer screen as ambiguous primes (e.g. batter, shot). Threat/neutral homograph primes were immediately followed by target words in the context of a lexical decision task (i.e. a task in which participants are instructed to decide whether the target string of letters is an actual word or a non-word). Each word target was consistent with one of the two meanings of the homograph or unrelated to the homograph. The speed with which participants responded to each target indicated the degree to which their performance on that trial was facilitated by the prime. Richards and French found that when presented with homograph primes containing both neutral and threatening possible meanings, high trait-anxious individuals accessed the threatening meanings more readily than their low trait-anxious counterparts (as evidenced by faster reaction times to the threat-related targets relative to unrelated targets). Similar lexical decision task results were found for test anxiety participants when ambiguous sentences served as primes (Calvo, Eysenck, & Estevez, 1994). MacLeod and Cohen (1993) presented high and low trait-anxious participants with sentence pairs, administered one sentence at a time at a self-paced rate. The first sentence of each pair was ambiguous, while the subsequent sentence disambiguated the first sentence consistent with either its threatening or its non-threatening meaning. Each trial was preceded by a cue word reflecting either meaning of the ambiguous sentence or by a cue word unrelated to the ambiguous sentence. Comprehension latency results suggested that high trait-anxiety participants were more prone than low trait-anxiety participants to interpret the ambiguous sentence as threatening. Of particular interest, MacLeod and Cohen also found a general slowing in comprehension latencies when the cue word suggested one meaning for an ambiguous sentence, but the continuation sentence reflected its other meaning. If anxious individuals are more likely than nonanxious individuals to interpret such ambiguity as threatening, they might also rely more on available preceding information to make their interpretations. Such a finding would extend previous interpretive bias research to more naturalistic conditions, as naturally occurring ambiguity in the environment rarely appears in the absence of preceding interpretive cues.