Effects of Competing Speech on Sentence-Word Priming: Semantic, Perceptual, and Attentional Factors

Effects of Competing Speech on Sentence-Word Priming: Semantic, Perceptual, and Attentional Factors Katherine Moll ( Katherine.Moll@keble.ox.ac.uk ) Keble College, University of Oxford Oxford OX1 3PG United Kingdom Eileen Cardillo ( Eileen.Cardillo@st-johns.ox.ac.uk ) Department of Experimental Psychology, University of Oxford South Parks Road, Oxford OX1 3UD United Kingdom Jennifer Aydelott Utman ( Jennifer.Utman@psy.ox.ac.uk ) Department of Experimental Psychology, University of Oxford South Parks Road, Oxford OX1 3UD United Kingdom Abstract This study examined the effects of a competing signal on sentence-word priming using an auditory lexical decision paradigm. Previous studies have suggested that the facilitatory component of the sentential priming effect is particularly sensitive to acoustic distortions that reduce the perceptibility of the sentence context, whereas the inhibitory component is more sensitive to increased attentional demand. Three competing signal conditions were compared: forward speech presented to a different ear, backward speech presented to a different ear, and forward speech presented to the same ear. The results demonstrate that the competing signal has different effects on priming depending upon the semantic content of the signal and its perceptual isolability from the sentence context. Introduction The influence of sentence meaning on lexical processing has been studied extenstively in sentence- word priming studies, which have demonstrated that sentence context has both facilitatory and inhibitory effects on responses to single words (e.g., Stanovich & West, 1983; Meyer & Schvaneveldt, 1976; Simpson, Peterson, Casteel, & Burgess, 1989; Duffy, Morris, & Henderson, 1989). In other words, reaction times for words preceded by a highly congruent sentence context are faster than those preceded by a neutral context, whereas responses to words presented in an incongruent are slowed relative to a neutral context. Further, facilitatory and inhibitory effects tend to emerge under different experimental conditions in both sentence-word and word-word priming studies. Specifically, facilitation effects emerge at brief stimulus onset asynchronies (SOAs), and are generally insensitive to expectancy and processing strategies (Neely, 1991; Utman & Bates, 1998a,b), to the extent that facilitation is observed even when a prime stimulus is presented briefly and then masked, such that subjects are not consciously aware of the identity of the prime (Neely, 1991). In contrast, inhibitory effects are more pronounced at longer SOAs, and are sensitive to factors that affect expectancy, such as the proportion of related/unrelated test trials in the stimulus set (Neely, 1991), and tend to be reduced in populations with limited attentional capacity (e.g., Faust, Balota, Duchek, Gernsbacher, & Smith, 1997). Based on this evidence, researchers have argued that facilitation occurs rapidly and requires little in the way of attentional and/or processing resources, whereas inhibition occurs later in the time course of lexical access, and may reflect more controlled or strategic processing (Faust & Gernsbacher, 1996; Gernsbacher, 1997; Neely, 1991; Utman & Bates, 1998a,b). Recent studies have revealed that the facilitatory and inhibitory components of the sentence-word priming effect respond differently to acoustic distortion of the semantic context. Specifically, facilitatory effects are particularly sensitive to distortions that reduce the intelligibility of the acoustic signal, whereas inhibitory effects are more sensitive to distortions that reduce processing time and/or increase attentional demand (Utman & Bates, 1998 a,b; Utman, Dick, Prat, & Mills, 1999). For example, low-pass filtering of the sentence context significantly reduces facilitation of congruent targets (Utman & Bates, 1998a,b). In contrast, temporal compression of the context significantly reduces inhibition of incongruent targets, but has no effect on facilitation (Utman & Bates, 1998a,b). These findings suggest that facilitation effects are more dependent on bottom-up information from the acoustic signal, whereas inhibition effects are more dependent on attentional resources. In the present study, we sought to investigate how competing speech influences the facilitatory and inhibitory components of the sentence-word priming