Pronunciation performance under speeded conditions was examined for various kinds of letter strings, including pseudohomophones (e.g., TRAX), their real word counterparts (e.g., TRACKS), and a set of nonword controls (e.g., PRAX). Experiment 1 yielded a pronunciation advantage for the pseudohomophones relative to the controls, which was largest among items having few or no orthographic neighbors. No effect of base word frequency was found on pseudohomophone pronunciation. Experiment 2 ruled out an account of the pseudohomophone advantage based on differences between pseudohomophones and controls in initial phonemes. Experiment 3 established the existence of a large frequency effect on pronunciation of the base words themselves. These results are taken to suggest that whole word representations in the phonological output lexicon are consulted in the course of assembling a pronunciation. Implications of this conclusion for theories of lexical involvement in the assembly of phonology are discussed. In contrast to all current accounts of word-frequency effects, the present results also suggest that representations in a phonological output lexicon are insensitive to word frequency. A distinction between lexical representations and the connections between lexical representations is made, and it is suggested that these connections are a source of word-frequency effects in naming.

The item-specific proportion congruent (ISPC) effect is the observation that the Stroop effect is larger for words that are presented mostly in congruent colours (e.g., BLUE presented 75% of the time in blue), and smaller for words that are presented mostly in a given incongruent colour (e.g., YELLOW presented 75% of the time in orange). One account of the ISPC effect, the modulation hypothesis, is that participants modulate attention based on the identity of the word (i.e., participants allow the word to influence responding when it is presented mostly in its congruent colour). Another account, the contingency hypothesis, is that participants use the word to predict the response that they will need to make (e.g., if the word is YELLOW, then the response is probably orange). Reanalyses of data from Jacoby, Lindsay, and Hessels (2003) along with results from new experiments are inconsistent with the modulation hypothesis, but entirely consistent with the contingency hypothesis. A response threshold mechanism for using contingency information is proposed and tested. Contingency Learning 3The Stroop Effect: Why Proportion Congruent has Nothing to do with Congruency and Everything to do with Contingency Contingency learning is a lively area of research (e.g., Jacoby, Lindsay, & Hessels, 2003;Musen & Squire, 1993;Schmidt, Crump, Cheesman, & Besner, 2007). One popular domain for this research is the Stroop paradigm. The standard Stroop effect is the finding that participants take longer to identify the print colour of an incongruent colour word (e.g., the word GREEN printed in red; GREEN red ) relative to a congruent colour word (RED red ;Stroop, 1935; see MacLeod, 1991, for a review). The magnitude of the Stroop effect changes when the proportion of congruent items is manipulated (Lowe & Mitterer, 1982). In particular, the Stroop effect increases as the proportion on congruent trials increases. The standard account of the influence of proportion congruent (Cheesman & Merikle, 1986;Lindsay & Jacoby, 1994;Lowe & Mitterer, 1982) is that the detection of these proportions allows participants to modulate attention to the word, thereby changing the size of the Stroop effect. However, Schmidt et al. (2007) suggest that simple contingency learning provides a sufficient account of the proportion congruency effect. Here, we provide a reanalysis of the Jacoby et al. participants use contingency information to control responding will also be considered. Proportion Congruency and the Modulation HypothesisA number of experiments (Cheesman & Merikle, 1986;Lindsay & Jacoby, 1994;Lowe & Mitterer, 1982) have shown that the magnitude of the Stroop effect can be modulated by varying the proportion of congruent trials. Specifically, the Stroop effect is larger when most of the items in the experiment are congruent (high proportion congruent) than when most of the Contingency Learning 4 items are incongruent (low proportion congruent). The standard explanation of this effect (Cheesman & Merikle, 1986;Lindsay & Jacoby, 1994;Lowe ...

Although many models of word recognition have postulated loci for the simple effects of Context, Stimulus Quality, and Word Frequency, most of them are problematic in that they do not account for the pattern of joint effects among these factors. The experiments reported here show that, among other things, Word Frequency interacts with Context but is additive with Stimulus Quality in the context of a lexical decision experiment that also produces an interaction between Stimulus Quality and Context. The pattern of joint effects among these factors is accommodated by a multistage activation model that is based on the framework proposed by Besner and Smith (1992a).

A widespread view in cognition is that once acquired through extensive practice, mental skills such as reading are automatic. Lexical and semantic analyses of single words are said to be uncontrollable in the sense that they cannot be prevented. Over the past 60 years, apparently convincing support for this assumption has come from hundreds of experiments in which skilled readers have processed an irrelevant word in the Stroop task despite explicit instructions not to, even when so doing would hurt color identification performance. This basic effect was replicated in two experiments, which also showed that a considerable amount of semantic processing is locally controlled by elements of the task. For example, simply coloring a single letter instead of the whole word eliminated the Stroop effect. This outcome flies in the face of any automaticity account in which specified processes cannot be prevented from being set in motion, but it is consistent with the venerable idea that mental set is a powerful determinant of performance. 221Many low-level human behaviors are automatic, in that a stimulus serves to elicit the behavior in the absence of conscious awareness or intention (e.g., an eye blink in response to a puff of air; the patellar reflex; the Babinski reflex), Learned behaviors such as reading are also widely argued to be automatic in a similar sense. For example, it is well established that identifying the color of an incongruent word (e.g., green letters spelling the word "red") is slower than identifying the color of a congruent word (e.g., green letters spelling the word "green"). This Stroop effect (Stroop, 1935) and its many variants have been explored empirically, theoretically, and computationally by cognitive and developmental psychologists, psycholinguists, neuropsychologists, and cognitive scientists in more than 500 papers over the past 60 years (see MacLeod's 1991 review). A core assumption of virtually all the theoretical accounts is that skilled readers process the irrelevant word without consciousness or intent. Reading the word is said to be automatic in the sense that readers cannot refrain from computing the meaning of the word despite explicit instructions not to do SO:I Reading is such an automatic process that it is difficult to inhibit and it will interfere with processing other information about the word.

The results of four experiments provide evidence for controlled processing in the absence of awareness. Participants identified the colour of a neutral distracter word. Each of four words (e.g., MOVE) was presented in one of four colours 75% of the time (Experiments 1 and 4) or 50% of the time (Experiment 2 and 3). Colour identification was faster when the words appeared in the colour they were most often presented in relative to when they appeared in another colour, even for participants who were subjectively unaware of any contingencies between the words and colours. An analysis of sequence effects showed that participants who were unaware of the relation between distracter words and colours nonetheless controlled the impact of the word on performance depending on the nature of the previous trial. A block analysis of contingencyunaware participants revealed that contingencies were learned rapidly in the first block of trials.Experiment 3 showed that the contingency effect does not depend on level of awareness, thus ruling out explicit strategy accounts. Finally, Experiment 4 showed that the contingency effect results from behavioural control and not from semantic association or stimulus familiarity. These results thus provide evidence for implicit control. Implicit Control 3Contingency Learning without Awareness: Evidence for Implicit Control Cognitive processes that are controlled are conventionally assumed to operate in a slow, effortful, and voluntary manner (Posner & Cohen, 1984;Posner & Snyder, 1975; Shiffrin & Schnieder, 1977). Thus, when researchers discuss the influence of "controlled" processes, it is typically assumed that such processes are explicit (i.e., conscious; cf., Besner & Stolz, 1999). As such, the term "implicit control" would seem to be nonsensical, because "implicit" (i.e., unconscious) seems to preclude the possibility of control. However, etymologically speaking this is not a necessary conclusion. The Oxford English Dictionary (2001) Evidence for cognitive control, which is assumed to be explicit and strategic in nature, has been drawn from the Stroop literature (Stroop, 1935). In the Stroop task, identification of the print colour of colour words is slower when the word and ink colour are incongruent (e.g., the word GREEN in orange; GREEN orange ) than when they are congruent (e.g., ORANGE orange ; see MacLeod, 1991, for a review). Probably the most important demonstration of putatively controlled processes in the Stroop literature is the proportion congruent effect. The proportion congruent effect refers to the finding that the size of the Stroop effect is influenced by the proportion of congruent items in a block of trials (Lindsay & Jacoby, 1994;Logan & Zbrodoff, 1979). Specifically, the Stroop effect is much larger in a high proportion congruent block of trials than in a low proportion congruent block of trials. This effect is commonly attributed to Implicit Control 4 participants explicitly learning to predict the colour from the word. Specifically, because the word us...

The spelling-sound correspondences in written Persian are always consistent, but some of the words include vowels as a fixed part of their spelling (phonologically transparent words), whereas for other words the vowels are typically not specified (phonologically opaque words). Two speeded naming studies show that semantic relatedness and word frequency affect performance (a) on both classes of words when the context excludes nonwords, and (b) affects opaque words but not transparent words when nonwords form part of the context. A further study shows that (a) transparent words yield word frequency effects when nonwords are absent from the context, and (b) the frequency effect disappears when nonwords form part of the context. The data favor a flexible multiple route model of word recognition whose operation is inconsistent with both the orthographic depth hypothesis and the definitional facts of parallel distributed processing.

M. M. Botvinick, T. S. Braver, D. M. Barch, C. S. Carter, and J. D. Cohen (2001) implemented their conflict-monitoring hypothesis of cognitive control in a series of computational models. The authors of the current article first demonstrate that M. M. Botvinick et al.'s (2001) conflict-monitoring Stroop model fails to simulate L. L. Jacoby, D. S. Lindsay, and S. Hessels's (2003) report of an item-specific proportion-congruent (ISPC) effect in the Stroop task. The authors then implement a variant of M. M. Botvinick et al.'s model based on the assumption that control must be able to operate at the item level. This model successfully simulates the ISPC effect. In addition, the model provides an alternative to M. M. Botvinick et al.'s explanation of the list-level proportion-congruent effect in terms of an ISPC effect. Implications of the present modeling effort are discussed.

Parallel distributed processing (PDF) models represent a new and exciting approach to the study of visual word recognition in reading. Seidenberg and McClelland's (1989) model is examined because the strongest and widest claims for the viability of a connectionist account of visual word recognition have been made on the basis of their model. The current implemented version of their model fails to account for important facts concerning how human subjects read aloud and carry out lexical decisions, despite the fact that these tasks are central to the performance domain that the model purports to explain. The incorporation of multiple routines and an explicit lexical level of representation into the model may help resolve some of the difficulties. OverviewEvery field has its sacred cows, and visual word recognition is no exception. Two such sacred cows are the assumptions that (a) the mind contains several lexica of word forms and (b) there are a number of routines that make use of these word forms in various ways to read aloud, make lexical decisions, and access meaning. These assumptions are common to many otherwise quite different word-recognition models (e.g., see Besner & Mc-Cann, 1987;Besner & Johnston, 1989;Carr&Pollatsek, 1985;Norris, 1986). Moreover, these basic assumptions had gone unchallenged until recently. The parallel distributed processing (PDF) model developed by McClelland and his colleagues (e.g.,