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Unlike other visual objects which are invariant to the left-right orientation, mirror letters (e.g., b and d) represent different object identities. Previous masked priming lexical decision studies have suggested that the identification of a mirror letter involves suppression of its mirror image counterpart reporting as evidence that a pseudoword prime containing the mirror letter counterpart slowed down the recognition of target word relative to a control prime containing an unrelated letter (e.g., ibea-idea > ilea-idea). Furthermore, it has been reported recently that this inhibitory mirror priming effect is sensitive to the distributional bias of left/right orientation in the Latin alphabet such that only the more dominant (frequent) right-facing mirror letter prime (e.g., b) produced interference. In the present study, we examined mirror letter priming with single letters and nonlexical letter strings with adult readers. In all experiments, relative to a visually dissimilar control letter prime, both the right-facing and left-facing mirror letter prime consistently facilitated, rather than slowed down the recognition of a target letter (e.g., b-d < w-d). Assessed against an identity prime, mirror primes showed a rightward bias, although it was small in magnitude and not always significant within an individual experiment. These results provide no support for a mirror suppression mechanism in the identification of mirror letters, and an alternative interpretation in terms of noisy perception is suggested.

Social-cognitive models propose that the other-race effect in face recognition is caused by different motivational tendencies when processing own- and other-race faces. More specifically, we tend to individuate own-race faces which facilitates face recognition, but racially categorize other-race faces which inhibits face recognition. This study tests whether a novel experimental manipulation aimed at promoting individuation or categorization encoding of faces moderates the other-race effect in an old/new recognition task. We found that categorization encoding eliminated the other-race effect when list length was short (Experiment 2) but not when list length was long (Experiment 1B). Inconsistent with social-cognitive predictions, individuation encoding failed to reduce the other-race effect, regardless of list length. We compare these findings with previous attempts to promote individuation and categorization encoding and suggest that the recognition benefits of individuation encoding might be more limited for faces that are most difficult to individuate i.e., other-race faces.

The present study investigated how response mode (oral vs. manual) modulates the Stroop effect using a picture variant of the Stroop task in which participants named orally, or identified with a manual keypress, line drawings of animals (e.g., camel). Consistent with previous color-response Stroop studies, relative to the nonlinguistic neutral distractor (a row of "#" symbols), incongruent distractors (e.g., GIRAFFE) interfered with responding to pictures, and that interference was reduced for the manual, compared with the oral, response. Additionally, pseudoword distractors with no phonological overlap with the picture name (e.g., NUST--camel) interfered with the oral, but not the manual, response. The novel finding is that relative to this pseudoword distractor, the oral response was facilitated when the distractor shared the onset segment with the picture name, regardless of orthographic overlap (e.g., CUST--camel = KUST--camel < NUST--camel); in contrast, for the manual response, there was no difference between the three pseudoword distractor conditions. These results are explained in terms of phonological encoding, a speech production process involved in computing a phonetic plan for generating an oral, but not a manual, response.

It is well-established that allographs like the uppercase and lowercase forms of the Roman alphabet (e.g., a and A) map onto the same "abstract letter identity," orthographic representations that are independent of the visual form. Consistent with this, in the allograph match task ("Are 'a' and 'A' the same letter?"), priming by a masked letter prime is equally robust for visually dissimilar prime-target pairs (e.g., d and D) and similar pairs (e.g., c and C). However, in principle this pattern of priming is also consistent with the possibility that allograph priming is purely phonological, based on the letter name. Because different allographic forms of the same letter, by definition, share a letter name, it is impossible to rule out this possibility a priori. In the present study, we investigated the influence of shared letter names by taking advantage of the fact that Japanese is written in two distinct writing systems, syllabic kana--that has two parallel forms, hiragana and katakana--and logographic kanji. Using the allograph match task, we tested whether a kanji prime with the same pronunciation as the target kana (e.g., ?- ?, both pronounced /i/) produces the same amount of priming as a kana prime in the opposite kana form (e.g., ?- ?). We found that the kana primes produced substantially greater priming than the phonologically identical kanji prime, which we take as evidence that allograph priming is based on abstract kana identity, not purely phonology.

Using the oral and manual Stroop tasks we tested the claim that retrieval of meaning from a written word is automatic, in the sense that it cannot be controlled. The semantic interference effect (greater interference caused by color-related words than color-neutral words) was used as the index of semantic activation. To manipulate the level of attentional control over the task of reading, the proportion of nonreadable, neutral trials (a row of #s) was varied (75% vs. 25%). In all four experiments a high-neutral proportion magnified the interference caused by word distractors. With the color-associated words presented in incongruent color (e.g., LEMON in blue), the semantic Stroop effect was weak and did not interact with neutral proportion (Experiment 1 and 2). Experiment 3 and 4 used color names (e.g., GREEN) not in the response set, and here the semantic interference effect was more robust, and the effect was magnified in the high-neutral proportion condition. We take these results to argue that semantic retrieval is controlled by endogenous attention in the Stroop task.

In 2 variants of the color-word Stroop task, we compared 5 types of color-neutral distractors--real words (e.g., "HAT"), pseudowords (e.g., "HIX"), consonant strings (e.g., "HDK"), symbol strings (e.g., #$%), and a row of Xs (e.g., "XXX")--as well as incongruent color words (e.g., "GREEN" displayed in red). When participants named the color, relative to a row of Xs, words and pseudowords interfered equally and more than the consonant strings, which in turn interfered more than the symbols. In contrast, when participants identified the color by manual key-press responses, all 5 types of neutral strings produced equal color response latencies. In both tasks, the incongruent color words produced robust interference relative to the color-neutral words. Reaction time (RT) distribution analyses showed that all interference effects (relative to the row of Xs) increased across the quantiles. We interpret these results in terms of an evidence accumulation process in which the interfering distractor reduces the effective rate of evidence accumulation for the color target. We take the results to argue that the task of reading, even when triggered unintentionally, is not an invariant process driven solely by the stimulus properties, and is instead guided by the task goal.

Semantic priming effects are popularly explained in terms of an automatic spreading activation process, according to which the activation of a node in a semantic network spreads automatically to interconnected nodes, preactivating a semantically related word. It is expected from this account that semantic priming effects should be routinely observed when the prime identity is veiled from conscious awareness, but the extant literature on masked semantic priming effects is notoriously mixed. The authors use the same prime--target pairs in the lexical decision task and the semantic categorization task and show that although masking the prime eliminates the semantic priming effect in lexical decision, reliable semantic priming effects are observed with both masked and unmasked primes in the semantic categorization task. The authors explain this task dependence in terms of their account of semantic priming effects based on notions of evidence accumulation and source confusion and support their account by means of reaction time distribution analyses.

Semantic priming effects at a short prime-target stimulus onset asynchrony are commonly explained in terms of an automatic spreading activation process. According to this view, the proportion of related trials should have no impact on the size of the semantic priming effect. Using a semantic categorization task ("Is this a living thing?"), we show that on the contrary, there is a robust effect of relatedness proportion on the size of the semantic priming effect. This effect is not due to the participants using the prime to predict the target category/response, as manipulating the proportion of category/response-congruent trials produces a very different pattern. Taken together with response time distribution analysis, we argue that the semantic priming effect observed here is best explained in terms of an evidence accumulation process and source confusion between the prime and target.

People are better at recognizing own-race faces than other-race faces. This other-race effect in face recognition typically manifests in sensitivity (i.e., better discrimination). However, research also consistently finds that people respond more liberally (and thus produce more false alarm errors) when recognizing other-race faces, rather than own-race faces. In an old/new recognition paradigm, we examined whether providing White participants with base rate information could attenuate the differences that they demonstrate, both in terms of response bias and sensitivity, when attempting to recognize Black and White faces. During the test phase of an old/new recognition task, participants viewed own-race and other-race faces surrounded by a red or green border. Participants were informed that these borders indicated a 25 percent or 75 percent likelihood of the face having been presented earlier. Border cues were either valid (Experiment 1) or invalid (actual probability was 50%; Experiment 2). Across both experiments, participants shifted their response criterion in line with border cues but did so equally for own-race and other-race faces. This finding suggests that the liberal bias for other-race faces is likely to originate early during encoding and is unlikely to be moderated by manipulations that target later, decision-making processes operating during retrieval. [ABSTRACT FROM AUTHOR]

The goal of research on how letter identity and order are perceived during reading is often characterized as one of "cracking the orthographic code." Here, we suggest that there is no orthographic code to crack: Words are perceived and represented as sequences of letters, just as in a dictionary. Indeed, words are perceived and represented in exactly the same way as other visual objects. The phenomena that have been taken as evidence for specialized orthographic representations can be explained by assuming that perception involves recovering information that has passed through a noisy channel: the early stages of visual perception. The noisy channel introduces uncertainty into letter identity, letter order, and even whether letters are present or absent. We develop a computational model based on this simple principle and show that it can accurately simulate lexical decision data from the lexicon projects in English, French, and Dutch, along with masked priming data that have been taken as evidence for specialized orthographic representations. (Contains 6 footnotes, 7 tables, and 21 figures.)

In lexical decision, to date few studies in English have found a reliable pseudohomophone priming advantage with orthographically similar primes (the "klip-plip effect"; Frost, Ahissar, Gotesman, & Tayeb, 2003; see Rastle & Brysbaert, 2006, for a review). On the basis of the Bayseian reader model of lexical decision (Norris, 2006, 2009), we hypothesized that this was because in previous studies, lexical decisions could have been made without finding a match between the input and a unique lexical representation. Consistent with our hypothesis, we found that words from dense neighborhoods showed neither an orthographic form priming effect nor a pseudohomophone priming advantage; in contrast, with words from a sparse lexical neighborhood, a sizeable orthographic form priming effect was found, and a robust pseudohomophone priming advantage, which was not limited to the overlap of onset phoneme, was also observed. Identity primes produced greater facilitation than pseudohomophone primes. We consider the implication of these findings for the role of assembled phonology in lexical access. (Contains 3 tables and 8 footnotes.)

Theories of language production generally describe the segment as the basic unit in phonological encoding (e.g., Dell, 1988; Levelt, Roelofs, & Meyer, 1999). However, there is also evidence that such a unit might be language specific. Chen, Chen, and Dell (2002), for instance, found no effect of single segments when using a preparation paradigm. To shed more light on the functional unit of phonological encoding in Japanese, a language often described as being mora based, we report the results of 4 experiments using word reading tasks and masked priming. Experiment 1 demonstrated using Japanese kana script that primes, which overlapped in the whole mora with target words, sped up word reading latencies but not when just the onset overlapped. Experiments 2 and 3 investigated a possible role of script by using combinations of romaji (Romanized Japanese) and hiragana; again, facilitation effects were found only when the whole mora and not the onset segment overlapped. Experiment 4 distinguished mora priming from syllable priming and revealed that the mora priming effects obtained in the first 3 experiments are also obtained when a mora is part of a syllable. Again, no priming effect was found for single segments. Our findings suggest that the mora and not the segment (phoneme) is the basic functional phonological unit in Japanese language production planning. (Contains 3 footnotes and 7 tables.)

In reaction time research, there has been an increasing appreciation that response-initiation processes are sensitive to recent experience and, in particular, the difficulty of previous trials. From this perspective, the authors propose an explanation for a perplexing property of masked priming: Although primes are not consciously identified, facilitation of target processing by a related prime is magnified in a block containing a high proportion of related primes and a low proportion of unrelated primes relative to a block containing the opposite mix (Bodner & Masson, 2001). In the present study, this phenomenon is explored with a parity (even/odd) decision task in which a prime (e.g., 2) precedes a target that can be either congruent (e.g., 4) or incongruent (e.g., 3). It is shown that the effect of congruence proportion with masked primes cannot be explained in terms of the blockwise prime-target contingency. Specifically, with masked primes, there is no congruency disadvantage in a block containing a high proportion of incongruent primes, but there is a congruency advantage when the block contains an equal proportion of congruent and incongruent primes. In qualitative contrast, visible primes are sensitive to the blockwise prime-target contingency. The authors explain the relatedness proportion effect found with masked primes in terms of a model according to which response-initiation processes adapt to the statistical structure of the environment, specifically the difficulty of recent trials. This account is supported with an analysis at the level of individual trials using the linear mixed effects model. (Contains 6 tables, 5 figures and 6 footnotes.)

Using the same-different task, Perea, Dunabeitia, Pollatsek, and Carreiras (2009) showed that digits resembling letters ("leet digits"; e.g., 1 = "I", 4 = "A") primed pseudoword strings (e.g., "V35Z3D-VESZED"), but letters resembling digits ("leet letters") did not prime digit strings (e.g., "9ES7E2-935732"), and suggested that this is due to top-down feedback available for letter, but not digit, strings. Here we show that (a) single letters show as much leet priming as 3-letter words (Experiment 1); (b) leet priming is equally robust for digit strings and pseudowords when the string is 4 items long but not when 6 items long (Experiment 2); and (c) with 6-item strings, orthotactically illegal letter strings (e.g., "OIAUEQ") behave just like digit strings (Experiment 3). These results indicate that the asymmetry in leet priming is not due to top-down feedback available selectively for letter strings. We offer an alternative explanation based on the Bayesian reader account of masked priming proposed by Norris and Kinoshita (2008), and the role played by the orthotactic knowledge used to extend the functional capacity of visual working memory involved in performing the same-different task. (Contains 4 tables, 2 figures and 3 footnotes.)

Early on during word recognition, letter positions are not accurately coded. Evidence for this comes from transposed-letter (TL) priming effects, in which letter strings generated by transposing two adjacent letters (e.g., "jugde") produce large priming effects, more than primes with the letters replaced in the corresponding position (e.g., "junpe"). Dominant accounts of TL priming effect such as the Open Bigrams model ([Grainger and van Heuven, 2003] and [Whitney and Cornelissen, 2008]) and the SOLAR model (Davis & Bowers, 2006) explain this effect by proposing a higher level of representation than individual letter identities in which letter position is not coded accurately. An alternative to this is to assume that position coding is noisy (e.g., Gomez, Ratcliff, & Perea, 2008). We propose an extension to the Bayesian Reader (Norris, 2006) that incorporates letter position noise during sampling from perceptual input. This model predicts "leakage" of letter identity to nearby positions, which is not expected from models incorporating alternative position coding schemes. We report three masked priming experiments testing predictions from this model. (Contains 3 tables and 5 figures.)

A prime generated by transposing two internal letters (e.g., jugde) produces strong priming of the original word (judge). In lexical decision, this transposed-letter (TL) priming effect is generally weak or absent for nonword targets; thus, it is unclear whether the origin of this effect is lexical or prelexical. The authors describe the Bayesian Reader theory of masked priming (D. Norris & S. Kinoshita, 2008), which explains why nonwords do not show priming in lexical decision but why they do in the cross-case same-different task. This analysis is followed by 3 experiments that show that priming in this task is not based on low-level perceptual similarity between the prime and target, or on phonology, to make the case that priming is based on prelexical orthographic representation. The authors then use this task to demonstrate equivalent TL priming effects for nonwords and words. The results are interpreted as the first reliable evidence based on the masked priming procedure that letter position is not coded absolutely within the prelexical, orthographic representation. The implications of the results for current letter position coding schemes are discussed.

Masked repetition primes produce greater facilitation in naming in a block containing a high, rather than low proportion of repetition trials. [Bodner, G. E., & Masson, M. E. J. (2004). "Beyond binary judgments: Prime-validity modulates masked repetition priming in the naming task". "Memory & Cognition", 32, 1-11] suggested this phenomenon reflects a strategic shift in the use of masked prime as a function of its validity. We propose an alternative explanation based on the "Adaptation to the statistics of the environment (ASE)" framework, which suggests the proportion effect reflects adaptation of response-initiation processes to recent trial difficulty. Consistent with ASE's prediction, (1) stimuli that produce the proportion effect also produced an "asymmetric blocking effect", showing a smaller fall in response latencies of hard items than the rise of easy items when the two item types were intermixed relative to pure blocks comprised of only one item type, and (2) manipulation of prime validity was neither necessary nor sufficient to modulate the size of masked-priming effect.

In semantic categorization, masked primes that are category-congruent with the target (e.g., "Planets: mars-VENUS") facilitate responses relative to category-incongruent primes (e.g., "tree-VENUS"). The present study investigated why this category congruence effect is more consistently found with narrow categories (e.g., "Numbers larger/smaller than 5, Planets") than with broad categories (e.g., "Animals"). Experiments 1 and 2 used broad and narrow categories, respectively, and both experiments showed robust frequency effects for non-exemplar targets. This was in contradiction to Forster's [Forster, K. I. (2004). Category size effects revisited: Frequency and masked priming effects in semantic categorization. "Brain & Language," 90(1-3), 276-286.] category search hypothesis, which suggests that frequency-sensitive lexical access is by-passed for narrow categories. These experiments also showed that for non-exemplar targets, semantic feature overlap of non-exemplar primes (e.g., "pistol-RIFLE" vs. "boots-RIFLE") facilitated NO decisions for a broad category but not narrow categories. Experiments 3 and 4 showed that non-exemplar primes which share features with members of narrow categories (e.g., "Planets: moon"), which we call "impostors", facilitated responses to exemplar targets and interfered with responses to non-exemplar targets, relative to unrelated non-exemplar primes. These results suggest that category decisions are made by selectively monitoring semantic features relevant to, but not restricted to those that define, category membership, and they inform the debate regarding the extent to which masked primes are processed semantically.

The authors argue that perception is Bayesian inference based on accumulation of noisy evidence and that, in masked priming, the perceptual system is tricked into treating the prime and the target as a single object. Of the 2 algorithms considered for formalizing how the evidence sampled from a prime and target is combined, only 1 was shown to be consistent with the existing data from the visual word recognition literature. This algorithm was incorporated into the Bayesian Reader model (D. Norris, 2006), and its predictions were confirmed in 3 experiments. The experiments showed that the pattern of masked priming is not a fixed function of the relations between the prime and the target but can be changed radically by changing the task from lexical decision to a same-different judgment. Implications of the Bayesian framework of masked priming for unconscious cognition and visual masking are discussed. (Contains 4 figures, 5 tables and 1 footnote.)

Previous studies of letter recognition have not found priming for abstract letter identities. We used a task that required participants to decide whether a target is the same or different from a reference letter presented in opposite case, which avoids the shortcomings of tasks used in previous studies. We found robust priming effects in this task, which were the same size for letter pairs that have similar visual features across case (e.g., c/C, x/X) and dissimilar features (e.g., a/A, b/B). Also, the pattern of priming was the same whether the prime was in the same or different case as the reference. We take these findings as evidence that abstract letter identities support priming in this task. We suggest that the same--different match task is a useful tool for studying representations used to support masked priming in letter recognition and with other stimuli with limited set size. Keywords: Abstract letter identity; Letter recognition; Masked priming.