Basic processes in reading: Two phonological codes.

In Exp I, 16 undergraduates viewed letter strings that varied in phonological similarity and lexical status. Under a no-interference condition, phonologically distinct lists were better recalled than phonologically confusable ones, and lists with entries in a phonological lexicon (e.g., BRANE) were better recalled than lists without lexical status (e.g., SLINT). When Ss were required to articulate irrelevant sounds, the phonological similarity effect was completely eliminated, but a lexicality effect persisted. In Exp II, another 16 Ss viewed letter strings that varied in syllabic length and lexical status. Pseudohomophones were better recalled than control nonwords under both quiet and articulation conditions, but a syllabic length effect was obtained only in the no-articulation condition. Results show that at least 2 phonological codes underlie performance in a memory-span task. The 1st code permits lexical access from print; suppression does not prevent this code from accessing lexical memory. The 2nd underlies both word length and phonological similarity effects in span; suppression prevents the formation or utilization of this code. Implications for understanding normal reading and developmental reading problems are noted. (French abstract) (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming by numb3r5 does not involve top-down feedback.

Using the same–different task, Perea, Du?abeitia, 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Basic processes in reading: Computation of abstract letter identities.

A speeded classification experiment examined the hypothesis that an early processing stage in reading involves the computation of abstract letter identities. When 20 undergraduates were asked to base their classification on physical criteria, letter strings that differed in case but shared the same letter identities (e.g., HILE/hile) were classified as "different" less efficiently than strings with a common phonological code but different spelling (e.g., HILE/hyle). Letter strings with a common phonological code but different spelling were classified as efficiently as letter strings without a common phonological code (e.g., HILE/hule). Results of the present experiment, along with other experimental findings and some neuropsychological observations, provide converging evidence for a representation and comparison process that is neither visual nor phonological but is based on abstract letter identities. It is suggested that the computation of abstract letter identities is a precursor to lexical access during reading. Implications for the interpretation of certain developmental reading difficulties are noted. (French abstract) (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming and response selection processes in letter classification and identification tasks.

The processing of isolated visual letters was studied by means of a priming paradigm. In alphabetic (letter vs nonletter) classification, any letter prime reduced response times to letter targets. Additional facilitation occurred only with primes physically identical to the target. In letter naming, facilitation was seen with primes nominally identical to the target even when they were physically different. This result is not due to phonological priming because phonologically similar primes had no effect on naming times. Primes nominally different from the target but physically similar to it increased naming times. The classification task seems to be performed through the global monitoring of stored visual knowledge of letters. In contrast, the absolute identification of letters appears to rest on a signal-to-noise statistic derived from an abstract encoding of letter identities. Connectionist simulations provide support for these proposals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual interactions in two-word displays: Familiarity and similarity effects.

Previous studies have demonstrated the existence of perceptual interactions in the processing of 2-word displays such as SAND LANE. Four experiments were conducted with 99 undergraduates to study the role of familiarity and similarity of the stimuli on these interactions. Exp I examined whether migration errors, and the effect of surround similarity on these errors depend on the fact that the migrating letters fit together with the surround in which they occur to form familiar higher order units. Exp II replicated the results of Exp I using a slightly different paradigm. Exp III examined the role of lexicality, independent of orthographic regularity, by comparing word stimuli to orthographically regular nonword stimuli, and Exp IV examined the role of physical, as opposed to abstract, similarity of the stimuli. Overall findings indicate that when postcued to report 1 of the 2 words, Ss often made migration errors, in that the report of the specified word included a letter of the other word (e.g., LAND or SANE instead of SAND). Migrations depended on the abstract, structural similarity of the strings, but not on the physical similarity; on whether the strings were words; and on whether the possible migration responses were words. Results reveal that migration errors could not be attributed to a guessing strategy. Findings are interpreted in terms of models in which both strings simultaneously access high-level structural knowledge about what sequences of letters fit together to form familiar wholes. (50 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociative prime–probe contextual similarity effects on negative priming and repetition priming: A challenge to episodic retrieval as a unified account of negative priming.

This study examined the dependence of repetition priming (RP) and negative priming (NP) as a function of prime–probe contextual similarity in a paradigm in which participants were required to respond to a letter flanked by incompatible distractor letters (e.g., ABA). Experiment 1 used prime and probe displays containing a pair of "+" symbols that were presented horizontally or vertically. Experiments 2 and 3 manipulated whether the letter triplets contained the "!" symbol. In all experiments, regardless of whether the RP trials were intermixed with the NP trials (Experiment 2) or not (Experiment 3), RP was stronger in the prime–probe similar conditions than in the prime–probe dissimilar conditions, but NP was independent of prime–probe contextual similarity. These findings suggest that NP is not necessarily stronger in conditions in which episodic retrieval of the prime is more likely. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chunks are not enough: The insufficiency of feature frequency-based explanations of artificial grammar learning.

Two experiments with a total of 104 undergraduates tested chunk frequency explanations of artificial grammar learning, which hold that classification performance is dependent on some metric derived from the frequency with which certain features occur within the letter string stimuli. Exp 1 revealed that classification performance was affected by close graphemic similarity between specific training (e.g., MXRVXT) and test strings (e.g., MXRMXT), despite the fact that similar strings did not contain frequently occurring features (e.g., bigrams or trigrams). This effect was replicated in Exp 2a, and Exp 2b demonstrated that substituting letters to make the consonant strings pronounceable (e.g., substituting X, R, and T, in the consonant string MXRMXT with Y, A, I, to produce MYAMYI) affected classification performance, despite the fact that objective measures of feature frequency were not altered. It is argued that models of classification that focus entirely on the frequency of features within the literal stimulus are insufficient, and that some allowance must be made for how the stimulus is encoded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The contributions of phonological awareness and letter-name knowledge to letter-sound acquisition—a cross-classified multilevel model approach.

In the present study, we investigated critical factors in letter-sound acquisition (i.e., letter-name knowledge and phonological awareness) with data from 653 English-speaking kindergartners in the beginning of the year. We examined (a) the contribution of phonological awareness to facilitating letter-sound acquisition from letter names and (b) the probabilities of letter-sound acquisition as a function of letter characteristics (i.e., consonant–vowel letters, vowel–consonant letters, letters with no sound cues, and vowel letters). The results show that letter-name knowledge had a large impact on letter-sound acquisition. Phonological awareness had a larger effect on letter-sound knowledge when letter names were known than when letter names were unknown. Furthermore, students were more likely to know the sounds of consonant–vowel letters (e.g., b and d) than vowel–consonant letters (e.g., l and m) and letters with no sound cues (e.g., h and y) when the letter name was known and phonological awareness was accounted for. Sounds were least likely to be known for letters with no sound cues, but reliable differences from other groups of letters depended on students' levels of phonological awareness and letter-name knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why is word recognition impaired by disorientation while the identification of single letters is not?

Past research has shown that speed of identifying single letters or digits is largely indifferent to orientation, whereas the recognition of single words or connected text is markedly disrupted by disorientation. In a series of four experiments, we attempted to reconcile these findings. The results suggest that disorientation does not impair the identification of the characters but disrupts the perception of their spatial arrangement. When spatial order information is critical for distinguishing between different stimuli, disorientation is disruptive because some rectification process is required to restore order information. Utilizing the similarity between the letter B and the number 13, we found strong effects of orientation when a stimulus was interpreted as the two-digit number 13 but not when interpreted as the single letter B. This, however, occurred only when the set of numbers to be classified included permutations of the same digits. Odd–even decisions on single-digit and two-digit numbers (Experiment 3) yielded strong effects of stimulus orientation for order-dependent numbers (e.g., 32), weaker effects for order-independent numbers (e.g., 24), and none for repeated-digit (e.g., 22) or single-digit numbers. Classification time for two-letter Hebrew words evidenced strong effects of orientation for words that differed only in letter order but much weaker effects for words that had no letters in common, even when these were embedded within some words that did (Experiment 4). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Types and tokens in visual letter perception.

Five experiments demonstrate that in briefly presented displays, subjects have difficulty distinguishing repeated instances of a letter or digit (multiple tokens of the same type). When subjects were asked to estimate the numerosity of a display, reports were lower for displays containing repeated letters, for example, DDDD, than for displays containing distinct letters, for example, NRVT. This homogeneity effect depends on the common visual form of adjacent letters. A distinct homogeneity effect, one that depends on the repetition of abstract letter identities, was also found: When subjects were asked to report the number of As and Es in a display, performance was poorer on displays containing two instances of a target letter, one appearing in uppercase and the other in lowercase, than on displays containing one of each target letter. This effect must be due to the repetition of identities, because visual form is not repeated in these mixed-case displays. Further experiments showed that this effect was not influenced by the context surrounding the target letters, and that it can be tied to limitations in attentional processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonological similarity effect is abolished by a silent mouthing task

This experiment was designed to examine the effect of silent mouthing on the phonological similarity effect. 16 undergraduates were tested for serial recall of visually presented letter sequences that were either phonologically similar or dissimilar. The letter sequences had to be remembered under two conditions, a control condition and a silent mouthing condition in which subjects had to articulate irrelevant words silently during the study period. Analysis showed the clear advantage of the dissimilar sequence over the similar one in the control condition. In contrast, this phonological similarity effect disappeared in the silent mouthing condition. This result is consistent with the working memory model.     

When writing impairs reading: Letter perception’s susceptibility to motor interference.

The effect of writing on the concurrent visual perception of letters was investigated in a series of studies using an interference paradigm. Participants drew shapes and letters while simultaneously visually identifying letters and shapes embedded in noise. Experiments 1–3 demonstrated that letter perception, but not the perception of shapes, was affected by motor interference. This suggests a strong link between the perception of letters and the neural substrates engaged during writing. The overlap both in category (letter vs. shape) and in the perceptual similarity of the features (straight vs. curvy) of the seen and drawn items determined the amount of interference. Experiment 4 demonstrated that intentional production of letters is not necessary for the interference to occur, because passive movement of the hand in the shape of letters also interfered with letter perception. When passive movements were used, however, only the category of the drawn items (letters vs. shapes), but not the perceptual similarity, had an influence, suggesting that motor representations for letters may selectively influence visual perception of letters through proprioceptive feedback, with an additional influence of perceptual similarity that depends on motor programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pictorial mnemonics for phonics.

Evaluated whether picture mnemonics help prereaders learn letter–sound associations in 2 experiments with 20 1st graders (Exp I), 30 preschoolers, and kindergartners (Exp II). Pictures integrating the associations were compared with disassociated pictures and with a no-picture control condition. Ss in the integrated-picture group learned 5 letter-sound associations (e.g., f, /f/), each represented by a picture whose shape included the letter (e.g., letter f drawn as the stem of a flower) and whose name (flower) began with the letter's sound. Ss in the disassociated-picture group learned letter–sound associations with pictures having the same names as the integrated pictures, but drawn differently—without letter shapes. Ss in the control group learned associations with picture names but no pictures. Prior to letter–sound training, all groups were taught how to segment the initial sounds of the picture names. Results reveal that Ss taught with integrated mnemonics learned more letter–sound associations and also more letter–picture associations than did the other 2 groups, which did not differ. Integrated pictures were effective because they linked 2 otherwise unconnected items in memory. It is concluded that the shape of letters included in pictures reminded learners of previously seen pictures with those shapes whose names began with the relevant letter sounds. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency discrimination: Assessing global-level and element-level units in memory.

Assessed the retention of memory units for word-like strings of letters using the perceptions of 120 undergraduates in 2 experiments in determining how frequently various letters appeared. A series of strings was presented at 1 of 3 exposure durations. Within the series, the frequencies of occurrence of different strings and of the letters composing the strings were varied orthogonally. Results indicate that, at relatively long exposure durations, Ss could discriminate the frequency of occurrence for both strings and their constituent letters. The formation of global-level (string) memory units was indicated by judgments of string frequency being unaffected by either the frequencies of their component letters or experimental conditions (brief exposures) that prohibited accurate judgment of letter frequency. Although judgments of letter frequency were sometimes biased by the frequency of the strings containing the letters, the success with which the judgments discriminated different levels of letter frequency did not depend on the activation of string-level memory units. Furthermore, Ss' frequency judgments for letters were not predictable from their recall of the strings containing the letters. Results provide evidence for the formation of element-level (letter) memory units. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Presenting words without interior letters: Superiority over single letters and influence of postmask boundaries.

In 5 experiments with a total of 32 Ss, exterior letter pairs from 4-letter words (e.g., d??k from dark) were presented in pattern-postmasked displays, in the positions they would occupy if the whole word were shown. In Exp 1, letter pairs (d??k) were reported more accurately than single letters (d) (the pair–letter effect). In Exps 2 and 3, performances with letter pairs dropped to those for single letters when each letter in a pair was masked individually or when masks were much wider than letter pairs. In Exps 4 and 5, the pair–letter effect and mask influence were both removed when one letter in each pair was replaced by a number sign (d??#) or when letter pairs were not the exterior letters of real words (e.g., y??f). These findings suggest that the exterior letter combinations of words are represented psychologically and access to these representations is affected by mask configuration. Implications for current word-recognition models are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defining the knowledge units of a synthetic language: Comment on Vokey and Brooks (1992).

J. R. Vokey and L. R. Brooks (see record 1992-18658-001) reported a set of experiments intended to demonstrate that judgments of grammaticality are determined by 2 characteristics of the test items: their similarity with a specific study item and their conformity with an abstract representation of the generative grammar. The author argues that both effects may be encompassed within a unified account, which requires neither a specific-item retrieval process nor an abstractive capacity. The basic assumption is that the primary knowledge units are not whole strings of letters, as postulated in models relying on specific similarity or abstraction, but rather fragments of 2 or 3 letters. Partial memorization of these small units provides a convenient account of the whole pattern of Vokey and Brooks's findings because study items have more units in common with similar than with dissimilar test items, and likewise with grammatical than with ungrammatical ones. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parafoveal identification asymmetry: interactive effects of shape and color

If two adjacent letters project to the parafoveal region of the retina, both accuracy and discriminability measures have revealed that a letter flanked to its foveal side is identified more accurately than a letter the same distance from the fovea that is flanked to its peripheral side. This parafoveal identification asymmetry is greater if the letters are dissimilar in shape than if they are similar. Color and brightness were introduced as variables in the present experiments. The identification asymmetry was greatest for dissimilar letters in different (complementary) colors. Although those colors differed also in brightness, two letters that were achromatic but merely different in brightness did not produce an asymmetry interaction with shape. Interletter separation was varied between .15 and 1.95 deg, and the pattern of results just described persisted across both distances. The synergistic interaction of shape relation and color relation in determining the amount of identification asymmetry suggests that color and shape affect perceptual processing at the same level.     

Letter position information and printed word perception: The relative-position priming constraint.

Six experiments apply the masked priming paradigm to investigate how letter position information is computed during printed word perception. Primes formed by a subset of the target's letters facilitated target recognition as long as the relative position of letters was respected across prime and target (e.g., "arict" vs. "acirt" as primes for the target "apricot"). Priming effects were not influenced by whether or not absolute, length-dependent position was respected (e.g., "a-ric-t" vs. "arict"/"ar-i-ct"). Position of overlap of relative-position primes (e.g., apric-apricot; ricot-apricot; arict-apricot) was found to have little influence on the size of priming effects, particularly in conditions (i.e., 33 ms prime durations) where there was no evidence for phonological priming. The results constrain possible schemes for letter position coding. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Specialized processors subserving visual word recognition: Evidence for local control.

One of the assumptions inherent in a distributed processing view of cognition is that specialized processors tend to run to completion because they are autonomous rather than being immediately subject to top-down constraints such as goals or intentions. Two experiments, with 60 undergraduates, demonstrated that early processes in visual word recognition ran to completion, even when the task was designed such that the product of these processes did nothing but interfere with performance. Ss made same–different judgments to letter strings that were either familiar (e.g., FBI) or unfamiliar (e.g., IBF). Familiarity disrupted performance, despite the fact that the task called for a classification based solely on physical criteria. The interference effect observed in the present experiments may have been a consequence of local control and was consistent with the assumptions of modular, distributed processing. (French abstract) (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of shared structure and content on reading nonwords: Evidence for a CV skeleton.

Four experiments examined the effect of shared skeletal structure versus content overlap on naming printed nonwords. Experiments 1–2 compared priming among nonwords sharing either skeletal structure and content (e.g., dus-DUS) or structure alone (e.g., pid-BAF) with controls that differed from the target in the number of skeleton slots (e.g., pid-BAF vs. plid-BAF). Conversely, in Experiments 3–4, same versus different-structure primes contrasted only in the ordering of CV skeletal slots (e.g., fap-DUS vs. ift-DUS). Priming effects were modulated by shared content and skeletal similarity. The sensitivity of skeletal priming to the abstract arrangement of consonants and vowels suggests that skeletal representations assign distinct slots for consonants and vowels. Readers' sensitivity to skeletal structure in nonword identification indicates that assembled phonological representations are constrained by linguistic knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)