Word-fragment cuing: The lexical search hypothesis.

In four experiments we evaluated aspects of the hypothesis that word-fragment completion depends on the results of lexical but not semantic search. Experiment 1 showed that the number of meaningful associates linked to a studied word does not affect its recovery when the test cue consists of letters and spaces for missing letters. Experiments 2 and 3 showed retroactive interference effects in fragment completion when words in a second list were lexically related to words in a first list but not when the words in the second list were meaningfully related. Experiment 4 indicated that for studied words, instructions to search at the word level facilitated completion performance and that instructions to generate letters to fill missing spaces had no effect. Other findings indicate that completion was affected by the number of words lexically related to the fragment and by the number of letters missing from the fragment. In general, experimental manipulations that focused on lexical characteristics were effective, and those that focused on semantic characteristics were ineffective. The findings support the conclusion that word fragments engender a lexical search process that does not depend on retrieving encoded meaning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are individual or consecutive letters the unit affected by repetition blindness?

When 2 similar words (e.g., react reach) are briefly sequentially displayed, the 2nd word may be omitted from the report, a phenomenon known as repetition blindness (RB). Previous researchers have suggested that consecutive letters are the unit affected by RB. Six experiments provided new data on orthographic RB. Two letters at the beginning or end of words resulted in RB, as did alternating interior letters (tactile earthly) and 3 letters with different relative positions (arid bird). However, no RB was found with a single final letter (show view). Observed RB may reflect pattern completion because RB for pairs like throat theory was reduced when the nonrepeated letters (eory) were consistent with only a single word. The experiments point to a model of orthographic RB in which both individual letters and letter sequences of length 2 or more play a role. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alphabet-letter instruction on young children's word recognition.

This study examined the influence of letter-name instruction on beginning word recognition. Thirty-three preschool children from low-socioeconomic-status families participated in 16 weeks of letter-name or comprehension-focused instruction. After instruction, children's ability to learn 3 types of word spellings was examined: words phonetically spelled with letters children had been taught (e.g., BL for ball), words phonetically spelled with letters children had not been taught, and words with visually distinct letter spellings that were nonphonetic. Children who received letter-name instruction learned words phonetically spelled with letters included in instruction significantly better than other words. Children receiving comprehension instruction performed significantly better on visually distinct word spellings. Results demonstrate the beneficial effects of alphabet-letter instruction on beginning phonetic word recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Why do non-color words interfere with color naming?

In the non-color-word Stroop task, university students' response latencies were longer for low-frequency than for higher frequency target words. Visual identity primes facilitated color naming in groups reading the prime silently or processing it semantically (Experiment 1) but did not when participants generated a rhyme of the prime (Experiment 3). With auditory identity primes, generating an associate or a rhyme of the prime produced interference (Experiments 2 and 3). Color-naming latencies were longer for nonwords than for words (Experiment 4). There was a small long-term repetition benefit in color naming for low-frequency words that had been presented in the lexical decision task (Experiment 5). Facilitation of word recognition speeds color naming except when phonological activation of the base word increases response competition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct Assessments of the Processing Time Hypothesis for the Missing-Letter Effect.

When participants search for a target letter while reading, they make more omissions if the target letter is embedded in frequently used words or in the most frequent meaning of a polysemic word. According to the processing time hypothesis, this occurs because familiar words and meanings are identified faster, leaving less time for letter identification. Contrary to the predictions of the processing time hypothesis, with a rapid serial visual presentation procedure, participants were slower at detecting target letters for more frequent words or the most frequent meaning of a word (Experiments 1 and 2) or at detecting the word itself instead of a target letter (Experiment 3). In Experiments 4 and 5, participants self-initiated the presentation of each word, and the same pattern of results was observed as in Experiments 1 and 3. Positive correlations were also found between omission rate and response latencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of lexicality and distinctiveness on repetition blindness.

The repetition blindness (RB) paradigm developed by K. M. Arnell and P. Jolic?ur (1997) was used to examine effects of lexicality (word vs. nonword target pairs) and target distinctiveness on RB. Distinctiveness was manipulated by having both targets (Experiments 1 and 2) or only the first target (Experiment 3) brighter than nontarget items. All 3 experiments demonstrated strong RB for word targets but no RB for nonword targets. This confirms that RB depends on pre-existing memory representations. In fact, there was repetition facilitation for nonwords in Experiments 2 and 3. These experiments also demonstrated that RB is reduced when targets are distinctive. This finding is better understood in terms of RB as a failure of memory rather than as a failure of perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Focal/nonfocal cue effects in prospective memory: Monitoring difficulty or different retrieval processes?

We investigated whether focal/nonfocal effects (e.g., Einstein et al., 2005) in prospective memory (PM) are explained by cue differences in monitoring difficulty. In Experiment 1, we show that syllable cues (used in Einstein et al., 2005) are more difficult to monitor for than are word cues; however, initial-letter cues (in words) are similar in monitoring difficulty to word cues (Experiments 2a and 2b). Accordingly, in Experiments 3 and 4, we designated either an initial letter or a particular word as a PM cue in the context of a lexical decision task, a task that presumably directs attention to focal processing of words but not initial letters. We found that the nonfocal condition was more likely than the focal condition to produce costs to the lexical decision task (task interference). Furthermore, when task interference was minimal or absent, focal PM performance remained relatively high, whereas nonfocal PM performance was near floor (Experiment 4). Collectively, these results suggest that qualitatively different retrieval processes can support prospective remembering for focal versus nonfocal cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Masked priming effects with syllabic neighbors in a lexical decision task.

Four lexical decision experiments using a masked priming paradigm were conducted to analyze whether the previous presentation of a syllabic neighbor (a word sharing the same 1st syllable) influences recognition performance. The results showed an inhibitory effect of more frequent syllabic primes and some facilitation of nonword syllabic primes (Experiments 1-3). When monosyllabic pairs were used (Experiment 3), no priming effects of the 2 initial letters were found. Finally, when using only syllables as primes, latencies to words were shorter when preceded by primes that corresponded to the 1st syllable than by primes that contained 1 letter more or less than the lst syllable (Experiment 4). Results are interpreted using activation models that take into account a syllabic level of representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A sublexical locus for repetition blindness: Evidence from illusory words.

Six experiments used an illusory words paradigm to demonstrate that repetition blindness (RB) in orthographically similar words affects only the words' shared letters. Rapid serial visual presentation streams of words and word fragments allowed the unique letters of the 2nd critical word to combine with a subsequent fragment to create a word, as in rock shock ell. The illusory word shell was reported 2–3 times as frequently in RB conditions as in control conditions. Further experiments ruled out letter migration, contour summation, and differences in processing load as explanations for the results. These findings are inconsistent with current proposals that orthographic RB represents similarity inhibition or lexical competition or that it reflects problems with word-level token individuation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detecting letters in continuous text: Effects of display size.

In three letter detection experiments, subjects responded to each instance of the letter t in continuous text (a) typed in a standard paragraph, (b) typed with one to four words per line, or (c) shown for a fixed duration on a computer screen either one or four words at a time. In the multiword and the standard paragraph conditions, errors were greatest and latencies longest on the word the when it was correctly spelled. This effect was diminished or reversed in the one-word conditions. These findings support a set of unitization hypotheses about the reading process, according to which subjects do not process the constituent letters of a word once that word has been identified unless no other word is in view. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the nonautomaticity of visual word processing: Electrophysiological evidence that word processing requires central attention.

The present study used event-related potentials (ERPs) to determine the degree to which people can process words while devoting central attention to another task. Experiments 1-4 measured the N400 effect, which is sensitive to the degree of mismatch between a word and the current semantic context. Experiment 5 measured the P3 difference between low- and high-frequency words. Because these effects can occur only if a word has been identified, both ERP components index word processing. The authors found that the N400 effect (Experiments 1, 3, and 4) and the P3 difference (Experiment 5) were strongly attenuated for Task 2 words presented nearly simultaneously with Task 1. No such attenuation was found when the Task 1 stimulus was presented but required no response (Experiment 2). Strong attenuation was also evident when the Task 2 word was presented before the Task 1 stimulus (Experiment 4), suggesting that central resources are not allocated to stimuli first-come, first-served but rather are strategically locked to Task 1. The authors conclude that visual word processing is not fully automatic but rather requires access to limited central attentional resources. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The quiet clam is quite calm: Transposed-letter neighborhood effects on eye movements during reading.

In responses time tasks, inhibitory neighborhood effects have been found for word pairs that differ in a transposition of two adjacent letters (e.g., clam/calm). Here, the author describes two eye-tracking experiments conducted to explore transposed-letter (TL) neighborhood effects within the context of normal silent reading. In Experiment 1, sentences contained a target word that either has a TL neighbor (e.g., angel, which has the TL neighbor angle) or does not (e.g., alien). In Experiment 2, the context was manipulated to examine whether semantic constraints attenuate neighborhood effects. Readers took longer to process words that have a TL neighbor than control words but only when either member of the TL pair was likely. Furthermore, this interference effect occurred very late in processing and was not affected by relative word frequency. These interference effects can be explained either by the spreading of activation from the target word to its TL neighbor or by the misidentification of target words for their TL neighbors. Implications for models of orthographic input coding and models of eye-movement control are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multicentre survey of the comparative in-vitro activity of piperacillin/tazobactam against bacteria from hospitalized patients in the British Isles

In five experiments, in which subjects were to identify a target word as it was gradually clarified, we manipulated the target's frequency of occurrence in the language and its neighborhood size--the number of words that can be constructed from a target word by changing one letter, while preserving letter position. In Experiments 1-4, visual identification performance to screen-fragmented words was measured. In Experiments 1 and 2, we used the ascending method of limits, whereas Experiments 3 and 4 presented a fixed-level fragment. In Experiment 1, there was no relation between overall accuracy and neighborhood size for words between three and six letters in length. However, more errors of commission (guesses) were made for high-neighborhood words and more errors of omission (blanks) were made for low-neighborhood words. Letter errors within guesses occurred at serial positions having many neighbors, and these positions were also likely to contain consonants rather than vowels. In Experiment 2, a small facilitatory effect of neighborhood size on both high- and low-frequency words was found. In contrast, in Experiments 3 and 4, using the same set of words, inhibitory effects of neighborhood size, but only for low-frequency words, were found. Experiment 5, using a speeded identification task, showed results parallel to those of Experiments 3 and 4. We suggest that whether neighborhood effects are facilitatory or inhibitory depends on whether feedback allows subjects to disconfirm initial hypotheses that the target is a high-frequency neighbor.     

Role of study strategy in recall of mixed lists of common and rare words.

Experiment 1 confirmed previous findings that common words are more recallable than are rare words when the 2 kinds of words are presented in separate lists but not when they are presented in the same list. Experiment 2 showed much the same pattern when an orienting task was performed during word presentation. In Experiment 3 common words were found to be more recallable than rare words even for mixed lists when no warning was given of the memory test, although the effect was less pronounced than for pure lists. In Experiment 4 stronger measures were taken to preclude anticipation of the memory test, and the effect of word commonness was found to be just as pronounced with mixed lists as it was with pure lists. It was suggested that lists are studied in a way believed to optimize recall and that mixed lists foster a strategy of favoring the rare words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading student essays may be hazardous to your spelling: Effects of reading incorrectly and correctly spelled words.

Examined the effects on spelling of reading and of reproducing correctly and incorrectly spelled words in 2 experiments involving 108 undergraduate students. Reading correctly and incorrectly spelled words influenced later spelling accuracy for those same words. Reproducing the spelling of words did not have any effects on later spelling accuracy beyond those produced by reading the words. However, reproducing a correctly spelled word did speed the production of a later correct spelling for the word, whereas reading did not speed later production. Effects on spelling accuracy were dissociated from recognition memory for previously presented words. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On detecting words embedded in a stream of auditory letters.

Presented 40 undergraduates with a stream of auditory letters in which some of the letters formed words. Ss were or were not given cues for the start of the words. It was found that (a) Ss required an indication of which letters started words. If certain letters formed part of more than 1 word, S detected the word for which a cue was provided but more often than not failed to detect the other word. When cues were provided on both words, the probability of getting both depended on the extent to which the 2 words "overlapped" in common letters. Results are discussed in the light of current work on serial processing. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Guessing strategies, aging, and bias effects in perceptual identification

In the typical single-stimulus perceptual identification task, accuracy is improved by prior study of test words, a repetition priming benefit. There is also a cost, inasmuch as previously studied words are likely to be produced (incorrectly) as responses if the test word is orthographically similar but not identical to a studied word. In two-alternative forced-choice perceptual identification, a test word is flashed and followed by two alternatives, one of which is the correct response. When the two alternatives are orthographically similar, test words identical to previously studied items are identified more accurately than new words (a benefit) but tests words orthographically similar to studied words are identified less accurately than new words (a cost). Ratcliff and McKoon (in press) argue that these are bias effects that arise in the decision stage of word identification. We report five experiments that examined the alternative hypothesis that these bias effects arise from postperceptual guessing strategies. In single-stimulus perceptual identification, repetition priming benefits were equally great for young and older adults who claimed to use deliberate guessing strategies and those who did not (Experiment 1). In contrast, only groups of young and older people who claimed to deliberately guess studied words in a two-alternative forced-choice task (Experiments 2 and 5) showed reliable benefits and costs. Costs and benefits were abolished in the two-alternative forced-choice task when a very long study list was used, presumably because the increased retrieval burden made the use of deliberate guessing strategies less attractive (Experiment 3). Under conditions similar to those of Experiment 3, repetition priming was observed in single-stimulus perceptual identification (Experiment 4). These results are consistent with the view that costs and benefits in the forced-choice perceptual identification task arise from deliberate guessing strategies but that those in the single-stimulus task do not. The possibility that the observed relationship between strategy reports and priming effects reflects erroneous postexperimental assessments of strategies by participants is also considered.     

Now you see it, now you don't: Repetition blindness for nonwords.

Repetition blindness (RB) for nonwords has been found in some studies, but not in others. The authors propose that the discrepancy in results is fueled by participant strategy; specifically, when rapid serial visual presentation lists are short and participants are explicitly informed that some trials will contain repetitions, participants are able to use partial orthographic information to correctly guess repetitions on repetition trials while avoiding spurious repetition reports on control trials. The authors first replicated V. Coltheart and R. Langdon's (2003) finding of RB for words but repetition advantage for nonwords (Experiment 1). When all participants were encouraged to utilize partial information in a same/different matching task along with an identification task, a repetition advantage was observed for both words and nonwords (Experiment 2). When guessing of repetitions was made detectable by including non-identical but orthographically similar items in the experiments, the repetition advantage disappeared; instead, RB was found for both words and nonwords (Experiments 3 and 4). Finally, when experiments did not contain any identical items, participants almost never reported repetitions, and reliable RB was found for orthographically similar words and nonwords (Experiments 5 and 6). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concreteness-dependent associative priming: Separate lexical organization for concrete and abstract words.

Four experiments used associated, unrelated, and neutral ({blank}–word) pairs that varied on prime and target concreteness. In Experiment 1, associated targets were named faster than neutral targets when primes and targets were homogeneous for concreteness (i.e., concrete–concrete or abstract–abstract), but not when they were heterogeneous (i.e., concrete–abstract or abstract–concrete). Experiments 2 and 3, using lexical decision, showed priming for all pairs irrespective of prime and target concreteness. In Experiment 4, the prime was presented for 16.7 ms, followed immediately by a 168-ms random letter mask. Lexical decision times showed priming similar to that in Experiment 1. If priming in Experiments 1 and 4 reflected lexical processes, whereas priming in Experiments 2 and 3 entailed postlexical processes, then lexical processes may be functionally distinct for concrete versus abstract words. These findings are more consistent with dual-coding than common-coding explanations of concreteness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automaticity of word recognition under phonics and whole-word instruction.

38 undergraduates learned to read words spelled with novel letters under phonics or whole-word conditions. Training was carried through several overlearning trials, and vocalization latency of word recognition responses was measured. On initial overlearning trials, vocalizations of phonics Ss were faster than those of whole-word Ss. At no stage of overlearning were whole-word Ss faster than phonics Ss. Vocalization latencies declined as overlearning progressed at approximately equal rates for phonics and whole-word Ss but did not reach fully automated speeds. Correlations of vocalization latencies from overlearning trials and a baseline task indicated that whole-word instruction resulted in word recognition mechanisms similar to fully automated mechanisms but that phonics instruction did not. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)