Mixed-case effects in lateralized word recognition

Effects of case alternation and word length were studied in a lateralized visual lexical decision task. The previously reported visual field and word length interaction was found for upper- and lowercase presentations, but not for MiXeD CaSe, where both fields were affected by word length. We discuss the results in light of two contrasting models of lateralized word recognition.     

Word length and orthographic neighborhood size effects in the left and right cerebral hemispheres

Previous studies have reported an interaction between visual field (VF) and word length such that word recognition is affected more by length in the left VF (LVF) than in the right VF (RVF). A reanalysis showed that the previously reported effects of length were confounded with orthographic neighborhood size (N). In three experiments we manipulated length and N in lateralized lexical decision tasks. Results showed that length and VF interacted even with N controlled (Experiment 1); that N affected responses to words in the LVF but not the RVF (Experiment 2); and that when length and N were combined, length only affected performance in the LVF for words with few neighbors.     

An examination of the lateralized abstractive/form specific model using MiXeD-CaSe primes

CaSe AlTeRnAtIoN effects on the two cerebral hemispheres were studied in a lateralized visual lexical decision task with 32 right-handed participants. The study aimed to compare two well-known lateralization theories, the two processing modes and the abstractive/form-specific theories, that differ in the predictions regarding case alternation effects on the hemispheres. The experiment employed the masked priming paradigm, where prime and target words were presented in mixed case. The results of the experiment demonstrated no hemispheric differences in priming size when prime and target were similar in (mixed) case, thus were in line with the two modes theory. However, a new interpretation to the abstractive/form-specific model may also account for the results.     

Case-mixing effects on children's word recognition: Lexical feedback and development

Presenting words in MiXeD cAsE has previously been shown to disrupt naming performance of adult readers. This effect is greater on nonwords than it is on real words. There have been two main accounts of this interaction. First, case mixing may disrupt naming via non-lexical spellingto-sound correspondences to a greater extent than it disrupts lexical naming. Alternatively, stored lexical knowledge of words may feed back to a visual analysis level during processing of a visually presented word, helping known words to overcome the visual disruption caused by case mixing. In the present study, when young children (aged 6 and 8 years) were tested, case mixing did not disrupt nonword naming more than word naming. However, slightly older children (aged 9 years) demonstrated the same pattern of performance as adults. These results support the view that topdown lexical information can aid overcoming visual disruption to words, and that beginning readers have not developed the stored word knowledge necessary to allow this. In addition, a greater case-mixing effect on high-frequency words for the youngest age group (6-year-olds) suggests that their word recognition may be based more on wholistic visual features than is that of older children.     

The effect of visual word features on the acquisition of orthographic knowledge

Research with adults has shown that the distortion of visual word features, and in particular of the multiletter features within words, hampers word recognition. In this study, "CaSe MiXiNg" was employed to examine the effect of disrupting visual word features on the acquisition of orthographic knowledge in children. During the training, 18 beginning and 27 advanced readers (in Grades 2, 4, and 5) repeatedly read a set of pseudowords in either lowercase or mixed case. During this training, case mixing appeared to impair reading speed in both reader groups. At posttest, 1 day after the training, case format was either the same as or different from that during the training. Lowercase pseudowords were recognized faster after a lowercase training than after a mixed-case training. In a second study, case was found not to affect the rapid naming of single letters. The combined results suggest that case mixing disrupted the multiletter features in pseudowords and that the disruption of these features can affect the acquisition of orthographic knowledge.     

Do You ‘See’ What I ‘See’? Differentiation of Visual Action Words

Dickinson and Szeligo (Can J Exp Psychol 62(4):211–222, 2008) found that processing time for simple visual stimuli was affected by the visual action participants had been instructed to perform on these stimuli (e.g., see, distinguish). It was concluded that these effects reflected the differences in the durations of these various visual actions, and the results were compared to participants’ subjective ratings of word meaning but it was also possible that word characteristics like length might have influenced response times. The present study takes advantage of word length differences between French and English visual action words in order to address this issue. The goals of the present study were to provide evidence that (1) the processing time differences previously found were due to differences in the cognitive actions represented by these words (and not due to characteristics to the words themselves), and (2) that individuals subjectively differentiate visual action words in such a way that allows for predictable differences in behaviour. Participants differentiated 14 French visual action words along two dimensions. Four of these words were then used in the instructions for a size-discrimination task. Processing time depended on the visual action word in the instruction to the task and differed in a predictable manner according to word meaning but not word length.     

Repetition priming within and between the two cerebral hemispheres

Two experiments explored repetition priming benefits in the left and right cerebral hemispheres. In both experiments, a lateralized lexical decision task was employed using repeated target stimuli. In the first experiment, all targets were repeated in the same visual field, and in the second experiment the visual field of presentation was switched following repetition. Both experiments demonstrated hemispheric specialization for the task (a RVF advantage for word identification) and hemispheric interaction for word processing (lexicality priming from contralateral distracters). In the first experiment, words were identified more quickly and accurately following repetition, with repetition facilitating faster but fewer correct responses for non-words. Complex interactions between visual field of first and second presentation in the second experiment indicate asymmetric interhemispheric repetition priming effects. These results provide a broad picture of hemispheric asymmetries in word processing and of complex interaction between the hemispheres during word recognition.     

Right hemisphere sensitivity to word- and sentence-level context: evidence from event-related brain potentials

Researchers using lateralized stimuli have suggested that the left hemisphere is sensitive to sentence-level context, whereas the right hemisphere (RH) primarily processes word-level meaning. The authors investigated this message-blind RH model by measuring associative priming with event-related brain potentials (ERPs). For word pairs in isolation, associated words elicited more positive ERPs than unassociated words with similar magnitudes and onset latencies in both visual fields. Embedded in sentences, these same pairs showed large sentential context effects in both fields. Small effects of association were observed, confined to incongruous sentences after right visual hemifield presentation but present for both congruous and incongruous sentences after left visual hemifield presentation. Results do not support the message-blind RH model but do suggest hemispheric asymmetries in the use of word and sentence context during real-time processing.     

Reaction time reduction after parafoveal preview in a lexical decision task

Time and the accuracy of a lexical decision performed on a letter string (either a word or nonword), presented foveally after a parafoveal preview displayed at 5 degrees of eccentricity and 100 msec. duration were measured. Students of Padova University, 10 women and 7 men, ages 19 to 23 years were subjects. The hypothesis investigated was whether the facilitatory effect, a reduction in lexical decision time due to the parafoveal preview, was tied to global visual information acquired in the visual periphery during the preview presentation. In Exp. 1, eight subjects performed the task either with no preview (No Preview) or with a preview presented at 5 degrees eccentricity in two conditions, preview of the same foveal string (Preview-Letters) and preview of symbols ("x xx...") of the same length as the foveal string (Preview Symbols). In Exp. 2, 9 subjects performed the task with two preview conditions, No Preview and preview of the foveal string in uppercase letters at 5 degrees of eccentricity (Preview Uppercase). Analyses suggested the reduction in lexical decision time due to the Preview with respect to the No Preview condition is tied to global information extracted during parafoveal presentation. The reduction in lexical decision time depends on word texture, i.e., letters' identities and also word boundary, in addition to word length.     

How brand names are special: brands,words, and hemispheres

Previous research has consistently shown differences between the processing of proper names and of common nouns, leading to the belief that proper names possess a special neuropsychological status. We investigate the category of brand names and suggest that brand names also have a special neuropsychological status, but one which is different from proper names. The findings suggest that the hemispheric lexical status of the brand names is mixed--they behave like words in some respects and like nonwords in others. Our study used familiar upper case brand names, common nouns, and two different types of nonwords ("weird" and "normal") differing in length, as stimuli in a lateralized lexical decision task (LDT). Common nouns, brand names, weird nonwords, and normal nonwords were recognized in that decreasing order of speed and accuracy. A right visual field (RVF) advantage was found for all four lexical types. Interestingly, brand names, similar to nonwords, were found to be less lateralized than common nouns, consistent with theories of category-specific lexical processing. Further, brand names were the only type of lexical items to show a capitalization effect: brand names were recognized faster when they were presented in upper case than in lower case. In addition, while string length affected the recognition of common nouns only in the left visual field (LVF) and the recognition of nonwords only in the RVF, brand names behaved like common nouns in exhibiting length effects only in the LVF.     

The right hemisphere maintains solution-related activation for yet-to-be-solved problems

In five experiments, we examined the time course of hemispheric differences in solution activation for insight-like problems. We propose that solving insight problems requires retrieval of unusual interpretations of problem elements, and that right-hemisphere (RH) coarse semantic coding is more likely than left-hemisphere (LH) fine semantic coding to maintain semantic activation of such interpretations. In four experiments, participants attempted word problems for 7 sec (Experiments 1A and 1B) or 2 sec (Experiments 2A and 2B), and 750 msec later responded to lateralized target words. After 7 sec of solving effort, Experiment 1A participants showed greater solution-related priming (i.e., they named solutions faster than unrelated words) for left visual field-RH (lvf-RH) targets than for right visual field-LH (rvf-LH) targets, and Experiment 1B participants made faster solution decisions on target words presented to the RH, as previously demonstrated following 15 sec of effort. After 2 sec of solving effort in Experiment 2A, women showed symmetric solution-related priming, although men showed a slight lvf-RH advantage in priming; and in Experiment 2B participants made equally quick solution decisions for targets presented to the LH and to the RH. In Experiment 3, participants viewed the problems for 1,250 msec then named lateralized target words; they showed symmetric solution-related priming. These experiments demonstrate solution activation initially in both hemispheres, but maintained solution activation only in the RH.     

任务与字频对汉字情绪启动反转效应的影响

本研究使用ERP技术对比了效价判断与真假字判断两种任务形式下的汉字情绪启动效应。结果发现,在效价判断任务中高频目标字出现情绪启动的反转效应,效价不一致比一致条件下反应时短,诱发了较大的P200;低频目标字出现情绪启动的一致性效应,效价一致比不一致条件下反应时短,诱发了较大的P200与N400。真假字判断任务中高频和低频目标字均出现情绪启动的一致性效应。情绪启动的反转效应依赖于刺激材料的可通达性与注意导向,启动字与目标字的反应竞争关系导致了情绪启动的反转效应。     

Fast priming during eye fixations in reading.

Near-threshold primes were "flashed" in a target location prior to the onset of a target word while Ss read. The type and duration of the prime were manipulated. In Exp. 1, identical, related, and unrelated primes were presented for 60, 45, or 30 ms from onset of an eye fixation. The prime was then replaced with the target word, which remained in place while Ss finished reading the sentence. Fixation time on the target word was measured. Exp. 2 replicated Exp. 1, with two exceptions: A random letter string replaced the identical prime condition, and prime durations of 39, 30, or 21 ms were used. In both experiments, significant priming effects (related vs. unrelated) were obtained when the prime was presented for 30 ms. Results are discussed with regard to subliminal priming effects. Applications to the study of word recognition processes are also discussed.     

The relationship between reading ability and lateralized lexical decision

Although lexical decision remains one of the most extensively studied cognitive tasks, very little is known about its relationship to broader linguistic performance such as reading ability. In a correlational study, several aspects of lateralized lexical decision performance were related to vocabulary and reading comprehension measures, as assessed using the Nelson-Denny Reading Test. This lateralized lexical decision task has been previously shown to demonstrate (1) independent contributions from both hemispheres, as well as (2) interhemispheric interactions during word recognition. Lexical decision performance showed strong relationships with both reading measures. Specifically, vocabulary performance correlated significantly with left visual field (LVF) word accuracy and LVF non-word latency, both measures of right hemisphere performance. There were also significant, though somewhat weaker, correlations between reading comprehension and RVF non-word latency. Lexicality priming, a measure of interhemispheric communication during lexical decision, was also correlated with reading comprehension. These results suggest that hemispheric interaction during word recognition is common, and that lexical processing contribution from the right hemisphere, something commonly taken as minor and inconsequential, can lead to significant performance benefits and to individual differences in reading.     

Imageability and word recognition in the left and right visual fields: a signal detection analysis

Identifying the information processing constraints that determine whether or not imagery moderates visual field asymmetries is essential for constructing a dynamic model of hemispheric interaction during language processing. In this investigation, we manipulated the global experimental context in which imageable and nonimageable words were presented by contrasting mixed and blocked word lists using a lateralized lexical decision task. Signal detection analyses were employed to assess whether global stimulus context and imageability differentially affect word discriminability (d prime) and response bias (log beta) across visual fields. Both discriminability and response bias varied with imageability and stimulus context, but to a comparable extent across visual fields. This suggests that both hemispheres are sensitive to the global context in which words are presented, and can adjust processing based not only on semantic characteristics of the words themselves, but also on the variability of items in the stimulus environment.     

Masked priming is abstract in the left and right visual fields

Two experiments assessed masked priming for words presented to the left and right visual fields in a lexical decision task. In both Experiments, the same magnitude and pattern of priming was obtained for visually similar (kiss-KISS) and dissimilar (read-READ) prime-target pairs. These findings provide no support for the hypothesis that word identification is mediated by separate and lateralized abstract and specific visual form systems. Strikingly, equivalent priming was observed when primes and targets were presented to the same or opposite visual fields, suggesting that priming occurs after visual information from the two hemispheres is integrated.     

Syllabic length effects in visual word recognition and naming

Two experiments investigated the role of the number of syllables in visual word recognition and naming. Experiment 1 (word and nonword naming) showed that effects of number of syllables on naming latencies were observed for nonwords and very low-frequency words but not for high-frequency words. In Experiment 2 (lexical decision), syllabic length effects were also obtained for very low-frequency words but not for high-frequency words and nonwords. These results suggest that visual word recognition and naming do require syllabic decomposition, at least for very low-frequency words in French. These data are compatible with the multiple-trace memory model for polysyllabic word reading [Psychol. Rev. 105 (1998) 678]. In this model, reading depends on the activity of two procedures: (1) a global procedure that operates in parallel across a letter string (and does not generate a strong syllabic length effect) and that is the predominant process in generating responses to high-frequency words, and (2) an analytic procedure that operates serially across a letter string (and generates a strong syllabic length effect) and that is the predominant process in generating responses to very low-frequency words. A modified version of the dual route cascaded model [Psychol. Rev. 108 (1) (2001) 204] can also explain the present results, provided that syllabic units are included in this model. However, the Parallel Distributed Processing model [Psychol. Rev. 96 (1989) 523; J. Exp. Psychol.: Human Perception Perform. 16 (1990) 92] has difficulties to account for these results.     

Masked priming is abstract in the left and right visual fields

Two experiments assessed masked priming for words presented to the left and right visual fields in a lexical decision task. In both Experiments, the same magnitude and pattern of priming was obtained for visually similar (kiss-KISS) and dissimilar (read-READ) prime–target pairs. These findings provide no support for the hypothesis that word identification is mediated by separate and lateralized abstract and specific visual form systems. Strikingly, equivalent priming was observed when primes and targets were presented to the same or opposite visual fields, suggesting that priming occurs after visual information from the two hemispheres is integrated.     

Influence of endogenous and exogenous orientations of attention on inhibition of return in a cross-modal target-target aiming task

The authors conducted 2 experiments in which participants (N = 16 in each) executed successive unimanual aiming movements to target locations that were indicated by the onset of either an auditory or a visual stimulus. In Experiment 1 (exogenous orientation), inhibition of return (IOR) effects were observed, with reliable reaction time (RT) costs associated with movements returning to the same target and a trend toward larger IOR effects in left than in right space. There was no influence of stimulus modality on the magnitude of IOR. IOR was also observed in Experiment 2 (endogenous orientation), except the influence of stimulus modality reliably mediated those effect. In that case, IOR was evident only when the previous modality was visual and the current modality was auditory. Together, the results of those 2 experiments suggest that in situations in which 2 paired movements constitute the response criteria, IOR is both supramodal and lateralized to contralateral space.