Age-of-acquisition and frequency effects in speeded word naming

Are Faster Participants Always Faster? Assessing Reliability of Participants' Mean Response Speed in Picture Naming

Studies of language production often make use of picture naming tasks to investigate the cognitive processes involved in speaking, and many of these studies report a wide range of individual variability in how long speakers need to prepare the name of a picture. It has been assumed that this variability can be linked to inter-individual differences in cognitive skills or abilities (e.g., attention or working memory); therefore, several studies have tried to explain variability in language production tasks by correlating production measures with scores on cognitive tests. This approach, however, relies on the assumption that participants are reliable over time in their picture naming speed (i.e., that faster speakers are consistently fast). The current study explicitly tested this assumption by asking participants to complete a simple picture naming task twice with one to two weeks in between sessions. In one experiment, we show that picture naming speed has excellent within-task reliability and good test-retest reliability, at least when participants perform the same task in both sessions. In a second experiment with slight task variations across sessions (a speeded and non-speeded picture naming task), we replicated the high split-half reliability and found moderate consistency over tasks. These findings are as predicted under the assumption that the speed of initiating responses for speech production is an intrinsic property or capacity of an individual. We additionally discuss the consequences of these results for the statistical power of correlational designs.

Are they really stronger? Comparing effects of semantic variables in speeded deadline and standard picture naming

Investigations of effects of semantic variables on picture naming have often been inconclusive, with some studies reporting significant and others non-significant effects. One potential explanation may relate to the specific naming tasks used: While most previous studies have used standard picture naming, others have used speeded naming that requires participants to prioritise naming speed over accuracy. Speeded naming has been suggested to cause enhanced effects of item-inherent word characteristics due to disruptions of cognitive control and resulting modulations of responsiveness to input. Consequently, this study investigated whether effects are stronger in speeded compared to standard picture naming, focusing on six feature-based semantic variables: number of semantic features, intercorrelational density, number of near semantic neighbours, semantic similarity, typicality, and distinctiveness. The results showed few differences in the variables' effects between the two naming tasks: In the naming latency analysis, the inhibitory effect of distinctiveness was stronger in the speeded naming task, while in the accuracy analysis the effect of number of semantic features was stronger in the standard naming task. These findings cannot, therefore, be exclusively accounted for by increased responsiveness to input in speeded naming and we discuss possible underlying mechanisms. We conclude that, while some differences in effects of semantic variables between previous studies may have been caused by the specific naming task used, differences between studies more likely depend on statistical power and control of other influential variables in the experiment.

The adaptation of the Object and Action Naming Battery into Moroccan Arabic: Norms for name agreement, frequency, imageability, visual complexity, and age of acquisition

INTRODUCTION

The ability to name pictures has been investigated widely in healthy people and clinical populations. The Object and Action Naming Battery (OANB) is widely used for psycholinguistic research, aphasia research, and clinical practice. Normative databases for pictorial stimuli have been conducted in language processing studies to control for various psycholinguistic variables known to affect the availability of picture names. The present study provides Moroccan Arabic norms for name agreement, familiarity, imageability, visual complexity, and age of acquisition for 100 line drawings of actions and 162 line drawings of objects taken from Druks and Masterson.

METHODS AND PROCEDURES

160 healthy Moroccan Arabic-speaking individuals participated in this study. Name agreement values for the OANB items were collected from forty subjects, followed by collecting data for the psycholinguistic variables: spoken-word frequency, imageability, visual complexity, and age of acquisition from 120 participants.

RESULTS

The Moroccan Arabic OANB (MA-OANB) comprises 70 objects and 60 action pictures. 77% of the nouns and 68% of the verbs obtained 100% target responses. A minimum of 93 percent name agreement was reached for the remaining items. Norms were also collected for the following psycholinguistic variables: spoken-word frequency, imageability, age of acquisition, and visual complexity.

CONCLUSION

The stimuli can be used for various psycholinguistic investigations and also for assessment and therapeutic purposes in Morocco.

Objective ages of acquisition for 3300+ simplified Chinese characters

We report the construction of two age-of-acquisition (AoA) norms for 3300+ characters in simplified Chinese, which make up about 99% of the texts used in daily life. We determined a character's AoA according to the time in which the character is formally learned in two sets of leading textbooks of Chinese in compulsory education, published respectively on the basis of the 2001 and 2011 national curriculum. Apart from having a significantly larger coverage of characters than previous norms, the current norms also outperformed them in explaining accuracy and reaction times in four large-scale databases for character decision, character naming, or character handwriting, even after controlling for the effects of frequency, number of meanings, and number of strokes. The explanatory advantage of the current norms suggests that, compared to earlier norms, the current norms capture more up-to-date character AoAs; these findings also highlight the diachronic nature of some lexical variables such as AoA and frequency. The developed objective AoA norms can be used for subsequent research on Chinese character recognition or production.

Age of acquisition effects in recognition without identification tasks

The Age of Acquisition (AoA) effect results in early-acquired words being processed more quickly and accurately than later-acquired words. This effect is argued to result from a gradual development of semantic representations and a changing neural network throughout development (Chang, Y.-N., Monaghan, P., & Welbourne, S., 2019). Some forms of the Recognition Without Identification (RWI) effects have been observed at a perceptual level. The present study used the RWI paradigm to examine whether the AoA effect is located at the perceptual loci. A total of 174 participants were presented a list of pictures (Experiment 1) or words (Experiment 2) followed by a list of mixed early- and late-acquired picture or word fragments that participants had to identify; half of which corresponded to studied words and half of which to unstudied words. Irrespective of whether the item was identified, participants then rated the likelihood that the item appeared in the study phase. In both experiments, results showed that studied items were recognised more accurately than unstudied items, even when they could not be identified and late-acquired items were recognised more than early-acquired items, even when they were not identified. Finally, RWI interacted with the AoA effect only in pictorial stimuli, suggesting that the RWI and AoA effects are located at the perceptual level.

The hunt for the age of acquisition effect: It's in the links!

The Age of Acquisition (AoA) effect is such that words acquired early in life are processed more quickly than later-acquired words. One explanation for the AoA effects is the arbitrary mapping hypothesis (Ellis & Lambon-Ralph, 2000), stating that the AoA effects are more likely to occur in items that have an arbitrary, rather than a systematic, nature between input and output. Previous behavioural findings have shown that the AoA effects are larger in pictorial than word items. However, no behavioural studies have attempted to directly assess the AoA effects in relation to the connections between representations. In the first two experiments, 48 participants completed a word-picture verification task (Experiments 1A and 2A), together with a spoken (Experiment 1B) or written (Experiment 2B) picture naming task. In the third and fourth experiments, 48 participants complete a picture-word verification task (Experiments 3A and 4A), together with a spoken (Experiment 3B) or written (Experiment 4B) word naming task. For each pair of experiments the subtraction of the naming latencies from the verification tasks for each item per participant was calculated (Experiments 1-4C; e.g. Santiago, Mackay, Palma & Rho, 2000). Results showed that early-acquired items were responded to more quickly than late-acquired ones for all experiments, except for Experiment 3B (spoken word naming) where the AoA effect was shown for only low-frequency words. In addition, the subtraction results for pictorial stimuli demonstrated strong AoA effects. This strengthens the case for the AM hypothesis, also suggesting the AoA effect resides in the connections between representations.

Razak R, Treffers-Daller J, Yap NT, Abboud L, Talebi A, Gureghian M, Tuller L, Haman E. Age of acquisition of 299 words in seven languages: American English, Czech, Gaelic, Lebanese Arabic, Malay, Persian and Western Armenian

We present a new set of subjective Age of Acquisition (AoA) ratings for 299 words (158 nouns, 141 verbs) in seven languages from various language families and cultural settings: American English, Czech, Scottish Gaelic, Lebanese Arabic, Malaysian Malay, Persian, and Western Armenian. The ratings were collected from a total of 173 participants and were highly reliable in each language. We applied the same method of data collection as used in a previous study on 25 languages which allowed us to create a database of fully comparable AoA ratings of 299 words in 32 languages. We found that in the seven languages not included in the previous study, the words are estimated to be acquired at roughly the same age as in the previously reported languages, i.e. mostly between the ages of 1 and 7 years. We also found that the order of word acquisition is moderately to highly correlated across all 32 languages, which extends our previous conclusion that early words are acquired in similar order across a wide range of languages and cultures.

Effects of Lexical Variables on Silent Reading Comprehension in Individuals With Aphasia: Evidence From Eye Tracking

PURPOSE

Previous eye-tracking research has suggested that individuals with aphasia (IWA) do not assign syntactic structure on their first pass through a sentence during silent reading comprehension. The purpose of the present study was to investigate the time course with which lexical variables affect silent reading comprehension in IWA. Three lexical variables were investigated: word frequency, word class, and word length.

METHODS

IWA and control participants without brain damage participated in the experiment. Participants read sentences while a camera tracked their eye movements.

RESULTS

IWA showed effects of word class, word length, and word frequency that were similar to or greater than those observed in controls.

CONCLUSIONS

IWA showed sensitivity to lexical variables on the first pass through the sentence. The results are consistent with the view that IWA focus on lexical access on their first pass through a sentence and then work to build syntactic structure on subsequent passes. In addition, IWA showed very long rereading times and low skipping rates overall, which may contribute to some of the group differences in reading comprehension.

A normative database and determinants of lexical retrieval for 186 Arabic nouns: effects of psycholinguistic and morpho-syntactic variables on naming latency

Research into lexical retrieval requires pictorial stimuli standardised for key psycholinguistic variables. Such databases exist in a number of languages but not in Arabic. In addition there are few studies of the effects of psycholinguistic and morpho-syntactic variables on Arabic lexical retrieval. The current study identified a set of culturally and linguistically appropriate concept labels, and corresponding photographic representations for Levantine Arabic. The set included masculine and feminine nouns, nouns from both types of plural formation (sound and broken), and both rational and irrational nouns. Levantine Arabic speakers provided norms for visual complexity, imageability, age of acquisition, naming latency and name agreement. This delivered a normative database for a set of 186 Arabic nouns. The effects of the morpho-syntactic and the psycholinguistic variables on lexical retrieval were explored using the database. Imageability and age of acquisition were the only significant determinants of successful lexical retrieval in Arabic. None of the other variables, including all the linguistic variables, had any effect on production time. The normative database is available for the use of clinicians and researchers in the Arab world in the domains of speech and language pathology, neurolinguistics and psycholinguistics. The database and the photographic representations will be soon available for free download from the first author's personal webpage or via email.

Emotion and language: valence and arousal affect word recognition

Emotion influences most aspects of cognition and behavior, but emotional factors are conspicuously absent from current models of word recognition. The influence of emotion on word recognition has mostly been reported in prior studies on the automatic vigilance for negative stimuli, but the precise nature of this relationship is unclear. Various models of automatic vigilance have claimed that the effect of valence on response times is categorical, an inverted U, or interactive with arousal. In the present study, we used a sample of 12,658 words and included many lexical and semantic control factors to determine the precise nature of the effects of arousal and valence on word recognition. Converging empirical patterns observed in word-level and trial-level data from lexical decision and naming indicate that valence and arousal exert independent monotonic effects: Negative words are recognized more slowly than positive words, and arousing words are recognized more slowly than calming words. Valence explained about 2% of the variance in word recognition latencies, whereas the effect of arousal was smaller. Valence and arousal do not interact, but both interact with word frequency, such that valence and arousal exert larger effects among low-frequency words than among high-frequency words. These results necessitate a new model of affective word processing whereby the degree of negativity monotonically and independently predicts the speed of responding. This research also demonstrates that incorporating emotional factors, especially valence, improves the performance of models of word recognition.

Norms and reading times for acronyms in French

We collected subjective frequency, age-of-acquisition, and imageability norms for 319 acronyms from French adults. Objective printed frequency, bigram frequency, and lengths in letters, phonemes, and syllables, as well as orthographic neighbors, were computed. The time taken to read acronyms aloud was also recorded. Correlational analyses indicated that the relations between the psycholinguistic variables were similar to those usually found for common words (e.g., highly imageable acronyms were more frequent and learned earlier in life than less imageable acronyms), but were generally weaker in the former than in the latter. Linear mixed-model analyses performed on the reading latencies revealed that the main determinants were the voicing feature of initial phonemes, the type of pronunciation of the acronyms (ambiguous vs. unambiguous, typical vs. atypical characteristics), length (number of letters and number of syllables), together with bigram frequency, printed frequency, and imageability. Both objective frequency and imageability interacted reliably with the ambiguous typical and ambiguous atypical properties. Accuracy was predicted by the number of letters and by imageability factors: More errors occurred on longer than on shorter acronyms, and also more errors on less imageable than on more imageable acronyms. The theoretical and methodological implications of the findings for the understanding of acronym reading are discussed. The entire set of norms and the acronym reading times (and accuracy scores), together with the acronym definitions, are provided as supplemental materials.

The Effect of Age of Acquisition on Older Individuals with and without Cognitive Impairments

The present study compared the effects of age of acquisition (AoA) on object naming across groups of older individuals with cognitive impairments, healthy older controls, and young healthy controls. All participants named a set of 80 pictures, within which both AoA and frequency were manipulated orthogonally. Early-acquired objects were named faster than late-acquired objects across all groups. Response time also declined with age and with cognitive impairment between the groups. The effect of AoA differed across groups, with AoA effects being largest for the older group with cognitive impairments and smallest for the young control group. The present study adds strength to the suggestion that AoA of picture names is one of the factors that influence survival or loss of memories in dementia and cognitive decline, and this could therefore be used as a potential screening test for cognitive impairment disorders in the future.

Does frequency trajectory influence word identification? A cross-task comparison

In a series of six experiments, the influence of frequency trajectory in visual word recognition was investigated. In Experiment 1, frequency trajectory was found to exert a strong and reliable influence on age of acquisition (AoA) ratings. In word reading (Experiment 2), lexical decision (Experiments 3 and 6), proper name decision (Experiment 4), progressive demasking (Experiment 5), and a multiple regression analysis of lexical decision times taken from the French Lexicon Project, the effect of frequency trajectory was not reliable. In contrast, in all the experiments and in the multiple regression analysis, cumulative frequency had a strong and reliable influence on word recognition times. The findings firmly establish that in alphabetic languages such as French, age-limited learning effects do not surface readily in word recognition. In contrast, the total exposure to words across the lifetime is a strong determinant of word recognition speed. The implications of the findings are discussed.

Imageability and age of acquisition effects in disyllabic word recognition

Imageability and age of acquisition (AoA) effects, as well as key interactions between these variables and frequency and consistency, were examined via multiple regression analyses for 1,936 disyllabic words, using reaction time and accuracy measures from the English Lexicon Project. Both imageability and AoA accounted for unique variance in lexical decision and naming reaction time performance. In addition, across both tasks, AoA and imageability effects were larger for low-frequency words than high-frequency words, and imageability effects were larger for later acquired than earlier acquired words. In reading aloud, consistency effects in reaction time were larger for later acquired words than earlier acquired words, but consistency did not interact with imageability in the reaction time analysis. These results provide further evidence that multisyllabic word recognition is similar to monosyllabic word recognition and indicate that AoA and imageability are valid predictors of word recognition performance. In addition, the results indicate that meaning exerts a larger influence in the reading aloud of multisyllabic words than monosyllabic words. Finally, parallel-distributed-processing approaches provide a useful theoretical framework to explain the main effects and interactions.

A normative study of acronyms and acronym naming

Acronyms are an idiosyncratic part of our everyday vocabulary. Research in word processing has used acronyms as a tool to answer fundamental questions such as the nature of the word superiority effect (WSE) or which is the best way to account for word-reading processes. In this study, acronym naming was assessed by looking at the influence that a number of variables known to affect mainstream word processing has had in acronym naming. The nature of the effect of these factors on acronym naming was examined using a multilevel regression analysis. First, 146 acronyms were described in terms of their age of acquisition, bigram and trigram frequencies, imageability, number of orthographic neighbors, frequency, orthographic and phonological length, print-to-pronunciation patterns, and voicing characteristics. Naming times were influenced by lexical and sublexical factors, indicating that acronym naming is a complex process affected by more variables than those previously considered.

Effects of Age-of-Acquisition in the Word-Fragment Completion Task

Barry, Hirsh, Johnston, and Williams (2001) found that Age-of-Acquisition (AoA) interacted with repetition priming in the picture naming task (greater priming for late- than for early-acquired words), and proposed that AoA might affect the stage of access to lexical-phonological representations. The present experiment examined the possibility that AoA may influence the retrieval of visual-orthographic information, by studying its effects in the Word-Fragment Completion Task (WFCT). Results showed that the overall percentages of correct completion were greater for early- than for late-acquired words, while repetition priming was higher for late- than for early-acquired items. Furthermore, the interaction between AoA and WFCT priming remained significant even when the fragments were exposed for only 4 s, reducing possible contributions from phonological and semantic processes. These findings suggest that AoA can affect implicit memory by facilitating the retrieval of the orthographic properties of the studied words.

Effects of word frequency and modality on sentence comprehension impairments in people with aphasia

PURPOSE

It is well known that people with aphasia have sentence comprehension impairments. The present study investigated whether lexical factors contribute to sentence comprehension impairments in both the auditory and written modalities using online measures of sentence processing.

METHOD

People with aphasia and non brain-damaged controls participated in the experiment (n = 8 per group). Twenty-one sentence pairs containing high- and low-frequency words were presented in self-paced listening and reading tasks. The sentences were syntactically simple and differed only in the critical words. The dependent variables were response times for critical segments of the sentence and accuracy on the comprehension questions.

RESULTS

The results showed that word frequency influences performance on measures of sentence comprehension in people with aphasia. The accuracy data on the comprehension questions suggested that people with aphasia have more difficulty understanding sentences containing low-frequency words in the written compared to auditory modality. Both group and single-case analyses of the response time data also indicated that people with aphasia experience more difficulty with reading than listening.

CONCLUSION

Sentence comprehension in people with aphasia is influenced by word frequency and presentation modality.

Age of word acquisition effects in treatment of children with phonological delays

The effects of the age of acquisition (AoA) of words were examined in the clinical treatment of 10 preschool children with phonological delays. Using a single-subject multiple-baseline experimental design, children were enrolled in one of four conditions that varied the AoA of the treated words (early vs. late acquired) relative to their corresponding word frequency (high vs. low frequency). Phonological generalization to treated and untreated sounds in error served as the dependent variable. Results showed that late acquired words induced greater generalization, with an effect size four times greater than early acquired words, whereas the effects of word frequency were minimized. Results are discussed relative to hypotheses about the role of AoA in language acquisition and the relevance of this variable for phonological learning.

Age of acquisition effects on an object-name verification task

Naming latencies for words, objects and faces have been shown to be affected by the age at which an item is acquired (AoA). Originally, this effect was explained in terms of differential access to name representations. However, a number of recent studies have found AoA effects in tasks which do not require access to names (e.g. Brysbaert, Van Wijnendaele, & De Deynes, 2000; Lewis, 1999; Moore, Smith Spark, & Valentine, 2004; Moore & Valentine, 1999). Ellis and Lambon Ralph (2000) propose an alternative account of AoA, predicting that the effect should arise in any task where previously stored information is retrieved. The current study explored the effect of AoA on an object-name verification task. Experiments 1 and 2 demonstrated that early acquired objects were verified significantly faster than later acquired objects. A third experiment collected naming latencies for the same picture stimuli in order to allow a comparison of the magnitude of the AoA effect for object verification and naming. The implications of these findings for accounts of AoA and its locus of effect are discussed.

Comparing electrophysiological correlates of word production in immediate and delayed naming through the analysis of word age of acquisition effects

Most EEG studies analysing speech production with event related brain potential (ERP) have adopted silent metalinguistic tasks or delayed or tacit picture naming in order to avoid possible artefacts during motor preparation. A central issue in the interpretation of these results is whether the processes involved in those tasks are comparable to those involved in overt speech production. In the present study we addressed a methodological issue about the integration of stimulus-aligned and response-aligned ERPs in immediate overt picture naming in comparison to delayed production, coupled with a theoretical point on the effect of word Age of Acquisition (AoA). High density EEG recordings were used and waveform analyses and spatio-temporal segmentation were combined on stimulus-aligned and response-aligned ERPs. The same sequence and duration of topographic maps appeared in the immediate and delayed production until around 350 ms after picture onset, revealing similar encoding processes until the beginning of phonological encoding, but modulations linked to word AoA were only observed in the immediate production. Considering stimulus-aligned and response-aligned ERPs together allowed to identify that a stable topography starting around 350 ms lasts 30 ms longer for late-acquired than for early-acquired words. This difference falls within the time-window of phonological encoding and its modulation can be linked to the longer production latencies for late-acquired words.

Contribution of the pre-SMA to the production of words and non-speech oral motor gestures, as revealed by repetitive transcranial magnetic stimulation (rTMS)

An emerging theoretical perspective, largely based on neuroimaging studies, suggests that the pre-SMA is involved in planning cognitive aspects of motor behavior and language, such as linguistic and non-linguistic response selection. Neuroimaging studies, however, cannot indicate whether a brain region is equally important to all tasks in which it is activated. In the present study, we tested the hypothesis that the pre-SMA is an important component of response selection, using an interference technique. High frequency repetitive TMS (10 Hz) was used to interfere with the functioning of the pre-SMA during tasks requiring selection of words and oral gestures under different selection modes (forced, volitional) and attention levels (high attention, low attention). Results show that TMS applied to the pre-SMA interferes selectively with the volitional selection condition, resulting in longer RTs. The low- and high-attention forced selection conditions were unaffected by TMS, demonstrating that the pre-SMA is sensitive to selection mode but not attentional demands. TMS similarly affected the volitional selection of words and oral gestures, reflecting the response-independent nature of the pre-SMA contribution to response selection. The implications of these results are discussed.

Age of acquisition affects early orthographic processing during Chinese character recognition

Three experiments investigated age of acquisition (AoA) effects on early orthographic processing during Chinese character recognition. In Experiment 1, we measured the accuracy of identification of brief masked characters, accuracy was higher for early compared to late acquired characters. In Experiment 2, the visual duration threshold (VDT) was measured for both early and late acquired Chinese characters. The results showed that early acquired characters were successfully identified at shorter display durations than late acquired characters. Significant AoA effects were also found in Experiment 3, using a lexical decision task requiring mainly orthographic processing (discriminating real Chinese characters from orthographically illegal and unpronounceable characters). In summary, three experiments provide converging empirical evidence, for AoA effects on the early orthographic processing stages of Chinese character recognition. These results suggest that AoA effects during word identification go beyond the phonological or semantic processing stages. These results aslo provide cross-linguistic evidence for an AoA effect on early perceptual processing during identification.

The varying effects of age of acquisition

There are a number of theories that suggest that age of acquisition (AoA) effects are not uniform across different tasks. Catling and Johnston (2006a) found greater AoA effects within an object-naming task than in a semantic classification task. They explained these findings by suggesting that AoA effects might accumulate according to how many levels of representation a task necessitates access to. Brysbaert and Ghyselinck (2006) explain the difference in AoA effects by proposing two distinct types of AoA (frequency dependent and frequency independent), the first accounted for by a connectionist-type mechanism and the latter situated at the interface between semantics and word production. Moreover, Moore, Smith-Spark, and Valentine (2004) and Holmes and Ellis (2006) have suggested that there are two loci of AoA effects: at the phonological level and somewhere within the perceptual level of representation. Again, this could account for the varying degrees of AoA effects. This study sets about testing these ideas by assessing the effect size of AoA across a series of different tasks that necessitate access to various levels of representation. Experiments 1–4 demonstrate significant effects of AoA in a novel picture–picture verification task, an object classification task, a picture verification task, and an object-naming task. Experiment 5 showed no effects of initial phoneme on the naming of the critical objects used within Experiments 1–4. The implication of the varying AoA effect sizes found within Experiments 1–4 in relation to explanations of AoA are discussed.

The many places of frequency: evidence for a novel locus of the lexical frequency effect in word production

The effect of lexical frequency on language-processing tasks is exceptionally reliable. For example, pictures with higher frequency names are named faster and more accurately than those with lower frequency names. Experiments with normal participants and patients strongly suggest that this production effect arises at the level of lexical access. Further work has suggested that within lexical access this effect arises at the level of lexical representations. Here we present patient E.C. who shows an effect of lexical frequency on his nonword error rate. The best explanation of his performance is that there is an additional locus of frequency at the interface of lexical and segmental representational levels. We confirm this hypothesis by showing that only computational models with frequency at this new locus can produce a similar error pattern to that of patient E.C. Finally, in an analysis of a large group of Italian patients, we show that there exist patients who replicate E.C.'s pattern of results and others who show the complementary pattern of frequency effects on semantic error rates. Our results combined with previous findings suggest that frequency plays a role throughout the process of lexical access.

Estimating when and how words are acquired: a natural experiment on the development of the mental lexicon

PURPOSE

Sensitivity of subjective estimates of age of acquisition (AOA) and acquisition channel (AC; printed, spoken, signed) to differences in word exposure within and between populations that differ dramatically in perceptual experience was examined.

METHODS

Fifty participants with early-onset deafness and 50 participants with normal hearing rated 175 words in terms of subjective AOA and AC. Additional data were collected using a standardized test of reading and vocabulary.

RESULTS

Participants with early-onset deafness rated words as learned later (M = 10 years) than did participants with normal hearing (M = 8.5 years), F(1, 99) = 28.59, p < .01. Group-averaged item ratings of AOA were highly correlated across the groups (r = .971) and with normative order of acquisition (deaf: r = .950, hearing: r = .946). The groups differed in their ratings of AC (hearing: printed = 30%, spoken = 70%, signed = 0%; deaf: printed = 45%, spoken = 38%, signed = 17%).

CONCLUSIONS

Subjective AOA and AC measures are sensitive to between- and within-group differences in word experience. The results demonstrate that these subjective measures can be applied as proxies for direct measures of lexical development in studies of lexical knowledge in adults with prelingual onset deafness.

Age of acquisition and repetition priming effects on picture naming of children who do and do not stutter

The effects of age of acquisition and repetition priming on picture naming latencies and errors were studied in 22 children who stutter (CWS) and 22 children who do not stutter (CWNS) between the ages of 3;1 and 5;7. Children participated in a computerized picture naming task where they named pictures of both early and late acquired (AoA) words in two consecutive stages. Findings revealed that all children's picture naming latencies and errors were reduced following repetition priming and in response to early AoA words relative to late AoA words. AoA and repetition priming effects were similar for children in both talker groups, with one exception. Namely, CWS benefitted significantly more, in terms of error reduction, than CWNS from repetition priming for late AoA words. In addition, CWNS exhibited a significant, positive association between linguistic speed and measures of vocabulary, but CWS did not. These findings were taken to suggest that the (a) semantic-phonological connections of CWS may not be as strong as those of CWNS, and (b) existing lexical measures may not be sensitive enough to differentiate CWS from CWNS in lexically related aspects of language production.

EDUCATIONAL OBJECTIVES

After reading this article, the learner will be able to: (a) describe the effects of repetition priming and age of word acquisition in speech production; (b) summarize the performance similarities and differences of children who stutter and children who do not stutter on a computerized picture naming task; and (c) compare the results of the present study with previous work in this area.

The influence of semantic processing on phonological decisions in children and adults: a magnetoencephalography (MEG) study

PURPOSE

To examine the behavioral effects and neural activation patterns associated with implicit semantic processing influences on phonological judgments during reading in children and adults.

METHOD

Whole-head magnetoencephalography (MEG) recordings were obtained from 2 groups, children (9-13 years) and adults, performing a homophone judgment task. The stimuli consisted of pairs of sequentially presented written words that were either homophones, synonym foils, or unrelated control words.

RESULTS

The difference in the time taken to respond to synonym pairs relative to control pairs of stimuli, called the semantic interference effect (SIE), was, on average, 24 ms for adults and 86 ms for children. Source analysis of the MEG data using minimum-norm estimation (MNE) yielded less activation in the adults for the synonym condition compared with the control condition in right anterior temporal and inferior frontal cortex 300-500 ms after the onset of the 2nd word in a pair, suggestive of semantic priming as well as inhibition of the SIE. A similar priming effect was observed for the children in left-anterior temporal cortex.

CONCLUSION

The observed group differences in the magnitude of the SIE and brain activation patterns may reflect developmental differences in the effects of semantic information on phonological decisions during word processing.

Age-of-acquisition effects in word and picture identification

Words and pictures with earlier learned labels are processed faster than words and pictures with later learned labels. This age-of-acquisition (AoA) effect has been extensively investigated in many different types of tasks. This article provides a review of these studies including picture naming, word naming, speeded word naming, word pronunciation durations, lexical decisions, eye fixation times, face recognition, and episodic memory tasks. The measurement and validity of AoA ratings is discussed, along with statistical techniques used for exploring AoA's influence. Finally, theories of AoA are outlined, and evidence for and against the various theories is presented.

Timed picture naming norms for 590 pictures in Dutch

The present study presents timed norms for 590 pictures in Belgian Dutch. We determined name agreement and response latencies. Furthermore, we assessed which factors influenced the naming latencies of the pictures. It appeared that age-of-acquisition, the H-statistic (an index of name agreement), and the number of syllables of the dominant response were significant predictors of the naming latencies. These results are discussed in comparison with previous findings.

Age of acquisition modulates the amplitude of the P300 component in spoken word recognition

Words acquired earlier in life are easier to process in adulthood than words acquired later; this is known as the age of acquisition (AoA) effect. The goal of this study was to establish whether the P300 component of event-related potentials (ERPs) is sensitive to AoA. Early-acquired words (12.5%), late-acquired words (12.5%) and pseudo-words (75%) were presented in an auditory lexical decision task. The two sets of words were matched for length, word type, concreteness, imageability and, crucially, word frequency. Early-acquired words were recognised faster and more accurately than late-acquired words. In addition, AoA modulated ERP activity in centroparietal electrode sites, with early-acquired words eliciting a larger positivity (P300) than late-acquired words. This is the first study to demonstrate an ERP correlate of AoA effects. An important implication of our findings is that AoA may need to be controlled in ERP studies of lexical processing, especially in designs in which it is likely to be a confound (e.g., studies of lexical category effects).