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 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.     

Differential impacts of age of acquisition on letter and semantic fluency in Alzheimer's disease patients and healthy older adults

The degree to which the typical age of acquisition (AoA) of words and word frequency have separable influences on verbal production tasks has been strongly debated. To examine the overlap between these factors in verbal fluency tasks, the performance of Alzheimer's disease (AD) patients (N = 34) and normal elderly controls (N = 36) was compared on semantic (e.g., vegetables) and letter (e.g., words that begin with F) fluency tasks. These comparisons revealed that words generated for the semantic fluency task had an earlier AoA while words generated for the letter fluency task had a higher word frequency. Differences in AoA between AD patients and controls were larger for semantic than letter fluency. These results suggest that AoA has an effect on verbal production that is independent of word frequency and that AoA has a semantic locus.     

Differential impacts of age of acquisition on letter and semantic fluency in Alzheimer's disease patients and healthy older adults

The degree to which the typical age of acquisition (AoA) of words and word frequency have separable influences on verbal production tasks has been strongly debated. To examine the overlap between these factors in verbal fluency tasks, the performance of Alzheimer's disease (AD) patients (N?=?34) and normal elderly controls (N?=?36) was compared on semantic (e.g., vegetables) and letter (e.g., words that begin with F) fluency tasks. These comparisons revealed that words generated for the semantic fluency task had an earlier AoA while words generated for the letter fluency task had a higher word frequency. Differences in AoA between AD patients and controls were larger for semantic than letter fluency. These results suggest that AoA has an effect on verbal production that is independent of word frequency and that AoA has a semantic locus.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

What causes the effect of age of acquisition in lexical processing?

Three hypotheses for effects of age of acquisition (AoA) in lexical processing are compared: the cumulative frequency hypothesis (frequency and AoA both influence the number of encounters with a word, which influences processing speed), the semantic hypothesis (early-acquired words are processed faster because they are more central in the semantic network), and the neural network model (early-acquired words are faster because they are acquired when a network has maximum plasticity). In a regression study of lexical decision (LD) and semantic categorization (SC) in Italian and Dutch, contrary to the cumulative frequency hypothesis, AoA coefficients were larger than frequency coefficients, and, contrary to the semantic hypothesis, the effect of AoA was not larger in SC than in LD. The neural network model was supported.     

Reading in Spanish and Italian: Effects of age of acquisition in transparent orthographies?

Despite the similar transparency of their orthographies, reading in Italian has been found to be affected by frequency but not age of acquisition (AoA) [Barca, L., Burani, C., & Arduino, L. S. (2002). Word naming times and psycholinguistic norms for Italian nouns. Behaviour Research Methods, Instruments and Computers, 34, 424–434] while reading in Spanish is affected by AoA but not frequency [Cuetos, F., & Barbón, A. (2006). Word naming in Spanish. European Journal of Cognitive Psychology, 18, 415–436]. We examined this cross-linguistic difference, firstly, through a reanalysis of the Italian and Spanish reading latencies. After eliminating several between-experiment differences, we replicated the AoA effect in Spanish but not in Italian and the frequency effect in Italian but not in Spanish. The cross-linguistic comparison could not equate stimulus imageability; therefore, secondly, we compared the Italian reading latencies with new Spanish reading latencies for imageability-matched words. We found frequency effects but neither an AoA effect nor a language by AoA interaction. We argue that the previously reported cross-linguistic difference in the AoA effect resulted from a between-study difference in stimulus imageability. More imageable words induced more semantic involvement in reading, yielding an AoA effect in Spanish.     

Age of acquisition in face categorisation: is there an instance-based account?

An instance-based model of the effects of age of acquisition (AoA) is offered and derived predictions are considered. A face-categorisation experiment is reported which tested these predictions. Nine participants made speeded-categorisation judgements of 185 faces from two TV shows. Ratings were given for the faces' frequency of occurrence in the shows and, for each face, the length of time the character was in the show and the time since they had left was found. Regression analyses were used to find how the factors affected the speed of categorisation. Speed of categorisation was found to follow a negative power function of the frequency and time on the show and a positive power function of the time since they had left. This was supportive of the instance-based account and suggests that effects of AoA with words and objects can be explained in terms of cumulative frequency.     

汉语词汇习得的年龄效应：语义假设的证据

通过三个实验考察了词汇加工中的习得年龄效应。实验一对比了汉字命名和图片命名中词汇习得的年龄效应,发现图片命名中存在着较大的词汇习得的年龄效应,汉字命名中没有出现这种效应。实验二和实验三分别采用语义范畴判断任务和图片语义分类任务,两个实验均发现了词汇习得的年龄效应。实验结果说明,词汇习得的年龄效应至少部分来源于语义加工的层次,结果支持了语义假设的观点     

Age-of-acquisition differences in young and older adults affect latencies in lexical decision and semantic categorization

An ongoing discussion about the role of age of acquisition (AoA) in word processing concerns the confound with word frequency. This study removed possible frequency confounds by comparing AoA and word familiarity differences in young (18-23 years) and older (52-56 years) adults. A first study investigated the differences in AoA and word familiarity ratings. The norms of AoA and familiarity were significantly different for young and older adults whereas these were previously considered equivalent [Morrison, C. M., Hirsh, K. W., Chappell, T., & Ellis, A. W. (2002). Age and age of acquisition: An evaluation of the cumulative frequency hypothesis. European Journal of Cognitive Psychology, 14, 435-459]. In the second study, AoA and familiarity effects were significantly different for the older and young adults in a lexical decision task. The third study replicated these findings in a semantic artifact/naturally occurring categorization experiment, thus providing further evidence for AoA-effects when word processing requires semantic mediation. Results from both studies were in line with the hypothesis that AoA effects on word processing cannot be accounted for by word frequency or other possible confounds.     

Re-evaluating age-of-acquisition effects: are they simply cumulative-frequency effects?

The time it takes to read or produce a word is influenced by the word's age of acquisition (AoA) and its frequency (e.g. Quarterly Journal of Experimental Psychology 12 (1973) 85). Lewis (Cognition 71 (1999) B23) suggested that a parsimonious explanation would be that it is the total number of times a word has been encountered that predicts reaction times. Such a cumulative-frequency hypothesis, however, has always been rejected because the statistical effects of AoA and frequency are additive. Here, it is demonstrated mathematically that the cumulative-frequency hypothesis actually predicts such results when applied to curvilinear learning. Further, the data from four influential studies (two of which claim support for independent effects of AoA and frequency) are re-analyzed to reveal that, in fact, they are consistent with a cumulative-frequency hypothesis. The conclusion drawn is that there is no evidence with which to refute the most parsimonious of explanations, i.e. cumulative frequency can account for both frequency and AoA effects.     

Frequency trajectory effects in Chinese character recognition: Evidence for the arbitrary mapping hypothesis

Frequency trajectory is a better measure to investigate age-limited learning effects than age of acquisition (AoA) ratings (Zevin, J. D., & Seidenberg, M. S. (2002). Age of acquisition effects in word reading and other tasks. Journal of Memory and Language, 47(1), 1-29). The current study uses frequency trajectory as a variable to investigate age-limited learning effects in Chinese character recognition, and tests predictions of the arbitrary mapping hypothesis as applied in a non-alphabetic writing system. In Experiment 1, regression analyses showed that, compared to rated AoA, frequency trajectory of characters was less affected by other lexical properties, and could explain a significant proportion of variance of AoA. In Experiment 2, the frequency trajectory and predictability from orthography to pronunciation of characters were orthogonally manipulated in a character naming task. The frequency trajectory effect appeared only for the arbitrary mapping condition. In Experiment 3, frequency trajectory and predictability from orthography to meaning of characters were manipulated in a semantic category judgment task. The frequency trajectory effects were found only when the mapping from orthography to semantic is less consistent. In summary, the study confirmed that AoA is a genuine factor affecting word processing, and the AoA effects were limited to those situations in which mapping between input and output representation was arbitrary. These results provide strong cross-linguistic evidence in support of the arbitrary mapping hypothesis.     

Exploring a neural-network account of age-of-acquisition effects using repetition priming of faces

The question of whether age-of-acquisition (AoA), frequency, and repetition priming effects occur at a common stage or at different stages of processing is addressed. Two single-stage accounts (i.e., cumulative frequency and a neural-network simulation) are considered in regard to their predictions concerning the interactions between AoA and frequency with aging and priming effects. A repetition-priming face-classification task was conducted on both older and younger participants to test these predictions. Consistent with the predictions of the neural-network simulation, AoA had an effect on reaction times that could not be explained by cumulative frequency alone. Also, as predicted by the simulation, the size of the priming effect was determined by the cumulative frequency of the item. It is discussed how this evidence is supportive of the notion that AoA , frequency, and priming all have effects at a common and single stage during face processing.     

聋大学生的词汇习得年龄效应

通过3个实验, 考察了聋大学生的词汇习得年龄效应。实验1采用汉字命名任务和图片命名任务, 被试使用手语命名, 发现在图片命名中存在着词汇习得年龄效应, 在汉字命名中未出现此效应。实验2和实验3分别采用汉字词语义分类任务和图片语义分类任务, 要求被试做生命物和非生命物的判断, 发现在两个语义分类任务中均出现了词汇习得年龄效应。整个研究表明, 在控制了语音因素之后, 语义因素在聋生的词汇习得年龄效应产生中具有重要的作用, 从而支持了语义假设。     

Age-of-acquisition effects in semantic processing tasks

In two experiments, we examined whether word age-of-acquisition (AoA) is a reliable predictor of processing times in semantic tasks. In the first task, participants were asked to say the first associate that came to mind when they saw a stimulus word; the second task involved a semantic categorisation between words with a definable meaning and first names. In both tasks, there were significantly faster responses to earlier-acquired than to later-acquired words. On the basis of these results, we argue that age-of-acquisition effects do not originate solely from the speech output system, but from the semantic system as well.     

Are age-of-acquisition effects on object naming due simply to differences in object recognition? Comments on Levelt (2002)

Levelt (2002) argued that apparent effects of word frequency and age of acquisition (AoA) reported in recent picture naming studies might actually be confounded effects operating at the level of object recognition, rather than relevant to theories of lexical retrieval. In order to investigate this issue, AoA effects were examined in an object recognition memory task (Experiments 1 and 2) and a word-picture verification task (Experiment 3) and compared with those found in naming tasks using the same pictures. Contrary to Levelt's concerns, the results of the three experiments show that the AoA effect on picture naming has a lexical origin and does not simply result from a possible confound of object identification times.     

Age of acquisition effects in picture naming: evidence for a lexical-semantic competition hypothesis

In many tasks the effects of frequency and age of acquisition (AoA) on reaction latencies are similar in size. However, in picture naming the AoA-effect is often significantly larger than expected on the basis of the frequency-effect. Previous explanations of this frequency-independent AoA-effect have attributed it to the organisation of the semantic system or to the way phonological word forms are stored in the mental lexicon. Using a semantic blocking paradigm, we show that semantic context effects on naming latencies are more pronounced for late-acquired than for early-acquired words. This interaction between AoA and naming context is likely to arise during lexical-semantic encoding, which we put forward as the locus for the frequency-independent AoA-effect.     

Age of acquisition and the cumulative-frequency hypothesis: a review of the literature and a new multi-task investigation

Early-acquired words are processed faster than late-acquired words. This is a well-accepted effect within the word recognition literature. Different explanations have been proposed, either localizing the effect of age of acquisition (AoA) in a particular substage of word processing or seeing it as the result of the way in which information is stored and accessed in the brain in general. The cumulative-frequency hypothesis is an example of the latter type of explanation: it states that the total number of times a system has come across a particular stimulus will determine the speed with which the stimulus can be recognized. The present multi-task investigation provides a critical test of the different explanations. Results show that in a variety of word processing tasks the effects of frequency and AoA are highly correlated, and that the impact of AoA is consistently higher than would be expected on the basis of the cumulative-frequency hypothesis. The findings are interpreted as evidence for recent demonstrations of a loss of plasticity in neural networks due to training and/or for mathematical models that describe the growth of the lexico-semantic network as the attachment of new nodes to existing nodes.     

Lexical and semantic age-of-acquisition effects on word naming in Spanish

We report a study of the factors that affect reading in Spanish, a language with a transparent orthography. Our focus was on the influence of lexical semantic knowledge in phonological coding. This effect would be predicted to be minimal in Spanish, according to some accounts of semantic effects in reading. We asked 25 healthy adults to name 2,764 mono- and multisyllabic words. As is typical for psycholinguistics, variables capturing critical word attributes were highly intercorrelated. Therefore, we used principal components analysis (PCA) to derive orthogonalized predictors from raw variables. The PCA distinguished components relating to (1) word frequency, age of acquisition (AoA), and familiarity; (2) word AoA, imageability, and familiarity; (3) word length and orthographic neighborhood size; and (4) bigram type and token frequency. Linear mixed-effects analyses indicated significant effects on reading due to each PCA component. Our observations confirm that oral reading in Spanish proceeds through spelling–sound mappings involving lexical and sublexical units. Importantly, our observations distinguish between the effect of lexical frequency (the impact of the component relating to frequency, AoA, and familiarity) and the effect of semantic knowledge (the impact of the component relating to AoA, imageability, and familiarity). Semantic knowledge influences word naming even when all the words being read have regular spelling–sound mappings.     

The effects of age of acquisition and frequency trajectory on object naming: Comments on Pérez (2007)

Pérez (2007) reported that objective age of acquisition (AoA) was a major determinant of adult object naming latencies when frequency trajectory and cumulative frequency were included in the same regression analysis. In this comment, we discuss several issues concerning the influence of frequency trajectory and AoA and argue that objective AoA is a behavioural outcome and a natural covariate of frequency trajectory. Bonin, Barry, Méot, and Chalard (2004) argued that the critical test of age-limited learning effects is finding an effect of frequency trajectory when AoA was not included as a factor. This critical test was lacking in Pérez's (2007) study, but several re-analyses of his data show that frequency trajectory is a reliable predictor of naming speed when objective AoA is not included in the regression. We conclude that frequency trajectory remains an important independent variable for the study of the effects of age-limited learning.