Age-related differences in lexical access, spreading activation, and simple pronunciation

An experiment was conducted to address age-related differences in lexical access, spreading activation, and pronunciation. Both young and older adults participated in a delayed pronunciation task to trace the time course of lexical access and a semantic priming task to trace the time course of spreading activation. In the delayed pronunciation task, subjects were presented a word and then, after varying delays, were presented a cue to pronounce the word aloud. Older adults benefited considerably more from the preexposure to the word than did the younger adults, suggesting an age-related difference in lexical access time. In the semantic priming pronunciation task, semantic relatedness (related vs. neutral), strength of the relationship (high vs. low), and prime-target stimulus onset asynchrony (200 ms, 350 ms, 500 ms, 650 ms, and 800 ms) were factorially crossed with age to investigate age-related differences in the buildup of semantic activation across time. The results from this task indicated that the activation pattern of the older adults closely mimicked that of the younger adults. Finally, the results of both tasks indicated that older adults were slower at both their onset to pronounce and their actual production durations (i.e., from onset to offset) in the pronunciation task. The results were interpreted as suggesting that input and output processes are slowed with age, but that the basic retrieval mechanism of spreading activation is spared by age.     

Influence of mild cognitive impairment on visual word recognition

The present study examined the effects of normal aging and mild cognitive impairment (MCI) on visual word recognition. Madden et al. (1999) reported evidence of general slowing of cognitive processes in Alzheimer's disease (AD) patients relative to younger adults and healthy older adults using a lexical decision task. It was of interest to determine whether similar effects would be observed in MCI patients relative to healthy younger and older adults. We extended the lexical decision task paradigm developed by Allen et al. (2004b) on younger adults to an examination of the effect(s) of MCI on visual word recognition. Results from the present study showed that healthy older adults and MCI patients performed similarly. That is, both groups took longer than younger adults to process words presented in mixed-case than in consistent-case letters. Mild cognitive impairment patients, however, responded significantly more slowly than healthy older adults across all lexical decision task conditions and showed a trend toward larger case-mixing effects than healthy older adults, which suggests that MCI may result in poorer analytic processing ability. Based on the current findings, evidence of a generalized slowing of cognitive processes using a standard lexical decision task can be expanded to include not only AD patients, but also the preclinical stages of the disease as well.     

The effects of sad mood on memory in older adults: a test of the mood congruence effect

Mood congruence effects have long been studied in younger adults, but not in older adults. Socioemotional selectivity theory (SST) suggests that mood congruence could operate differently in older adults. One hundred and nineteen younger and 78 older adults were randomly assigned to sad or neutral mood inductions, using combined Velten and music induction procedures. Results indicated that during sad mood induction both older and younger adults showed enhanced recall of sad words on delayed word list recall task and in autobiographical memory. However, only older adults displayed mood congruence effects on lexical ambiguity and lower recall of positive words in the word list task. Results provided partial support for developmental effects on mood congruence derived from SST.     

Orthography shapes the perception of speech: The consistency effect in auditory word recognition

Inconsistency in the spelling-to-sound mapping hurts visual word perception and reading aloud (i.e., the traditional consistency effect). In the present experiment, we found a consistency effect in auditory word perception: Words with phonological rimes that could be spelled in multiple ways produced longer auditory lexical decision latencies and more errors than did words with rimes that could be spelled only one way. This finding adds strong support to the claim that orthography affects the perception of spoken words. This effect was predicted by a model that assumes a coupling between orthography and phonology that is functional in both visual and auditory word perception.     

Visual word recognition without central attention: evidence for greater automaticity with advancing age

The present experiments examined the automaticity of word recognition. The authors examined whether people can recognize words while central attention is devoted to another task and how this ability changes across the life span. In Experiment 1, a lexical decision Task 2 was combined with either an auditory or a visual Task 1. Regardless of the Task 1 modality, Task 2 word recognition proceeded in parallel with Task 1 central operations for older adults but not for younger adults. This is a rare example of improved cognitive processing with advancing age. When Task 2 was nonlexical (Experiment 2), however, there was no evidence for greater parallel processing for older adults. Thus, the processing advantage appears to be restricted to lexical processes. The authors conclude that greater cumulative experience with lexical processing leads to greater automaticity, allowing older adults to more efficiently perform this stage in parallel with another task.     

汉语双字多义词的识别优势效应

采用词汇判断法、命名法考察汉语双字多义词的识别优势效应。结果发现,在词汇判断任务中存在着多义词较单义词的识别优势,但这种识别优势只表现在低频词中。在命名任务中未发现多义词的识别优势。作者根据分布表征模型的观点对双字多义词的识别优势效应做出了可能的解释。     

Length effect in reading and lexical decision: evidence from skilled readers and a developmental dyslexic participant

A number of experimental data have shown that naming latency increases with length for pseudo-words but not for frequent real words. Different interpretations have been proposed by current models of reading to account for such a length effect. The aim of the present study was to assess the impact of lexicality on length effect in both the reading and lexical decision tasks. For this purpose, skilled readers were asked to either name or make a lexical decision on words and pseudo-words differing in length from one to three syllables. Skilled readers' results show that length effect is modulated by lexicality in the reading task but no length effect was found in the lexical decision task. The tasks were further proposed to a well-compensated dyslexic participant who exhibited a visual attentional disorder in the absence of any associated phonological problems. A length effect on RTs was found for both words and pseudo-words in lexical decision but naming latencies were affected by length for the pseudo-words only. The present results largely conform to the predictions of the ACV98 model of reading. They are not compatible with the PDP models of reading and can only be partially accounted for by dual route models.     

The oral and written side of word production in young and older adults: generation of lexical neighbors

The aim of the present study was to investigate the effects of aging on both spoken and written word production by using analogous tasks. To do so, a phonological neighbor generation task (Experiment 1) and an orthographic neighbor generation task (Experiment 2) were designed. In both tasks, young and older participants were given a word and had to generate as many words as they could think of by changing one phoneme in the target word (Experiment 1) or one letter in the target word (Experiment 2). The data of the two experiments were consistent, showing that the older adults generated fewer lexical neighbors and made more errors than the young adults. For both groups, the number of words produced, as well as their lexical frequency, decreased as a function of time. These data strongly support the assumption of a symmetrical age-related decline in the transmission of activation within the phonological and orthographic systems.     

Lexical access in younger and older adults: the case of the mass/count distinction.

Although lexicosemantic deficits are not typically seen in older adults, some studies indicate that age-related changes in semantic processing may occur. We had groups of older and younger adults perform speeded lexical decision on mass (e.g., honey), count (e.g., car), and dual nouns, which may be either mass or count (e.g., lamb). Singular dual nouns engendered significantly faster response times in older adults than mass and count nouns, whereas younger adults manifested similar response times to count and dual nouns. These results point toward a three-way distinction in the lexicon between mass, count, and dual nouns. Older adults appear to treat a larger set of nouns as dual than do younger adults. This may be due to awareness of the mass/count ambiguity present in a greater number of lexical items, as a result of their greater linguistic experience. Alternatively, in order to conserve processing resources, older adults may not activate mass/count information when recognizing a dual noun unless a mass or count reading is forced by context.     

Effects of Induced Emotional State on Lexical Processing in Younger and Older Adults

The authors investigated the effects of an induced emotional mood state on lexical decision task (LDT) performance in 50 young adults and 25 older adults. Participants were randomly assigned to either happy or sad mood induction conditions. An emotional mood state was induced by having the participants listen to 8 min of classical music previously rated to induce happy or sad moods. Results replicated previous studies with young adults (i.e., sad-induced individuals responded faster to sad words and happy-induced individuals responded faster to happy words) and extended this pattern to older adults. Results are discussed with regard to information processing, aging, and emotion.     

Effects of induced emotional state on lexical processing in younger and older adults

The authors investigated the effects of an induced emotional mood state on lexical decision task (LDT) performance in 50 young adults and 25 older adults. Participants were randomly assigned to either happy or sad mood induction conditions. An emotional mood state was induced by having the participants listen to 8 min of classical music previously rated to induce happy or sad moods. Results replicated previous studies with young adults (i.e., sad-induced individuals responded faster to sad words and happy-induced individuals responded faster to happy words) and extended this pattern to older adults. Results are discussed with regard to information processing, aging, and emotion.     

Priming with Horizontal Reading Influences the Deployment of Visual Attention During Word Processing1

Previous studies on parallel processing of words have demonstrated that the orthographic properties of multiple words can be processed simultaneously. However, whether parallel lexical processing (which requires attentional allocation towards a subsequent N + 1 word) is possible has been much debated. We examined this controversy in the Japanese language with the flanker lexical decision task and investigated whether the deployment of attention changed after priming with horizontal reading. Participants allocated to the priming group read short passages written in Japanese before the flanker task. The results showed that the parallel processing of a lexical property was observed after priming, which implicates that reading facilitates the attentional allocation to the right during the processing of a current word. The results suggested that strategies to allocate attention to the right are at work during reading. Furthermore, the current study points to the possibility that word processing during reading can be assessed by combining the priming procedure and flanker lexical decision task.     

The attentional control of lexical processing pathways: Reversing the word frequency effect

In two experiments, we investigated the influence of word frequency in speeded word naming and in a relatively novel regularization task in which participants were required to pronounce words on the basis of spelling-to-sound correspondences instead of giving their normal pronunciations (e.g., pronounce pint so that it rhymes with hint). Participants were presented high- and low-frequency regular words and exception words, along with a set of nonwords. The results indicated that there was a normal word frequency effect (i.e., high-frequency words faster than low-frequency words) in the standard speeded naming task, whereas, for the regularization task, the word frequency effect was reversed for regular words, even though the regular words were pronounced in an identical fashion in both the normal naming and the regularization tasks. This reversal of the word frequency effect was not obtained for the exception words. The discussion focuses on the implication of these results for attentional control models of lexical processing.     

Conscious and unconscious lexical retrieval blocking in younger and older adults

The effects of orthographically overlapping prime words in a word fragment completion task (modified from S. M. Smith & D. R. Tindell, 1997) were studied in younger and older adults. Participants studied words and then completed word fragments corresponding to those words. Fragments were preceded by a blocking, unrelated, or neutral prime. In Experiment 1, all participants were slower and less likely to complete the word fragments correctly in the blocking prime condition. Older adults also were more likely to use the blocking prime to incorrectly complete the word fragment compared with younger adults, even when warned against doing so (Experiment 2). Experiment 3 used a masked priming paradigm in younger adults to examine whether conscious processing of the prime word was necessary to produce blocking effects. Reliable blocking effects were obtained, including an intrusion rate similar to that observed in older adults in the first two experiments. These results suggest that certain aspects of word-finding failures in normal aging may be related to the reduced ability to control the activation of a lexical competitor when attempting to retrieve a target word.     

听觉条件下词汇获得年龄效应产生机制的初探

通过三个实验考察听觉词汇的获得年龄效应。实验1采用基于语音的词汇判断任务,在错误率上存在词汇获得年龄效应,即早期习得词汇的正确率高于晚期习得词汇;实验2、3分别采用基于字形和语义的词汇判断任务,在反应时上存在词汇获得年龄效应,即早期习得词汇的反应快于晚期习得词汇。结果支持任意映射假说的观点：⒈词汇获得年龄效应产生于音、形、义加工的多个方面;⒉映射程度高低是决定词汇获得年龄效应大小的重要因素。     

Unpredictability and complexity of print-to-speech correspondences increase reliance on lexical processes: more evidence for the orthographic depth hypothesis

The Orthographic Depth Hypothesis [Katz, L., & Frost, R. (1992). The reading process is different for different orthographies: The orthographic depth hypothesis. In R. Frost & L. Katz (Eds.), Orthography, phonology, morphology, and meaning (pp. 67–84). Amsterdam: Elsevier Science] proposes cross-linguistic differences in the involvement of lexical processing during reading. In orthographies with complex, inconsistent, and/or incomplete sublexical correspondences, decoding is more difficult and therefore slower. This gives more time to the lexical route to retrieve information, and leads to a greater ratio of lexical processing. We test whether this mechanism applies both for words with inconsistent (in English) and for words with complex (in French) correspondences. As complex correspondences are sufficient to derive a correct pronunciation, an increase in lexical processing may not occur. In a reading-aloud task, we used the frequency effect to measure lexical processing. The data showed stronger involvement of lexical processing for inconsistent compared to consistent words, and for complex compared to simple words. The results confirm that Katz and Frost’s proposed mechanism applies to different sources of orthographic depth.     

Children’s and adults’ use of spelling-sound information in three reading tasks

This research examined the effects of irregular spelling and irregular spelling-sound correspondences on word recognition in children and adults. Previous research has established that, among skilled readers, these irregularities influence the reading of only lower frequency words. However, this research involved the lexical decision and naming tasks, which differ from the demands of normal reading in important ways. In the present experiments, we compared performance on these tasks with that on a task requiring words to be recognized in sentence contexts. Results indicated that adults showed effects of spelling and spelling-sound irregularities in reading lower frequency words on all three tasks, whereas younger and poorer readers also showed effects on higher frequency words. The fact that irregular spelling-sound correspondences affected performance on the sentence task indicates that access of phonological information is not an artifact of having to read a word aloud or perform a lexical decision. Two other developmental trends were observed: As children became more skilled in reading, the effects of irregular spelling were overcome before the effects of irregular spelling-sound correspondences; the latter effects were eliminated on silent reading tasks earlier than on the naming task.     

The role of vocabulary ability during visual word recognition in younger and older adults

The role that vocabulary ability plays in adult age differences in word recognition was investigated. In Experiment 1, 44 older adults (ages 61-93 years) were compared with 44 younger adults (ages 18-39 years) on a standard lexical-decision task, with ambiguous words, unambiguous words, and pseudowords serving as stimuli. In Experiment 1, the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981) vocabulary performance was uncontrolled across the younger and older adults, and the older adults had higher WAIS-R scores. There was no Group x Stimulus interaction. In Experiment 2, the data from the same 44 older adults were compared with data from a new sample of 44 younger adults (ages 18-44). Both groups were then matched on WAIS-R performance. Results revealed a significant Group x Stimulus interaction. Reaction time differences between the younger and older groups on the ambiguous words and unambiguous words were identical. The differences in reaction times for words and pseudowords were greater in the older adults. The importance of vocabulary ability during word recognition and lexical processing is discussed.     

Age differences in overlapping-task performance: evidence for efficient parallel processing in older adults

Two psychological refractory period (PRP) experiments were conducted to examine overlapping processing in younger and older adults. A shape discrimination task (triangle or rectangle) for Task 1 (T1) and a lexical-decision task (word or nonword) for Task 2 (T2) were used. PRP effects, response time for T2 increasing as stimulus onset synchrony (SOA) decreased, were obtained for both age groups. The effect of word frequency on T2 was smaller at the short SOA than at the long SOA, reflecting slack effects, which were larger for older than younger adults in both experiments. These results suggest that older adults can perform lexical access of T2 in parallel with the processing of T1 at least as efficiently as younger adults.