Age of acquisition's effect on memory for semantically associated word pairs

This experiment investigated the effects of age of acquisition (AoA) in memory for associated word pairs in a cued recall task. Participants studied a list of frequency-controlled early- and late-acquired words in semantically related pairs and then were asked to recall the second word of the pair when cued with the first. Reaction time effects were found, showing that a late-acquired cue for an early-acquired target word was responded to significantly faster than other combinations. Additionally, late-acquired target words resulted in significantly more accurate responses. As significant differences were found even when frequency was controlled, the effects must therefore stem from the manipulations ofAoA. Given this evidence, the implications for AoA's effects on the organization of semantic memory are explored.     

The negative generation effect: Delineation of a phenomenon

In four experiments employing between-list designs, generation was found to have negative effects on free recall of word pairs and on cued recall of the second word. In addition, generation had negative effects on measures of word-pair integration and on clustering in recall. In contrast, positive effects of generation were found on free recall of second words alone, and on a recognition test for memory of the second word. It was concluded that in between-list designs, generation led to greater individual-item processing of the generated term than reading, but this processing occurred at the expense of processing the relation between the words in a pair and processing the relations between different pairs in a list.     

Age-of-acquisition affects word naming in Italian only when stress is irregular

In Italian, effects of age of acquisition (AoA) have been found in object naming, semantic categorization of words and lexical decision, but not in word naming (reading aloud). The lack of an AoA effect in Italian word naming is replicated in Experiment 1 which involved reading aloud two-syllable words which all have regular spelling-sound correspondences and regular stress patterns. Studies of English word naming have reported stronger effects of AoA for irregular or exception words than for words with regular, consistent spelling-sound correspondences. There are no grapheme-phoneme irregularities in Italian, but words containing three or more syllables can carry either regular stress on the penultimate syllable or irregular stress on the antepenultimate syllable. Experiment 2 found effects of AoA on reading three-syllable words for words with irregular stress. The results are interpreted in terms of the 'mapping hypothesis' of AoA, with effects arising as a result of a difficulty to generalize earlier-acquired patterns to irregular late-acquired words.     

Is scanning in probed order recall articulatory?

We consider how theories of serial recall might apply to other short-term memory tasks involving recall of order. In particular, we consider the possibility that when participants are cued to recall an item at an arbitrary position in a sequence, they covertly serially recall the list up to the cued position. One question is whether such “scanning” is articulatory in nature. Two experiments are presented in which the syllabic length of words preceding and following target positions were manipulated, to test the prediction of an articulatory-based mechanism that time to recall an item at a particular position will depend on the number of preceding long words. Although latency was dependent on target position, no word length effects on latency were observed. Additionally, the effects of word length on accuracy replicate recent demonstrations in serial recall that recall accuracy is dependent on the word length of all list items, not just that of target items, in line with distinctiveness assumptions. It is concluded that if scanning does occur, it is not carried out by covert or overt articulation.     

Integrative and semantic relations equally alleviate age-related associative memory deficits

Two experiments compared effects of integrative and semantic relations between pairs of words on lexical and memory processes in old age. Integrative relations occur when two dissimilar and unassociated words are linked together to form a coherent phrase (e.g., horse-doctor). In Experiment 1, older adults completed a lexical-decision task where prime and target words were related either integratively or semantically. The two types of relation both facilitated responses compared to a baseline condition, demonstrating that priming can occur in older adults with minimal preexisting associations between primes and targets. In Experiment 2, young and older adults completed a cued recall task with integrative, semantic, and unrelated word pairs. Both integrative and semantic pairs showed significantly smaller age differences in associative memory compared to unrelated pairs. Integrative relations facilitated older adults' memory to a similar extent as semantic relations despite having few preexisting associations in memory. Integratability of stimuli is therefore a new factor that reduces associative deficits in older adults, most likely by supporting encoding and retrieval mechanisms.     

Since when or how often? Dissociating the roles of age of acquisition (AoA) and lexical frequency in early visual word processing

The aim of the study was to investigate the effect of both word age of acquisition (AoA) and frequency of occurrence on the timing and topographical distribution of ERP components. The processing of early- versus late-acquired words was compared with that of high-frequency versus low-frequency words. Participants were asked to perform an orthographic task while EEG was recorded from 128 sites. RTs showed an effect of both word AoA and lexical frequency. ERPs revealed a neuro-functional dissociation between AoA and frequency effects in early word processing. AoA modulated the amplitude of left occipito-temporal selection-negativity, suggesting an effect of AoA on early orthographic and lexical access and revealing the crucial role of AoA in determining how words are neurally represented in the ventral pathway. Lexical frequency modulated the amplitude of left anterior negativity, providing evidence for the involvement of the left inferior frontal cortex in the processing of low-frequency words.     

Primacy and recency in primed free association and associative cued recall

Two experiments compared the serial positions of primed words in an implicit free association test with words recalled in a cued recall test. In both tests, weakly or strongly related word pairs were studied, and the first words of each pair formed the test cues. In the implicit test, weakly related words pairs showed primacy and extended recency effects but strongly related word pairs did not. In the explicit test, both weakly and strongly related word pairs showed primacy and extended recency effects. These functional dissociations between implicit and explicit memory tests indicate that strongly related word pairs are encoded together because they have unitized memory representations that function as integrated units without requiring any additional associative links to be made, but that an additional system or process is required to strengthen weakly related word pairs during encoding. In addition, a further additional system or process is accessed by explicit retrieval.     

习得年龄对客体和动作图画口语命名的不同影响：ERP研究

词汇习得年龄指人们最早理解单词意义时的年龄, 已有研究发现早习得词汇的阅读反应时间短于晚习得词汇, 研究者对于词汇习得年龄效应的认知机制存在争论。本研究运用事件相关电位技术, 考察了词汇习得年龄(早与晚)对客体图画和动作图画命名的影响。研究中采用图画命名任务, 要求被试在看到图画后迅速且准确地说出图画名称。结果发现早习得名词的命名快于晚习得名词, 而早习得动词的命名却慢于晚习得动词; 习得年龄对于名词产生的影响发生在图画呈现后的250~300 ms之间, 表现为早习得名词波幅小于晚习得名词, 而习得年龄对于动词产生的影响发生在图画呈现后的200~600 ms之间, 表现为早习得动词波幅大于晚习得动词。这表明名词产生中的习得年龄效应发生在词汇选择阶段, 支持了语义假设的观点; 动词产生过程中的习得年龄效应出现在多个加工阶段, 包括了词汇选择、音韵编码和语音编码阶段, 这与动词语义的多重性及其与动作相关的脑区激活有关, 支持了网络可塑性假说的观点。     

Age-of-acquisition effects in visual word recognition: evidence from expert vocabularies

Three experiments assessed the contributions of age-of-acquisition (AoA) and frequency to visual word recognition. Three databases were created from electronic journals in chemistry, psychology and geology in order to identify technical words that are extremely frequent in each discipline but acquired late in life. In Experiment 1, psychologists and chemists showed an advantage in lexical decision for late-acquired/high-frequency words (e.g. a psychologist responding to cognition) over late-acquired/low-frequency words (e.g. a chemist responding to cognition), revealing a frequency effect when words are perfectly matched. However, contrary to theories that exclude AoA as a factor, performance was similar for the late-acquired/high-frequency and early-acquired/low-frequency words (e.g. dragon) even though their cumulative frequencies differed by more than an order of magnitude. This last finding was replicated with geologists using geology words matched with early-acquired words in terms of concreteness (Experiment 2). Most interestingly, Experiment 3 yielded the same pattern of results in naming while controlling for imageability, a finding that is particularly problematic for parallel distributed processing models of reading.     

The role of age of acquisition in memory: effects on judgements of learning and recall

Judgements of learning (JOLs) are self-made predictions of the likelihood that one will later recall information. The influence of stimulus characteristics on JOLs and recall continues to receive attention, yet there are still a number of unexplored lexical word features that may exert an effect on mnemonic processing. Using a standard cue-target paradigm, we focused on the role of word age of acquisition (AoA) and evaluated the role of both cue and target AoA on responses. We replicated the robust delayed-JOL effect and used a novel items analysis approach to examine the relationship between intrinsic word features and accuracy and reaction times for both JOLs and recall. A consistent effect of target AoA was found, even after controlling for a range of covariates previously shown to impact JOLs and recall. These results expand the role of AoA in word processing and suggest that it is a key variable in memory and metacognition; they also support Koriat's (1997) cue utilization framework.     

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。     

Do novel associative word stem completion and cued recall share the same memory retrieval processes?

The aim of this study was to determine whether word stem completion for novel associations between cue and target words was mediated by automatic unconscious memory processes or effortful memory processes under conscious control. This was done by applying full and divided attention conditions at test to stem completion, cued recall, and recognition, and by administering a questionnaire that probed the memory strategies used by subjects during the completion test. Divided attention had no effect on stem completion performance, but did reduce associative cued recall. Recognition performance was weakened overall by divided attention, but the associative effect was similar under both attention conditions. This suggested that novel associative word stem completion was mediated by automatic retrieval processes. However, the results of the questionnaire indicated that only subjects who attempted to remember the words from the study phase during the completion task showed any novel associative effect. It is concluded that novel association word stem completion and cued recall share automatic retrieval processes, which nevertheless give rise to the experience of remembering.     

Selective access in cued recall: The roles of retrieval cues and domains of encoding

The purpose of these experiments was to determine whether retrieval access in cued recall can be selectively restricted to a single domain of encoding when information has been encoded within two domains as different as word sound and word meaning. In Experiment 1, the subjects studied pairs of rhyming words differing in rhyme set size under verbal-repetition or interactive-imagery instructions. Recall was cued with study-context rhymes, with extralist rhymes, or with extralist associates. The results indicated that rhyme set size and instructional effects were found no matter how recall was cued, indicating that both domains of encoding were always accessed. In Experiment 2, potential effects of study time and overt naming of the test cues were explored. These results indicated that both domains of encoding were accessed, except when long study times were available and subjects did not have to name the rhyme test cues. Rhyme set-size effects were eliminated under these conditions, suggesting that selective access to encoded meaning is possible in cued recall. Retrieval access in this task appears to be more controlled by domains of encoding than by information directly available in the cue, and access to encoded information can be restricted to a single domain.     

Effects of level of retrieval success on recall-related frontal and medial temporal lobe activations

Brain dedicated single photon emission computed tomography (SPECT) was used to compare the neuroactivation produced by the cued recall of response words in a set of studied word pairs with that produced by the cued retrieval of words semantically related to unstudied stimulus words. Six of the 12 subjects scanned were extensively trained so as to have good memory of the studied pairs and the remaining six were minimally trained so as to have poor memory. When comparing episodic with semantic retrieval, the well-trained subjects showed significant left medial temporal lobe activation, which was also significantly greater than that shown by the poorly trained subjects, who failed to show significant medial temporal lobe activation. In contrast, the poorly trained subjects showed significant bilateral frontal lobe activation, which was significantly greater than that shown by the well-trained subjects who failed to show significant frontal lobe activation. The frontal activations occurred mainly in the dorsolateral region, but extended into the ventrolateral and, to a lesser extent, the frontal polar regions. It is argued that whereas the medial temporal lobe activation increased as the proportion of response words successfully recalled increased, the bilateral frontal lobe activation increased in proportion to retrieval effort, which was greater when learning had been less good.     

Semantic specificity in cued recall

In three cued recall experiments, extralist retrieval cues that were congruous in meaning to an encoded target pair of words produced better recall of the targets than wh6n the cuetarget relation was incongruous. However, this result, which differs from that of other experiments, depended in some cases on scoring recall of a target pair when either member of the pair was recalled. It is argued that (1) pairs of words are typically stored as higher order units, (2) the best test procedure is to request recall of both members of the pair when an extralist cue is presented, and (3) semantic features provide an important dimension in the mnemonic representation of word events.     

Episodic intertrial learning of younger and older participants: Effects of age of acquisition

There is clear evidence of a deficit in episodic memory for older adults compared to younger adults. Using an intertrial technique previous research has investigated whether this deficit can be attributed to a decline in encoding or consolidation. On standard memory tests, these two aspects of memory function can be measured by examining the items forgotten or acquired across multiple learning trials. The present study assessed whether age deficits in episodic memory were affected by stimulus characteristics, specifically age of acquisition (AoA). A standard intertrial design was implemented whereby participants studied word lists over several study-test trials. The stimulus characteristics of AoA were manipulated using a pure-list technique. Our findings showed that older adults demonstrate an overall recall deficit which appeared to be a consequence of both an encoding deficit and consolidation weakness. Earlier-acquired words were recalled significantly better than later-acquired words and this was apparently due to both enhanced encoding and consolidation of earlier- over later-acquired words. The key finding is that older adults show a recall advantage for earlier- compared to later-acquired words over the entire experiment to a greater degree than younger adults.     

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.     

Effects of emotion and age on performance during a think/no-think memory task

Recent studies have demonstrated that young adults can voluntarily suppress information from memory when directed to. After learning novel word pairings to criterion, participants are shown individual words and instructed either to "think" about the associated word, or to put it out of mind entirely ("no-think"). When given a surprise cued recall test, participants typically show impaired recall for no-think words relative to think or "control" (un-manipulated) words. The present study investigated whether this controlled suppression effect persists in an aged population, and examined how the emotionality of the to-be-suppressed word affects suppression ability. Data from four experiments using the think/no-think task demonstrate that older and younger adults can suppress information when directed to (Experiment 1), and the age groups do not differ significantly in this ability. Experiments 2 through 4 demonstrate that both age groups can suppress words that are emotional (positive or negative valence) or neutral. The suppression effect also persists even if participants are tested using independent probe words that are semantically related to the target words but were not the studied cue words (Experiments 3 and 4). These data suggest that the cognitive functioning necessary to suppress information from memory is present in older adulthood, and that both emotional and neutral information can be successfully suppressed from memory.     

Incidental formation of episodic associations: The importance of sentential context

The influence of relevant semantic context on the incidental formation of episodic associations between words was probed in two experiments. In Experiment 1, we examined the influence of associations formed incidentally between unrelated words presented either in isolation or embedded in a sentential context on subsequent explicit paired-associate leaning tested by cued recall. The results of Experiment 1 showed that the cued-recall rate of words studied in sentential context was higher than that of words co-occurring in isolated pairs. A subsequent single-items recognition test showed equal item memory for words studied in sentences than for words studied in isolated pairs, suggesting that the sentential context effect in cued recall indeed reflected stronger associations between paired words rather than better memory for single words. In Experiment 2, we ruled out memory for the entire sentence as an alternative explanation for the results of Experiment 1. We suggest two possible mechanisms to account for this advantage: First, pairs embedded in a sentence undergo semantic elaboration that might lead to the incidental formation of an association between them. Second, words embedded in a sentence enjoy the conjoint activation of compatible semantic features, a fact that may also facilitate the formation of an episodic association between them. The implications of these results for computational models using word representations based on co-occurrence data are discussed.     

Implicit and explicit memory bias for threat in post-traumatic stress disorder.

We investigated explicit (cued recall) and implicit (word completion) memory in Vietnam combat veterans with (n = 24) and without (n = 24) post-traumatic stress disorder (PTSD). Half of the subjects in each group encoded combat, social threat, positive, and neutral words elaboratively, whereas the others encoded these words nonelaboratively. On the cued recall test, under both encoding conditions, both groups recalled more combat words than other words. However, difference scores obtained by subtracting the mean recall for neutral words from the mean recall scores for the other words revealed that PTSD patients exhibited a relative explicit memory bias for combat words. That is, PTSD patients tended to exhibit poor memory for everything but combat words. On the word completion test, only PTSD subjects exhibited an implicit memory bias for combat words. This bias was greater for primed than for unprimed words, thereby ruling out a response bias. Such memory bias may underlie the 'reexperiencing' symptoms characteristic of PTSD (e.g. intrusive thoughts, nightmares).