Encoding processes and the spacing effect

The differential encoding theory of the spacing effect was tested utilizing Martin's (1968) encoding variability notion, in which it is hypothesized that low-meaningfulness items are more variable in their encodings than are high-meaningfulness items. In a series of three experiments using a continuous paired associate learning task, it was predicted that the spacing vs. performance curves for CCC items would show a faster improvement in performance than would the curves for high-meaningfulness CVC items. None of the experiments supported this prediction. In addition, it was found that items recognized on their second presentation were more likely to be recalled than were those items not recognized. It was concluded that an item's repetitions are more effective if one code is formed and elaborated with each repetition rather than if more than one code is formed.     

Retention by “fast” and “slow” learners

Four experiments were conducted to replicate and extend the findings by Shuell and Keppel (1970) as well as others, that when properly equated for original learning, “fast” and “slow” learners have parallel forgetting curves. In Experiments I and II, the Shuell-Keppel findings, originally demonstrated on American students learning lists of words, were replicated on samples of Nigerian students. In Experiments III and IV, Nigerian and American students, respectively, learned poems to a criterion of 75–90% correct and were tested for retention. In all studies, “fast” and “slow” learners were brought to a similar learning criterion, with the result that their forgetting curves were parallel.     

外显、内隐记忆中不同认知方式个体的社会定向

以中文双字词为实验材料,分别从两个层面探讨场依存个体与场独立个体对社会词或非社会词的记忆有无偏向。实验一采用双任务,分散注意学习条件,实验二引入加工分离程序(PDP)。研究结果表明:(1)在双任务分散注意学习条件下,场依存个体对非目标社会词存在记忆偏向。(2)在内隐记忆成绩上,场依存个体对社会词存在记忆偏向,场独立个体对非社会词存在记忆偏向。     

Effects of Word Processing and Short-term Memory Deficits on Verbal Learning: Evidence from Aphasia

We report two experiments that investigate the abilities of aphasic subjects with lexical and short-term memory impairments to learn supraspan lists of 10 words. We examined effects of stimulus factors (characteristics of words and lists to be learned) and subject factors (verbal and nonverbal STM span, nature of language impairment). Learning ability was influenced by the imageability and frequency of the words to be learned (Experiment 1) and by the linguistic relationship among words in a list (Experiment 2). Additionally, learning ability was affected by the nature of a subject's word processing deficit (whether it involved semantic and/or phonological processes). Phonological ability was positively associated with learning in both experiments, and semantic ability was associated with learning when words in a list were high in both frequency and imageability (Experiment 1) or were contextually related to one another (Experiment 2). Finally, verbal STM span was positively related to learning performance, but the effect was more pronounced for word span than digit span. These relationships among word processing ability, verbal STM span, and learning ability are discussed with reference to learning in aphasia and to models of learning more generally.     

Category learning in the color-word contingency learning paradigm

In the typical color-word contingency learning paradigm, participants respond to the print color of words where each word is presented most often in one color. Learning is indicated by faster and more accurate responses when a word is presented in its usual color, relative to another color. To eliminate the possibility that this effect is driven exclusively by the familiarity of item-specific word-color pairings, we examine whether contingency learning effects can be observed also when colors are related to categories of words rather than to individual words. To this end, the reported experiments used three categories of words (animals, verbs, and professions) that were each predictive of one color. Importantly, each individual word was presented only once, thus eliminating individual color-word contingencies. Nevertheless, for the first time, a category-based contingency effect was observed, with faster and more accurate responses when a category item was presented in the color in which most of the other items of that category were presented. This finding helps to constrain episodic learning models and sets the stage for new research on category-based contingency learning.     

Turning an advantage into a disadvantage: Ambiguity effects in lexical decision versus reading tasks

When performing a lexical decision task, participants can correctly categorize letter strings as words faster if they have multiple meanings (i.e., ambiguous words) than if they have one meaning (i.e., unambiguous words). In contrast, when reading connected text, participants tend to fixate longer on ambiguous words than on unambiguous words. Why are ambiguous words at an advantage in one word recognition task, and at a disadvantage in another? These disparate results can be reconciled if it is assumed that ambiguous words are relatively fast to reach a semantic-blend state sufficient for supporting lexical decisions, but then slow to escape the blend when the task requires a specific meaning be retrieved. We report several experiments that support this possibility.     

Learning the Experimenter's Design Tacit: Sensitivity to the Structure of Memory Lists

Two experiments are reported that draw an analogy between experiments on verbal memory and experiments on tacit learning. Rules that experimenters use to select words for memory experiments, such as frequency, length, and grammatical class, produce consistencies to which subjects can become sensitive. Replicating the key results from the tacit learning literature, subjects in our experiments discriminated new words consistent with the experimenters' selection rules from inconsistent words, even when they could not describe those rules. The results also reveal a close relation between the information underlying both recognition memory and classification judgements. In particular, a 'mirror effect' (Glanzer & Bowles, 1976) is found with both tasks. Implications for research on memory and learning are discussed.     

Fine-grained sensitivity to statistical information in adult word learning

A language learner trying to acquire a new word must often sift through many potential relations between particular words and their possible meanings. In principle, statistical information about the distribution of those mappings could serve as one important source of data, but little is known about whether learners can in fact track multiple word-referent mappings, and, if they do, the precision with which they can represent those statistics. To test this, two experiments contrasted a pair of possibilities: that learners encode the fine-grained statistics of mappings in the input - both high- and low-frequency mappings - or, alternatively, that only high frequency mappings are represented. Participants were briefly trained on novel word-novel object pairs combined with varying frequencies: some objects were paired with one word, other objects with multiple words with differing frequencies (ranging from 10% to 80%). Results showed that participants were exquisitely sensitive to very small statistical differences in mappings. The second experiment showed that word learners' representation of low frequency mappings is modulated as a function of the variability in the environment. Implications for Mutual Exclusivity and Bayesian accounts of word learning are discussed.     

Memorability judgments for high- and low-frequency words

Five experiments were conducted in order to examine subjects’ judgments of the memorability of high- (HF) and low-frequency (LF) words in the context of a recognition memory task. In Experiment 1, the subjects were provided study/test experience with a list of HF and LF words prior to making memorability judgments for a new list of HF and LF items. The findings were consistent with previous evidence (Greene & Thapar, 1994; Wixted, 1992) suggesting that subjects are not explicitly aware of the greater recognition memorability of LF words. Experiments 2–5 embedded the memorability judgment task within the recognition test itself. In these experiments, the subjects consistently gave higher memorability ratings to LF items. The contrast between the pattern of results found when the subjects made their judgments at the time of list presentation (Experiment 1) and that when they made their judgments during the recognition test (Experiments 2–5) is consistent with recent evidence that even seemingly highly related metamnemonic judgments (e.g., ease of learning judgments vs. judgments of learning for the same items) may be based on very different factors if they occur at different points in the study/test cycle. The present findings are also consistent with the possibility that very rapid retrieval of memorability information for HF and LF words may affect recognition decisions and may contribute to the recognition memory word frequency effect.     

Recruitment of newly acquired category exemplars into unconscious processing systems is rapid and durable

In a series of 3 unconscious priming experiments, we investigated if newly acquired English language words can become integrated into unconscious processing systems, and what preconditions are required to enable this process. In each experiment participants learned English language names of extremely rare fish and flowers in a single learning session. After a varying interval of time and in some cases a brief session of repeated conscious exposure (relearning), the newly learned words were presented as briefly flashed, visually masked primes in a standard unconscious category priming procedure. Results show that newly acquired words are recruited quickly into unconscious processing systems. Furthermore, this acquisition persists for at least 48 h and is dependent on prime duration. Since priming was only obtained after an interval that included overnight sleep, consolidation during sleep may play a role in the integration of novel words into unconscious processing systems.     

Propose but verify: Fast mapping meets cross-situational word learning

We report three eyetracking experiments that examine the learning procedure used by adults as they pair novel words and visually presented referents over a sequence of referentially ambiguous trials. Successful learning under such conditions has been argued to be the product of a learning procedure in which participants provisionally pair each novel word with several possible referents and use a statistical-associative learning mechanism to gradually converge on a single mapping across learning instances [e.g., Yu, C., & Smith, L. B. (2007). Rapid word learning under uncertainty via cross-situational statistics. Psychological Science, 18(5), 414–420]. We argue here that successful learning in this setting is instead the product of a one-trial procedure in which a single hypothesized word-referent pairing is retained across learning instances, abandoned only if the subsequent instance fails to confirm the pairing – more a ‘fast mapping’ procedure than a gradual statistical one. We provide experimental evidence for this propose-but-verify learning procedure via three experiments in which adult participants attempted to learn the meanings of nonce words cross-situationally under varying degrees of referential uncertainty. The findings, using both explicit (referent selection) and implicit (eye movement) measures, show that even in these artificial learning contexts, which are far simpler than those encountered by a language learner in a natural environment, participants do not retain multiple meaning hypotheses across learning instances. As we discuss, these findings challenge ‘gradualist’ accounts of word learning and are consistent with the known rapid course of vocabulary learning in a first language.     

Interference of Sentence and Picture Contexts on Learning Prepositions

The effects of extra stimulus cues, such as pictures and sentences, on learning of preposition words were examined in two experiments. A one-way repeated-measures design was applied in the study. The results show that both sentences and pictures interfered with and blocked the learning of these context-dependent words in the simultaneous presentations. The superiority of feedback presentations over simultaneous presentations indicate that feedback techniques neutralize the blocking effect. More interestingly, however, the prepositions were learned more quickly in the absence of any context cues and this suggested that it is better to teach basic preposition words either by the presentation of them alone or if extra stimulus cues are to be used they should be presented as feedback.     

How does the provision of semantic information influence the lexicalization of new spoken words?

The integration of a novel spoken word with existing lexical items can proceed within 24 hours of learning its phonological form. However, previous studies have reported that lexical integration of new spoken words can be delayed if semantic information is provided during learning. One possibility is that this delay in lexical integration reflects reduced phonological processing during learning as a consequence of the need to learn the semantic associations. In the current study, adult participants learnt novel words via a phoneme monitoring task, in which half of the words were associated with a picture referent, and half were phonological forms only. Critically, participants were instructed to learn the forms of the novel words, with no explicit goal to learn the word–picture mappings. Results revealed significant lexical competition effects emerging one week after consolidation, which were equivalent for the picture-present and form-only conditions. Tests of declarative memory and shadowing showed equivalent performance for picture-present and form-only words, despite participants showing good knowledge of the picture associations immediately after learning. These data support the contention that provided phonological information is recruited sufficiently well during learning, the provision of semantic information does not slow the time-course of lexical integration.     

Retrieval dynamics in recognition and list discrimination: Further evidence of separate processes of familiarity and recall

Two experiments tested the hypothesis that the time course of retrieval from memory is different for familiarity and recall. The response-signal method was used to compare memory retrieval dynamics in yes-no recognition memory, as a measure of familiarity, with those of list discrimination, as a measure of contextual recall. Responses were always made with regard to membership in two previous study lists. In Experiment 1 an exclusion task requiring positive responses to words from one list and negative responses to new words and words from the nontarget list was used. In Experiment 2, recognition and list discrimination were separate tasks. Retrieval curves from both experiments were consistent, showing that the minimal retrieval time for recognition was about 100 msec faster than that for list discrimination. Repetition affected asymptotic performance but had no reliable effects on retrieval dynamics in either the recognition or the list-discrimination task.     

Mood and memory: Mood-congruity effects in absence of mood

Themood-congruity effect refers to facilitated processing of information when the affective valence of this information is congruent with the subject’s mood. In this paper we argue that mood may be a sufficient but not a necessary condition to produce the mood-congruity effect of selective learning. Two experiments are presented in which subjects learned lists of words with neutral, positive, and negative affective valences. In the learning task the subjects were instructed to behave as if they were depressed or happy. The mood-congruity effect was indeed obtained. The effect was stronger with subjects who “predicted” the relationship between mood and affective word valence than with subjects who were unaware of this relationship. The results are not simply attributed to task demands, but are interpreted in terms of a model of cognitive processes and people’s knowledge about mood states.     

Does temporal contiguity moderate contingency learning in a speeded performance task?

In four experiments, we varied the time between the onset of distracting nonwords and target colour words in a word-word version of the colour-word contingency learning paradigm. Contingencies were created by pairing a distractor nonword more often with one target colour word than with other colour words. A contingency effect corresponds to faster responses to the target colour word on high-contingency trials (i.e., distractor nonword followed by the target colour word with which it appears most often) than on low-contingency trials (i.e., distractor nonword followed by a target colour word with which it appears only occasionally). Roughly equivalent-sized contingency effects were found at stimulus-onset asynchronies (SOAs) of 50, 250, and 450?ms in Experiment 1, and 50, 500, and 1,000?ms in Experiment 2. In Experiment 3, a contingency effect was observed at SOAs of -50, -200, and -350?ms. In Experiment 4, interstimulus interval (ISI) was varied along with SOA, and learning was equivalent for 200-, 700-, and 1,200-ms SOAs. Together, these experiments suggest that the distracting stimulus does not need to be presented in close temporal contiguity with the response to induce learning. Relations to past research on causal judgement and implications for further contingency learning research are discussed.     

The importance of the keyword-generation method in keyword mnemonics

Keyword mnemonics is under certain conditions an effective approach for learning foreign-language vocabulary. It appears to be effective for words with high image vividness but not for words with low image vividness. In this study, two experiments were performed to assess the efficacy of a new keyword-generation procedure (peer generation). In Experiment 1, a sample of 363 high-school students was randomly into four groups. The subjects were required to learn L1 equivalents of a list of 16 Latin words (8 with high image vividness, 8 with low image vividness), using a) the rote method, or the keyword method with b) keywords and images generated and supplied by the experimenter, c) keywords and images generated by themselves, or d) keywords and images previously generated by peers (i.e., subjects with similar sociodemographic characteristics). Recall was tested immediately and one week later. For high-vivideness words, recall was significantly better in the keyword groups than the rote method group. For low-vividness words, learning method had no significant effect. Experiment 2 was basically identical, except that the word lists comprised 32 words (16 high-vividness, 16 low-vividness). In this experiment, the peer-generated-keyword group showed significantly better recall of high-vividness words than the rote method groups and the subject generated keyword group; again, however, learning method had no significant effect on recall of low-vividness words.     

情绪确定性对学习判断的影响

为了揭示情绪的确定性维度对学习判断的影响,本研究通过使用即时学习判断范式的两个实验,分别探讨了高确定性情绪(愤怒、快乐)和低确定性情绪(恐惧、惊喜)的被试在学习判断中的表现。结果显示:(1)愤怒组和快乐组花费在项目学习上的时间显著少于恐惧组和惊喜组;(2)愤怒组的学习判断值显著高于恐惧组;(3)愤怒组的学习判断准确性显著低于恐惧组。从而证明了情绪的确定性维度与学习判断之间的因果关系。     

Talker-specific learning in speech perception

The effects of perceptual learning of talker identity on the recognition of spoken words and sentences were investigated in three experiments. In each experiment, listeners were trained to learn a set of 10 talkers’ voices and were then given an intelligibility test to assess the influence of learning the voices on the processing of the linguistic content of speech. In the first experiment, listeners learned voices from isolated words and were then tested with novel isolated words mixed in noise. The results showed that listeners who were given words produced by familiar talkers at test showed better identification performance than did listeners who were given words produced by unfamiliar talkers. In the second experiment, listeners learned novel voices from sentence-length utterances and were then presented with isolated words. The results showed that learning a talker’s voice from sentences did not generalize well to identification of novel isolated words. In the third experiment, listeners learned voices from sentence-length utterances and were then given sentence-length utterances produced by familiar and unfamiliar talkers at test. We found that perceptual learning of novel voices from sentence-length utterances improved speech intelligibility for words in sentences. Generalization and transfer from voice learning to linguistic processing was found to be sensitive to the talker-specific information available during learning and test. These findings demonstrate that increased sensitivity to talker-specific information affects the perception of the linguistic properties of speech in isolated words and sentences.     

How do students improve their value-based learning with task experience?

When learning items that vary in reward, students improve their scores (i.e., earned reward) with task experience. In four experiments, we examined whether such improvements arise from better selective encoding of items that would earn more (vs. less) reward. Participants studied and recalled words across multiple study-test trials. On each trial, 12 words were slated with different values (typically from 1 to 12), and participants earned the point value assigned to a given word if it was correctly recalled. In all experiments, participants earned more points across the first two trials. In Experiment 1, participants either self-paced their study or had experimenter-paced study and in Experiment 2, some participants were penalised for each second spent during study. Improvements in points earned were related to increases in overall recall but not to selective encoding. In Experiment 3, some participants were given value-emphasised instructions, yet they did not demonstrate selective encoding. In Experiment 4, we used a larger range of point values, but selective encoding still did not account for the improvement in point scores across lists. These results suggest that metacognitively-driven selective encoding is not necessary to observe improvements in value-based learning.