Production benefits on encoding are modulated by language experience: Less experience may help.

Several lines of research have shown that performing movements while learning new information aids later retention of that information, compared to learning by perception alone. For instance, articulated words are more accurately remembered than words that are silently read (the production effect). A candidate mechanism for this movement-enhanced encoding, sensorimotor prediction, assumes that acquired sensorimotor associations enable movements to prime associated percepts and hence improve encoding. Yet it is still unknown how the extent of prior sensorimotor experience influences the benefits of movement on encoding. The current study addressed this question by examining whether the production effect is modified by prior language experience. Does the production effect reduce or persist in a second language (L2) compared to a first language (L1)? Two groups of unbalanced bilinguals, German (L1) - English (L2) bilinguals (Experiment 1) and English (L1) - German (L2) bilinguals (Experiment 2), learned lists of German and English words by reading the words silently or reading the words aloud, and they subsequently performed recognition tests. Both groups showed a pronounced production effect (higher recognition accuracy for spoken compared to silently read words) in the first and second languages. Surprisingly, the production effect was greater in the second languages compared to the first languages, across both bilingual groups. We discuss interpretations based on increased phonological encoding, increased effort or attention, or both, when reading aloud in a second language.

Language switching when writing: The role of phonological and orthographic overlap.

While language switching of bilinguals has been investigated extensively in the spoken domain, there has been little research on switching while writing. The factors that impact written language switching may differ from those that impact language switching while speaking. Thus, the study's goal was to test to what extent phonological and/or orthographic overlap impacts written language switching. In four experiments (NExp.1 = 34; NExp. 2 = 57; NExp. 3 = 39; NExp. 4 = 39), German-English bilinguals completed a cued language switching task where responses had to be typed. To-be-named translation-equivalent concepts were selected to be similar phonologically, orthographically or neither. Participants switching between languages while writing was facilitated by both phonological and orthographic overlap. Maximum orthographic overlap between translation-equivalent words with dissimilar pronunciations facilitated switching to the extent that no switch costs could be observed. These results imply that overlapping orthography can strongly facilitate written language switching and that orthography's role should be considered more thoroughly in models of bilingual language production.

What have we learned from 15 years of research on cross-situational word learning? A focused review.

In 2007 and 2008, Yu and Smith published their seminal studies on cross-situational word learning (CSWL) in adults and infants, showing that word-object-mappings can be acquired from distributed statistics despite in-the-moment uncertainty. Since then, the CSWL paradigm has been used extensively to better understand (statistical) word learning in different language learners and under different learning conditions. The goal of this review is to provide an entry-level overview of findings and themes that have emerged in 15 years of research on CSWL across three topic areas (mechanisms of CSWL, CSWL across different learner and task characteristics) and to highlight the questions that remain to be answered.

Assessing Proactive Language Control: Does Predictability of Language Sequences Benefit Language Switching?

Multilinguals often switch between the languages they speak. One open question is to what extent they can use anticipatory-or proactive-language control to reduce interference from non-target languages during language switching. In three experiments, unbalanced German-English bilinguals (N1 = 24; N2 = 35; N3 = 37) named pictures in their L1 or L2 in mixed blocks. In all but the penultimate block, the language sequence in which pictures were named was predictable (e.g., L1, L1, L2, L2, etc.), thus allowing participants to prepare for upcoming trials. Performance in the non-predictable block was compared to average performance in predictable sequence blocks right before and after, thus controlling for practice effects. We predicted that language switching would be facilitated during predictable language trials, indicative of proactive language control. However, for Experiments 1-2, there was no evidence for a predictability benefit across both experiments. When the number of items that had to be switched between was reduced to two (Experiment 3), a limited repetition-specific predictability effect emerged. These findings suggest that people do not use preparatory processes endogenously on the basis of regularities in the language sequence to reduce interference during language switching, unless the specific item that needs to be produced can be anticipated.

Multiple components of statistical word learning are resource dependent: Evidence from a dual-task learning paradigm.

It is increasingly understood that people may learn new word/object mappings in part via a form of statistical learning in which they track co-occurrences between words and objects across situations (cross-situational learning). Multiple learning processes contribute to this, thought to reflect the simultaneous influence of real-time hypothesis testing and graduate learning. It is unclear how these processes interact, and if any require explicit cognitive resources. To manipulate the availability of working memory resources for explicit processing, participants completed a dual-task paradigm in which a cross-situational word-learning task was interleaved with a short-term memory task. We then used trial-by-trial analyses to estimate how different learning processes that play out simultaneously are impacted by resource availability. Critically, we found that the effect of hypothesis testing and gradual learning effects showed a small reduction under limited resources, and that the effect of memory load was not fully mediated by these processes. This suggests that neither is purely explicit, and there may be additional resource-dependent processes at play. Consistent with a hybrid account, these findings suggest that these two aspects of learning may reflect different aspects of a single system gated by attention, rather than competing learning systems.

Automaticity as an independent trait in predicting reading outcomes in middle-school.

Many middle-school students struggle with basic reading skills. One reason for this might be a lack of automaticity in word-level lexical processes. To investigate this, we used a novel backward masking paradigm, in which a written word is either covered with a mask or not. Participants (N = 444 [after exclusions]; nfemale = 264, nmale = 180) were average to struggling middle-school students from an urban area in Eastern Iowa that were all native speakers of English and were roughly equally from grades 6, 7, and 8 (average age: 13 years). Two-hundred-fifty-five students qualified for free or reduced-price lunch, a proxy for economic disadvantage. Participants completed different masked and unmasked task versions where they read a word and selected a response (e.g., a pictured referent). This was related to standardized measures of decoding, fluency, and reading comprehension. Decoding was uniquely predicted by knowledge (unmasked performance), whereas fluency was uniquely predicted by automaticity (masked performance). Automaticity was stable across two testing points. Thus, automaticity should be considered an individually reliable marker/reading trait that uniquely predicts some skills in average to struggling middle-school students. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Simultaneous training on overlapping grapheme phoneme correspondences augments learning and retention.

An important component of learning to read is the acquisition of letter-to-sound mappings. The sheer quantity of mappings and many exceptions in opaque languages such as English suggests that children may use a form of statistical learning to acquire them. However, whereas statistical models of reading are item-based, reading instruction typically focuses on rule-based approaches involving small sets of regularities. This discrepancy poses the question of how different groupings of regularities, an unexamined factor of most reading curricula, may affect learning. Exploring the interplay between item statistics and rules, this study investigated how consonant variability, an item-level factor, and the degree of overlap among the to-be-trained vowel strings, a group-level factor, influence learning. English-speaking first graders (N = 361) were randomly assigned to be trained on vowel sets with high overlap (e.g., EA, AI) or low overlap (e.g., EE, AI); this was crossed with a manipulation of consonant frame variability. Whereas high vowel overlap led to poorer initial performance, it resulted in more learning when tested immediately and after a 2-week-delay. There was little beneficial effect of consonant variability. These findings indicate that online letter/sound processing affects how new knowledge is integrated into existing information. Moreover, they suggest that vowel overlap should be considered when designing reading curricula.

Field tests of learning principles to support pedagogy: Overlap and variability jointly affect sound/letter acquisition in first graders.

Many details in reading curricula (e.g., the order of materials) have analogues in laboratory studies of learning (e.g., blocking/interleaving). Principles of learning from cognitive science could be used to structure these materials to optimize learning, but they are not commonly applied. Recent work bridges this gap by "field testing" such principles: Rather than testing whole curricula, these studies teach students a small set of sound-spelling-regularities over a week via an internet-delivered program. Training instantiates principles from cognitive science to test their application to vowel acquisition, a critical part of reading. The current study is a follow-up of Apfelbaum, Hazeltine, and McMurray (2013) and Roembke, Freedberg, Hazeltine, and McMurray (submitted), which found differing effects of consonant variability for learning vowels. In addition to investigating this discrepancy, this study examined a new principle: blocking/interleaving. While interleaved training is typically beneficial, this is difficult to apply in reading where there are many regularities. We compared a fully interleaved regime (six vowels) to two blocked regimes teaching two vowels on each block. Blocked conditions differed on whether vowels overlapped (EA with OA) or not (EA with OU). Blocking was crossed with consonant variability. 417 first graders were pre-tested on 6 vowels, and underwent 3-5 days of training, followed by a post-test and retention test. Blocking had little effect. However, there was a variability benefit when overlapping vowel strings were blocked together, and no effect of variability for interleaved training. Thus, benefits may only be observed if blocking highlights contrast between regularities. When applied to real-world skills, learning principles from cognitive science may interact in complex ways.

Cross-Situational Statistical Learning of New Words Despite Bilateral Hippocampal Damage and Severe Amnesia.

Word learning requires learners to bind together arbitrarily-related phonological, visual, and conceptual information. Prior work suggests that this binding can be robustly achieved via incidental cross-situational statistical exposure to words and referents. When cross-situational statistical learning (CSSL) is tested in the laboratory, there is no information on any given trial to identify the referent of a novel word. However, by tracking which objects co-occur with each word across trials, learners may acquire mappings through statistical association. While CSSL behavior is well-characterized, its brain correlates are not. The arbitrary nature of CSSL mappings suggests hippocampal involvement, but the incremental, statistical nature of the learning raises the possibility of neocortical or procedural learning systems. Prior studies have shown that neurological patients with hippocampal pathology have word-learning impairments, but this has not been tested in a statistical learning paradigm. Here, we used a neuropsychological approach to test whether patients with bilateral hippocampal pathology (N = 3) could learn new words in a CSSL paradigm. In the task, patients and healthy comparison participants completed a CSSL word-learning task in which they acquired eight word/object mappings. During each trial of the CSSL task, participants saw two objects on a computer display, heard one novel word, and selected the most likely referent. Across trials, words were 100% likely to co-occur with their referent, but only 14.3% likely with non-referents. Two of three amnesic patients learned the associations between objects and word forms, although performance was impaired relative to healthy comparison participants. Our findings show that the hippocampus is not strictly necessary for CSSL for words, although it may facilitate such learning. This is consistent with a hybrid account of CSSL supported by implicit and explicit memory systems, and may have translational applications for remediation of (word-) learning deficits in neurological populations with hippocampal pathology.

Symbolic flexibility during unsupervised word learning in children and adults.

Considerable debate in language acquisition concerns whether word learning is driven by domain-general (symbolically flexible) or domain-specific learning mechanisms. Prior work has shown that very young children can map objects to either words or nonlinguistic sounds, but by 20 months of age this ability narrows to only words. This suggests that although symbolically flexible mechanisms are operative early, they become more specified over development. However, such research has been conducted only with young children in ostensive teaching contexts. Thus, we investigated symbolic flexibility at later ages in more referentially ambiguous learning situations. In Experiment 1, 47 6- to 8-year-olds acquired eight symbol-object mappings in a cross-situational word learning paradigm where multiple mappings are learned based only on co-occurrence. In the word condition participants learned with novel pseudowords, whereas in the sound condition participants learned with nonlinguistic sounds (e.g., beeps). Children acquired the mappings, but performance did not differ across conditions, suggesting broad symbolic flexibility. In Experiment 2, 41 adults learned 16 mappings in a comparable design. They learned with ease in both conditions but showed a significant advantage for words. Thus, symbolic flexibility decreases with age, potentially due to repeated experiences with linguistic materials. Moreover, trial-by-trial analyses of the microstructure of both children's and adults' performance did not reveal any substantial differences due to condition, consistent with the hypothesis that learning mechanisms are generally employed similarly with both words and nonlinguistic sounds.

Learning in rich networks involves both positive and negative associations.

Adaptive behaviors are believed to be shaped by both positive (the strengthening of correct associations) and negative (the pruning of incorrect associations or the building of inhibitory associations) forms of associative learning. However, there has been little direct documentation of how these basic processes participate in the learning of rich associative networks that support cognitive behaviors like categorization. Although negative associative learning is an important component of theories of development, it is not clear whether it involves acquiring specific (experience-dependent) content or represents a more general aspect of (experience-expectant) development. The authors thus trained pigeons on a complex many-to-many learning paradigm previously established as an analog to human word learning. Pigeons learned to map 16 objects onto 16 distinct report tokens; the authors manipulated the amount of negative associative learning that could occur by restricting which tokens were available as incorrect options. In testing, accuracy was lower on trials with foils that had not been presented with a target than on trials with previously experienced foils. Moreover, when the correct token was withheld, pigeons preferred foils novel to the target object over previously experienced foils. A second experiment replicated these results and further found that these effects only emerged after some positive associations had been acquired. Findings indicate that the learning of rich associative networks does not depend solely on positive associative learning, but also on negative associative learning; this conclusion has important implications for basic learning theories in both animals and humans, as well as for theories of development. (PsycINFO Database Record

Observational Word Learning: Beyond Propose-But-Verify and Associative Bean Counting.

Learning new words is difficult. In any naming situation, there are multiple possible interpretations of a novel word. Recent approaches suggest that learners may solve this problem by tracking co-occurrence statistics between words and referents across multiple naming situations (e.g. Yu & Smith, 2007), overcoming the ambiguity in any one situation. Yet, there remains debate around the underlying mechanisms. We conducted two experiments in which learners acquired eight word-object mappings using cross-situational statistics while eye-movements were tracked. These addressed four unresolved questions regarding the learning mechanism. First, eye-movements during learning showed evidence that listeners maintain multiple hypotheses for a given word and bring them all to bear in the moment of naming. Second, trial-by-trial analyses of accuracy suggested that listeners accumulate continuous statistics about word/object mappings, over and above prior hypotheses they have about a word. Third, consistent, probabilistic context can impede learning, as false associations between words and highly co-occurring referents are formed. Finally, a number of factors not previously considered in prior analysis impact observational word learning: knowledge of the foils, spatial consistency of the target object, and the number of trials between presentations of the same word. This evidence suggests that observational word learning may derive from a combination of gradual statistical or associative learning mechanisms and more rapid real-time processes such as competition, mutual exclusivity and even inference or hypothesis testing.