Lexical learning in bilingual adults: the relative importance of short-term memory for serial order and phonological knowledge

Studies of monolingual speakers have shown a strong association between lexical learning and short-term memory (STM) capacity, especially STM for serial order information. At the same time, studies of bilingual speakers suggest that phonological knowledge is the main factor that drives lexical learning. This study tested these two hypotheses simultaneously in participants with variable levels of English-French bilingual proficiency. A word-nonword paired-associate learning task was administered, with nonwords obeying French phonotactic patterns. French phonological knowledge was estimated by a composite French proficiency score summarizing productive and receptive French vocabulary knowledge as well as quantitative and qualitative measures of French exposure. STM measures maximized retention of order information (serial order reconstruction) or retention of phonological item information (single nonword delayed repetition). The French proficiency score and the serial order STM measure independently predicted performance on the paired-associate learning task. These results highlight the conjoined role of phonological knowledge and serial order STM in lexical learning. Importantly, serial order STM remains a strong predictor of lexical learning, even for bilingual individuals who have broad phonological knowledge.     

Determinants of phrasing effects in rat serial pattern learning

Two experiments investigated how brief pauses introduced into serial patterns as phrasing cues would affect pattern learning in rats. In Experiment 1, a 24-element pattern consisted of eight 3-element chunks, whereas a 20-element pattern consisted of four 5-element chunks. In both patterns, 3.0-s temporal pauses placed at chunk boundaries (synchronous phrasing cues) facilitated learning compared to no phrasing. Cues "out of sync" with pattern structure (asynchronous phrasing cues) facilitated learning for the 24-element pattern and retarded learning for the 20-element pattern. Evidence suggested that in the latter case, 3.0-s pauses served as "blank" trials that induced rats to "skip" to the next serial position in sequence. In Experiment 2, shorter 0.5-s pauses served as phrasing cues in the 20-element pattern of Experiment 1. Synchronous short cues facilitated learning, whereas asynchronous phrasing cues had no effect. Furthermore, removal of synchronous cues produced deficits in performance on formerly cued trials, whereas removal of asynchronous cues had no effect. The results of Experiment 2 support the notion that in both experiments phrasing cues served as discriminative cues and indirectly suggest that rats are concurrently sensitive to pattern element cues, extra-sequence cues (such as phrasing cues), and to the relative timing of sequential events.     

Sequential responding to arabic numerals with wild cards by the chimpanzee (Pan troglodytes)

One adult female chimpanzee (Pan troglodytes) was trained to respond serially to three arabic numerals between 1 and 9, presented on a cathode-ray-tube (CRT) screen. To examine the factors affecting her sequential responding behavior, wild-card items were added to the three-item sequences. When this wild-card item remained until the subject responded to the last numeral (i.e., the terminator condition), her response to the terminator at each point of the sequence was controlled by the ordinal distance between numerals. Thus, the number of responses to the terminator increased as the ordinal distance between numerals increased. When the wild-card item was eliminated by the subject’s response (wild-card conditions), the probability of responses to the wild card before the first numeral increased as a function of the serial position of the first numeral. These results were consistent with previous studies of response time and suggest both serial position and symbolic distance effects. It is suggested that the subject might form the integrated 9-item linear representations by training of possible subsets of three-item sequences. Knowledge concerning the ordinal position of each numeral was established through this training. Received: 27 October 1999 / Accepted: 22 November 1999     

How are base‐rates used,when they are used: a comparison of additive and Bayesian models of base‐rate use

Previous research has uncovered many conditions that encourage base‐rate use. The present research investigates how base‐rates are used when conditions are manipulated to encourage their use in the lawyer/engineer paradigm. To examine the functional form of the response to base‐rate, a factorial design was employed in which both base‐rate and the individuating information were varied within‐subject. We compared the performance of several models of base‐rate use, including a model that allows base‐rate and individuating information to be combined in a strictly additive fashion, and a model which presumes that respondents use Bayes' Rule in forming their judgments. Results from 1493 respondents showed that the additive model is a stronger predictor of base‐rate use than any other model considered, suggesting that the base‐rate and individuating information are processed independently in the lawyer/engineer paradigm. A possible mechanism for this finding is discussed. Copyright © 1999 John Wiley & Sons, Ltd.     

Organic Unities, Non-Trade-Off, and the Additivity of Intrinsic Value

Whether or not intrinsic valueis additively measurable is often thought todepend on the truth or falsity of G. E. Moore'sprinciple of organic unities. I argue that thetruth of this principle is, contrary to received opinion, compatible with additivemeasurement. However, there are other veryplausible evaluative claims that are moredifficult to combine with the additivity ofintrinsic value. A plausible theory of the goodshould allow that there are certain kinds ofstates of affairs whose intrinsic value cannotbe outweighed by any number of states ofcertain other, less valuable, kinds. Such``non-trade-off' cannot reasonably be explainedin terms of organic unities, and it can bereconciled with the additivity thesis only ifwe are prepared to give up some traditionalclaims about the nature of intrinsic value.     

Children's judgements of gambles: a disordinal violation of utility

Violations of utility are often attributed to people's differential reactions to risk versus certainty or uncertainty, or more generally to the way that people perceive outcomes and consequences. However, a core feature of utility is additivity, and violations may also occur because of averaging effects. Averaging is pervasive in intuitive riskless judgement throughout many domains, as shown with Anderson's Information Integration approach. The present study extends these findings to judgement under risk. Five‐ to 10‐year old children showed a disordinal violation of utility because they averaged the part worths of duplex gambles rather than add them, as adults do, and as normatively prescribed. Thus adults realized that two prizes are better than one, but children preferred a high chance to win one prize to the same gamble plus an additional small chance to win a second prize. This result suggests that an additive operator may not be a natural component of the intuitive psychological concept of expected value that emerges in childhood. The implications of a developmental perspective for the study of judgement and decision are discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

Similarity and binding in memory: Bound to be detrimental

The process of binding information from different modalities and sources into an object is ubiquitous in cognition and has been a problem for research and modelling efforts in psychology. This process has been considered by most researchers as necessarily always beneficial to memory. In the present study we provide evidence that binding can be detrimental through the propagation of vulnerabilities to interference. Phonologically similar and dissimilar letters were presented sequentially at different locations on a computer monitor. Participants had to recall either the letters in their order of presentation or the spatial locations at which the letters had appeared. Whether binding was encouraged or not—providing prior knowledge of which dimension to remember—phonological similarity had a detrimental effect on recall of locations. Such a finding poses a challenge to the view that binding is the panacea in enhancing memory capacity.     

Syntax and serial recall: How language supports short-term memory for order

The extent to which familiar syntax supports short-term serial recall of visually presented six-item sequences was shown by the superior recall of lists in which item pairs appeared in the order of “adjective–noun” (items 1–2, 3–4, 5–6)—congruent with English syntax—compared to when the order of items within pairs was reversed. The findings complement other evidence suggesting that short-term memory is an assemblage of language processing and production processes more than it is a bespoke short-term memory storage system.     

Primitive computations in speech processing

Previous research suggests that artificial-language learners exposed to quasi-continuous speech can learn that the first and the last syllables of words have to belong to distinct classes (e.g., Endress & Bonatti, 2007; Peña, Bonatti, Nespor, & Mehler, 2002). The mechanisms of these generalizations, however, are debated. Here we show that participants learn such generalizations only when the crucial syllables are in edge positions (i.e., the first and the last), but not when they are in medial positions (i.e., the second and the fourth in pentasyllabic items). In contrast to the generalizations, participants readily perform statistical analyses also in word middles. In analogy to sequential memory, we suggest that participants extract the generalizations using a simple but specific mechanism that encodes the positions of syllables that occur in edges. Simultaneously, they use another mechanism to track the syllable distribution in the speech streams. In contrast to previous accounts, this model explains why the generalizations are faster than the statistical computations, require additional cues, and break down under different conditions, and why they can be performed at all. We also show that that similar edge-based mechanisms may explain many results in artificial-grammar learning and also various linguistic observations.