Children retain implicitly learned phonological sequences better than adults: a longitudinal study

Whereas adults often rely on explicit memory, children appear to excel in implicit memory, which plays an important role in the acquisition of various cognitive skills, such as those involved in language. The current study aimed to test the assertion of an age‐dependent shift in implicit versus explicit learning within a theoretical framework that explains the link between implicit sequence memory and word‐form acquisition, using the Hebb repetition paradigm. We conducted a one‐year, multiple‐session longitudinal study in which we presented auditory sequences of syllables, co‐presented with pictures of aliens, for immediate serial recall by a group of children (8–9 years) and by an adult group. The repetition of one Hebb sequence was explicitly announced, while the repetition of another Hebb sequence was unannounced and, therefore, implicit. Despite their overall inferior recall performance, the children showed better offline retention of the implicit Hebb sequence, compared with adults who showed a significant decrement across the delays. Adults had gained more explicit knowledge of the implicit sequence than children, but this could not explain the age‐dependent decline in the delayed memory for it. There was no significant age‐effect for delayed memory of the explicit Hebb sequence, with both age groups showing retention. Overall performance by adults was positively correlated with measures of post‐learning awareness. Performance by children was positively correlated with vocabulary knowledge. We conclude that children outperform adults in the retention over time of implicitly learned phonological sequences that will gradually consolidate into novel word‐forms. The findings are discussed in the light of maturational differences for implicit versus explicit memory systems that also play a role in language acquisition. A video abstract of this article can be viewed at: https://youtu.be/G5nOfJB72t4     

Item performance in visual word recognition

Standard factorial designs in psycholinguistics have been complemented recently by large-scale databases providing empirical constraints at the level of item performance. At the same time, the development of precise computational architectures has led modelers to compare item-level performance with item-level predictions. It has been suggested, however, that item performance includes a large amount of undesirable error variance that should be quantified to determine the amount of reproducible variance that models should account for. In the present study, we provide a simple and tractable statistical analysis of this issue. We also report practical solutions for estimating the amount of reproducible variance for any database that conforms to the additive decomposition of the variance. A new empirical database consisting of the word identification times of 140 participants on 120 words is then used to test these practical solutions. Finally, we show that increases in the amount of reproducible variance are accompanied by the detection of new sources of variance.     

Influence of affective meaning on memory for contextual information

In 4 experiments, the authors investigated the influence of the affective meaning of words on memory for 2 kinds of contextual features that differ in the amount of effortful processes they require to be encoded in memory (i.e., color and spatial location). The main results showed that memory for color, in which words were typed, was better for emotional than for neutral words, but only when color information was learned incidentally. In contrast, spatial location of the words was better remembered for emotional than for neutral words whatever the encoding conditions (intentional vs. incidental). It is suggested that the influence of affective meaning on context memory may involve an automatic attraction of attention to contextual features associated with emotional words.     

Hiding in the crowd: can mortality salience promote affiliation with others who oppose one's worldviews?

The present research highlights affiliation defenses in the psychological confrontation with death. In 3 experiments, it was found that mortality salience led to increased affiliation strivings, as indicated by a greater preference for sitting within a group as opposed to sitting alone. Mortality salience actually led to increased affiliation with a worldview-threatening group (Experiments 1-2), even when affiliation with the group forced participants to attack their own worldviews (Experiment 3). Taken together, the findings support a distinct role of affiliation defenses against existential concerns. Moreover, affiliation defenses seem powerful enough to override worldview validation defenses, even when the worldviews in question are personally relevant and highly accessible.     

Phenomenal characteristics of autobiographical memories for social and non-social events in social phobia

Previous studies failed to show clear differences between people with social phobia and non-anxious individuals regarding the specificity and affective intensity of their autobiographical memories for social events. However, these studies did not assess the subjective experience associated with remembering. In this study, people with social phobia and non-anxious control participants recalled social and non-social events, and rated the phenomenal characteristics of their memories. The memories of people with social phobia for social events contained fewer sensorial details but more self-referential information than controls' memories. In addition, people with social phobia remembered social situations from an observer perspective, viewing themselves as if from outside, to a greater extent than controls. By contrast, the two groups did not differ concerning their memories for non-social events. These findings are discussed in relation to cognitive models of social phobia.     

First- and third-person approaches in implicit learning research

How do we find out whether someone is conscious of some information or not? A simple answer is “We just ask them”! However, things are not so simple. Here, we review recent developments in the use of subjective and objective methods in implicit learning research and discuss the highly complex methodological problems that their use raises in the domain.     

Does the mastery of center-embedded linguistic structures distinguish humans from nonhuman primates?

In a recentScience article, Fitch and Hauser (2004; hereafter, F&H) claimed to have demonstrated that cotton-top tamarins fail to learn an artificial language produced by a phrase structure grammar (Chomsky, 1957) generating center-embedded sentences, whereas adult humans easily learn such a language. We report an experiment replicating the results of F&H in humans but also showing that subjects learned the language without exploiting in any way the center-embedded structure. When the procedure was modified to make the processing of this structure mandatory, the subjects no longer showed evidence of learning. We propose a simple interpretation for the difference in performance observed in F&H’s task between humans and tamarins and argue that, beyond the specific drawbacks inherent in F&H’s study, researching the source of the inability of nonhuman primates to master language within a framework built around Chomsky’s hierarchy of grammars is a conceptual dead end.     

Intuitive decision making in complex situations: Somatic markers in an artificial grammar learning task

In this article, we explore the extent to which implicit learning is subtended by somatic markers, as evidenced by skin conductance measures. On each trial, subjects were asked to decide which “word” from a pair of “words” was the “correct” one. Unknown to the subjects, each “word” of a pair was constructed using a different set of rules (Grammar Aand Grammar B). A (monetary) reward was given if the subject chose the “word” from Grammar A. Choosing the Grammar B word resulted in (monetary) punishment. Skin conductance was measured during each of 100 trials. After each set of 10 trials, the subjects were asked how they selected the “correct word.” Task performance increased long before the subjects could even formulate a single relevant rule. In this preconceptual phase of the experiment, skin conductance was larger before incorrect than before correct choices. Thus, it was shown that artificial grammar learning is accompanied by a somatic marker, possibly “warning” the subject of the incorrect decision.     

Graphemic complexity and multiple print-to-sound associations in visual word recognition

It has recently been reported that words containing a multiletter grapheme are processed slower than are words composed of single-letter graphemes (Rastle & Coltheart, 1998; Rey, Jacobs, Schmidt-Weigand, & Ziegler, 1998). In the present study, using a perceptual identification task, we found in Experiment 1 that this graphemic complexity effect can be observed while controlling for multiple print-to-sound associations, indexed by regularity or consistency. In Experiment 2, we obtained cumulative effects of graphemic complexity and regularity. These effects were replicated in Experiment 3 in a naming task. Overall, these results indicate that graphemic complexity and multiple print-to-sound associations effects are independent and should be accounted for in different ways by models of written word processing.     

Mining event-related brain dynamics

This article provides a new, more comprehensive view of event-related brain dynamics founded on an information-based approach to modeling electroencephalographic (EEG) dynamics. Most EEG research focuses either on peaks 'evoked' in average event-related potentials (ERPs) or on changes 'induced' in the EEG power spectrum by experimental events. Although these measures are nearly complementary, they do not fully model the event-related dynamics in the data, and cannot isolate the signals of the contributing cortical areas. We propose that many ERPs and other EEG features are better viewed as time/frequency perturbations of underlying field potential processes. The new approach combines independent component analysis (ICA), time/frequency analysis, and trial-by-trial visualization that measures EEG source dynamics without requiring an explicit head model.