Knowledge of memory functions in European and Asian American adults and children: The relation to autobiographical memory

This study investigated explicit knowledge of autobiographical memory functions using a newly developed questionnaire. European and Asian American adults (N = 57) and school-aged children (N = 68) indicated their agreement with 13 statements about why people think about and share memories pertaining to four broad functions—self, social, directive and emotion regulation. Children were interviewed for personal memories concurrently with the memory function knowledge assessment and again 3 months later. It was found that adults agreed to the self, social and directive purposes of memory to a greater extent than did children, whereas European American children agreed to the emotion regulation purposes of memory to a greater extent than did European American adults. Furthermore, European American children endorsed more self and emotion regulation functions than did Asian American children, whereas Asian American adults endorsed more directive functions than did European American adults. Children's endorsement of memory functions, particularly social functions, was associated with more detailed and personally meaningful memories. These findings are informative for the understanding of developmental and cultural influences on memory function knowledge and of the relation of such knowledge to autobiographical memory development.     

Explicit and implicit motor sequence learning in children and adults; the role of age and visual working memory

This study investigated explicit and implicit motor learning, and the influence of visual working memory (VWM) and age. Sixty children and 28 adults learned a nine-button sequence task explicitly and implicitly. Performance in explicit and implicit learning improved with age. Learning curves were similar across ages for implicit learning. In explicit learning, learning curves differed across ages: younger children started slower, but their learning rate was higher compared to older children. Learning curves were similar across VWM scores, but performance in explicit learning was positively influenced by VWM scores. Further research and implications for education and rehabilitation are discussed.     

Learning New Letter-like Writing Patterns Explicitly and Implicitly in Children and Adults

A handwriting task was used to test the assumption that explicit learning is dependent on age and working memory, while implicit learning is not. The effect of age was examined by testing both, typically developing children (5–12 years old, n = 81) and adults (n = 27) in a counterbalanced within-subjects design. Participants were asked to repeatedly write letter-like patterns on a digitizer with a non-inking pen. Reproduction of the pattern was better after explicit learning compared to implicit learning. Age had positive effects on both explicit and implicit learning; working memory did not affect learning in either conditions. These results show that it may be more effective to learn writing new letter-like patterns explicitly and that an explicit teaching method is preferred in mainstream primary education.     

Do young adults show conceptual knowledge of previous distractors?

Using implicit tests, older adults have been found to retain conceptual knowledge of previously seen task-irrelevant information. While younger adults typically do not show the same effect, evidence from one study [Gopie, N., Craik, F. I. M., & Hasher, L. (2011). A double dissociation of implicit and explicit memory in younger and older adults. Psychological Science, 22, 634–640. doi:10.1177/0956797611403321] suggests otherwise. In that study, young adults showed greater explicit than implicit memory for previous distractors on a word fragment completion task. This was interpreted as evidence for maintaining access to previous conceptual knowledge of the distractors. Here, we report two failures to replicate that original finding, followed by a third study designed to test directly whether young adults use conceptual-level information that was previously irrelevant. Our findings agree with others that young adults show weak to no evidence of conceptual knowledge of previously irrelevant information.     

Age differences in the rejection of false memories: The effects of giving warning instructions and slowing the presentation rate

Two experiments were conducted to examine whether children of different ages differ in their ability to reject associative false memories with the Deese–Roediger–McDermott (DRM) paradigm. Two different types of manipulations that are thought to facilitate false memory rejection in adults—slowing the presentation rate and issuing explicit warnings—were analyzed in younger and older children. The results showed that older children were more able than younger children to reject associative false memories through warnings and by slowing the presentation rate. We conclude that although older children are, in general, more prone to produce false memories with the DRM paradigm, they are also more able to reject them when certain conditions facilitate the editing process.     

幼儿对具体图片与抽象图片内隐记忆的实验研究

本研究选择３—６岁幼儿为被试,采用具体图片与抽象图片两种材料,分别交叉使用内隐学习与外显学习两种方式,探讨不同年龄幼儿内隐记忆与外显记忆的效果及特点。实验结果表明：幼儿期幼儿确实存在内隐学习,幼儿对抽象材料的内隐记忆效果优于外显记忆效果;幼儿内隐记忆与外显记忆两种效果均随年龄增长而逐步发展。     

The role of working memory capacity in implicit and explicit sequence learning of children: Differentiating movement speed and accuracy

This study investigated the role of working memory capacity on implicit and explicit motor sequence learning in young children. To this end, a task was utilized that required a gross motor response (flexing the elbow) and that could differentiate between movement speed (i.e., reaction time and movement time) and movement accuracy. Children aged 7–9 years practiced a serial reaction time task that involved the production of a fixed sequence of elbow flexions of prescribed magnitude across two consecutive days. Children in the explicit group were informed about the presence of the sequence and were shown this sequence, while children in the implicit group were not made aware of the sequence. Additionally, children's verbal and visuospatial working memory capacity was assessed. Results of day 1 regarding movement speed revealed no evidence of sequence learning for either group, but movement accuracy results suggested that sequence learning occurred for the implicit group. For both groups, only improvements in movement accuracy were consolidated on day 2, indicating both general and sequence specific learning. Working memory capacity did not correlate with learning in either of the groups. Children in the explicit group accumulated more sequence knowledge compared to children in the implicit group, but this knowledge did not translate to more or better sequence learning. The minimal differences found between the implicit and explicit condition and the absence of a role for working memory capacity add to the increasing evidence that the observed differences between implicit and explicit sequence learning in adults may be less distinct in children.     

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     

When memory fails, intuition reigns: midazolam enhances implicit inference in humans

People often make logically sound decisions using explicit reasoning strategies, but sometimes it pays to rely on more implicit "gut-level" intuition. The transitive inference paradigm has been widely used as a test of explicit logical reasoning in animals and humans, but it can also be solved in a more implicit manner. Some researchers have argued that the hippocampus supports relational memories required for making logical inferences. Here we show that the benzodiazepene midazolam, which inactivates the hippocampus, causes profound explicit memory deficits in healthy participants, but enhances their ability in making implicit transitive inferences. These results are consistent with neurocomputational models of the basal ganglia-dopamine system that learn to make decisions through positive and negative reinforcement. We suggest that disengaging the hippocampal explicit memory system can be advantageous for this more implicit form of learning.     

Remembering Early Childhood: How Much, How, and Why (or Why Not)

In this article, we consider recent research on three questions about people's memories for their early childhood: whether childhood amnesia is a real phenomenon, whether implicit memories survive when explicit memories do not, and why early episodic memories are sketchy. The research leads us to form three conclusions. First, we argue that childhood amnesia is a real phenomenon, as long as the term is defined clearly. Specifically, people are able to recall parts of their lives from the period between ages 2 and 5 years, but they recall less from that period than from other periods. Second, we conclude that implicit memories from early childhood may be evident even when explicit memories are not, a finding that suggests early experience may affect behavior in ways that people do not consciously recognize. Third, we argue that although young children are well known to be wonderfully efficient learners of semantic information, they have difficulty in either encoding or retrieving the interlinked aspects of events that lend them their autobiographical character. Although more evidence is needed, the relative lack of episodic memories of early childhood may be linked to maturation of prefrontal cortex.     

Children's implicit attitude acquisition: Evaluative statements succeed,repeated pairings fail

From the earliest ages tested, children and adults show similar overall magnitudes of implicit attitudes toward various social groups. However, such consistency in attitude magnitude may obscure meaningful age‐related change in the ways that children (vs. adults) acquire implicit attitudes. This experiment investigated children's implicit attitude acquisition by comparing the separate and joint effects of two learning interventions, previously shown to form implicit attitudes in adults. Children (N = 280, ages 7–11 years) were taught about novel social groups through either evaluative statements (ES; auditorily presented verbal statements such as ‘Longfaces are bad, Squarefaces are good’), repeated evaluative pairings (REP; visual pairings of Longface/Squareface group members with valenced images such as a puppy or snake), or a combination of ES+REP. Results showed that children acquired implicit attitudes following ES and ES+REP, with REP providing no additional learning beyond ES alone. Moreover, children did not acquire implicit attitudes in four variations of REP, each designed to facilitate learning by systematically increasing verbal scaffolding to specify (a) the learning goal, (b) the valence of the unconditioned stimuli, and (c) the group categories of the conditioned stimuli. These findings underscore the early‐emerging role of verbal statements in children's implicit attitude acquisition, as well as a possible age‐related limit in children's acquisition of novel implicit attitudes from repeated pairings.     

Developmental change on a five-term transitive inference

Three experiments are reported which utilize the five-term transitive inference task developed by P. E. Bryant and T. Trabasso (Nature (London) 1971, 232, 456–458). In Experiment I, preschool children (mean age = 4 years 8 months) required fewer trials to learn the premises and showed a higher proportion of correct responses on the inferences when the presentation order was serial (i.e., AB, BC, CD, DE) throughout training as compared to when a nonserial presentation order (i.e., BC, DE, AB, CD) was used. In Experiments II and III, preschool (mean age = 4 years 7 months), second grade (mean age = 7 years 8 months), fourth grade (mean age = 9 years 9 months), and college students (mean age = 18 years 11 months) were administered the nonserial presentation version of the five-term transitive inference. An ontogenetic decrease in trials to learn the premises and corresponding increase in proportion correct on both premises and inferences was observed. A developmental model specifying changes at two stages of constructing an internal linear order is proposed to explain the results.     

Looking at the past through a telescope: adults postdated their earliest childhood memories

ABSTRACT

Our previous studies have consistently shown a telescoping error in children’s dating of earliest childhood memories. Preschool children through adolescents systematically date their earliest memories at older ages, in comparison with the age estimates provided by their parents or by themselves previously. In the current study, we examined the dating of earliest childhood memories in two samples of college adults and collected independent age estimates from their parents. Consistent with our findings with children, adults significantly postdated their earlier memories by approximately 12 months (Study 1) and 6 months (Study 2). The actual age of earliest memories was 2.5 years after adjusted for telescoping errors, 1 year earlier than what is commonly believed at 3.5 years. These findings challenge commonly held theoretical assumptions about childhood amnesia and highlight critical methodological issues in the study of childhood memory.     

Eliciting false memories on implicit and explicit memory tests after incidental learning

Abstract: In a false memory experiment, lists of semantic associates (e.g., newspaper, letter, book, etc.) were presented to three groups of participants to induce false memories for critical nonpresented (CN) words (e.g., read) in an incidental learning task. The control group simply estimated the frequency rate in everyday Japanese discourse of each word on a list. The imagery instruction group received an additional instruction to imagine a thematically related converging word from the target words on a list. Participants in the imagery plus writing group received the same instructions as those in the imagery instruction group, but were also required to write down the word they imagined for each list. The results from the implicit and explicit memory tests given after the incidental learning episode showed that the level of priming for CN words was equivalent to that for actually presented target words for all three groups on the implicit test, whereas explicit memory results showed that participants explicitly recognized more target words than CN words. The implications for implicit associative response and fuzzy‐trace theories of false memory, as well as implicit priming, are discussed.     

Children over-imitate adults and peers more than puppets

Researchers commonly use puppets in development science. Amongst other things, puppets are employed to reduce social hierarchies between child participants and adult experimenters akin to peer interactions. However, it remains controversial whether children treat puppets like real-world social partners in these settings. This study investigated children's imitation of causally irrelevant actions (i.e., over-imitation) performed by puppet, adult, or child models. Seventy-two German children (Age_Range = 4.6–6.5 years; 36 girls) from urban, socioeconomically diverse backgrounds observed a model retrieving stickers from reward containers. The model performed causally irrelevant actions either in contact with the reward container or not. Children were more likely to over-imitate adults’ and peers’ actions as compared to puppets’ actions. Across models, they copied contact actions more than no-contact actions. While children imitate causally irrelevant actions from puppet models to some extent, their social learning from puppets does not necessarily match their social learning from real-world social agents, such as children or adults.

Research Highlights

• We examined children's over-imitation from adult, child, and puppet models to validate puppetry as an approach to simulate non-hierarchical interactions.
• Children imitated adults and child models at slightly higher rates than puppets.
• This effect was present regardless of whether the irrelevant actions involved physical contact to the reward container or not.
• In our study children's social learning from puppets does not match their social learning from human models.

     

不同表面特征图片对内隐记忆和外显记忆的影响

该研究选取30名被试,采用任务分离实验研究范式探讨不同表面特征图片对内隐记忆和外显记忆的影响。以32张动物图片为实验材料,其中鱼类和鸟类图片各半。两类图片中一半为黑白图片,另一半为彩色图片,所有实验材料用E—Prime软件呈现在电脑上。结果表明：（1）不同表面特征图片的再认成绩（外显记忆）显著好于偏好再认成绩（内隐记忆）,即外显记忆成绩好于内隐记忆;（2）在再认测验和偏好判断测验中,再认成绩和偏好再认成绩在图片表面特征的两个水平上存在显著差异;（3）控制组的偏好再认成绩显著好于实验组的偏好再认成绩,即控制组的内隐记忆好于实验组。结论：刺激材料的表面特征既是外显记忆的内容,也是影响外显记忆的重要因素;内隐记忆的作业成绩高度依赖于刺激材料的表面特征,刺激材料的表面特征是影响两种记忆的重要因素。     

Examining the Response Competition Hypothesis of Age Effects in Implicit Memory

ABSTRACT

Age reductions in priming have been explained by differences in processing demands across implicit memory tests. According to one hypothesis, older adults show reduced priming relative to younger adults on implicit tests that require production of a response because these tests typically allow for response competition. In contrast, older adults do not show reductions in priming on identification tests that contain little response competition. The following experiments tested the specific role of response competition in mediating age effects in implicit memory. In Experiment 1, younger and older adults studied a list of words and were then given an implicit test of word stem completion. They studied a second list of words and were given an implicit test of general knowledge. Each implicit test contained items with unique solutions (the low response competition condition) and items with multiple solutions (the high response competition condition). In Experiment 2, younger and older adults were given explicit versions of the word stem completion and the general knowledge tests. Results showed an effect of age on explicit memory (Experiment 2), but no effect of age or response competition on priming (Experiment 1). Results are inconsistent with the theory that response competition leads to age effects on production tests of implicit memory.     

New perspectives on childhood memory: introduction to the special issue

ABSTRACT

This special issue brings together the scholarship that contributes diverse new perspectives on childhood amnesia – the scarcity of memories for very early life events. The topics of the studies reported in the special issue range from memories of infants and young children for recent and distant life events, to mother–child conversations about memories for extended lifetime periods, and to retrospective recollections of early childhood in adolescents and adults. The methodological approaches are diverse and theoretical insights rich. The findings together show that childhood amnesia is a complex and malleable phenomenon and that the waning of childhood amnesia and the development of autobiographical memory are shaped by a variety of interactive social and cognitive factors. This collective body of work will facilitate discussion and deepen our understanding of the dynamics that influence the accessibility, content, accuracy, and phenomenological qualities of memories from early childhood.     

Finger counting habit and spatial–numerical association in children and adults

Sensory-motor experiences are known to build up concrete and abstract concepts during the lifespan. The present study aimed to test how finger counting habits (right-hand vs. left-hand starters) could influence the spatial–numerical representation in number-to-position (explicit) and digit-string bisection (implicit) tasks. The subjects were Italian primary school children (N = 184, from the first to the fifth year) and adults (N = 42). No general preference for right- or left-starting in the finger counting was found. In the explicit task, right- or left-starting did not affect performance. In the implicit task, the right-hand starters shifted from the left to the right space when bisecting small and large numbers respectively, while the left-hand starters shifted from the right to the left space with higher leftward bias for large numbers. The finger configuration in Italian children and adults influences the spatial–numerical representation, but only when implicit number processing is required by the task.