The Development of Implicit Memory From Infancy to Childhood: On Average Performance Levels and Interindividual Differences

A perspective-based analysis of attachment from prenatal period to second year postnatal life

Attachment is one of the foundational themes in the history of the psychological development of human beings. For this reason, we assume that it must be approached by taking into account multiple scientific perspectives. The present review aims at analyzing the state of the art regarding the genetic, neurobiological and cognitive mechanisms underlying the development of attachment bonding, considering the child as the frame of reference. We hypothesize that attachment may be present in prototypical forms even in the prenatal period, thus our analysis has a temporal origin in the intrauterine period preceding birth. The intrauterine period is assumed to be a period of maximum sensitivity to stimuli and in particular to those coming from a potential primary caregiver: the biological mother. We conclude with a reframing of the state of the art and propose that future research work would benefit from a superordinate model of attachment, capable of containing and regulating all its components and variables.

The Influence of Memory on Visual Perception in Infants, Children, and Adults

Perception is not an independent, in-the-moment event. Instead, perceiving involves integrating prior expectations with current observations. How does this ability develop from infancy through adulthood? We examined how prior visual experience shapes visual perception in infants, children, and adults. Using an identical task across age groups, we exposed participants to pairs of colorful stimuli and implicitly measured their ability to discriminate relative saturation levels. Results showed that adult participants were biased by previously experienced exemplars, and exhibited weakened in-the-moment discrimination between different levels of saturation. In contrast, infants and children showed less influence of memory in their perception, and they actually outperformed adults in discriminating between current levels of saturation. Our findings suggest that as humans develop, their perception relies more on prior experience and less on current observation.

Memory integration into visual perception in infancy, childhood, and adulthood

We compared the influence of prior knowledge on visual perception in infants, children, and adults in order to explore the developmental trajectory by which prior knowledge is integrated with new sensory input. Using an identical task across age groups, we tested how participants' accumulated experience affected their ability to judge the relative saturation levels within a pair of sequentially-presented stimuli. We found that infants and children, relative to adults, showed greater influence of the current observation and reduced influence of memory in their perception. In fact, infants and children outperformed adults in discriminating between different levels of saturation, and their performance was less biased by previously-experienced exemplars. Thus, the development of perceptual integration of memory leads to less precise discrimination in the moment, but allows observers to make use of their prior experience in interpreting a complex sensory environment.

Memory: Normative development of memory systems

During the past decades, abundant behavioral, clinical, and neuroimaging data have shown several memory systems in the brain. A memory system is a type of memory that processes a particular type of information, using specific mechanisms, with distinct neural correlates. What we call memory is therefore not a unitary capacity but a collection of distinct systems. From a developmental perspective, each memory system has its own developmental course. This explains the heterogeneity of children's mnemonic competencies: for example, 3-year-olds learn many new words and concepts every day but have trouble recalling in detail an event that happened the week before. In this chapter, we sum up major findings regarding the development from infancy to early adulthood of the main memory systems. Specifically, we report recent data regarding the development of declarative memory (i.e., episodic and semantic memory), and the relationship between the maturation of their neural correlates and the phenomena of infantile and childhood amnesia. We conclude by indicating some of the possible avenues for future research.

Influence of weight status at 2 years on memory performance at 4-5 years of age

Background: Memory performance is a cognitive function that is affected by environmental, genetic and socioeconomic factors, as well as by weight status.Aim: To evaluate the association of weight status at 2 years of age with the memory performance of children at 4-5 years of age.Subjects and methods: A cross-sectional study that used baseline data (2012) and data from two follow-up periods (2014 and 2016) of the PREDI Cohort Study. Participants were mother-child pairs 4-5 years after delivery who were seen between July 2016 and August 2017. The children's memory performance was evaluated individually using a validated Brazilian instrument.Results: Of the 203 children included in the study, 117 (57.6%), 52 (25.6%) and 34 (16.8%) had low, moderate and high memory performance, respectively. After adjusting for potential confounders, children with a BMI > 85th percentile had 3.33-times higher odds of exhibiting lower memory performance at 4-5 years of age than those with a BMI ≤ 85th percentile. In addition to the children's BMI at 2 years of age, mother's education was another independent determinant of children's memory performance. There was a progressive increase in the odds of children having lower memory performance at 4-5 years of age as the mother's education decreased.Conclusion: Primary prevention of overweight and management of cognitive functions may be important strategies to improve the cognitive development of children in the future.

Determinants of memory development in childhood and adolescence

Research on the development of memory has a long history and constitutes one of the most active research areas in the field of cognitive development. In this article, we first describe major historical developments in the literature on children's memory, focusing on systematic research that began in the late 1960s. We then examine new developments in the field, describing four important lines of inquiry: (a) the development of implicit memory, (b) short- and long-term memory development in infancy, (c) longitudinal research on memory strategies and metamemory, and (d) developmental cognitive neuroscience of memory. Finally, promising lines of future research on memory development are briefly discussed.