Amy E. Learmonth

Children's Use of Landmarks: Implications for Modularity Theory

Previous studies have shown that disoriented children use the geometric features of the environment to reorient, but the results have not consistently demonstrated whether children can combine such information with landmark information. Results indicating that they cannot suggest the existence of a geometric module for reorientation. However, results indicating that children can use geometric information in combination with landmark information challenge the modularity interpretation. An uncontrolled variable in the studies yielding conflicting results has been the size of the experimental space. In the present studies, which tested young children in spaces of two different sizes, the size of the space affected their ability to use available landmark information. In the small space, the children did not use the landmark to reorient, but in the large space they did. The ability of children to use landmarks in combination with geometric information raises important questions about the existence of an encapsulated geometric module.

Infants’ coding of location in continuous space

The ability to code location in continuous space is fundamental to spatial behavior. Existing evidence indicates a robust ability for such coding by 12 months, but systematic evidence on earlier origins is lacking. A series of studies investigated 5-month-olds’ ability to code the location of an object hidden in a sandbox, using a looking-time paradigm. In Experiment 1, after familiarization with a hiding-and-finding sequence at one location, infants looked longer at an object being disclosed from a location 12 inches (30 cm) away than at an object emerging from the hiding location, showing they were able to code location in continuous space. In Experiment 2, infants reacted with greater looking when objects emerged from locations 8 inches (20 cm) away from the hiding location, showing that location coding was more finely grained than could be inferred based on the first study. In Experiment 3, infants were familiarized with an object shown in hiding-and-finding sequences at two different locations. Infants looked longer at objects emerging 12 inches (30 cm) away from the most recent hiding location than to emergence from the other location, showing that infants could code location even when events had previously occurred at each location. In Experiment 4, after familiarization with two objects with different shapes, colors, and sounding characteristics, shown in hiding-and-finding sequences in two locations, infants reacted to location violations as they had in Experiment 3. However, they did not react to object violations, that is, events in which the wrong object emerged from a hiding location. Experiment 5 also found no effect of object violation, even when the infants initially saw the two objects side by side. Spatiotemporal characteristics may play a more central role in early object individuation than they do later, although further study is required.

Infants Form Associations Between Memory Representations of Stimuli That Are Absent

Traditional models of learning assume that an association can be formed only between cues that are physically present. Here, we report that when two objects that had never appeared together were simultaneously activated in memory, young human infants associated the representations of those objects. Neither object was physically present at the time the association was formed. The association remained latent for up to 2 weeks, when the infants used it to perform a deferred imitation task. These findings reveal that what infants merely see “brings to mind” what they saw before and combines it in new ways. In addition to challenging a fundamental tenet of classic learning models, these findings have major theoretical and practical implications for early cognitive development. Every day, in the same manner, young infants probably form numerous associations between activated memories of objects that are physically absent, creating a potential knowledge base of untold dimensions.

Maturation of Spatial Navigation Strategies: Convergent Findings from Computerized Spatial Environments and Self-Report

Using 2 computerized spatial navigation tasks, we examined the development of cue and place learning in children ages 3 to 10 years, comparing their data to adults. We also examined relations between place learning in computerized and real space. Results showed children use the 2-dimensional space as if it were real space. Results also demonstrated that children ages 3 to 10 years cue learn (locating a visible target) but do not show evidence of mature place learning (locating an invisible target) until around age 10 years. Self-report data indicated an age-related increase in use of relations among distal cues during place learning. Children ages 3 to 4 years did not report using distal cues; most 9- to 10-year-old children reported using multiple distal cues to guide their search during place learning. Results suggest that, as maturation proceeds, children make increasing use of relations among multiple distal cues to guide a search for places in space.

CHANGE AND CONTINUITY IN EARLY SPATIAL DEVELOPMENT: CLAIMING THE "RADICAL MIDDLE"

Debate over change and continuity in cognitive development has revolved around questions of qualitative transitions versus quantitative and incremental improvement. Piaget’s stage theory is the best-known example of a change/qualitative transition approach, while both nativism and empiricism have, for very different reasons, taken a continuity/quantitative increment stance. Recent proposals have, however, attempted to transcend this stark dichotomy, in a move that can be termed claiming the “radical middle.” This paper presents two examples of developmental analyses in spatial development. These two transitions are characterizable as either qualitative or quantitative, but are best thought of as both. A position of this kind allows for much more precise answers to practical questions about issues such as sensitive periods than would otherwise be possible.

A dissociation between recognition and reactivation: The renewal effect at 3 months of age.

Extinction allows organisms to adapt to an ever-changing environment. Despite its theoretical and applied significance, extinction has never been systematically studied with human infants. Using the operant mobile task, we examined whether 3-month-olds would exhibit evidence of original learning following extinction. In a recognition paradigm, infants exhibited renewal when tested in the acquisition context (ABA renewal) or a neutral context (ABC and AAB renewal) 1 day following extinction (Experiment 1a) and spontaneous recovery 3 days following extinction (Experiment 1b). In Experiments 2a-2b, we used a reminder paradigm to examine whether the extinguished response could be reinstated after the operant response had been forgotten. We failed, however, to find reinstatement of extinguished responding after spontaneous forgetting, regardless of the reminder and test contexts. We attributed this retention failure to competing responses at test. Although extinguished responding is recovered during infancy, this effect is elusive after the response has been forgotten.

An encyclopedic overview of child development and directions for the future

Within the literature of many academic disciplines, an encyclopedia of the current state of the field appears periodically. The Cambridge Encyclopedia of Child Development reviewed here is the second edition and reflects the change and expansion of the discipline of child development in the twelve years since the publication of the first edition. This revised and substantially expanded second edition of the Cambridge Encyclopedia of Child Development is a 900-page tome that covers most of the wide variety topics important to an understanding of child development. It is a wide-ranging volume that covers more topics than I can discuss in a single review. The overarching theme offered in the introductory chapter by Brian Hopkins is one of integration and complexity. The volume is described as an effort to offer a historical and theoretical overview of the complexity of the developing human. In general the entries, authored by a wide variety of experts in areas across the spectrum of researchers in human development, arewell integrated. Each entry has a “see also” section at the end referring the reader to other entries in the volume that are relevant to the topic discussed. For example, the entry on Attention, written by Burack, Jeffries, Ringo, and Landry, discussed development of general features of attention and the relevance of attention to all of cognition, as well as the development of several different modes of attention. The “see also” section at the end refers the reader to entries on themethods, populations, and cognitive systems touched on in their discussion of attention. This kind of integration across entries is a monumental task. That the entries do such a complete job of referring the reader to more information makes the volume itself more useful. Although this volume covered the topics I think of when we talk about an overview of the field of child development, I was pleasantly surprised by the number of entries that included a brief comparison to other mammals or delved into the history or philosophy of the topic. This thematic element can be seen with theoretical entries that cover categories of theories, instead of individual theories themselves, most of which also addressed the connections between theories and even types of theories. Two of the five theoretical entries, Ethological theories by Bolhuis and Hogan and Evolutionary developmental biology by Michel (who specifically mentions developmental psychobiology), offer strong comparative perspectives on human development and all of them touch on philosophical origins of the field. The comparative theme carries through the section on Prenatal development and the newborn, in which all of the entries offer some insights from animal models in their discussion of early human development. The exception to the comparative theme is the comprehensive twenty-seven entry methodology section, which covers a variety of methodological approaches, specific techniques, analysis options, different types of modeling, and ethical considerations. These entries are for themost part focused on techniques usedwith humans, orwere general enough not to be relevant to the comparative theme. This is not to dismiss the value of these entries. Many of them covered methodologies that I am not familiar with and this is certainly the section where I learned something new from each entry. Even the two separate entries on eye tracking–one exploring head-mounted eye tracking and the other eye tracking using equipment that was not head-mounted–were not redundant. In addition to the discussions of methodologies and equipment, there were entries on different types of analysis, Bayesian data analysis, Connectionist modeling, Multilevel modeling, and more that all seemed to be detailed enough to give a reasonable overview and also did not require much previous knowledge. The first edition of this encyclopedia had a section on different domains of development, with a small number of entries per domain (Hopkins, 2005). However, the current edition now has full and expansive sections for most of the domains. For instance, instead of three entries covering cognitive and perceptual development, there is now a fifteen-entry section on Perceptual and cognitive development that offers a more comprehensive view. This section starts with an entry on Attention and includes a look at the connections between sensory systems and the role of sleep in cognitive development. Also added in the second edition were sections covering language and communication development, social and emotional development, motor development, and postnatal brain development. The twenty-one entries section on Developmental pathology also represents a substantial expansion in this second edition. This section starts with an entry covering Resilience and vulnerability and an entry covering classification. Both of these entries serve to orient the reader to bigger issues that are relevant to how we think of the more specific pathologies that follow. The chapter on classification is particularly