Catherine M. Sandhofer

A Theory of the Discovery and Predication of Relational Concepts

Relational thinking plays a central role in human cognition. However, it is not known how children and adults acquire relational concepts and come to represent them in a form that is useful for the purposes of relational thinking (i.e., as structures that can be dynamically bound to arguments). The authors present a theory of how a psychologically and neurally plausible cognitive architecture can discover relational concepts from examples and represent them as explicit structures (predicates) that can take arguments (i.e., predicate them). The theory is instantiated as a computer program called DORA (Discovery Of Relations by Analogy). DORA is used to simulate the discovery of novel properties and relations, as well as a body of empirical phenomena from the domain of relational learning and the development of relational representations in children and adults.

The spacing effect in children’s memory and category induction

The spacing effect describes the robust phenomenon whereby memory is enhanced when learning events are distributed, instead of being presented in succession. We investigated the effect of spacing on childrens memory and category induction. Three-year-old children were presented with two tasks, a memory task and a category induction task. In the memory task, identical instances of an object were presented and then tested in a multiple choice test. In the category induction task, different instances of a category were presented and tested in a multiple choice test. In both tasks, presenting the instances in a spaced sequence resulted in more learning than presenting the instances in a massed sequence, despite the difficulty created by the spaced sequence. The spaced sequence increased the difficulty of the task by allowing children time to forget the previous instance during the spaced interval.

Gestures convey substantive information about a child’s thoughts to ordinary listeners

The gestures that spontaneously occur in communicative contexts have been shown to offer insight into a child’s thoughts. The information gesture conveys about what is on a child’s mind will, of course, only be accessible to a communication partner if that partner can interpret gesture. Adults were asked to observe a series of children who participated ‘live’ in a set of conservation tasks and gestured spontaneously while performing the tasks. Adults were able to glean substantive information from the children’s gestures, information that was not found anywhere in their speech. ‘Gesture-reading’ did, however, have a cost – if gesture conveyed different information from speech, it hindered the listener’s ability to identify the message in speech. Thus, ordinary listeners can and do extract information from a child’s gestures, even gestures that are unedited and fleeting.

Fast Mapping Across Time: Memory Processes Support Children’s Retention of Learned Words

Children’s remarkable ability to map linguistic labels to referents in the world is commonly called fast mapping. The current study examined children’s (N = 216) and adults’ (N = 54) retention of fast-mapped words over time (immediately, after a 1-week delay, and after a 1-month delay). The fast mapping literature often characterizes children’s retention of words as consistently high across timescales. However, the current study demonstrates that learners forget word mappings at a rapid rate. Moreover, these patterns of forgetting parallel forgetting functions of domain-general memory processes. Memory processes are critical to children’s word learning and the role of one such process, forgetting, is discussed in detail – forgetting supports extended mapping by promoting the memory and generalization of words and categories.

Distributing Learning Over Time: The Spacing Effect in Children’s Acquisition and Generalization of Science Concepts

The spacing effect describes the robust finding that long-term learning is promoted when learning events are spaced out in time rather than presented in immediate succession. Studies of the spacing effect have focused on memory processes rather than for other types of learning, such as the acquisition and generalization of new concepts. In this study, early elementary school children (5- to 7-year-olds; N = 36) were presented with science lessons on 1 of 3 schedules: massed, clumped, and spaced. The results revealed that spacing lessons out in time resulted in higher generalization performance for both simple and complex concepts. Spaced learning schedules promote several types of learning, strengthening the implications of the spacing effect for educational practices and curriculum.

Why Children Learn Color and Size Words So Differently: Evidence From Adults' Learning of Artificial Terms

An adult simulation study examined why childrens learning of color and size terms follow different developmental patterns, one in which word comprehension precedes success in nonlinguistic matching tasks versus one in which matching precedes word comprehension. In 4 experiments, adults learned artificial labels for values on novel dimensions. Training mimicked that characteristic for children learning either color words or size words. The results suggest that the learning trajectories arise from the different frames in which different dimensions are trained: Using a comparison (size-like) training regimen helps learners pick out the relevant dimension, and using a categorization (color-like) training regimen helps the learner correctly comprehend and produce dimension terms. The results indicate that the training regimen, not the meanings of the terms or the specific dimensions, determines the pattern of learning.

At the Same Time or Apart in Time? The Role of Presentation Timing and Retrieval Dynamics in Generalization

Several bodies of research have found different results with regard to presentation timing, categorization, and generalization. Both presenting instances at the same time (simultaneous) and presenting instances apart in time (spacing) have been shown to facilitate generalization. In this study, we resolved these results by examining simultaneous, massed, and spaced presentations in 2-year-old childrens (N = 144) immediate and long-term performance on a novel noun generalization task. Results revealed that, when tested immediately, children in the simultaneous condition outperformed children in all other conditions. However, when tested after 15 min, children in the spaced condition outperformed children in all other conditions. Results are discussed in terms of how retrieval dynamics during learning affect abstraction, retention, and generalization across time.

Learning Adjectives in the Real World: How Learning Nouns Impedes Learning Adjectives

Previous studies have documented that children are slow to acquire adjectives into their productive vocabulary. Yet in laboratory studies, even very young children can extend novel adjectives to new instances. Two studies examined the relation between childrens acquisition of adjectives and childrens emerging knowledge about nouns. In Study 1, the input parents provide to children when talking about properties was examined. The results indicate that the type of input provided in laboratory experiments is infrequent in parent speech to children, and that parents often talk about adjectives using syntax that is ambiguous as to the adjectival status of the words and confusable with nouns. In Study 2 children participated in a training study designed to teach children color words without strong syntactic cues. In Study 3 children participated in a training study designed to teach children color words with syntactic cues that strongly indicated the adjectival status of the word. The results show that younger children who had fewer nouns in their productive vocabulary learned more without strong syntactic cues whereas the older children who had more nouns in their productive vocabulary were more likely to benefit from hearing strong syntactic cues.

Gender Biases in Early Number Exposure to Preschool-Aged Children:

Despite dramatically narrowing gender gaps, women remain underrepresented in mathematics and math-related fields. Parents can shape expectations and interests, which may predict later differences in achievement and occupational choices. This study examines children’s early mathematical environments by observing the amount that mothers talk to their sons and daughters (mean age 22 months) about cardinal number, a basic precursor to mathematics. In analyses of naturalistic mother–child interactions from the Child Language Data Exchange System (CHILDES) database, boys received significantly more number-specific language input than girls. Greater amounts of early number-related talk may promote familiarity and liking for mathematical concepts, which may influence later preferences and career choices. Additionally, the stereotype of male dominance in math may be so pervasive that culturally prescribed gender roles may be unintentionally reinforced to very young children.

ORDER OF PRESENTATION EFFECTS IN LEARNING COLOR CATEGORIES

Two studies, an experimental category learning task and a computational simulation, examined how sequencing training instances to maximize comparison and memory affects category learning. In Study 1, 2-year-old children learned color categories with three training conditions that varied in how categories were distributed throughout training and how similarity between exemplars progressed across instances. The results indicate that beginning learning by interacting with a limited set of highly similar exemplars leads to more learning than when the instances are distributed and dissimilar. In Study 2, order effects were examined with a symbolic connectionist model of general learning and representation discovery (DORA). The results of the studies suggest that when the presentation of instances is ordered in such a way that discrete instances of a category can be more readily connected in memory, category learning and discovery are more likely to occur.