Sex differences in direction giving: Are boys better than girls?

Previous research has extensively documented sex differences favoring boys in various domains of spatial cognition. However, relatively little research has examined sex differences in children's direction giving. The current study aimed to bridge this gap. A total of 143 children aged 3 to 10 years were asked to describe and recall routes from survey perspectives (via maps) and route perspectives (via videos). Significant sex effects (favoring boys) in direction-giving accuracy were found in describing route trials. However, boys and girls did not differ in the frequency of utterances encoding landmarks and direction of turns, suggesting that the quality rather than the quantity of words played a more important role in explaining sex differences. In addition, there was no sex difference in the route recall task. Although accuracy was overall higher in the map condition than in the video condition, it did not moderate sex differences. Overall, our study showed a robust sex difference in direction giving, which has important theoretical implications for understanding the development of human sex differences and critical clinical implications for designing training programs to improve children's spatial cognition.

"Dividing the labor": Lexical verbs and the linguistic encoding of physical support in 2- to 4.5-year-old children.

Infants reason about support configurations (e.g., teddy bear on table) and young children talk about a variety of support relations, including support-from-below (e.g., apple on table) and many other types (e.g., Band-Aid on leg, picture on wall). Given this wide variation in support types, we asked whether early differentiation of the semantic space of support may play a key role in helping children to learn spatial language in this domain. Previous research has shown such differentiation with 20-month-olds mapping the basic locative construction (BE on) to support-from-below (cube on top of box), but not to a mechanical support configuration (cube on side of box via adhesion). Older children and adults show the same differentiation, with preferential mapping of BE on to support-from-below and lexical verbs to mechanical support. We further explored the development of this differentiation by testing how children aged 2 to 4.5 years map lexical verbs to a wide variety of support configurations. In Experiment 1, using an intermodal preferential pointing paradigm, we found that 2- to 3.5-year-olds map a lexical verb phrase ("sticks to") to mechanical support via adhesion. In Experiments 2 and 3, we expanded the range of mechanical support relations and used production and forced-choice tasks to ask whether 2- to 4.5-year-olds also encode mechanical relations using lexical verbs. We found that they do. These findings suggest continuity between infancy and childhood in the way that children use spatial language to differentially map to support-from-below versus mechanical support and raise new questions about how mechanical support language develops.

The privileging of 'Support-From-Below' in early spatial language acquisition.

Spatial terms that encode support (e.g., "on", in English) are among the first to be understood by children across languages (e.g., Bloom, 1973; Johnston & Slobin, 1979). Such terms apply to a wide variety of support configurations, including Support-From-Below (SFB; cup on table) and Mechanical Support, such as stamps on envelopes, coats on hooks, etc. Research has yet to delineate infants' semantic space for the term "on" when considering its full range of usage. Do infants initially map "on" to a very broad, highly abstract category - one including cups on tables, stamps on envelopes, etc.? Or do infants begin with a much more restricted interpretation - mapping "on" to certain configurations over others? Much infant cognition research suggests that SFB is an event category that infants learn about early - by five months of age (Baillargeon & DeJong, 2017) - raising the possibility that they may also begin by interpreting the word "on" as referring to configurations like cups on tables, rather than stamps on envelopes. Further, studies examining language production suggests that children and adults map the basic locative expression (BE on, in English) to SFB over Mechanical Support (Landau et al., 2016). We tested the hypothesis that this 'privileging' of SFB in early infant cognition and child and adult language also characterizes infants' language comprehension. Using the Intermodal-Preferential-Looking-Paradigm in combination with infant eye-tracking, 20-month-olds were presented with two support configurations: SFB and Mechanical, Support-Via-Adhesion (henceforth, SVA). Infants preferentially mapped "is on" to SFB (rather than SVA) suggesting that infants differentiate between two quite different kinds of support configurations when mapping spatial language to these two configurations and more so, that SFB is privileged in early language understanding of the English spatial term "on".

The relationship between pre-verbal event representations and semantic structures: The case of goal and source paths.

We explored the nature of infants' concepts for goal path and source path in motion events (e.g., the duck moved into the bowl/out of the bowl), specifically asking how infants' representations could support the acquisition of the semantic roles of goal path and source path in language. The results showed that 14.5-month-old infants categorized goal paths across different motion events (moving to X, moving on Y), and they also categorized source paths if the source reference objects were highly salient (relatively large in size and colorful). Infants at 10months also categorized goal paths, suggesting that the broad concept GOAL PATH precedes the acquisition of the relevant spatial terms (e.g., "to", "onto"). These results are discussed in terms of the nature of goal and source path representations in infancy (e.g., whether they are represented at a general level - one that encompasses specific relations such as containment and support) as well as the possible mechanisms that may be involved in the mapping of these representations to language.

And, the Winner Is A Visual Preference for Endpoints over Starting Points in Infants' Motion Event Representations.

Infants represent objects that are endpoints in motion events and show a preference for encoding the endpoint (the duck waddles into a bowl) over the starting point (the duck waddles out of a box). This asymmetry continues to appear in nonlinguistic cognition and language throughout development. This study tests whether this asymmetry also shows up in 16-month-old infants' visual preferences for motion events, and if so, for which types of events. Infants looked longer at events depicting an "agentive" figure (e.g., duck) moving into an object (endpoint) than out of an object (starting point), and this asymmetry persisted even when the starting point object was larger and more colorful than the endpoint object and when it caused the motion of the figure. However, an asymmetry was not found when motion into/out of the endpoint/starting point involved was performed by a "nonagentive" (e.g., leaf) figure. These findings suggest that an endpoint/starting point asymmetry in infant cognition (1) extends to infants' visual preferences of motion events, (2) shows up most strongly for events that involve an "agentive" figure, and (3) is largely unaffected by the physical saliency of the starting point object. How a visual endpoint preference may support the acquisition of spatial language is considered.

Does Making Something Move Matter? Representations of Goals and Sources in Motion Events With Causal Sources.

Previous studies have shown a robust bias to express the goal path over the source path when describing events ("the bird flew into the pitcher," rather than "… out of the bucket into the pitcher"). Motivated by linguistic theory, this study manipulated the causal structure of events (specifically, making the source cause the motion of the figure) and measured the extent to which adults and 3.5- to 4-year-old English-speaking children included the goal and source in their descriptions. We found that both children's and adults' encoding of the source increased for events in which the source caused the motion of the figure compared to nearly identical events in which the source played no such causal role. However, a goal bias persisted overall for both causal and noncausal motion events. These findings suggest that although the goal bias in language is highly robust, properties of the source (such as causal agency) influence its likelihood of being encoded in language, thus shedding light on how properties of an event can influence the mapping of event components into language.

Twelve-Month-Old Infants' Encoding of Goal and Source Paths in Agentive and Non-Agentive Motion Events.

Across languages and event types (agentive and non-agentive motion, transfer, change of state, attach/detach), goal paths are privileged over source paths in the linguistic encoding of events. Furthermore, some linguistic analyses suggest that goal paths are more central than source paths in the semantic and syntactic structure of motion verbs. However, in the non-linguistic memory of children and adults, a goal bias shows up only for events involving intentional, goal-directed, action. Three experiments explored infants' non-linguistic representations of goals and sources in motion events. The findings revealed that 12-month-old infants privilege goals over sources only when the event involves action of an agent. Thus, unlike language (but similar to the memory of children and adults), an endpoint bias in infant thought may be restricted to events involving goal-directed motion by an agent. These results raise the question of how children later learn to collapse over conceptual domains for purposes of coding paths in language.

Language and memory for motion events: origins of the asymmetry between source and goal paths.

When people describe motion events, their path expressions are biased toward inclusion of goal paths (e.g., into the house) and omission of source paths (e.g., out of the house). In this paper, we explored whether this asymmetry has its origins in people's non-linguistic representations of events. In three experiments, 4-year-old children and adults described or remembered manner of motion events that represented animate/intentional and physical events. The results suggest that the linguistic asymmetry between goals and sources is not fully rooted in non-linguistic event representations: linguistic descriptions showed the goal bias for both kinds of events, whereas non-linguistic memory for events showed the goal bias only for events involving animate, goal-directed motion. The findings are discussed in terms of the mapping between non-linguistic representations of goals and sources in language, focusing on the role that linguistic principles play in producing a more absolute goal bias from more gradient non-linguistic representations of paths.

The intention-to-CAUSE bias: evidence from children's causal language.

The current study explored causal language in 3.5- to 4-year-old children by manipulating the type of agent (human acting intentionally or unintentionally, or inanimate object) and the type of effect (motion or state change) in causal events. Experiment 1 found that the type of agent, but not the type of effect, influenced children's production of causal language. Children produced more causal language for intentionally caused events than for either unintentionally- or object-caused events, independent of the type of effect. Experiment 2, which tested children's judgments of descriptions for the events, found a similar pattern. Children preferred causal descriptions more for the intentionally caused events than the unintentionally- and the object-caused events. Experiment 3 found no evidence of bias in children's non-linguistic representations of the events. Taken together, these results suggest an intention-to-CAUSE bias in children's mapping of conceptual representations of causality into linguistic structure. We discuss the implications of these results for the acquisition of causal language and for the development of conceptual representations of causality.

Deficits in adults with autism spectrum disorders when processing multiple objects in dynamic scenes.

People with autism spectrum disorders (ASD) process visual information in a manner that is distinct from typically developing individuals. They may be less sensitive to people's goals and, more generally, focus on visual details instead of the entire scene. To examine these differences, people with and without ASD were asked to detect changes in dynamic scenes with multiple elements. Participants viewed a brief video of a person or an inanimate object (the "figure") moving from one object to another; after a delay, they reported whether a second video was the same or different. Possible changes included the figure, the object the figure was moving from, or the object the figure was moving toward (the "goal"). We hypothesized that individuals with ASD would be less sensitive to changes in scenes with people, particularly elements that might be the person's goal. Alternately, people with ASD might attend to fewer elements regardless of whether the scene included a person. Our results indicate that, like controls, people with ASD noticed a change in the "goal" object at the end of a person's movement more often than the object at the start. However, the group with ASD did not undergo the developmental improvement that was evident typically when detecting changes in both the start and end objects. This atypical development led to deficits in adults with ASD that were not specific to scenes with people or to "goals." Improvements in visual processing that underlie mature representation of scenes may not occur in ASD, suggesting that late developing brain processes are affected.

Impaired geometric reorientation caused by genetic defect.

The capacity to reorient in one's environment is a fundamental part of the spatial cognitive systems of both humans and nonhuman species. Abundant literature has shown that human adults and toddlers, rats, chicks, and fish accomplish reorientation through the construction and use of geometric representations of surrounding layouts, including the lengths of surfaces and their intersection. Does the development of this reorientation system rely on specific genes and their action in brain development? We tested reorientation in individuals who have Williams syndrome (WS), a genetic disorder that results in abnormalities of hippocampal and parietal areas of the brain known to be involved in reorientation. We found that in a rectangular chamber devoid of surface feature information, WS individuals do not use the geometry of the chamber to reorient, failing to find a hidden object. The failure among people with WS cannot be explained by more general deficits in visual-spatial working memory, as the same individuals performed at ceiling in a similar task in which they were not disoriented. We also found that performance among people with WS improves in a rectangular chamber with one blue wall, suggesting that some individuals with WS can use the blue wall feature to locate the hidden object. These results show that the geometric system used for reorientation in humans can be selectively damaged by specific genetic and neural abnormalities in humans.

Spatial representation across species: geometry, language, and maps.

We review growing evidence that the reorientation system-shared by both humans and nonhuman species-privileges geometric representations of space and exhibits many of the characteristic features of modular systems. We also review evidence showing that humans can move beyond the limits of nonhuman species by using two cultural constructions, language and explicit maps. We argue that, although both of these constructions are uniquely human means of enriching the spatial system we share with other species, their representational formats, functions, and developmental trajectories are quite different, yielding distinctly different tools for empowering human spatial cognition.The capacity to reorient using geometry is present in humans by the age of 18 months.

The Role of Verbal Repetition in the Development of Infant Speech Preferences From 4 to 14 Months of Age.

Four experiments investigated infants' preferences for age-appropriate and age-inappropriate infant-directed speech (IDS) over adult-directed speech (ADS). Two initial experiments showed that 6-, 10-, and 14-month-olds preferred IDS directed toward younger infants, and 4-, 8-, 10-, and 14-month-olds, but not 6-month-olds, preferred IDS directed toward older infants. In Experiment 3. 6-month-olds preferred IDS directed toward older infants when the frequency of repeated utterances matched IDS to younger infants. In Experiment 4, 6-month-olds preferred repeated IDS utterances over the same IDS utterances organized without repetition. Attention to repeated utterances precedes word segmentation and sensitivity to statistical cues in continuous speech, and might play a role in the discovery of these and other aspects of linguistic structure.

Using Language to Navigate the Infant Mind.

How do infants represent objects, actions, and relations in events? In this review, we discuss an approach to studying this question that begins with linguistic theory-specifically, semantic structures in language. On the basis of recent research exploring infant cognition and prominent linguistic analyses, we examine whether infants representations of motion events are articulated in terms of the components proposed by Talmy (1985; e.g., path, manner) and whether infants' event representations are defined in terms of broad semantic roles (agent, patient, source, goal) as proposed by Jackendoff (1990) and Dowty (1991). We show how recent findings in infant cognition are consistent with the idea that the infant's representation of events is a close reflection of the linguistic categories. We especially highlight research that is explicitly guided by linguistic categories likely to have correlates in nonlinguistic cognition to illustrate the usefulness of using language to pose questions about early conceptual representations.

Starting at the end: the importance of goals in spatial language.

We explored the linguistic encoding of Paths in children between the ages of three and seven, in children with Williams syndrome, and in normal adults, focusing specifically on Source and Goal Paths. The results showed an asymmetry, with Goal Paths regularly and systematically encoded, but Source Paths often omitted. This pattern occurred among all groups and across a broad range of domains including Manner of Motion, Change of Possession, Change of State, and Attachment/Detachment events. It also occurred whether participants spontaneously described events or were asked to use a specific verb that biased them towards a Goal or Source Path (e.g. 'give' vs. 'get'). The results are discussed in terms of non-linguistic foundations of spatial language and the linguistic mapping biases that arise when we describe what we see.

A first step in form-based category abstraction by 12-month-old infants.

The present experiments investigate how young language learners begin to acquire form-based categories and the relationships between them. We investigated this question by exposing 12-month-olds to auditory structure of the form aX and bY (infants had to learn that a-elements grouped with Xs and not Ys). Infants were then tested on strings from their training language versus strings from the other language using a preferential-listening procedure. Importantly, the X and Y elements were new at test, requiring infants to generalize to novel pairings. We also manipulated the probability of encountering grammatical structures of the training language by mixing strings from two artificial languages according to 83/17 and 67/33 percentage ratios in Experiment 2. Experiment 1 shows that 12-month-olds are capable of forming categories of X- and Y-elements based on a shared feature and, furthermore, form associations between particular a- and b-elements and these categories. Experiment 2 shows that learning was sustained even when 17% of instances from another language were present during training. However, infants failed to generalize when exposed to a larger percentage of strings from another language. The findings demonstrate that the first step of form-based category abstraction (the ability to generalize based on marker-feature pairings) is in place by 12 months of age.