Optic Flow Drives Human Visuo-Locomotor Adaptation

SummaryTwo strategies can guide walking to a stationary goal: (1) the optic-flow strategy, in which one aligns the direction of locomotion or “heading” specified by optic flow with the visual goal [1, 2]; and (2) the egocentric-direction strategy, in which one aligns the locomotor axis with the perceived egocentric direction of the goal [3, 4] and in which error results in optical target drift [5]. Optic flow appears to dominate steering control in richly structured visual environments [2, 6–8], whereas the egocentric- direction strategy prevails in visually sparse environments [2, 3, 9]. Here we determine whether optic flow also drives visuo-locomotor adaptation in visually structured environments. Participants adapted to walking with the virtual-heading direction displaced 10° to the right of the actual walking direction and were then tested with a normally aligned heading. Two environments, one visually structured and one visually sparse, were crossed in adaptation and test phases. Adaptation of the walking path was more rapid and complete in the structured environment; the negative aftereffect on path deviation was twice that in the sparse environment, indicating that optic flow contributes over and above target drift alone. Optic flow thus plays a central role in both online control of walking and adaptation of the visuo-locomotor mapping

Testing a word is not a test of word learning

Although vocabulary acquisition requires children learn names for multiple things, many investigations of word learning mechanisms teach children the name for only one of the objects presented. This is problematic because it is unclear whether children's performance reflects recall of the correct name-object association or simply selection of the only object that was singled out by being the only object named. Children introduced to one novel name may perform at ceiling as they are not required to discriminate on the basis of the name per se, and appear to rapidly learn words following minimal exposure to a single word. We introduced children to four novel objects. For half the children, only one of the objects was named and for the other children, all four objects were named. Only children introduced to one word reliably selected the target object at test. This demonstration highlights the over-simplicity of one-word learning paradigms and the need for a shift in word learning paradigms where more than one word is taught to ensure children disambiguate objects on the basis of their names rather than their degree of salience

Sharing culture in a tech world: Grandparent–grandchild cultural exchanges over video chat.

Grandparents who were separated from their infant grandchildren during COVID-19 sought other ways to connect, including video chat. Video chat supports learning, and its features (e.g., contingent responsiveness) may allow for cultural exchange. However, technological problems may disrupt these exchanges. In a semi-naturalistic, longitudinal study, 47 families submitted up to three video chats and surveys. Families were predominantly White/Caucasian, highly-educated, and lived between 1 and 2700 miles apart. Multilevel models were used to predict the proportion of the sessions devoted to exchanging culture (e.g., holidays, parenting advice) and managing tech problems. Culture exchange did not change as a function of infant age, video chat experience, or when encountering tech problems. Although only marginally statistically significant, culture exchange increased as distance increased. Tech problems changed as a function of tech talk. A qualitative analysis revealed that cultural transmission occurred via a culture of care and sharing of information across video chat, that families adapted their behaviors to the new technology, and that technology disruptions rarely interfered with the flow of information. These findings demonstrate the ability to share culture when physically separated and in the presence of tech disruptions. Further, this study supports previous work on the emerging culture of video chat. Families adapted to being separated, and grandparents and infants successfully communicated through a new modality. Because video chat supports family relationships, equitable access to high-speed internet should be a priority to enable more families to use it

Ensemble coding of faces occurs in children and develops dissociably from coding of individual face identities

Ensemble coding allows adults to access useful information about average properties of groups, sometimes even in the absence of detailed representations of individual group members. This form of coding may emerge early in development with initial reports of ensemble coding for simple properties (size, numerosity) in young children and even infants. Here we demonstrate that ensemble coding of faces, which provides information about average properties of social groups, is already present in 6-8 year old children. This access to average information increases with age from 6 to 18 years and its development is dissociable from age-related improvements in the coding of individual face identities. This dissociation provides the first direct evidence that distinct processes underlie ensemble and individual coding of face identity, evidence that has been lacking from adult studies. More generally, our results add to the emerging evidence for impressively mature sensitivity to statistical properties of the visual environment in children. They indicate that children have access to gist information about social groups that may facilitate adaptive social behaviour

Accessing the Inaccessible: Redefining Play as a Spectrum

Defining play has plagued researchers and philosophers for years. From describing play as an inaccessible concept due to its complexity, to providing checklists of features, the field has struggled with how to conceptualize and operationalize “play.” This theoretical piece reviews the literature about both play and learning and suggests that by viewing play as a spectrum – that ranges from free play (no guidance or support) to guided play and games (including purposeful adult support while maintaining playful elements), we better capture the true essence of play and explain its relationship to learning. Insights from the Science of Learning allow us to better understand why play supports learning across social and academic domains. By changing the lens through which we conceptualize play, we account for previous findings in a cohesive way while also proposing new avenues of exploration for the field to study the role of learning through play across age and context

Accessing the Inaccessible: Redefining Play as a Spectrum.

Defining play has plagued researchers and philosophers for years. From describing play as an inaccessible concept due to its complexity, to providing checklists of features, the field has struggled with how to conceptualize and operationalize "play." This theoretical piece reviews the literature about both play and learning and suggests that by viewing play as a spectrum - that ranges from free play (no guidance or support) to guided play and games (including purposeful adult support while maintaining playful elements), we better capture the true essence of play and explain its relationship to learning. Insights from the Science of Learning allow us to better understand why play supports learning across social and academic domains. By changing the lens through which we conceptualize play, we account for previous findings in a cohesive way while also proposing new avenues of exploration for the field to study the role of learning through play across age and context

Two sides to every story: children learn words better from one storybook page at a time

Two experiments tested how the number of illustrations in storybooks influences 3.5-year-old children's word learning from shared reading. In Experiment 1, children encountered stories with two regular-sized A4 illustrations, one regular-sized A4 illustration, or one large-sized A3 illustration (in the control group) per spread. Children learned significantly fewer words when they had to find the referent within two illustrations presented at the same time. In Experiment 2, a gesture was added to guide children's attention to the correct page in the 2-illustration condition. Children who saw two illustrations with a guiding gesture learned words as well as children who had seen only one illustration per spread. Results are discussed in terms of the cognitive load of word learning from storybooks

Near or far: the effect of spatial distance and vocabulary knowledge on word learning

The current study investigated the role of spatial distance in word learning. Two-year-old children saw three novel objects named while the objects were either in close proximity to each other or spatially separated. Children were then tested on their retention for the name-object associations. Keeping the objects spatially separated from each other during naming was associated with increased retention for children with larger vocabularies. Children with a lower vocabulary size demonstrated better retention if they saw objects in close proximity to each other during naming. This demonstrates that keeping a clear view of objects during naming improves word learning for children who have already learned many words, but keeping objects within close proximal range is better for children at earlier stages of vocabulary acquisition. The effect of distance is therefore not equal across varying vocabulary sizes. The influences of visual crowding, cognitive load, and vocabulary size on word learning are discussed