Developmental changes in the visual, haptic, and bimodal perception of geometric angles.

Geometrical knowledge is typically taught to children through a combination of vision and repetitive drawing (i.e. haptics), yet our understanding of how different spatial senses contribute to geometric perception during childhood is poor. Studies of line orientation suggest a dominant role of vision affecting the calibration of haptics during development; however, the associated multisensory interactions underpinning angle perception are unknown. Here we examined visual, haptic, and bimodal perception of angles across three age groups of children: 6 to 8 years, 8 to 10 years, and 10 to 12 years, with age categories also representing their class (grade) in primary school. All participants first learned an angular shape, presented dynamically, in one of three sensory tracing conditions: visual only, haptic only, or bimodal exploration. At test, which was visual only, participants selected a target angle from four possible alternatives with distractor angle sizes varying relative to the target angle size. We found a clear improvement in accuracy of angle perception with development for all learning modalities. Angle perception in the youngest group was equally poor (but above chance) for all modalities; however, for the two older child groups, visual learning was better than haptics. Haptic perception did not improve to the level of vision with age (even in a comparison adult group), and we found no specific benefit for bimodal learning over visual learning in any age group, including adults. Our results support a developmental increment in both spatial accuracy and precision in all modalities, which was greater in vision than in haptics, and are consistent with previous accounts of cross-sensory calibration in the perception of geometric forms.

Children's spatial-numerical associations on horizontal, vertical, and sagittal axes.

There is substantial evidence linking numerical magnitude to the physical properties of space. The most influential support for this connection comes from the SNARC effect (spatial-numerical association of response codes), in which responses to small/large numbers are faster on the left/right side of space, respectively. The SNARC effect has been extensively replicated, and is understood as horizontal mapping of numerical magnitude. However, much less is known about how numbers are represented on the vertical and sagittal axes, and whether spatial-numerical associations on different axes emerge during childhood. To that end, we tested two groups of children, aged 5-7 years and 8 and 9 years, on a single-digit magnitude comparison task with response buttons positioned either upper/lower (vertical), left/right (horizontal) or near/far (sagittal). Our results provide evidence of spatial-numerical mapping on all three axes for both age groups that are similar in strength. This indicates that, even at an early stage of formal education, children can flexibly assign numerical magnitude to any spatial dimension. To examine the contribution of extracorporeal space and spatio-anatomical mapping to the SNARC effect across axes, these sources were pitted against each other by swapping the position of the response hands in Experiment 1b. Switching hand position did not reveal convincing evidence for SNARC effects on any axis. Results are discussed with respect to the utility of three-dimensional mental number lines, and potential avenues for future research are outlined.

How many apples make a quarter? The challenge of discrete proportional formats.

Proportional judgments are easier for children in continuous formats rather than discretized ones (e.g., liquid in a beaker vs. in a beaker with unit markings). Continuous formats tap a basic sense of approximation magnitude, whereas discretized formats evoke erroneous counting strategies. On this account, truly discrete formats with separated objects should be even harder. This study (N = 565 7- to 12-year-old children) investigated that prediction. It also examined whether the format effects vary with children's fraction knowledge (FK; part-whole relations, computation, and fraction number line estimation). As found previously, discretized formats were more challenging than continuous ones; as predicted, discrete formats were yet harder. The format effect interacted with FK. Low-FK children were above chance only with continuous formats, medium-FK children struggled with discrete formats only, and high-FK children did well with all three formats.

Move to learn: Integrating spatial information from multiple viewpoints.

Recalling a spatial layout from multiple orientations - spatial flexibility - is challenging, even when the global configuration can be viewed from a single vantage point, but more so when it must be viewed piecemeal. In the current study, we examined whether experiencing the transition between multiple viewpoints enhances spatial memory and flexible recall for a spatial configuration viewed simultaneously (Exp. 1) and sequentially (Exp. 2), whether the type of transition matters, and whether action provides an additional advantage over passive experience. In Experiment 1, participants viewed an array of dollhouse furniture from four viewpoints, but with all furniture simultaneously visible. In Experiment 2, participants viewed the same array piecemeal, from four partitioned viewpoints that allowed for viewing only a segment at a time. The transition between viewpoints involved rotation of the array or participant movement around it. Rotation and participant movement were passively experienced or actively generated. The control condition presented the dollhouse as a series of static views. Across both experiments, participant movement significantly enhanced spatial memory relative to array rotation or static views. However, in Exp. 2, there was a further advantage for actively walking around the array compared to being passively pushed. These findings suggest that movement around a stable environment is key to spatial memory and flexible recall, with action providing an additional boost to the integration of temporally segmented spatial events. Thus, spatial memory may be more flexible than prior data indicate, when studied under more natural acquisition conditions.

Multiple views of space: Continuous visual flow enhances small-scale spatial learning.

In the real word, we perceive our environment as a series of static and dynamic views, with viewpoint transitions providing a natural link from one static view to the next. The current research examined if experiencing such transitions is fundamental to learning the spatial layout of small-scale displays. In Experiment 1, participants viewed a tabletop array from 4 orientations in 1 of 3 conditions. The control condition presented the array sequentially, as a series of static views. In the remaining conditions, participants experienced the transition between viewpoints by rotating the array or moving around it. Both transitions improved spatial performance. Experiment 2 added a passive rotation condition to examine the effect of watching the transition without actively generating it. Spatial performance was equivalent across active and passive rotation conditions, with both outperforming static views. Together, these findings suggest that continuous visual flow is key to small-scale spatial learning. (PsycINFO Database Record

Sex differences and errors in the use of terrain slope for navigation.

Unlike most of the spatial cues that have received attention, a sloping terrain can be perceived by multimodal sensory inputs (vision, balance, and kinesthesia), making it potentially very salient for navigation. Furthermore, a homogeneous slope can be used like a compass to identify directions (e.g., uphill, downhill, and sideways), but not to determine distances. We briefly review recent evidence on navigation with slope, emphasizing two main findings. On the one hand, we focus on the conspicuous sex difference found in the ability to localize a target in a square, tilted enclosure; this has emerged in human adults and children, and we suggest that it is related to lower awareness of the slope for females. On the other hand, we describe the general pattern of errors that arises when localizing the target during the task; these errors indicate the use of a bi-coordinate representation of the slope. Limitations and ideas for future studies are proposed.