A computerized spatial orientation test.

In three experiments, we compared performance on a paper-based perspective-taking task (the Spatial Orientation Test [SOT]; Hegarty & Waller, 2004) with performance on a computer-based version of the task. The computer-based version automates scoring angular errors, allows for different stimulus orders to be given to each participant, and allows for different testing time limits. In Experiment 1, the two media used different objects and mirror-image stimulus arrays in the two versions to mitigate the effects of memory for specific objects or responses. In Experiments 2 and 3, the two media used identical objects (also in a mirrored arrangement), to provide a more equivalent between-media comparison. We also substituted new objects for objects in the original version that had an inherent front/back (e.g., a car) and/or that were animate; directional or animate objects may add variance that is unrelated to perspective-taking ability. Experiment 3 used clarified instructions and a sample size sufficient to examine relatively small differences between the media as well as sex differences. Overall, the computer-based version produced performance that was similar to that of the paper-based version in terms of the rank-order of the participants. The new computer and paper versions of the SOT also had similar correlations with the Money Road Map test and the Santa Barbara Sense of Direction questionnaire, adding support to the claim that the computerized SOT is tapping into the same skill as the paper-based version. We provide a Java version of the new SOT, along with pdf files of instructions and practice stimuli, on the Open Science Framework website.

Examining the Accuracy and Use of Portion Size Estimation Aids in Parents of Children With Obesity: A Randomized Controlled Trial.

OBJECTIVE: To determine parents' (1) accuracy in using portion size estimation aids (PSEAs) to estimate portion sizes and (2) use of PSEAs at home. METHODS: Parents (n = 37) of children in a pediatric weight management clinic were recruited, enrolled in a parallel-design, randomized, controlled trial, and assigned to receive a 2-dimensional (2D) or 3D PSEA. Percent absolute estimation accuracy was examined across groups and food types. Survey responses were organized according to frequencies and percentages were calculated. RESULTS: Main effects of group, food type, and group × food type interaction were significant (all P < .05). The 2D PSEAs yielded more accurate estimates of portion sizes for amorphous foods. Overall, parents' estimation accuracy was poor. Participants were satisfied and found the PSEAs to be useful. CONCLUSIONS AND IMPLICATIONS: The 2D PSEAs led to greater accuracy in estimating portions of amorphous foods. Parents showed poor accuracy in estimating portion sizes. This study highlights the role of dietitians and nutrition educators in enhancing portion estimation accuracy.

The contribution of nonrigid motion and shape information to object perception in pigeons and humans.

The ability to perceive and recognize objects is essential to many animals, including humans. Until recently, models of object recognition have primarily focused on static cues, such as shape, but more recent research is beginning to show that motion plays an important role in object perception. Most studies have focused on rigid motion, a type of motion most often associated with inanimate objects. In contrast, nonrigid motion is often associated with biological motion and is therefore ecologically important to visually dependent animals. In this study, we examined the relative contribution of nonrigid motion and shape to object perception in humans and pigeons, two species that rely extensively on vision. Using a parametric morphing technique to systematically vary nonrigid motion and three-dimensional shape information, we found that both humans and pigeons were able to rely solely on either shape or nonrigid motion information to identify complex objects when one of the two cues was degraded. Humans and pigeons also showed similar 80% accuracy thresholds when the information from both shape and motion cues were degraded. We argue that the use of nonrigid motion for object perception is evolutionarily important and should be considered in general theories of vision at least with respect to visually sophisticated animals.

Where are you? The effect of uncertainty and its visual representation on location judgments in GPS-like displays.

Two experiments revealed how nonexperts interpret visualizations of positional uncertainty on GPS-like displays and how the visual representation of uncertainty affects their judgments. Participants were shown maps with representations of their current location; locational uncertainty was visualized as either a circle (confidence interval) or a faded glyph (indicating the probability density function directly). When shown a single circle or faded glyph, participants assumed they were located at the center of the uncertain region. In a task that required combining 2 uncertain estimates of their location, the most common strategy-integration-was to take both estimates into account, with more weight given to the more certain estimate. Participants' strategies were not affected by how uncertainty was visualized, but visualization affected the consistency of responses, both within individuals and in relation to models of individual's preferred strategies. The results indicate that nonexperts have an intuitive understanding of uncertainty. Rather than arguing for a particular method of visualizing uncertainty, the data suggest that the best visualization method is task dependent. (PsycINFO Database Record

Systematic review of physical activity and cognitive development in early childhood.

OBJECTIVES: To comprehensively review all observational and experimental studies examining the relationship between physical activity and cognitive development during early childhood (birth to 5 years). DESIGN: Systematic review. METHODS: Electronic databases were searched in July, 2014. No study design, date, or language limits were imposed on the search. Included studies had to be published, peer reviewed articles that satisfied the a priori determined population (apparently healthy children aged birth to 5 years), intervention (duration, intensity, frequency, or patterns of physical activity), comparator (various durations, intensity, or patterns of physical activity), and outcome (cognitive development) study criteria. Study quality and risk of bias were assessed in December 2014. RESULTS: A total of seven studies, representing 414 participants from five different countries met the inclusion criteria, including two observational and five experimental studies. Six studies found increased or higher duration/frequency of physical activity had statistically significant (p<0.05) beneficial effects on at least one cognitive development outcome, including 67% of the outcomes assessed in the executive function domain and 60% in the language domain. No study found that increased or higher duration/frequency of physical activity had statistically significant detrimental effects on cognitive development. Six of the seven studies were rated weak quality with a high risk of bias. CONCLUSIONS: This review provides some preliminary evidence that physical activity may have beneficial effects on cognitive development during early childhood. Given the shortage of the information and the weak quality of available evidence, future research is needed to strengthen the evidence base in this area.

Systematic review of sedentary behavior and cognitive development in early childhood.

OBJECTIVE: To comprehensively review observational and experimental studies examining the relationship between sedentary behavior and cognitive development during early childhood (birth to 5years). METHOD: Electronic databases were searched in July, 2014 and no limits were imposed on the search. Included studies had to be peer-reviewed, published, and meet the a priori determined population (apparently healthy children aged birth to 5years), intervention (duration, types, and patterns of sedentary behavior), comparator (various durations, types, or patterns of sedentary behavior), and outcome (cognitive development) study criteria. Data extraction occurred in October and November 2014 and study quality and risk of bias were assessed in December 2014. RESULTS: A total of 37 studies, representing 14,487 participants from nine different countries were included. Thirty-one studies used observational study designs and six studies used experimental study designs. Across study designs, increased or higher screen time (most commonly assessed as television viewing (TV)), reading, child-specific TV content, and adult-specific TV content had detrimental (negative) associations with cognitive development outcomes for 38%, 0%, 8%, and 25% of associations reported, respectively, and beneficial (positive) associations with cognitive development outcomes for 6%, 60%, 13%, and 3% of associations reported, respectively. Ten studies were moderate quality and 27 studies were weak quality. CONCLUSIONS: The type of sedentary behavior, such as TV versus reading, may have different impacts on cognitive development in early childhood. Future research with reliable and valid tools and adequate sample sizes that examine multiple cognitive domains (e.g., language, spatial cognition, executive function, memory) are needed. Registration no. CRD42014010004.

Bayesian combination of two-dimensional location estimates.

We extend a Bayesian method for combining estimates of means and variances from independent cues in a spatial cue-combination paradigm. In a typical cue-combination experiment, subjects estimate a value on a single dimension-for example, depth-on the basis of two different cues, such as retinal disparity and motion. The mathematics for this one-dimensional case is well established. When the variable to be estimated has two dimensions, such as location (which has both x and y values), then the one-dimensional method may be inappropriate due to possible correlations between x and y and the fact that the dimensions may be inseparable. A cue-combination task for location involves people or animals estimating xy locations under two single-cue conditions and in a condition in which both cues are combined. We present the mathematics for the two-dimensional case in an analogous manner to the one-dimensional case and illustrate them using a numeric example. Our example involves locations on maps, but the method illustrated is relevant for any task for which the estimated variable has two or more dimensions.

Food portion estimation by children with obesity: the effects of estimation method and food type.

Several factors influence children's ability to report accurate information about their dietary intake. To date, one understudied area of dietary assessment research relates to children's ability to estimate portion sizes of food. The purpose of this cross-sectional research was to examine food portion size estimation accuracy in 7- to 18-year-old children with obesity. Two within-subject experiments (Experiment 1: n=28, Experiment 2: n=27) were conducted in Edmonton, Alberta, Canada, during 2007-2008. Three types of portion size measurement aids (PSMAs) (eg, measuring cups and spoons, household objects [full and half-sized], and modeling clay) were counterbalanced in a Latin Square design for participants to estimate four types of foods (ie, solid, liquid, amorphous pieces, and amorphous masses). Analyses of variance conducted on percent of signed and absolute errors yielded significant PSMA type×food type interactions (P<0.01) in both experiments. Across all food types, for Experiments 1 and 2, measuring cups and spoons produced the least accurate estimates with respect to absolute error (54.2% and 53.1%, respectively), whereas modeling clay produced the most accurate estimates (40.6% and 33.2%, respectively). Half sizes of household objects also yielded enhanced accuracy (47.9% to 37.2%). Finally, there were significant differences in accuracy between amorphous pieces (eg, grapes) vs amorphous masses (eg, mashed potatoes; P<0.01), indicating that there are qualitative differences in how different amorphous foods are estimated. These data are relevant when collecting food intake data from children with obesity and indicate that different PSMAs may be needed to optimize food portion size estimation accuracy for different food types.

Location memory for dots in polygons versus cities in regions: evaluating the category adjustment model.

We conducted 3 experiments to examine the category adjustment model (Huttenlocher, Hedges, & Duncan, 1991) in circumstances in which the category boundaries were irregular schematized polygons made from outlines of maps. For the first time, accuracy was tested when only perceptual and/or existing long-term memory information about identical locations was cued. Participants from Alberta, Canada and California received 1 of 3 conditions: dots-only, in which a dot appeared within the polygon, and after a 4-s dynamic mask the empty polygon appeared and the participant indicated where the dot had been; dots-and-names, in which participants were told that the first polygon represented Alberta/California and that each dot was in the correct location for the city whose name appeared outside the polygon; and names-only, in which there was no first polygon, and participants clicked on the city locations from extant memory alone. Location recall in the dots-only and dots-and-names conditions did not differ from each other and had small but significant directional errors that pointed away from the centroids of the polygons. In contrast, the names-only condition had large and significant directional errors that pointed toward the centroids. Experiments 2 and 3 eliminated the distribution of stimuli and overall screen position as causal factors. The data suggest that in the "classic" category adjustment paradigm, it is difficult to determine a priori when Bayesian cue combination is applicable, making Bayesian analysis less useful as a theoretical approach to location estimation.

The relative weight of shape and non-rigid motion cues in object perception: a model of the parameters underlying dynamic object discrimination.

Shape and motion are two dominant cues for object recognition, but it can be difficult to investigate their relative quantitative contribution to the recognition process. In the present study, we combined shape and non-rigid motion morphing to investigate the relative contributions of both types of cues to the discrimination of dynamic objects. In Experiment 1, we validated a novel parameter-based motion morphing technique using a single-part three-dimensional object. We then combined shape morphing with the novel motion morphing technique to pairs of multipart objects to create a joint shape and motion similarity space. In Experiment 2, participants were shown pairs of morphed objects from this space and responded "same" on the basis of motion-only, shape-only, or both cues. Both cue types influenced judgments: When responding to only one cue, the other cue could be ignored, although shape cues were more difficult to ignore. When responding on the basis of both cues, there was an overall bias to weight shape cues more than motion cues. Overall, our results suggest that shape influences discrimination more than motion even when both cue types have been made quantitatively equivalent in terms of their individual discriminability.

Representational pseudoneglect and reference points both influence geographic location estimates.

Our mental representation of the world is far from objective. For example, western Canadians estimate the locations of North American cities to be too far to the west. This bias could be due to a reference point effect, in which people estimate more space between places close to them than far from them, or to representational pseudoneglect, in which neurologically intact individuals favor the left side of space when asked to image a scene. We tested whether either or both of these biases influence the geographic world representations of neurologically intact young adults from Edmonton and Ottawa, which are in western and eastern Canada, respectively. Individuals were asked to locate North American cities on a two-dimensional grid. Both groups revealed effects of representational pseudoneglect in this novel paradigm, but they also each exhibited reference point effects. These results inform theories in both cognitive psychology and neuroscience.

View combination in recognition of 3-D virtual reality layouts.

We investigated whether a normalization model or view combination model fit the performance of scene recognition of 3-D layouts using a virtual-reality paradigm. Participants learned a layout of seven objects from two training views (e.g., 0° and 48°) by discriminating the "correct" layout from distracters. Later, they performed a discrimination task using the training views (e.g., 0° and 48°), an interpolated view (e.g., 24°), an extrapolated view (e.g., 72°), and a far view (e.g., 96°). The results showed that the interpolated view was easier to discriminate than the extrapolated view and even easier than the training views. These results extend the applicability of view combination accounts of recognition to 3-D stimuli with stereoscopic depth information.

View combination: a generalization mechanism for visual recognition.

We examined whether view combination mechanisms shown to underlie object and scene recognition can integrate visual information across views that have little or no three-dimensional information at either the object or scene level. In three experiments, people learned four "views" of a two dimensional visual array derived from a three-dimensional scene. In Experiments 1 and 2, the stimuli were arrays of colored rectangles that preserved the relative sizes, distances, and angles among objects in the original scene, as well as the original occlusion relations. Participants recognized a novel central view more efficiently than any of the Trained views, which in turn were recognized more efficiently than equidistant novel views. Experiment 2 eliminated presentation frequency as an explanation for this effect. Experiment 3 used colored dots that preserved only identity and relative location information, which resulted in a weaker effect, though still one that was inconsistent with both part-based and normalization accounts of recognition. We argue that, for recognition processes to function so effectively with such minimalist stimuli, view combination must be a very general and fundamental mechanism, potentially enabling both visual recognition and categorization.

Learning fine-grained and category information in navigable real-world space.

Spatial judgments are affected by both fine-grained and categorical knowledge. We investigated whether, and how, the two forms of knowledge are learned in real-world, navigable space, as well as the time course of learning each type of knowledge. Participants were Northwestern University undergraduates who estimated the locations of buildings and other landmarks on campus. The Northwestern campus is roughly divided into three regions whose borders are not easy to discern, either from a map or by navigation. Nevertheless, students often refer to these regions linguistically and use them when making housing decisions, choosing classes, and so forth. We found that knowledge of both the fine-grained configuration of locations and the regional distinctions increased with time. However, regional influences on judgments occurred later in students' time on campus. Consequently, computed distances across the nonexistent border between north and south campus locations became more biased with time. The results have implications for understanding how spatial representations develop in navigable environments.

Dice, golf balls, and CDs: assumptions about portion size measurement aids.

PURPOSE: Portion size measurement aids (PSMAs) are used extensively by dietitians. In this cross-sectional, descriptive study, we explored the degree of consistency and concordance between measured and putative volumes of selected household and sport-related PSMAs that are commonly used for nutrition education and dietary assessment. METHODS: An online search of portion size resources yielded several governmental and academic descriptions of household PMSAs (e.g., a compact disc, a nine-volt battery) and sport-related PMSAs (e.g., a golf ball) and their purported dimensions. The spherical items were purchased locally and measured using electronic digital calipers; measurements were then converted to volumes, in millilitres. RESULTS: Overall, we observed a high degree of heterogeneity in how different educational resources related sport-related PSMAs to portion sizes of food. The mean percentage of error between the measured and putative volumes of PSMAs varied considerably. CONCLUSIONS: Our findings indicate that the inaccurate use of PSMAs can lead to systematic bias in nutrition education and misreporting of dietary intake during dietary assessment. Dietitians should exercise caution when using PSMAs because these may not reflect the true portion size they are meant to represent.

Contributions of category and fine-grained information to location memory: when categories don't weigh in.

Several studies have shown that people's memory for location can be influenced by categorical information. According to a model proposed by Huttenlocher, Hedges, and Duncan (1991), people estimate location by combining fine-grained item-level information in memory with category-level information. When the fine-grained information is inexact, category-level information is given greater weight, which leads to biased responses. We manipulated the distribution of locations presented in order to alter the usefulness of category information, and we manipulated background texture in order to alter accuracy of fine-grained memory. The distributional information reduced bias without altering overall accuracy of responding, whereas the background texture manipulation affected accuracy without changing bias. Our results suggest that category information may weigh in only when it is actively processed.

Facilitation by view combination and coherent motion in dynamic object recognition.

We compared the effect of motion cues on people's ability to: (1) recognize dynamic objects by combining information from more than one view and (2) perform more efficiently on views that followed the global direction of the trained views. Participants learned to discriminate two objects that were either structurally similar or distinct and that were rotating in depth in either a coherent or scrambled motion sequence. The Training views revealed 60 degrees of the object, with a center 30 degrees segment missing. For similar stimuli only, there was a facilitative effect of motion: Performance in the coherent condition was better on views following the training views than on equidistant preceding views. Importantly, the viewpoint between the two training viewpoints was responded to more efficiently than either the Pre- or Post-Training viewpoints for both the coherent and scrambled condition. The results indicate that view combination and processing coherent motion cues may occur through different processes.

The role of categories and spatial cuing in global-scale location estimates.

Seven independent groups estimated the location of North American cities using both spatial and numeric response modes and a variety of perceptual and memory supports. These supports included having location markers for each city color coded by nation and identified by name, giving participants the opportunity to see and update all their estimates throughout the task, and allowing them to respond directly on a map. No manipulation mitigated the influence of categories on the judgments, but some manipulations improved within-region ordinal accuracy. The data provide evidence that the city and regional levels are independent, spatial and numeric response modalities affect accuracy differently at the different levels, biases at the regional level have multiple sources, and accurate spatial cues improve estimates primarily by limiting the use of global landmarks to partition the response space. Results support J. Huttenlocher, L. V. Hedges, and S. Duncan's (1991) theory of spatial location estimates and extend it to the domain of real-world geography.

View combination in moving objects: the role of motion in discriminating between novel views of similar and distinctive objects by humans and pigeons.

Humans and pigeons were trained to discriminate between views of similar and distinctive objects that rotated in depth coherently or non-coherently. We tested novel views that were either moving or static and were either between the training viewpoints or beyond them. With both types of motion, both species recognized views between the training viewpoints better than views beyond this range. Additionally, for humans, and to some extent for pigeons, when similar objects were learned via coherent motion, dynamic cues facilitated recognition of viewpoints predictable from the direction of motion. Overall, the results suggest that dynamic information may be added to object representations for both species.

Modulation of viewpoint effects in object recognition by shape and motion cues.

In three experiments, we examined the role of structural similarity and different types of motion on the efficiency of performing same--different shape judgments across changes in viewpoints. In all experiments, participants judged whether two novel, multi-part objects were structurally identical, and they were to ignore any viewpoint or motion differences between the objects. In experiment 1, participants were affected by viewpoint differences more for structurally similar than structurally distinct objects, but this interaction was mitigated by rigid motion. In experiments 2 and 3, we used only structurally similar objects that moved only some of their parts, either in a similar way between objects within a pair or in distinctive ways. Participants' recognition performance was facilitated by this articulated motion relative to both static and scrambled controls. We conclude that coherent motion facilitates generalisation across different views of dynamic objects under some conditions.