Age-Related Changes in Spatial Navigation Are Evident by Midlife and Differ by Sex.

Accumulating evidence suggests that distinct aspects of successful navigation-path integration, spatial-knowledge acquisition, and navigation strategies-change with advanced age. Yet few studies have established whether navigation deficits emerge early in the aging process (prior to age 65) or whether early age-related deficits vary by sex. Here, we probed healthy young adults (ages 18-28) and midlife adults (ages 43-61) on three essential aspects of navigation. We found, first, that path-integration ability shows negligible effects of sex or age. Second, robust sex differences in spatial-knowledge acquisition are observed not only in young adulthood but also, although with diminished effect, at midlife. Third, by midlife, men and women show decreased ability to acquire spatial knowledge and increased reliance on taking habitual paths. Together, our findings indicate that age-related changes in navigation ability and strategy are evident as early as midlife and that path-integration ability is spared, to some extent, in the transition from youth to middle age.

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.

Instructions matter: Individual differences in navigation strategy and ability.

Individual differences in navigation strategy in the dual-solution paradigm (DSP) indicate that some people prefer to take learned routes, while others prefer to take shortcuts (Boone, Gong, & Hegarty, Memory & Cognition, 46, 909-922, 2018; Marchette, Bakker, & Shelton, Journal of Neuroscience, 31, 15264-15268, 2011). Although work using the DSP has highlighted biases toward certain navigation strategies within individuals, a question remains as to why navigators do show a bias. Here, we questioned whether a bias toward navigation by learned routes indicates inability to take shortcuts, or whether other factors are at play, such as task demands and preferences. In two experiments, we began to untangle the association between the ability to construct survey knowledge, which is necessary if one is to take shortcuts (i.e., competence), and navigation strategy (i.e., performance) in virtual-reality navigation. Participants learned a route through a virtual environment and then navigated to goal locations in two experimental sessions. In Experiment 1, each participant navigated under two different instructions ("go to the goal" vs. "take the shortest path to the goal"), whereas in Experiment 2 two groups navigated under the same instructions in both sessions. Converging results from these experiments indicated that participants used more shortcuts overall under the shortcut instructions, and that this was not attributable to additional task exposure. Men were more likely to take shortcuts, under both the standard and shortcut instructions. This work indicates that the use of learned routes in the DSP does not necessarily imply that a person cannot take a shortcut, highlighting a dissociation between strategy and ability.

Sex differences in navigation strategy and efficiency.

Research on human navigation has indicated that males and females differ in self-reported navigation strategy as well as objective measures of navigation efficiency. In two experiments, we investigated sex differences in navigation strategy and efficiency using an objective measure of strategy, the dual-solution paradigm (DSP; Marchette, Bakker, & Shelton, 2011). Although navigation by shortcuts and learned routes were the primary strategies used in both experiments, as in previous research on the DSP, individuals also utilized route reversals and sometimes found the goal location as a result of wandering. Importantly, sex differences were found in measures of both route selection and navigation efficiency. In particular, males were more likely to take shortcuts and reached their goal location faster than females, while females were more likely to follow learned routes and wander. Self-report measures of strategy were only weakly correlated with objective measures of strategy, casting doubt on their usefulness. This research indicates that the sex difference in navigation efficiency is large, and only partially related to an individual's navigation strategy as measured by the dual-solution paradigm.

Measuring configural spatial knowledge: Individual differences in correlations between pointing and shortcutting.

People use environmental knowledge to maintain a sense of direction in daily life. This knowledge is typically measured by having people point to unseen locations (judgments of relative direction) or navigate efficiently in the environment (shortcutting). Some people can estimate directions precisely, while others point randomly. Similarly, some people take shortcuts not experienced during learning, while others mainly follow learned paths. Notably, few studies have directly tested the correlation between pointing and shortcutting performance. We compared pointing and shortcutting in two experiments, one using desktop virtual reality (VR) (N = 57) and one using immersive VR (N = 48). Participants learned a new environment by following a fixed route and were then asked to point to unseen locations and navigate to targets by the shortest path. Participants' performance was clustered into two groups using K-means clustering. One (lower ability) group pointed randomly and showed low internal consistency across trials in pointing, but were able to find efficient routes, and their pointing and efficiency scores were not correlated. The others (higher ability) pointed precisely, navigated by efficient routes, and their pointing and efficiency scores were correlated. These results suggest that with the same egocentric learning experience, the correlation between pointing and shortcutting depends on participants' learning ability, and internal consistency and discriminating power of the measures. Inconsistency and limited discriminating power can lead to low correlations and mask factors driving human variation. Psychometric properties, largely under-reported in spatial cognition, can advance our understanding of individual differences and cognitive processes for complex spatial tasks.

Understanding Differences in Wayfinding Strategies.

Navigating to goal locations in a known environment (wayfinding) can be accomplished by different strategies, notably by taking habitual, well-learned routes (response strategy) or by inferring novel paths, such as shortcuts, from spatial knowledge of the environment's layout (place strategy). Human and animal neuroscience studies reveal that these strategies reflect different brain systems, with response strategies relying more on activation of the striatum and place strategies associated with activation of the hippocampus. In addition to individual differences in strategy, recent behavioral studies show sex differences such that men use place strategies more than women, and age differences such that older adults use more response strategies than younger adults. This paper takes a comprehensive multilevel approach to understanding these differences, characterizing wayfinding as a complex information processing task. This analysis reveals factors that affect navigation strategy, including availability of the relevant type of environmental knowledge, momentary access to this knowledge, trade-offs between physical and mental effort in different navigation contexts, and risk taking. We consider how strategies are influenced by the computational demands of a navigation task and by factors that affect the neural circuits underlying navigation. We also discuss limitations of laboratory studies to date and outline priorities for future research, including relating wayfinding strategies to independent measures of spatial knowledge, and studying wayfinding strategies in naturalistic environments.

Habituation of the stress response multiplex to repeated cold pressor exposure.

Humans show remarkable habituation to aversive events as reflected by changes of both subjective report and objective measures of stress. Although much experimental human research focuses on the effects of stress, relatively little is known about the cascade of physiological and neural responses that contribute to stress habituation. The cold pressor test (CPT) is a common method for inducing acute stress in human participants in the laboratory; however, there are gaps in our understanding of the global state changes resulting from this stress-induction technique and how these responses change over multiple exposures. Here, we measure the stress response to repeated CPT exposures using an extensive suite of physiologic measures and state-of-the-art analysis techniques. In two separate sessions on different days, participants underwent five 90 s CPT exposures of both feet and five warm water control exposures, while electrocardiography (ECG), impedance cardiography, continuous blood pressure, pupillometry, scalp electroencephalography (EEG), salivary cortisol and self-reported pain assessments were recorded. A diverse array of adaptive responses are reported that vary in their temporal dynamics within each exposure as well as habituation across repeated exposures. During cold-water exposure there was a cascade of changes across several cardiovascular measures (elevated heart rate (HR), cardiac output (CO) and Mean Arterial Pressure (MAP) and reduced left ventricular ejection time (LVET), stroke volume (SV) and high-frequency heart rate variability (HF)). Increased pupil dilation was observed, as was increased power in low-frequency bands (delta and theta) across frontal EEG electrode sites. Several cardiovascular measures also habituated over repeated cold-water exposures (HR, MAP, CO, SV, LVET) as did pupil dilation and alpha frequency activity across the scalp. Anticipation of cold water induced stress effects in the time-period immediately prior to exposure, indexed by increased pupil size and cortical disinhibition in the alpha and beta frequency bands across central scalp sites. These results provide comprehensive insight into the evolution of a diverse array of stress responses to an acute noxious stressor, and how these responses adaptively contribute to stress habituation.

Developmental change in the nature of attention allocation in a dual task.

Younger children have more difficulty in sharing attention between two concurrent tasks than do older participants, but in addition to this developmental change, we documented changes in the nature of attention sharing. We studied children 6-8 and 10-14 years old and college students (in all, 104 women and 76 men; 3% Hispanic, 3% Black or African American, 3% Asian, 7% multiracial, and 84% White). On each dual-task trial, the participant received an array of colored squares to be retained for a subsequent probe recognition test and then an easy or more difficult signal requiring a quick response (a speeded task, clicking a key on the same side of the screen as the signal or the opposite side). Finally, each trial ended with the presentation of the array item recognition probe and the participant's response to it. In our youngest age group (6-8 years), array memory was often displaced by the speeded task performed under load, especially when it was the opposite-side task, but speeded-task accuracies were unaffected by the presence of an array memory load. In contrast, in older participants (10-14 years and college students), the memory load was maintained better, with some cost to the speeded task. With maturity, participants were better able to adopt a proactive stance in which not only present processing demands but also upcoming demands were taken into account, allowing them to balance the demands of the two tasks. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Explicit versus actionable knowledge: The influence of explaining graphical conventions on interpretation of hurricane forecast visualizations.

Visualizations of uncertainty in data are often presented to the public without explanations of their graphical conventions and are often misunderstood by nonexperts. The "cone of uncertainty" used to visualize hurricane forecasts is a case in point. Here we examined the effects of explaining graphical conventions on understanding of the cone of uncertainty. In two experiments, participants were given instructions with and without an explanation of these graphical conventions. We examined the effect of these instructions on both explicit statements of common misconceptions and users interpretation of hurricane forecasts, specifically their predictions of damage from the hurricane over space and time. Enhanced instructions reduced misconceptions about the cone of uncertainty as expressed in explicit beliefs, and in one experiment also reduced predictions of damage overall. Examination of individual response profiles for the damage estimate task revealed qualitative differences between individuals that were not evident in aggregate response profiles. This research reveals mixed results for the effectiveness of instructions on comprehension of uncertainty visualizations and suggests a more nuanced approach that focuses on the individual's knowledge and beliefs about the domain and visualization. (PsycINFO Database Record

Sex differences in mental rotation tasks: Not just in the mental rotation process!

The paper-and-pencil Mental Rotation Test (Vandenberg & Kuse, 1978) consistently produces large sex differences favoring men (Voyer, Voyer, & Bryden, 1995). In this task, participants select 2 of 4 answer choices that are rotations of a probe stimulus. Incorrect choices (i.e., foils) are either mirror reflections of the probe or structurally different. In contrast, in the mental rotation experimental task (Shepard & Metzler, 1971) participants judge whether 2 stimuli are the same but rotated or different by mirror reflection. The goal of the present research was to examine sources of sex differences in mental rotation, including the ability to capitalize on the availability of structure foils. In 2 experiments, both men and women had greater accuracy and faster reaction times (RTs) for structurally different compared with mirror foils in different versions of the Vandenberg and Kuse Mental Rotation Test (Experiment 1) and the Shepard and Metzler experimental task (Experiment 2). A significant male advantage in accuracy but not response time was found for both trial types. The male advantage was evident when all foils were structure foils so that mental rotation was not necessary (Experiment 3); however, when all foils were structure foils and participants were instructed to look for structure foils a significant sex difference was no longer evident (Experiment 4). Results suggest that the mental rotation process is not the only source of the sex difference in mental rotation tasks. Alternative strategy use is another source of sex differences in these tasks. (PsycINFO Database Record

Uncertainty Visualization by Representative Sampling from Prediction Ensembles.

Data ensembles are often used to infer statistics to be used for a summary display of an uncertain prediction. In a spatial context, these summary displays have the drawback that when uncertainty is encoded via a spatial spread, display glyph area increases in size with prediction uncertainty. This increase can be easily confounded with an increase in the size, strength or other attribute of the phenomenon being presented. We argue that by directly displaying a carefully chosen subset of a prediction ensemble, so that uncertainty is conveyed implicitly, such misinterpretations can be avoided. Since such a display does not require uncertainty annotation, an information channel remains available for encoding additional information about the prediction. We demonstrate these points in the context of hurricane prediction visualizations, showing how we avoid occlusion of selected ensemble elements while preserving the spatial statistics of the original ensemble, and how an explicit encoding of uncertainty can also be constructed from such a selection. We conclude with the results of a cognitive experiment demonstrating that the approach can be used to construct storm prediction displays that significantly reduce the confounding of uncertainty with storm size, and thus improve viewers' ability to estimate potential for storm damage.

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

On the Use of Response Chunking as a Tool to Investigate Strategies.

In this perspective we suggest that chunking can be used as an investigative tool to determine the characteristics of other cognitive phenomena. We present an example of the usefulness of chunking multiple responses to aid in understanding object switch costs. Switch costs refer to the shorter response times for manipulation of the same item on two trials in a row compared to a switch between items. It is presently unclear if this result is due to structural or strategic processes. We provide a short review of past literature on switch costs and a proof-of-concept example that chunking may shed new light on this topic. We examined this question with boxes filled with numbers to be arithmetically updated and memorized. A situation in which there were two response items to be manipulated per trial eliminated or reversed the switch cost effect. We suggest that participants use a strategy in which the two output responses were chunked together, making it unfeasible to prepare separately for a repetition of the most recent item as participants do in other circumstances. Our data suggest that even a well-studied phenomenon can benefit theoretically from the use of chunking as a research tool.