Considering environmental factors, navigation strategies, and age

Sex differences in navigation have been a topic of investigation for decades and has been subjected to various contradictory findings and debates. The aim of this work was to compare the spatial memory of men and women tested in various different types of spatial tasks, while controlling for navigation strategies and aging. It is generally thought that men outperform women in navigation and that women have higher scores on object location tasks. However, many studies fail to control for different factors that may bias one sex or the other. We aggregated the data of 465 participants (349 young adults, 127 older adults) who took part in various studies conducted in our laboratory, which include both published and original unpublished data, in order to investigate sex differences. In these studies, we used a number of different paradigms: virtual radial arm mazes, a virtual wayfinding task, an object location task, a virtual Morris Water Maze, and the invisible sensor task which is a real-life model of the Morris Water Maze. While our results may seem discordant at first glance, they demonstrate that several factors can impact the performance of men and women on spatial tasks, including spontaneous navigation strategies, environmental characteristics, and age. We replicated findings showing that women favor proximal landmarks compared to men who favor distal landmarks, women have better memory than men for the position of objects in the absence of reference frames, but they will have poorer scores when navigation requires specific angles, distances and polar coordinates. Moreover, we found that in aging, women who avoid the use of landmarks when navigating a radial maze show stronger reliance on these non-spatial strategies than men. On the other hand, women who rely on landmarks, do so to the same extent as men. Our findings highlight the need to carefully take into consideration these factors in order to produce a more harmonious understanding of sex differences in navigation. Finally, the interaction between spontaneous navigation strategies, sex, and age is discussed in terms of its implications for risk of Alzheimer’s disease

Spatial navigational strategies correlate with grey matter in the hippocampus of healthy older adults tested in a virtual maze

Healthy young adults use different strategies when navigating in a virtual maze. Spatial strategies involve using environmental landmarks while response strategies involve executing a series of movements from specific stimuli. Neuroimaging studies previously confirmed that people who use spatial strategies show increased activity and grey matter in the hippocampus, while those who use response strategies show increased activity and grey matter in caudate nucleus (Bohbot, Lerch, Thorndycraft, Iaria, & Zijdenbos, 2007; Iaria, Petrides, Dagher, Pike, & Bohbot, 2003). A growing number of studies report that cognitive decline that occurs with normal aging is correlated with a decrease in volume of the hippocampus. Here, we used voxel-based morphometry to examine whether spatial strategies in aging are correlated with greater grey matter in the hippocampus, as found in our previous study with healthy young participants. Forty-five healthy older adults were tested on a virtual navigation task that allows spatial and response strategies. All participants learn the task to criterion after which a special probe trial that assesses spatial and response strategies is given. Results show that spontaneous spatial memory strategies, and not performance on the navigation task, positively correlate with grey matter in the hippocampus. Since numerous studies have shown that a decrease in the volume of the hippocampus correlates with cognitive deficits during normal aging and increases the risks of ensuing dementia, the current results suggest that older people who use their spatial memory strategies in their everyday lives may have increased grey matter in the hippocampus and enhance their probability of healthy and successful aging

Stop and look! Evidence for a bias towards virtual navigation response strategies in children with ADHD symptoms

Studies in children show that the development of spatial competence emerges between seven and eight years of age. Multiple memory systems (hippocampus-dependent spatial and caudate nucleus-dependent response learning) are involved in parallel processing of information during navigation. As a hippocampus-dependent spatial strategy also relies on frontoparietal executive control and working memory networks that are impaired in ADHD, we predicted that children will be more likely to adopt a response strategy as they exhibit ADHD symptoms. We tested 285 healthy children on a virtual radial-arm maze paradigm in order to test this hypothesis. We found that children displaying at least one ADHD symptom were more likely to have a perfect performance on a probe trial, which suggests that they did not rely on environmental landmarks. Children with ADHD symptoms may primarily rely on caudate nucleus-dependent response learning strategies at the expense of hippocampus-dependent spatial strategies. Repetition and reward based learning strategies, which are hallmarks of response learning, may be most effective in children exhibiting ADHD symptoms

Stop and look! Evidence for a bias towards virtual navigation response strategies in children with ADHD symptoms

Studies in children show that the development of spatial competence emerges between seven and eight years of age. Multiple memory systems (hippocampus-dependent spatial and caudate nucleus-dependent response learning) are involved in parallel processing of information during navigation. As a hippocampus-dependent spatial strategy also relies on frontoparietal executive control and working memory networks that are impaired in ADHD, we predicted that children will be more likely to adopt a response strategy as they exhibit ADHD symptoms. We tested 285 healthy children on a virtual radial-arm maze paradigm in order to test this hypothesis. We found that children displaying at least one ADHD symptom were more likely to have a perfect performance on a probe trial, which suggests that they did not rely on environmental landmarks. Children with ADHD symptoms may primarily rely on caudate nucleus-dependent response learning strategies at the expense of hippocampus-dependent spatial strategies. Repetition and reward based learning strategies, which are hallmarks of response learning, may be most effective in children exhibiting ADHD symptoms

Caudate nucleus-dependent navigational strategies are associated with increased use of addictive drugs

ABSTRACT: This study aimed to investigate the relationship between navigational strategies and the use of abused substances in a sample of healthy young adults. Navigational strategies were assessed with the 4-on-8 virtual maze (4/8VM), a task previously shown to dissociate between hippocampal-dependent spatial navigational strategies and caudate nucleus-dependent stimulus-response navigational strategies. Spatial strategies involve learning the spatial relationships between the landmarks in an environment, while response learning strategies involve learning a rigid set of stimulus-response type associations, e.g., see the tree, turn left. We have shown that spatial learners have increased gray matter and fMRI activity in the hippocampus compared with response learners, while response learners have increased gray matter and fMRI activity in the caudate nucleus. We were interested in the prevalence of use of substances of abuse in spatial and response learners because of the evidence that people who score high on traits such as novelty seeking, sensation seeking, reward seeking, and impulsivity, are more cue-responsive and more likely to use substances of abuse. Since response learners show increased activity and gray matter in the caudate nucleus of the striatum, which is a brain area involved in addiction, we hypothesized that response learners would have a greater use of abused substances than spatial learners. Fifty-five young adults were tested on the 4/8VM and completed a time-line follow-back assessment of drug and alcohol use. We found that response learners had smoked a significantly greater number of cigarettes in their lifetime than spatial learners, were more likely to have used cannabis, and had double the lifetime alcohol consumption. We discuss the possible relationship between substance abuse and response strategies as well as the implications for the hippocampus, risks of neurological and psychiatric disorders, and healthy cognition

Stop and look! Evidence for a bias towards virtual navigation response strategies in children with ADHD symptoms

Studies in children show that the development of spatial competence emerges between seven and eight years of age. Multiple memory systems (hippocampus-dependent spatial and caudate nucleus-dependent response learning) are involved in parallel processing of information during navigation. As a hippocampus-dependent spatial strategy also relies on frontoparietal executive control and working memory networks that are impaired in ADHD, we predicted that children will be more likely to adopt a response strategy as they exhibit ADHD symptoms. We tested 285 healthy children on a virtual radial-arm maze paradigm in order to test this hypothesis. We found that children displaying at least one ADHD symptom were more likely to have a perfect performance on a probe trial, which suggests that they did not rely on environmental landmarks. Children with ADHD symptoms may primarily rely on caudate nucleus-dependent response learning strategies at the expense of hippocampus-dependent spatial strategies. Repetition and reward based learning strategies, which are hallmarks of response learning, may be most effective in children exhibiting ADHD symptoms