Gray Matter Differences Correlate with Spontaneous Strategies in a Human Virtual Navigation Task

Abstract

Young healthy participants spontaneously use different strategies in a virtual radial maze, an adaptation of a task typically used with rodents. Functional magnetic resonance imaging confirmed previously that people who used spatial memory strategies showed increased activity in the hippocampus, whereas response strategies were associated with activity in the caudate nucleus. Here, voxel based morphometry was used to identify brain regions covarying with the navigational strategies used by individuals. Results showed that spatial learners had significantly more gray matter in the hippocampus and less gray matter in the caudate nucleus compared with response learners. Furthermore, the gray matter in the hippocampus was negatively correlated to the gray matter in the caudate nucleus, suggesting a competitive interaction between these two brain areas. In a second analysis, the gray matter of regions known to be anatomically connected to the hippocampus, such as the amygdala, parahippocampal, perirhinal, entorhinal and orbitofrontal cortices were shown to covary with gray matter in the hippocampus. Because low gray matter in the hippocampus is a risk factor for Alzheimer's disease, these results have important implications for intervention programs that aim at functional recovery in these brain areas. In addition, these data suggest that spatial strategies may provide protective effects against degeneration of the hippocampus that occurs with normal aging.

Differences in navigation performance and postpartal striatal volume associated with pregnancy in humans

“…We also observed group differences in the proportion of hippocampal over striatal volumes that were positively associated correlated with allocentric task performance. These associations are in line with previous findings in human neuroimaging studies, showing that striatal activity and volume correlates with (egocentric) response learning and hippocampal activity and volume with (allocentric) place learning (Bohbot, Lerch, Thorndycraft, Iaria, & Zijdenbos, 2007;Hartley, Maguire, Spiers, & Burgess, 2003;Iaria et al, 2003;Voermans et al, 2004). The absence of a correlation between brain structure and performance when looking at the peripartal group highlight the need for further research and replication.…”

Social targets improve body-based and environment-based strategies during spatial navigation

“…The social group, therefore, did not show a preference towards the use of idiothetic cues. Our results suggest that individual differences in weighting of idiothetic and allothetic cues are not dependent on the encoded target (that is, object or person), but may rather depend on other factors such as individual age (Nardini et al 2008), the subjective noise level and reliability of sensory inputs (Cheng et al 2007;Chen et al 2017), anatomical variability in key structures of the navigation network (Bohbot et al 2007), or individual preferences in spatial encoding strategies (Gramann et al 2005(Gramann et al , 2006.…”

“…Both processes activate distinct and partly separate neuronal networks: whereas idiothetic encoding involves, in addition to subcortical structures, the posterior parietal cortex, in particular areas 7a and VIP (Britten 2008), allothetic encoding is assumed to be primarily supported by grid and place cells in the entorhinal-hippocampal network (Ono et al 1991;Hafting et al 2005). In everyday life, idiothetic-and allothetic-encoding strategies are usually combined, and there are individual differences with respect to which strategy is preferred (Wolbers and Hegarty 2010;Bohbot et al 2007). There is also evidence that both cue types are combined and weighted in a near to optimal fashion based on Bayesian principles (Cheng et al 2007;Nardini et al 2008;Chen et al 2017).…”

Applications of Virtual Reality Technology in Brain Imaging Studies

“…Various brain correlates were attributed to different cognitive strategies during spatial navigation. The hippocampus was specifically more involved in spatial strategy, and the caudate nucleus more associated with a non-spatial strategy [23,25].…”

“…Participants could navigate through the virtual environment with the use of keyboard, control pad, joystick, or mouse. The most frequently used virtual environment is the virtual maze, in which participants were instructed to learn and recall the topographical information to locate a target object or to find their way out of the maze [22][23][24][25][26][27]. Another frequently used virtual environment is a complex virtual town, in which participants were asked to freely navigate the environment first and later they were required to either head directly toward the goal location or follow a trail of arrows [28][29][30][31].…”