UCL researchers have found that the more connected a street, the higher the level of activity in the brain (Credit: Joao Pinelo Silva) 
 
 For anyone who finds reading maps or asking for directions troublesome, GPS might seem like a godsend – that is, until it leads you to the middle of nowhere thanks to a satellite error. However, apart from occasionally leading drivers astray, researchers at University College London (UCL) suggest that simply following instructions given by your navigational app could have another negative effect: allowing parts of your brain to go dormant. 
 
 In the UCL study, 24 volunteers were taken on a two-hour walking tour of London's Soho neighborhood and shown 23 goal locations. The next day, the researchers tested navigation by showing each volunteer 10 simulations of routes through Soho. After being given a specific starting point, they had to navigate their way through the simulation to get to a goal location. Five of the movies required participants to make navigational decisions while the other half functioned like a GPS unit, merely directing the participants on which buttons to push to make turns. 
 
 
 
 An example of the navigational decisions volunteers had to make (Credit: UCL) 
 
 The researchers found that there was a spike in hippocampal and prefrontal cortex activity when volunteers navigated and entered new streets on their own. This shot up even further when the number of navigational options increased when participants were in an area with several street segments. In contrast, no additional activity was detected when they simply followed the instructions given to them, a situation not dissimilar to driving based on the directions from your GPS unit. 
 
 "Entering a junction such as Seven Dials in London, where seven streets meet, would enhance activity in the hippocampus, whereas a dead-end would drive down its activity," explains senior author Hugo Spiers, a neuroscientist at UCL Experimental Psychology. "If you are having a hard time navigating the mass of streets in a city, you are likely putting high demands on your hippocampus and prefrontal cortex." 
 
 These results corroborate that of previous studies, including one by Cornell University researchers that found GPS causes drivers to disengage from and ignore their environment. 
 
 "Our results fit with models in which the hippocampus simulates journeys on future possible paths while the prefrontal cortex helps us to plan which ones will get us to our destination," says Spiers, who was involved in an earlier UCL study focusing on London taxi drivers. That study showed that the hippocampi of would-be taxi drivers expand as they memorize 25,000 of London' streets in order to pass the Knowledge, dubbed the world's hardest geography test. According to that study, London cabbies, especially those with decades of experience, have more grey matter in that region of the brain than most other people. 
 
 "When we have technology telling us which way to go, however, these parts of the brain simply don't respond to the street network," said Spiers. "In that sense our brain has switched off its interest in the streets around us." 
 
 Better buildings 
 
 The team also analyzed the street networks of other major cities to gauge their navigability and potential impact on the brain's memory systems. They found that those with grid layouts, such as Manhattan, are less strenuous on the hippocampus than cities with a complex network, such as London, since there are only three options at most junctions: straight, left or right. These findings are important, as the information could be used to design better care centers and hospitals. 
 
 "For example, we could look at the layouts of care homes and hospitals to identify areas that might be particularly challenging for people with dementia and help to make them easier to navigate," says Spiers. "Similarly, we could design new buildings that are dementia-friendly from the outset." 
 
 The study was published in Nature Communications. 
 
 Source: UCL ||||| If you've ever thought of your smartphone as your second brain, your analogy may not be far off. A new study shows that when we follow navigational instructions, such as those given by GPS devices, the parts of our actual brains that normally perform navigation remain quiet. 
 
 The findings show that "you delegate the task of navigation to your GPS, and you merely follow the directions, which is yet a demanding task, but perhaps not as demanding as actual route planning," said the study's first author, Amir-Homayoun Javadi, a neuroscientist at the University of Kent in the U.K. 
 
 This might mean that, over time, humans will get worse and worse at using their brains for pathfinding, Javadi told Live Science. [10 Things You Didn't Know About the Brain] 
 
 Our brain's inner GPS is one of the most prized wonders of the brain. The discovery of specialized nerve cells in the brains of mice that register where in the space the animals are has led to the Nobel Prize in Physiology or Medicinein 2014. 
 
 Those cells reside in a brain structure called the hippocampus. Numerous studies have shown we rely on the hippocampus for storing and recalling memories, planning future steps and generally finding our way in the world. 
 
 In the study, published today (March 21) in the journal Nature Communications, the researchers examined how the brain maps out the network of streets, plans for journeys and deals with unexpected detours. 
 
 Twenty-four participants navigated a simulation of the Soho area of central London while their brain activity was being monitored in a scanner. 
 
 In some trials, the participants had to find their way to a destination by indicating a left or right turn at every junction. In others, they simply had to push a button to follow the optimized path decided by the computer.The researchers analyzed the activity patterns in each participant's hippocampus, as well as the prefrontal cortex, which is involved in planning and decision-making. 
 
 They found that when the participants had to navigate by themselves, without the help of GPS, the activity of the hippocampus and prefrontal cortex closely matched the decisions they had to make. For example, when they entered a new street, the hippocampus activity indicated that the brain was tracking changes in the number of available paths that they could take from there. When forced to make a detour, people's prefrontal activity spiked, showing increased activity in line with the difficulty of planning a new route. 
 
 However, when the participants followed the computer's instructions to navigate through the area, they did not activate these brain areas as much, the researchers found. [6 Foods That Are Good For Your Brain 
 
 "Our results fit with models in which the hippocampus simulates journeys on future possible paths, while the prefrontal cortex helps us to plan which ones will get us to our destination," said Hugo Spiers, a researcher at University College London's Institute of Behavioural Neuroscience, who led the study. "When we have technology telling us which way to go, however, these parts of the brain simply don't respond to the street network. In that sense, our brain has switched off its interest in the streets around us." 
 
 The consequences of using tools instead of our brains are not necessarily all negative, however. By delegating a demanding mental task to a device, you may free up mental resources to serve other purposes. 
 
 "It can be a shift in skills," Javadi told Live Science. 
 
 In fact, children who grow up with smartphones may develop a different set of skills from the generations of people who first learned to navigate their surroundings naturally, or to memorize information instead of looking up everything online. 
 
 Insights from research suggest that for today’s children, "their whole brain, not only their hippocampus, develops differently," Javadi said. "The brain constantly changes to adapt to different environments, needs and opportunities. Now imagine these environments, needs and opportunities are totally different since birth." 
 
 These changes, however, do not mean that children will not activate their hippocampus for navigation anymore, Javadi said. They might have a GPS for the streets, but they still need to navigate the labyrinths of the internet. 
 
 Original article on Live Science. ||||| The brain contains a built-in GPS that relies on memories of past navigation experiences to simulate future ones. But how does it represent new environments in order to determine how to navigate them successfully? And what happens in the brain when we enter a new space, or use satellite navigation (SatNav) technology to help us find our way around? 
 
 Research published Tuesday in Nature Communications reveals two distinct brain regions that cooperate to simulate the topology of one’s environment and plan future paths through it when one is actively navigating. In addition, the research suggests both regions become inactive when people follow SatNav instructions instead of using their spatial memories. 
 
 In a previous study researchers at University College London took participants on a guided tour through the streets of London’s Soho district and then used functional magnetic resonance imaging (fMRI) to scan their brains as they watched 10 different simulations of navigating those streets. Some of the movies required them to decide at intersections which way would be the shortest path to a predetermined destination; others came with instructions about which way to go at each junction. 
 
 The researchers found that a brain structure called the hippocampus, which is involved in both memory and spatial navigation, appears to encode two different maps of the environment: One tracks the distance to the final destination as the crow flies and is encoded by the frontal region of the hippocampus, the other tracks the “true path” to the goal and is encoded by its rear region. 
 
 During the navigation tasks, the hippocampus acts like a flexible guidance system, flipping between these two maps according to changing demands. Activity in the hippocampal rear region acts like a homing signal, increasing as the goal gets closer. 
 
 For this new study, the researchers analyzed the layout of the streets in the movie simulations and calculated various measures for each one, such as how many other streets it is connected to and how close it is to the center of street network. They also reexamined the fMRI data from their earlier study, to look at the brain activity that occurred whenever the participants turned onto a new street. 
 
 Analysis of the brain-scanning data revealed activity in the rear right of the hippocampus increased whenever the participants entered a new street while navigating. It also varied with the number of new path options available. The more alternatives there were, the greater the brain activity. 
 
 The researchers also found that activity in the front of the hippocampus was associated with a property called centrality, defined by the proximity of each new street to the center of the network. Further, they observed activity in the participants’ prefrontal cortices when they were forced to make a detour and had to replan their route—and this, too, increased in relation to the number of options available. Intriguingly, when participants followed SatNav instructions, however, brain activity in these regions “switched off.” 
 
 Together, the new findings suggest the rear portion of the hippocampus reactivates spatial memories of possible navigation paths, with more available paths evoking more activity, and that the prefrontal cortex may contribute to path-planning by searching though different route options and selecting the best one. 
 
 Aidan Horner, a cognitive neuroscientist who studies memory and navigation at the University of York in England but was not involved in the work, praised the study. “This is a really interesting, novel approach to understanding how the hippocampus and prefrontal cortex contribute to spatial navigation and planning,” he wrote in an e-mail. The finding “aligns with the idea that the hippocampus not only represents our spatial environment but is also actively involved in simulating possible future paths.” What the study doesn’t show, he noted, is how the hippocampus performs such a simulation. 
 
 “There have been hundreds of papers about simulating the future, but nobody's looked at it in the context of spatial navigation,” says Hugo Spiers, senior author of the study. The neuroscientist was involved in a series of well-known studies that showed the hippocampus’s rear region is enlarged in London taxi drivers, and the extent of the increase is directly related to the driver’s experience. “The upshot of this [new] study is that the activity we saw at the back of the right hippocampus fits with theories that it’s simulating possibilities of paths to travel,” he says. The findings could aid in designing “spaces that are easier to navigate and increase well-being” and, because declining spatial navigation ability is among the earliest symptoms of Alzheimer’s disease, could facilitate the design of “new buildings that are dementia-friendly,” he adds. 
 
 Spiers is cautious about the observation that these brain regions were inactive when participants used SatNav instructions, however. “We found that you only engage the hippocampus and frontal areas when you’re using your memory of the environment to navigate, but this is just a one-off study, so we don’t know the long-term consequences of using SatNav.” 
 
 “If you think about the brain as a muscle, then certain activities, like learning maps of London’s streets, are like bodybuilding,” he says, “and all we can really say from our new findings is that you’re not working out these particular bits of the brain when you’re relying on SatNav.” ||||| It's been well established that men perform better than women when it comes to specific spatial tasks. But how much of that is linked to sex hormones versus cultural conditioning and other factors? 
 
 Researchers at the Norwegian University of Science and Technology (NTNU) decided to explore this idea by administering testosterone to women and testing how they performed in wayfinding tasks in a virtual environment. 
 
 Using fMRI, the researchers saw that men in the study took several shortcuts, oriented themselves more using cardinal directions and used a different part of the brain than the women in the study. 
 
 But when women got a drop of testosterone under their tongue, several of them were able to orient themselves better in the four cardinal directions. 
 
 "Men's sense of direction was more effective. They quite simply got to their destination faster," says Carl Pintzka, a medical doctor and PhD candidate at NTNU's Department of Neuroscience. 
 
 The directional sense findings are part of his doctoral thesis on how the brain functions differently in men and women. 
 
 Puzzle solving in a 3D maze 
 
 Pintzka used an MRI scanner to see whether there are any differences in brain activity when men and women orient themselves. Using 3D goggles and a joystick, the participants had to orient themselves in a very large virtual maze while functional images of their brains were continuously recorded. 
 
 Eighteen men and 18 women first took an hour to learn the layout of the maze before the scanning session. In the MRI scanner, they were given 30 seconds for each of the 45 navigation tasks. One of the tasks, for example, was to "find the yellow car" from different starting points. 
 
 Women often use a route 
 
 The men solved 50 per cent more of the tasks than the women. 
 
 According to Pintzka, women and men have different navigational strategies. Men use cardinal directions during navigation to a greater degree. 
 
 "If they're going to the Student Society building in Trondheim, for example, men usually go in the general direction where it's located. Women usually orient themselves along a route to get there, for example, 'go past the hairdresser and then up the street and turn right after the store'," he says. 
 
 The study shows that using the cardinal directions is more efficient because it is a more flexible strategy. The destination can be reached faster because the strategy depends less on where you start. 
 
 Women have better local memory 
 
 fMRI images of the brain showed that both men and women use large areas of the brain when they navigate, but some areas were different. The men used the hippocampus more, whereas women used their frontal areas to a greater extent. 
 
 "That's in sync with the fact that the hippocampus is necessary to make use of cardinal directions," says Pintzka. 
 
 He explains the findings in evolutionary terms. 
 
 "In ancient times, men were hunters and women were gatherers. Therefore, our brains probably evolved differently. For instance, other researchers have documented that women are better at finding objects locally than men. In simple terms, women are faster at finding things in the house, and men are faster at finding the house," Pintzka says. 
 
 A little testosterone under the tongue 
 
 Step two was to give some women testosterone just before they were going to solve the maze puzzles. 
 
 This was a different group of women than the group that was compared to men. In this step, 42 women were divided into two groups. Twenty-one of them received a drop of placebo, and 21 got a drop of testosterone under the tongue. The study was double-blinded so that neither Pintzka nor the women knew who got what. 
 
 "We hoped that they would be able to solve more tasks, but they didn't. But they had improved knowledge of the layout of the maze. And . And they used the hippocampus to a greater extent, which tends to be used more by men for navigating," says Pintzka. 
 
 Losing one's sense of direction is one of the first symptoms in Alzheimer's disease. 
 
 "Almost all brain-related diseases are different in men and women, either in the number of affected individuals or in severity. Therefore, something is likely protecting or harming people of one sex. Since we know that twice as many women as men are diagnosed with Alzheimer's disease, there might be something related to sex hormones that is harmful," says Pintzka. 
 
 He hopes that by understanding how men and women use different brain areas and strategies to navigate, researchers will be able to enhance the understanding of the disease's development, and develop coping strategies for those already affected. 
 
 ### 
 
 Reference: Changes in spatial cognition and brain activity after a single dose of testosterone in healthy women. Carl W.S. Pintzka et al. Behavioral Brain Research, Vol. 298, Part B, 1 February 2016, Pages 78-90.
– Maybe this helps explain why people drive into lakes because of their GPS. A study in Nature suggests that parts of our brain switch off when navigating with it. Indeed, as more and more people rely on GPS, the human ability to navigate as a whole could suffer, researchers at University College London tell Live Science. They took volunteers on a tour of London's Soho district, then recorded their brain activity as they completed 10 video simulations requiring them to navigate those streets. In five simulations the volunteers navigated alone, leading to increased activity in the parts of the brain responsible for route planning, especially when at junctions. But when they were given directions, a la GPS, these parts of the brain essentially turned off, reports New Atlas. "The hippocampus simulates journeys on future possible paths while the prefrontal cortex helps us to plan which ones will get us to our destination," study author Hugo Spiers explains. "When we have technology telling us which way to go, however, these parts of the brain simply don't respond." This study backs up research suggesting GPS causes people to ignore their surroundings. But researchers say there could be greater implications to a reliance on GPS. Spiers describes the brain as a muscle and navigating London as "bodybuilding," per Scientific American. Using GPS means the brain doesn't get its exercise, he says. A researcher theorizes that the hippocampus may begin to develop differently in humans over time. (Just hope GPS doesn't put you up a pole.)