Navigation
4/08
Welcome to Week 10 - Let's navigate Navigation!
Looking for the link to your Zoom Classroom? At the top of this page is a tab, The Zoom Classroom. Click on it, and then scroll down to the second row with the list of classes with days and times. Click on the name of the instructor and you will be taken directly into the Zoom class.
If you were unable to attend our zoom lessons, you can watch a recorded lesson by clicking HERE
Navigation in the Brain
As we are aware, each person’s ability to navigate through space varies widely. Some of us have no trouble finding our way around a new environment by recognizing familiar landmarks. Others may be successful as long as they have a map. And then some of us are navigationally challenged, lucky to find our way out of a paper bag! In this lesson, we will explain the types of memory systems involved when we navigate, investigate how spatial knowledge is represented and organized, and what parts of the brain is activated when we are trying to reach our destination. Lastly, we will also look at what type of an impact technology may have on our navigation skills.
Memory Systems During Navigation
There are two types of memory systems at work during navigation. One is allocentric navigation, which uses spatial knowledge or information about the location of key landmarks to help develop a mental map of the environment. This type of navigation uses regions of the brain that are critical to new learning and memory. The second type of memory system is egocentric navigation, which refers to a fixed, first-person perspective. This type of navigation is based on direction (left-right) responses and actions independent of environmental cues. For example, memorizing routes based on sequential turns is an egocentric strategy (Grech, 2018).
The egocentric approach uses areas of the brain that are important for “automatic” responses, and are relatively unaffected by age. However, allocentric navigation declines with age, which can increase the risk of becoming disoriented or lost, even in familiar areas.
Research from Harvard demonstrated individual differences in visualization abilities. For example, how we process information about the appearance of an object based on its shape, color, or texture called object visualization is different than spatial visualization, which describes how we process information about the space or distance between two or more objects. And spatial visualization can be further divided into "allocentric" and "egocentric." All of these abilities work together to determine your talent in navigating the real world. The study went further to predict what type of talents might be seen by people who exhibit strengths in one or more of the areas. The diagram below illustrates these findings (Development of Spatial Ability Tests, 2014).
How do you do on "Right Turn" in Brain HQ? This navigation exercise was originally developed as a test by researchers, Shepard and Metzler in early 70's. It measures your ability to mentally transform an object into another angle or viewpoint; thus, giving you a different spatial perspective. If this activity gives you trouble, it may indicate that you need to improve your allocentric navigational abilities (Development of Spatial Ability Tests, 2014).
Spatial Cognition and the Brain: Do you know where you are at?
Spatial cognition is an area of study that has become increasingly important, because of its practical significance in our everyday life (Ahmadpoor and Shahab, 2019). People use spatial knowledge to get from home to work, plan their trips between different places, and possibly give navigational directions to others. Examples of this knowledge stored in the brain are the name of places, distances, direction and relational organization between places. And this information stored in the brain determines people's behavior in the environment. In other words, people's behavior is generated by their spatial knowledge or mental representation of the physical environment. Acquiring spatial knowledge is crucial for adapting to new environments; otherwise, people will walk around in endless circles, never finding where they want to go.
In BrainHQ, the Mental Map activity challenges you to remember the relative location of two objects in a grid. You will need to reconstruct the grid from memory when it is rotated, flipped, or moved in different directions (up, down, right or left). Why would this be important? The objects serve as landmarks that provide information about your surrounding and the direction where you may need to go. When we move around, we perceive the environment around us, acquire knowledge about it, such as landmarks, and modify the information we've collected to help us reach our destination. In order to use landmark information effectively, you will need to create a mental map and remember the relative locations of important objects. The process of acquiring spatial knowledge that happens in people's every day life is referred to "cognitive mapping" (Gibbons, 2019). This is important because we certainly don't want to get lost, if we find ourselves entering a new scene from a different direction.
Cognitive Mapping in the Brain
The term cognitive mapping is a general term to explain how the brain process information about real physical environments. Cognitive maps are incomplete, segmented, and distorted internal representations of the environment (Ahmadpoor and Shahab, 2019). How so? The physical environment keeps getting updated, so what we see is merely a snapshot of "the state" of our spatial knowledge, and it will get changed as time goes on. For example, the road you drive to work daily is suddenly under construction to be widened out and you see a temporary lane to highlight work zones and realigned lanes. Even without construction changes, cognitive maps can help us make decision if information may be missing (such as the names of every street) when finding our way around a new surrounding. For example, using landmarks that cite a specific geographical location; i.e., at the intersection of Scripps Poway Parkway and Community Road there is an In-N-Out Burger two blocks from Vertical Hold, a rock climbing gym (destination goal).
Before and After: The Power of Designing with Pedestrians in Mind (Gaete, 2015).
You can see more examples here.
Obviously, people cannot fully comprehend the spatial layout of a large-scale environment, such as San Francisco downtown in its entirety from one view-point. But they should explore the area and integrate the spatial knowledge acquired from different viewpoints by either walking or driving experiences. This establishes a route knowledge that contains landmarks and related navigational decisions (e.g., go straight for two blocks and turn right at that landmark). If you don't see that particular landmark or sequence of landmarks, you might be thinking, "Where am I? Am I on the right path?" Routes can give shape to the knowledge that is representative of the environment. Our spatial knowledge develops over time as we experience a new area more often; so that, our cognitive maps will become more accurate over time.
Two Systems of Allocentric and Egocentric Work Together During Navigation
It was suggested that navigation was more directly an egocentric (first-person perspective) and not an allocentric process that utilizes external cues like landmarks in relation to each other to navigate. Research has since suggested that it's actually a complementary system and leans towards a "parallel" egocentric and allocentric representation in our memory system (Burgess, 2006). How does the brain process information using the self as a reference frame and external cues to help direct us where to go?
The hippocampus is a specialized region of the brain, also known as the "map reader." The hippocampus helps us determine where we are at, how we arrive at a particular place, and how to navigate to our next destination place. In fact, reading maps can help us develop our navigational skills and can cause the hippocampus and the brain to grow, forming more neural pathways - neuroplasticity - as the number of mental maps increase (Maxwell 2013). However, the hippocampus does not work alone in developing our spatial memory; it works alongside with the pre-frontal cortex, which is responsible for higher-level cognitive functioning. The prefrontal cortex is a part of the frontal lobe. The frontal lobe is involved in reasoning, motor control, emotions, and language.
So when we are gathering spatial information about our environment for the first time and "paying attention" to the street names and seeking landmarks, the prefrontal cortex is storing that information as working memory. During working memory, the brain is holding spatial information transiently in the service of comprehending, thinking, and planning (Funahasi, 2017). When we are looking at a map, for example, the occipital lobe, located at the very back of the brain, contains the primary visual cortex and is responsible for interpreting incoming visual information. There is a distinct path in which neurons fire from the visual processing within the occipital lobe.
Suppose you are looking for a particular street name and want to know where it is on the map. From the occipital lobe, a neuron fires in the dorsal region, which refers to the posterior or back portion of the brain. On the other hand, if you question "What is this on the map?" the neuron fires toward the ventral region, the anterior or front, portion of the brain during visual processing.
Thus, the association of egocentric responses from a self-perspective, allocentric visualization (size and structure of the environment that's complex or simple), and prior experience of the physical environment, all contribute to spatial memory.
How the Brain Navigates: The GPS in our Brain
Although some of us are better at it than others, what is it within the brain that gives us the ability to navigate? A group of researchers believes that it is the "rhythmic activity" of nerve cells found in the entorhinal cortex that supports spatial navigation called grid cells.
The entorhinal cortex (EC) is located in the temporal lobe, which serves as a network hub for memory, navigation and time perception. Notice that its close proximity to the hippocampus - the "map reader" of the brain and the neocortex. The neocortex makes up approximately half the volume of the human brain, and is responsible for attention, thought, perception and episodic memory (unique memory of a specific event).
Neurobiologists from Ruhr University Bochum, Germany, showed that EC cells oscillate with individual frequencies using electrophysiological records in animal models. They discovered that the rhythmic activity of neuron in the EC seems to create a kind of a map. If you are in a certain location, a certain neuron fires. And the activity of each EC cell enables the brain to code a set of positions that form a "grid" with perfect distances and angles.
A grid cell is a type of neuron within the entorhinal cortex that fires an action potential at regular intervals when a person navigates into an open area. The activation of grid cells allows us to understand where we are in space by storing and integrating information about where we are at, distance, and direction (Jeffery, 2007). Interestingly, grid cells are not only found in humans but also rats, mice, bats and monkeys (Thompson and Howe, 2021).
The diagram on top is a rat's entorhinal cortex and the red dots indicate location of particular grid cells fired (Khardcastle, 2020). The grid cells derive their name from the centers that connect their firing fields to produce a triangular shape grid with equal distances and angles at the bottom (Tomruen, 2018).
Grid cells constitute a positioning system in the brain and is suggested as a mechanism by which the brain computes self-position based on continuous updated information about where you are at and direction.
Watch the short video clip "How Does Your Grid Work?"
Effects of GPS and the Brain
Recall, we previously discussed a publication about taxi drivers in London as an example of the effect of navigation in the brain. The study was done by neuroscientist, Eleanor Maguire in 2000, who looked at the size of taxi drivers hippocampi before GPS. These drivers were chosen because they were especially astute at remembering alternate routes when there were road closures or delays. It was hypothesized that there may be a difference in how their brains looked, so scientists performed MRIs to determine changes in the brain. It was discovered that taxi drivers in London had larger hippocampi, and this area correlated to how long they had driven a cab. Those who had spent 40 years or more in a taxi had a significantly more developed hippocampi than those just starting out. The study confirms that the brain is plastic, and our cognitive navigational skills grow along with the grey matter in our brain. On the other hand, people with a smaller hippocampus are at a higher risk for psychiatric disorders including dementia, schizophrenia, and PTSD (Neyfakh, 2013).
One important role of the hippocampus is to facilitate spatial memory in the form of navigation. Increased hippocampal volume relative to brain and body size has been reported in small mammals and birds who engage in behavior requiring spatial memory, such as food storing. In some species, hippocampal volumes enlarge specifically during seasons when the demand for spatial ability is greatest (Lee, 1998).
At McGill University, researchers found that people who used spatial navigation (discussed above--allocentric and egocentric visualizations) have increased activity in the hippocampus compared with those who ran on “auto-pilot.” Spatial navigators also had a higher volume of grey matter (strong detection of sensory input), and they scored higher on standardized cognition tests than the other group who merely retraced their steps by rote; this mode was more closely related to the way a GPS is used to navigate (Maxwell, 2013).
Summary: Why is Mind Mapping So Important?
Mental mapping goes beyond better awareness of your environment. If you are a waiter, it helps you to remember who ordered what. If you are packing, it allows you to remember what to bring based on where you are going. If you are studying, it helps you to organize your materials. Research also suggests that you do not need to give up GPS or step-by-step instructions. In fact, step-by-step instructions may help you to construct your own mental map, if you pay attention. The GPS allows a sense of freedom to explore, which can benefit your brain.
The bottom line is to rely less on the GPS and more on the brain to where you are going. Pay attention to landmarks and take in the information that is presented as you are traveling. This will help you to develop your own mind map, which will, in turn, benefit your brain!
The Brain HQ Connection
There are four BrainHQ exercises that will help you improve your navigation skills, mental manipulations, verbal memory, and spatial memory. Click on the icon below to learn more about each exercise.
Videos
Video: (3:59 min) Get to know what happens in the brain when navigating including the grid cells
Have you ever wondered how our ancestors navigated before GPS technology? Watch this fun and interesting video of early inventions on how to navigate the seas before GPS as we know it today.
Works Cited
Ahmadpoor, N. and Shahab, S. (2019). Spatial Knowledge Acquisition in the Process of Navigation: A Review. Retreived from:https://www.scirp.org/journal/PaperInforCitation.aspx?PaperID=90459
Burgess, N. (2006, October 5). Spatial Memory: How Egocentric and Allocentric Combine. Retrieved from Trends Cognitive Science: http://www.researchgate.net/publication/6725489_Spatial_Memory_How_Egocentric_and_Allocentric_Combine
Development of Spatial Ability Tests. (2014, September). Retrieved from Harvard. EDU: http://www.nmr.mgh.harvard.edu/mkozhevnlab/?page_id=657
Enhancing Spatial Navigation with Noninvasive Brain Stimulation. (2015, October). Retrieved from National Institute on Aging: https://www.nia.nih.gov/alzheimers/clinical-trials/enhancing-spatial-navigation-noninvasive-brain-stimulation
Funahashi, S. (2017, May ). Working Memory in the Prefrontal Cortex. Retrieved from Brain Science: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5447931/
Gibbons, S. (2019, July). Cognitive Maps, Mind Maps, and Concept Maps: Definitions. Retrieved from NN/g Nielsen Norman Group:https://www.nngroup.com/articles/cognitive-mind-concept/
Grech, A. et al. (2018, March). The Importance of Distinguishing Allocentric Egocentric Search Strategies in Rodent Hipppocampal-Dependent Spatial Memory Paradigms: Getting more out of your data. Retrieved from: https://www.intechopen.com/chapters/61465
Jeffery, K.J. (2007, May). Self-localization and the entorhinal-hippocampal system. Retrieved from Current Opinion in Neurobiology: https://www.sciencedirect.com/science/article/abs/pii/S0959438807001262?via%3Dihub
Khardcastle (2020, January). Grid cell. Retrieved from: https://commons.wikimedia.org/wiki/File:Grid_cell_image_V2.jpg
Lee D W, Miyasato L E, Clayton N S. NeuroReport. 1998;9:R15–R27. [PubMed] [Google Scholar] [Ref list]
Maguire, E.A. et al., (2000, April). Navigation-related structural change in the hippocampi of taxi drivers. Retrieved from PNAS: https://www.pnas.org/content/97/8/4398.long
Maxwell, R. (2013, March 8). Spatial Orientation and the Brain: The Effects of Map Reading and Navigation. Retrieved from GIS Lounge: http://www.gislounge.com/spatial-orientation-and-the-brain-the-effects-of-map-reading-and-navigation/
Neyfakh, L. (2013, August 17). Do our Brains Pay a Price for GPS. Retrieved from Boston Globe.com: https://www.bostonglobe.com/ideas/2013/08/17/our-brains-pay-price-for-gps/d2Tnvo4hiWjuybid5UhQVO/story.html
Spatial Navigation-The GPS in Our Brains. (2011, October 14). Retrieved from Science 20: http://www.science20.com/news_articles/spatial_navigation_gps_our_brains-83602
Thompson, B. and Howe, N. (2021, August). The brain cells that help animals navigate in 3D. Retrieved from Nature Podcast: https://www.nature.com/articles/d41586-021-02204-3
Tomruen (2018, December) Grid cell. Retrieved from: https://commons.wikimedia.org/wiki/File:Uniform_tiling_63-t2.png