Imagine you’re in the cockpit of an airplane, flying through thick clouds with no horizon in sight. Your body tells you the plane is flying level, but your navigational instruments disagree. You’re actually in a slow bank, turning without realizing it. This unsettling disconnect between what you feel and what’s actually happening is called the reorientation illusion.

While this might seem like something that could only affects pilots, the principles behind the reorientation illusion have a lot to do with how all of us maintain our balance. In fact, understanding this unique phenomenon can teach us a lot about why we sometimes lose our balance or fall, especially as we age.

What is the Reorientation Illusion?

The reorientation illusion occurs when the brain receives conflicting information from the visual and vestibular systems about the body’s orientation in space relative to gravity. (1, 2) This sensory conflict can cause the brain to perceive a dramatic shift, such as feeling that the environment has rotated 90 degrees or more, or that things ‘feel’ inexplicably different.

Let’s say that again in a less academic way that wont hurt everyone’s brain!

Imagine you’re floating in space, and your brain is trying to figure out which way is up or down. Normally, your brain uses clues from what you see and feel to tell where you are. This usually does the trick, but sometimes, these clues don’t match up. Your eyes might say, ‘We’re upright!’ while your inner ear’s vestibular system (which helps with balance) says, ‘Nope, we’re sideways!’ This mix-up can make you feel like the room or world around you has suddenly turned or tilted, even though nothing really moved.

It’s like your brain is getting tricked by the different signals and can’t tell which one is right, so things feel a bit weird and confusing!

The reorientation illusion is most commonly experienced by people who fly planes or travel in space, where sensory signals can become confusing due to the lack of external visual cues, like the horizon. (3) This makes knowing which way is up, down, or level that much harder to grasp. However, it’s not just a flight or space issue. The same principles of sensory conflict can happen anytime our balance systems get tricked like when we spin in circles, ride a roller coaster, or even play certain video games.

How It Works

Our brain relies on three main systems to keep us balanced, which I call the Three Bodily Balance Systems:

1. Vision – Visual cues, such as the horizon, tell us where we are in space.

2. Vestibular system – Located in the inner ear, this system senses changes in motion and head position relative to gravity.

3. Proprioception – This is your body’s ability to sense where your limbs and body parts are, even if you can’t see them.

When all of these systems work together properly, we stay upright and balanced. But if one of these systems gives unreliable information, like if you’re flying through clouds and your eyes can’t see the horizon to know what is level, your brain might misinterpret your body’s position. That’s when the reorientation illusion kicks in and you can’t quite accurately tell your relative position in space

Example: "The Leans"

One common form of the reorientation illusion is something pilots call the leans. (3) Imagine you’re flying and slowly start to bank (turn) the plane without realizing it. Because the tilt happens gradually, your vestibular system doesn’t pick it up the sensation of turning and you visually feel like you are going straight. When you return the plane to level flight, your brain tells you that you’re banking in the opposite direction, so you instinctively “lean” into the turn, even though the plane is flying level. This type of misinterpretation can be dangerous because it leads to incorrect reactions, just like a fall caused by misreading your body’s position while safe on the ground.

Reorientation Illusion and Balance in Everyday Life

So, what does the reorientation illusion have to do with your balance on a day-to-day basis? More than you might think! While most of us aren’t flying planes, we still rely on the same systems, vision, vestibular, and proprioception, to keep us balanced. When these systems get confused, or rather conflict with one another, we can experience different forms of the reorientation illusion, which may lead to balance problems or even falls. (4 , 5, 6)

Sensory Conflicts in Real Life

Just like in aviation, your body can experience sensory conflicts in everyday situations. Here are some common scenarios where the same principles of the reorientation illusion can affect your balance:

• Walking in the Dark: At night, when your vision is limited, you rely more on your vestibular system and proprioception to maintain balance. Without visual cues to tell you where the ground is, you might feel disoriented or lose your balance, similar to a pilot flying through clouds or fog without a visible horizon,

• Standing on a Moving Bus or Boat: When you’re on a bus or boat, your body feels motion even if your eyes see a stable interior of the vehicle. This can create a sensory conflict between your vision and your vestibular system, leading to feelings of dizziness, disorientation or even sickness, again, similar to what a pilot feels when experiencing the reorientation illusion.

• Dizziness from Spinning: If you’ve ever spun around in circles and suddenly stopped, you know that dizzy feeling that follows. Your vestibular system has detected motion, but your visual and proprioceptive systems are trying to tell your brain that you’re stationary. The conflicting signals cause disorientation, which can lead to stumbling or falling as your body isn’t quite sure how to balance safely. This type of disorientation happens because your vestibular system is slow to reset after detecting continuous spinning.

Aging and Balance

As we age, our balance systems don’t work as well as they used to due to the general decline for most people. (5) Vision may decline, and the vestibular system becomes less sensitive to head movements and gravity. (7, 8, 9) Proprioception can also weaken, especially if you’re not physically active. (10) This means that older adults are more likely to experience the types of sensory conflicts that lead to the reorientation illusion. When your brain can’t rely on one or more of your balance systems, it has a harder time determining your body’s true position in space. This makes you more prone to misinterpreting your position and, ultimately, more likely to fall.

The Science Behind the Illusion

The reorientation illusion occurs because of the way the brain integrates sensory information. Let’s dive into how each system works and what happens when things go wrong:

1. The Vestibular System: This system consists of tiny canals in your inner ear filled with fluid. (11) When you move your head, the fluid shifts, stimulating hair cells that send signals to your brain about your head’s position relative to gravity. However, if you’re in a prolonged steady motion (no acceleration), like flying or even driving on a highway for a long time, the fluid might stop moving even though your body is still in motion. This can lead to a misinterpretation of whether you’re moving or stationary.

2. Vision: Your eyes are one of the most important tools for balance, as they give you a direct view of your environment. (12, 13) The brain relies heavily on visual cues, like the horizon or the vertical lines of buildings, to tell where you are in space. In the absence of these cues, like in foggy weather or darkness, your brain may become disoriented because it doesn’t have the usual reference points.

3. Proprioception: Your muscles, joints, and skin are equipped with nerve receptors that sense movement and body position. (14) Proprioception works seamlessly with vision and vestibular input to help maintain balance. But as proprioceptive function declines with age or injury, your brain gets less accurate information about where your body parts are, increasing the risk of falls.

When the brain receives conflicting or incomplete information from these systems, it has to make a judgment call on how to interpret the data. Sometimes, the brain makes a mistake, just like with the reorientation illusion.

How to Improve Your Balance and Avoid Falls

The good news? Just like pilots train to overcome the reorientation illusion, you can train your body to better handle sensory conflicts and improve your balance. Here are a few strategies you can use to strengthen your balance systems and reduce your risk of falls:

1. Practice Multi-Sensory Balance Exercises:

   • Try standing on one foot with your eyes closed. This forces your vestibular and proprioceptive systems to work harder without the help of visual cues, while improving their ability for low-light conditions.

   • Use a balance board or stability ball to challenge your balance in different ways and alter the sensations you are experiencing. These exercises mimic real-life situations where you might need to rely on more than just vision to maintain your balance.

2. Incorporate Balance Training into Your Workout Routine:

   • Exercises like yoga, tai chi, and Pilates are great for improving proprioception and coordination.

   • Strengthen the muscles around your core, hips, and legs, which play a critical role in keeping you stable. Dive deeper into the muscles of balance here.

3. Be Mindful of Your Environment:

   • Pay attention to low lighting, uneven surfaces, or cluttered walkways that can increase your risk of tripping or falling.

   • When in unfamiliar environments, take extra care and move more slowly to allow your balance systems time to adapt, or allow you to take in more information from your environment before making any movement decisions.

4. Train Your Brain:

   • Just as pilots are trained to rely on their cockpit instruments rather than their senses when they experience disorientation, you can train your brain to handle situations where your balance systems might not give you reliable information.

   • Practice focusing on a single point, feeling around more, utilizing a mental map of familiar areas, or use mental cues to keep yourself steady in disorienting environments, like walking in the dark.

Final Thoughts: Understanding Sensory Conflicts and Preventing Falls

The reorientation illusion may be best known in the world of aviation, but its lessons of sensory conflict apply to all of us. Whether you’re flying a plane or walking through your living room in the dark, your balance systems work together to keep you upright. When one of these systems fails, or when they send conflicting information, your brain can misinterpret your body’s position, leading to disorientation and increasing your risk of falls.

By understanding how these systems work, you can take steps to improve your balance, strengthen your body's response to sensory conflicts, and ultimately prevent falls. From balance exercises to environmental awareness, these strategies will help keep you steady on your feet, even when the world around you is trying to throw you off balance.

Stay balanced, stay safe, and remember: your body’s sense of space and balance is something you can train and improve at any age. If you want a complete and custom program for improving your balance check out my Beginner to Intermediate Balance Program. Keep working on your balance, and you’ll not only prevent falls, you’ll live a healthier, more independent life!

References

1. Howard IP, Hu G. Visually induced reorientation illusions. Perception. 2001;30(5):583-600. doi:10.1068/p3106

2. Visually-induced reorientation illusions as a function of age. PubMed. Published September 1, 2000. https://pubmed.ncbi.nlm.nih.gov/10993316/

3. Meeks RK, Anderson J, Bell PM. Physiology of spatial orientation. StatPearls - NCBI Bookshelf. Published August 14, 2023. https://www.ncbi.nlm.nih.gov/books/NBK518976/#:~:text=Aviation%2Dassociated%20spatial%20disorientation%2C%20as,effect%20can%20be%20spatial%20disorientation.

4. Wilson SJ, Garner JC, Loprinzi PD. The influence of multiple sensory impairments on functional balance and difficulty with falls among U.S. adults. Preventive Medicine. 2016;87:41-46. doi:10.1016/j.ypmed.2016.02.023

5. Mahoney JR, Cotton K, Verghese J. Multisensory integration predicts balance and falls in older adults. The Journals of Gerontology Series A. 2018;74(9):1429-1435. doi:10.1093/gerona/gly245

6. Öztürk ŞT, Şerbetçioğlu MB, Ersin K, Yılmaz O. The impact of optical illusions on the vestibular system. Journal of Audiology & Otology. 2021;25(3):152-158. doi:10.7874/jao.2021.00080

7. Saftari LN, Kwon OS. Ageing vision and falls: a review. Journal of PHYSIOLOGICAL ANTHROPOLOGY. 2018;37(1). doi:10.1186/s40101-018-0170-1

8. Coto J, Alvarez CL, Cejas I, et al. Peripheral vestibular system: Age-related vestibular loss and associated deficits. Journal of Otology. 2021;16(4):258-265. doi:10.1016/j.joto.2021.06.001

9. Xing L, Bao Y, Wang B, et al. Falls caused by balance disorders in the elderly with multiple systems involved: Pathogenic mechanisms and treatment strategies. Frontiers in Neurology. 2023;14. doi:10.3389/fneur.2023.1128092

10. Ferlinc A, Fabiani E, Velnar T, Gradisnik L. The Importance and Role of Proprioception in the Elderly: a Short Review. Materia Socio Medica. 2019;31(3):219. doi:10.5455/msm.2019.31.219-221

11. Casale J, Browne T, Murray IV, Gupta G. Physiology, vestibular system. StatPearls - NCBI Bookshelf. Published May 1, 2023. https://www.ncbi.nlm.nih.gov/books/NBK532978/

12. Redfern MS, Yardley L, Bronstein AM. Visual influences on balance. Journal of Anxiety Disorders. 2001;15(1-2):81-94. doi:10.1016/s0887-6185(00)00043-8

13. De Nava ASL, Somani AN, Salini B. Physiology, vision. StatPearls - NCBI Bookshelf. Published May 1, 2023. https://www.ncbi.nlm.nih.gov/books/NBK538493/

14. Proske U, Gandevia SC. The proprioceptive senses: their roles in signaling body shape, body position and movement, and muscle force. Physiological Reviews. 2012;92(4):1651-1697. doi:10.1152/physrev.00048.2011