<p><strong>Short answer</strong><br>
In general, sensory systems are not well equipped to perform absolute estimations of a stimulus level, especially since they adapt to the ambient level of stimulation, <em>i.e.</em>, their baseline is re-set continuously. Nonetheless, the vestibular system is quite well capable of estimating the degrees of rotation, as shown in blindfolded subjects that were rotated along the vertical axis.  </p>

<p><strong>Background</strong><br>
Rotation initiated by an object you are sitting or standing on is sensed by the <strong><a href="https://emedicine.medscape.com/article/1948576-overview" rel="nofollow noreferrer">visual system</a></strong> and the <strong><a href="https://en.wikipedia.org/wiki/Vestibular_system" rel="nofollow noreferrer">vestibular system</a></strong>. The visual system is the most accurate, as it immediately senses a change in the visual scene. When the eyes are closed, only the vestibular organ is functional.  </p>

<p>Movement in the horizontal plane is sensed by the <strong><a href="https://emedicine.medscape.com/article/883956-overview" rel="nofollow noreferrer">semicircular canals</a></strong> in the inner ear (Fig. 1). One fundamental principle in sensory organs in general is that they operate on a relative scale. In other words, sensory systems excel in <em>comparing</em> two stimulus intensities. They are, however, poorly equipped to provide an <em>absolute measure</em> of stimulus intensity. How bright is bright? Only through experience does one know the absolute value of a stimulus. I'm in the hearing sciences, and I can pretty well tell what the absolute stimulus level is of a stimulus between 20 and 70 dB. But that's only because I spent hours and hours providing well-defined stimuli to study subjects. If you ask me how bright a certain flash of light is, I surely can't tell you.</p>

<p>What's more - sensory systems adapt quickly <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501690/" rel="nofollow noreferrer">(Webster, 2012)</a>. For example, if you keep on moving in circles then the sensory end organs in the semicircular organs (hair cells and associated vestibular nerve) adapt and become less responsive to the ongoing stimulus <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060364/" rel="nofollow noreferrer">(St. george <em>et al</em>., 2011)</a>. However, short circular movements in a car are typically short accelerations and decelerations, which are pretty well encoded by the vestibular system. Indeed, blindfolded subjects do pretty well in regaining their original position when rotated about a head-centered vertical axis. It is not until adaptation comes into play that things start to deteriorate. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060364/" rel="nofollow noreferrer">(St. george <em>et al</em>., 2011)</a>.     </p>

<p><sub><strong>Reference</strong><br>
<strong>-</strong> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060364/" rel="nofollow noreferrer">St. george <em>et al</em>., <em>J Physiol</em> (2011); <strong>589</strong>(4): 843–53</a><br>
<strong>-</strong> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501690/" rel="nofollow noreferrer">Webster, <em>F1000 Biol Rep</em> (2012); <strong>4</strong>: 21</a></sub></p>

<p><a href="https://i.sstatic.net/3tTj3.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/3tTj3.jpg" alt="inner ear"></a><br>
<sup>Fig. 1. Inner ear. source: <a href="https://img.medscapestatic.com/pi/meds/ckb/80/25180.jpg" rel="nofollow noreferrer">MedScape</a></sup></p>

CC BY-SA 3.0
2018-04-11T20:14:21.067Z
2018-04-11T20:14:21.067Z
AliceD
<p>Since I was little I realized that when you close your eyes when being in a car and the car turns in a street to the side, you perceive the car turning more in one direction than it actually does.</p>

<p>Does this effect have a name? Is it an example of some well known effect? If so, what is it and where can I learn more about it?</p>

CC BY-SA 3.0
2018-04-09T05:27:05.877Z
You might start here - [*Sense of balance*](https://en.wikipedia.org/wiki/Sense_of_balance). Basically, in normal people vision plays a minor role in judging balance and movement (your fine judgment might be affected but you won't fall over).
user3169
CC BY-SA 3.0
2018-04-09T07:09:04.297Z
@user3169 - this looks like the beginnings of a good answer here.  If you could elaborate a bit more, I would write this up as an answer.
Chris Rogers
<neuroscience><perception>
Is the effect related to shutting your eyes when a car is turning well known?
KKZiomek
# Is the effect related to shutting your eyes when a car is turning well known?

(Asked by: username_0 on 2018-04-09)

Since I was little I realized that when you close your eyes when being in a car and the car turns in a street to the side, you perceive the car turning more in one direction than it actually does.

Does this effect have a name? Is it an example of some well known effect? If so, what is it and where can I learn more about it?

**Tags:** neuroscience, perception

> **Comments:**
> **username_1**: You might start here - [*Sense of balance*](https://en.wikipedia.org/wiki/Sense_of_balance). Basically, in normal people vision plays a minor role in judging balance and movement (your fine judgment might be affected but you won't fall over).  
> **username_2**: @username_1 - this looks like the beginnings of a good answer here.  If you could elaborate a bit more, I would write this up as an answer.  

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## 1 answers

### Answer by username_3 on 2018-04-11. Score: 4

**Short answer**  
In general, sensory systems are not well equipped to perform absolute estimations of a stimulus level, especially since they adapt to the ambient level of stimulation, *i.e.*, their baseline is re-set continuously. Nonetheless, the vestibular system is quite well capable of estimating the degrees of rotation, as shown in blindfolded subjects that were rotated along the vertical axis.

**Background**  
Rotation initiated by an object you are sitting or standing on is sensed by the **[visual system](https://emedicine.medscape.com/article/1948576-overview)** and the **[vestibular system](https://en.wikipedia.org/wiki/Vestibular_system)**. The visual system is the most accurate, as it immediately senses a change in the visual scene. When the eyes are closed, only the vestibular organ is functional.

Movement in the horizontal plane is sensed by the **[semicircular canals](https://emedicine.medscape.com/article/883956-overview)** in the inner ear (Fig. 1). One fundamental principle in sensory organs in general is that they operate on a relative scale. In other words, sensory systems excel in *comparing* two stimulus intensities. They are, however, poorly equipped to provide an *absolute measure* of stimulus intensity. How bright is bright? Only through experience does one know the absolute value of a stimulus. I'm in the hearing sciences, and I can pretty well tell what the absolute stimulus level is of a stimulus between 20 and 70 dB. But that's only because I spent hours and hours providing well-defined stimuli to study subjects. If you ask me how bright a certain flash of light is, I surely can't tell you.

What's more - sensory systems adapt quickly [(Webster, 2012)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501690/). For example, if you keep on moving in circles then the sensory end organs in the semicircular organs (hair cells and associated vestibular nerve) adapt and become less responsive to the ongoing stimulus [(St. george *et al*., 2011)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060364/). However, short circular movements in a car are typically short accelerations and decelerations, which are pretty well encoded by the vestibular system. Indeed, blindfolded subjects do pretty well in regaining their original position when rotated about a head-centered vertical axis. It is not until adaptation comes into play that things start to deteriorate. [(St. george *et al*., 2011)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060364/).

**Reference**  
**-** [St. george *et al*., *J Physiol* (2011); **589**(4): 843–53](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3060364/)  
**-** [Webster, *F1000 Biol Rep* (2012); **4**: 21](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501690/)

[![inner ear](https://i.sstatic.net/3tTj3.jpg)](https://i.sstatic.net/3tTj3.jpg)  
Fig. 1. Inner ear. source: [MedScape](https://img.medscapestatic.com/pi/meds/ckb/80/25180.jpg)


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