<p>Two areas in the visual cortex are associated with the perception of velocity, namely:  </p>

<ol>
<li>The <a href="http://thebrain.mcgill.ca/flash/d/d_02/d_02_cr/d_02_cr_vis/d_02_cr_vis.html" rel="nofollow noreferrer">primary visual cortex</a> (V1) and</li>
<li>The <a href="https://en.wikipedia.org/wiki/Visual_cortex" rel="nofollow noreferrer">middle temporal area</a> (MT or V5). </li>
</ol>

<p>Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, <em>i.e.</em>, these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 contains approximately 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned <a href="https://pdfs.semanticscholar.org/9af3/aa508469068d7c201b58461ed0962ff67a3d.pdf" rel="nofollow noreferrer">(Bradley &amp; Goyal, 2008)</a>.</p>

<p>Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing. </p>

<p><a href="https://i.sstatic.net/FrC1S.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/FrC1S.jpg" alt="streams"></a><br>
<sup>Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: <a href="http://jn.physiology.org/content/97/1/307" rel="nofollow noreferrer">Lehky &amp; Sereno (2007)</a></sup> </p>

<p><sub><strong>References</strong><br>
<strong>-</strong> <a href="https://pdfs.semanticscholar.org/9af3/aa508469068d7c201b58461ed0962ff67a3d.pdf" rel="nofollow noreferrer">Bradley &amp; Goyal, &amp;Nature Rev Neurosci (2008); <strong>9</strong>: 686-95</a><br>
<strong>-</strong> <a href="http://jn.physiology.org/content/97/1/307" rel="nofollow noreferrer">Lehky &amp; Sereno, *J Neurophysiol (2007); <strong>97</strong>(1): 307-19</a></sub></p>

CC BY-SA 3.0
2017-04-15T20:07:02.043Z
2017-04-16T14:28:04.360Z
2017-04-16T14:28:04.360Z
AliceD
<p>@AliceD gave a great answer on the bottom up pathway. Let me add some top-down processing bits into the picture, since that's what you are asking.</p>

<p>First of all, at a perceptual level, motion perception is biased by prior expectations and strength of motion signal. E.g., see:</p>

<ul>
<li>Stocker, A. A. and Simoncelli, E. P. (2006). Noise characteristics and prior expectations in human visual speed perception. Nature Neuroscience, 9(4):578-585. <a href="http://dx.doi.org/10.1038/nn1669" rel="noreferrer">http://dx.doi.org/10.1038/nn1669</a></li>
</ul>

<p>The neural activity of MT (and behavior) is known to be modulated by attention. E.g., see:</p>

<ul>
<li>Monkey Area MT Latencies to Speed Changes Depend on Attention and Correlate with Behavioral Reaction Times. Neuron. 78(4):740–750. <a href="http://doi.org/10.1016/j.neuron.2013.03.014" rel="noreferrer">http://doi.org/10.1016/j.neuron.2013.03.014</a></li>
</ul>

CC BY-SA 3.0
2017-04-16T14:14:22.683Z
2017-04-16T14:14:22.683Z
Memming
<p>Has there been any research on how mammals predict the speed of moving objects? In particular, how do they integrate top-down information? For instance, do they have greater difficulty estimating the speed of a fast-moving sloth more than a moving mouse?</p>

<cognitive-psychology><neuroscience><reference-request><vision>
How do mammals estimate the speed of moving objects?
Seanny123
# How do mammals estimate the speed of moving objects?

(Asked by: username_0 on 2016-01-04)

Has there been any research on how mammals predict the speed of moving objects? In particular, how do they integrate top-down information? For instance, do they have greater difficulty estimating the speed of a fast-moving sloth more than a moving mouse?

**Tags:** cognitive-psychology, neuroscience, reference-request, vision


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## 2 answers

### Answer by username_1 on 2017-04-15. Score: 3 | Accepted answer

Two areas in the visual cortex are associated with the perception of velocity, namely:

1. The [primary visual cortex](http://thebrain.mcgill.ca/flash/d/d_02/d_02_cr/d_02_cr_vis/d_02_cr_vis.html) (V1) and
2. The [middle temporal area](https://en.wikipedia.org/wiki/Visual_cortex) (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, *i.e.*, these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 contains approximately 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned [(Bradley & Goyal, 2008)](https://pdfs.semanticscholar.org/9af3/aa508469068d7c201b58461ed0962ff67a3d.pdf).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

[![streams](https://i.sstatic.net/FrC1S.jpg)](https://i.sstatic.net/FrC1S.jpg)  
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: [Lehky & Sereno (2007)](http://jn.physiology.org/content/97/1/307)

**References**  
**-** [Bradley & Goyal, &Nature Rev Neurosci (2008); **9**: 686-95](https://pdfs.semanticscholar.org/9af3/aa508469068d7c201b58461ed0962ff67a3d.pdf)  
**-** [Lehky & Sereno, \*J Neurophysiol (2007); **97**(1): 307-19](http://jn.physiology.org/content/97/1/307)


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### Answer by username_2 on 2017-04-16. Score: 4

@username_1 gave a great answer on the bottom up pathway. Let me add some top-down processing bits into the picture, since that's what you are asking.

First of all, at a perceptual level, motion perception is biased by prior expectations and strength of motion signal. E.g., see:

* Stocker, A. A. and Simoncelli, E. P. (2006). Noise characteristics and prior expectations in human visual speed perception. Nature Neuroscience, 9(4):578-585. <http://dx.doi.org/10.1038/nn1669>

The neural activity of MT (and behavior) is known to be modulated by attention. E.g., see:

* Monkey Area MT Latencies to Speed Changes Depend on Attention and Correlate with Behavioral Reaction Times. Neuron. 78(4):740–750. <http://doi.org/10.1016/j.neuron.2013.03.014>


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