However "coding" depends on how you interpret the data.
A phasic receptor to position really responds to velocity, a phasic
receptor to velocity really responds to acceleration. Also, as was
already pointed out, head rotations are very brief -- a sudden
movement followed by stillness. If the semicircular canals respond to
acceleration, they give a brief burst with frequency proportional to
acceleration and the stop (negative accelerations are not signaled.)
Therefore the number of action potentials in the burst is the integral
of acceleration with time, the velocity.
So how do you interpret the data?
On 6 Mar 2007 17:42:36 -0800, "Bill" <connelly.bill from gmail.com> wrote:
>When you say the vestibular system, you just mean the semi-circular
>canals and the Otoliths? The respond to acceleration. They can't
>respond to velocity, because velocity does not impart a force on the
>moving object. Though how this is coded further down the pathway, past
>the 8th nerve/vestibular neculei I have no idea.
>>On Mar 7, 12:15 am, Mathias <mathiasDOTfranz... from webDELETEME.de> wrote:
>> Dear ng,
>>>> I'm looking for a reference about whether the vestibular system yields
>> an acceleration and/or velocity signal (e.g. used for the head direction
>> and place cell system). Googling for this I found a website...http://paperairplane.mit.edu/16.423J/Space/SBE/neurovestibular/NeuroV...>> ... that claims the vestibular system outputs a velocity and not an
>> acceleration signal "over the range of normal head movements".
>> Unfortunately there is no reference and I'm not even certain about which
>> species they talk.
>>>> Any reference on this topic would be highly appreciated,