Caloric  vestibular  stimulation  (CVS)

CVS is a physiological manipulation used to interfere with the vestibular system functioning.  

It consists in the insertion (see figure 1 for equipment) of cold water (0° C) into the subject's auditory canal (note: according to the purpose of the experiment, the water can also be hot - here I refer to the use I make of this technique).

It is one of the cheapest but most powerful techniques available.  However, its effects are very short in time, lasting around 15 minutes. 

As with other techniques, the combined use of CVS and behavioural testing allows to explore modulation of this misterious and fascinating sensory system on cognitive functions. 

Figure 1
	CVS equipment. A syringe with a soft tube attached to it. Water is placed into the syringe and inserted into the subject's auditory canal.   Cautionary note: DO NOT TRY AT HOME - you could pierce the person's tympanum.