An olfactory receptor has an average survival time of just over a ____. At that point, a stem cell matures into a new olfactory cell in the same location as the first and expresses the same receptor proteins.
The axon of this new olfactory cell then has to find its way to the ____ ____ in the olfactory bulb.
Each olfactory neuron axon contains copies of its ____ ____ ____, which it uses like an identification card to find its correct partner.
olfactory receptor proteins
However, if the entire olfactory surface is damaged at once by a blast of ____ ____ so that the system has to replace all the receptors at same time, many of them fail to make the correct connections, and olfactory experience does not fully recover.
On average, women detect ____ more readily than men, and the brain responses to ____ are stronger in women than men.
If people repeatedly attend to some faint odour, ____ ____ ____ gradually become more and more sensitive to it, until they can detect it in concentrations 1/10000 of what they could at the start.
young adult woman
Pheromones. The ____ ____ (VNO) is a set of receptors located near, but seperate from, the olfactory receptors.
Unlike olfactory receptors, the VNO receptors are specialised to respond only to ____, chemicals released by an animal that affect the behaviour of other members of the same species.
Each VNO receptor responds to just one pheromone, in concentrations as low as one part in 100 billion. Furthermore, receptor does not ____ to a repeat stimulus.
The VNO receptors continue responding strongly even after ____ ____.
In adult humans, the VNO is ___ and has no receptors.
The behavioural effects of pheromones apparently occur ____.
Exposure to these chemicals – especially chemicals from the opposite sex - alters skin temperature and other ____ responses and increases activity in the hypothalamus.
The smell of a woman's sweat – especially if the woman was near her time of ovulation – increases the mans ____ secretions.
The smell of a males sweat causes women to increase the release of ____. Cortisol is a stress hormone, so the implication is that women are not altogether charmed by the smell of sweaty man.
____ is the experience some people have in which stimulation of one sense evokes a perception of that sense and another one also.
Various studies attest to the reality of synaesthesia. People reporting synaesthesia have increased amounts of ____ ____ in certain brain areas and altered connections to other areas. They also show behavioural peculiarities it would be hard to pretend.
Synaesthesia clusters in families, suggesting a genetic ____, but people are certainly not born with a letter-to-colour or number-to-colour synaesthesia.
Synaesthesia develops gradually over ___.
When people misperceive a stimulus – as in an illusion – the synthetic experience corresponds to what the person ____ the stimulus was, not what it actually was.
This result implies that the synesthesia phenomenon occurs in the ____ ____, not in the receptors or the first connections to the nervous system.
Furthermore, for some people, the idea of a word triggers a synesthetic experience ____ they thought of the word itself.
One of the hypotheses of synaesthesia is that some of the ____ from one cortical area branch into another cortical area.