
View through the glass floor of the
CN Tower in Toronto, Canada. A person with acrophobia might suffer a
panic attack or be immobilised by such a view, even though there is no immediate danger.
'Acrophobia' (from
Greek '', meaning "summit") is an extreme or irrational
fear of
heights. It belongs to a category of
specific phobias, called
space and motion discomfort that share both similar etiology and options for treatment.
Acrophobia can be dangerous, as sufferers can experience a
panic attack in a high place and become too agitated to get themselves down safely. Some acrophobics also suffer from urges to throw themselves off high places, despite not being suicidal.
"
Vertigo" is often used, incorrectly, to describe the fear of heights, but it is more accurately described as a spinning sensation, which may be caused by looking down from a high place, as well as by some other stimuli.
Causes of acrophobia
Traditionally, acrophobia has been attributed, like other irrational fears, to
conditioning or a
traumatic experience involving heights. Recent studies have cast doubt on this explanation
[1]; fear of falling, along with
fear of loud noises, is one of the most commonly suggested inborn or ''non-associative'' fears. The newer non-association theory is that fear of heights is an evolved adaptation to a prehistory where falls posed a significant danger. The degree of fear varies and the term phobia is reserved for those at the
extreme end of the spectrum. It has been argued by researchers that fear of heights is an instinct found in many mammals, including domestic animals and human beings. There have been experiments showing toddler babies and cats of various ages being terrified of venturing onto a glass floor with a view of a few meters of 'fall-space' below it.
This extreme fear can be counter-productive in normal everyday life though, with some sufferers being afraid to go up a flight of
stairs or a
ladder, or to stand on a
chair,
table, (etc.).
Another possible contributing factor is dysfunction in maintaining balance. In this case the anxiety is both well founded and secondary. According to the dysfunction model, a normal person uses both
vestibular and visual cues appropriately in maintaining balance.
[2][3] An acrophobic overrelies on visual signals whether because of inadequate vestibular function or incorrect strategy. Locomotion at a high elevation requires more than normal visual processing. The visual cortex becomes overloaded resulting in confusion. Some proponents of the alternative view of acrophobia warn that it may be ill-advised to encourage acrophobics to expose themselves to height without first resolving the vestibular issues. Research is underway at several clinics.
[4] [5]
References
1. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7677717&dopt=Abstract The Etiology of Acrophobia...
2. http://www.thefreelibrary.com/Acrophobia+and+pathological+height+vertigo:+indications+for+...-a0140560534 Acrophobia and pathological height vertigo...
3. http://www.springerlink.com/content/x84403511772np14/ Discomfort with space and motion
4. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids==15842192
5. http://www.pneuro.com/publications/dizzy/index.html]