Olivier Walusinski (Ed.): The Mystery of
Yawning in Physiology and Disease
Karger, Basel, 2010, 160 pp
Review in
the NATIONAL MEDICAL JOURNAL OF INDIA
2010;23(6): 368-369
This is a unique book of 12 chapters on
yawning, a physiological process which The
Mystery of Yawning in Physiology everyone
experiences but and Disease understands very
little. The science of yawning, 'chasmology' has
evolved considerably in the past 20 years. The
book begins with an excellent historical
perspective on yawning, quoting from the first
medical writing by Hippocrates in BC 400.
The chapter on 'Population knowledge and
beliefs' discusses the Indian belief that ghosts
enter the body through the mouth while yawning
and the so-called remedy for this is illustrated
on the cover page - putting your hand in front
of your mouth to scare the bad spirit away.
The chapter on foetal yawning aroused my
curiosity. It is suggested that yawning plays a
role in developmental disorders. The process of
yawning, which begins in foetal life and
continues into old age, changes throughout life.
It has been observed in numerous animal species
too.
The chapter on yawning and vigilance
discusses two hypotheses: (i) yawning is
triggered by drowsiness, and (ii) yawning
arouses the brain. The chapter on yawning in
non-primates and the effect ofpunishment-induced
fear and yawning would interest researchers in
basic sciences.
Does yawning cool the brain? Read the 'brain
cooling' hypotheses. ACTHIMSH, acetylcholine,
oxytocin, nitric oxide, dopamine, excitatory
amino acids, serotonin, opioids and GABA are
some neurotransmitters involved in the
physiology of yawning. Yawning is contagious and
can be transmitted from one to another species.
An interesting experiment showed dogs yawning
following a human yawn.
The chapters on 'Neuro-imaging of yawning'
and 'Associated movements in hemiplegic limbs
during yawning' makes for interesting
reading.
This book is simple reading and motivates
the reader to want to know more. I would
recommend the book, especially to residents and
faculty in physiology, neurology and sleep
medicine.
VINAY GOYAL
Department of Neurology All India Institute
of Medical Sciences
