An embryonic science

fetus.jpgWhat were you doing for the 38 weeks before you were born? A hell of a lot actually, according to Professor Peter Hepper at Queen’s University, Belfast, who’s written about the nascent field of fetal psychology in the latest issue of The Psychologist magazine.

The article is packed full of fascinating observations including the fact that the fetus demonstrates handedness by 10 weeks of gestation – before any signs of hemispheric asymmetry, thus suggesting a predilection for movements on one side might lead to brain lateralisation, rather than the other way around.

Hepper also mentions the controversy surrounding whether or not the fetus feels pain. Of course it can’t be asked, but by 23 weeks gestation, the fetus does show a biochemical stress response to a needle puncture (during a blood transfusion), which suggests it hurt.

Doctors have no way of directly assessing the brain function of a fetus, but advances in fetal psychology mean aberrant patterns of behaviour can increasingly be used to identify neural problems the fetus may have.

The article is locked to subscribers but will be freely available after six months.

Link to The Visible Embryo
Link to videos of the fetus

2 thoughts on “An embryonic science”

  1. I am not a member of the British Psychological Society, so I cannot read the article and tell if Prof. Pepper is inaccurately summarized, but I am extremely skeptical based on his using biochemical stress response to indicate pain, when it is more likely a reflexive response. A fetus will visibly react to touch and other stimulus at 8 weeks due to peripheral nerve endings, but these nerves are not connected to the spinal cord, nor do they properly conduct.
    The Myelin sheaths (the insulating cover on nerve pathways that is required for efficient conduction of pain signals) do not begin forming around nervous system cells (neurons) in the spinal cord until about 24 weeks, and not till after birth in most of the cerebral cortex. [1][2] Although sporadic brain waves can be etected by about 21 weeks gestation, genuine continuous brain waves do not begin until about 28 weeks, indicating that the nerve circuits needed to carry pain impulses to the brain are not fully connected till then. This also marks the beginnings of conscious awareness, which is generally considered a requirement for experiencing pain.
    Pain signals from the thalamus go to the cerebral cortex, the thinking and feeling part of the brain. A highly-developed cortex is required to perceive pain signals. Activity at the nerve endings, spinal cord, or thalamus is not enough. At 13 weeks gestation, the brain stem and thalamus are not functional, anyway. Working connections between the thalamus and the higher cortex do not begin to form until about 20 to 26 weeks, with significant development of neuronal activity continuing after birth.
    [1] LaRossa, Maureen Mulligan, R.N. and Sheena L. Carter, Ph.D.
    Understanding How the Brain Develops.
    http://med.emory.edu/PEDIATRICS/NEONATOLOGY/DPC/brain.htm
    [2] Moore, Keith L. and T.V.N. Persaud. 2003. Before We Are Born: Essentials of Embryology and Birth Defects. Saunders, Philadelphia, Penn. pp. 350

  2. The issue of whether the fetus can feel pain was one of many raised by Professor Hepper in a balanced review of fetal psychology. Hepper did not argue that the fetus can or cannot feel pain but described research interest in the area. He was careful to acknowledge that the biochemical stress response is an indirect measure of pain.
    Individuals who are not a member of The British Psychological Society can subscribe to The Psychologist magazine for £50 a year; £60 if overseas. See http://www.thepsychologist.org.uk

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