Originally Posted by foundit66

This "40 days" crap is an oft-repeated lie by anti-abortionists/pro-lifers who quote NOT peer-reviewed science, but rather refuted claims...


Sykes digs through the generations of pamphlets citing other pamphlets to find the original science on which the factoid is based, and comes up with a cite from a 1964 AMA convention speech transcript (not a research paper at all) published in the JAMA arguing for brain function rather than heart function to determine cessation of life, and a 1982 letter (not a peer-reviewed paper) published in the NEJM. As Sykes says, "no original research is being described here, which makes it dishonest and misleading to quote it as the source of a claim".

The quotes used by 'pro-lifers', when laid out in formal cite form, certainly do look impressive to anyone not in the habit or reading the original paper to evaluate a scientist's conclusions:


At only 40 days after fertilization electrical waves as measured by the EEG can be recorded from the baby's brain, indicating brain functioning47, 48.
47. Hamlin, H. (1964), "Life or Death by EEG," Journal of the American Medical Association, October 12, 113.




Brain function, as measured on the Electroencephalogram, "appears to be reliably present in the fetus at about eight weeks gestation," or six weeks after conception.

J. Goldenring, "Development of the Fetal Brain," New England Jour. of Med., Aug. 26, 1982, p. 564
Sykes dissects the misuse of these citations (both should strictly mention the status as convention proceedings/letters rather than research papers), showing that both of these opinion pieces incorrectly summarise science that is now either discredited or obsolete (and always refers to "electrical activity" rather than "brain waves"), then goes on to detail what medical science actually does show about the development of a functioning human brain:


When people, including physicians, talk about "brain waves" and "brain activity" they are referring to organized activity in the cortex. While no embryo or fetus has ever been found to have "brain waves," extensive EEG studies have been done on premature babies. A very good summary of their findings can be found in Pain and its effects in the human neonate and fetus," a review article (often cited by "pro-lifers" writing about fetal pain, but not about brain development) by K.J.S. Anand, a leading researcher on pain in newborns, and P.R. Hickey, published in NEJM:

"Functional maturity of the cerebral cortex is suggested by fetal and neonatal electroencephalographic patterns...First, intermittent electroencephalograpic bursts in both cerebral hemispheres are first seen at 20 weeks gestation; they become sustained at 22 weeks and bilaterally synchronous at 26 to 27 weeks."
http://tigtogblog.blogspot.com/2006/...myths-and.html