January 9, 2008

An increased difficulty in understanding spoken words a likely dividend paid to teenage smokers born of mothers who smoked during pregnancy.

A newly published article in The New Scientist recounts a study of 33 teenagers all born to mothers who smoked during pregnancy, who were studied by diffusion tensor imaging, which measures how water diffuses through brain tissue. Leslie Jacobsen of Yale University School of Medicine and her team conducted a research project that also included 34 teenagers whose mothers had not smoked during pregnancy. The study’s results have recently been published in The New Scientist.

The team discovered that children who have more white matter tend to have more problems interpreting sounds. The scans revealed the teens exposed to nicotine had more white matter than those who did not. Nicotine stimulates acetylcholine. Over-stimulated acetylcholine leads to the over-production of white matter.

The teens included in the study, aged 13-18 were tested with an exercise that required them to recognize words by hearing them while being exposed to background noise and visual images (distractions). The boys who had been exposed to nicotine got 77% of the words right, compared to 85% for those who had not been exposed. The girls who had been exposed got 84% right, compared to 90% for those who had not been exposed.

Researchers involved in the study explain that people who are affected will have problems in settings where there is a distraction, such as classrooms where conversation and ancillary noise are prevalent. This situation, the researchers found, coupled with other conditions, such as behavioral disorders, can decrease the child’s probability of success in school.

Source: Medical News Today