Annually more than 400,000 deaths may be attributed to tobacco smoking and here is an investigation which sheds light on the probable harmful effects of smoke. A latest study commenced by the UCLA scientists asserts that cigarette smoking paves way for deficits in attention and memory among youth. It was suggested that greater a teen’s addiction to nicotine, the less active is the prefrontal cortex.
The study examined a total of 25 smokers and 25 non-smokers between the ages of 15 to 21 years. At the time of the investigation, participants were subjected to a test that allegedly activated the prefrontal cortex and required them to inhibit responding. Termed as the Stop-Signal Task (SST), the test was conducted while the subjects underwent fMRI. During SST a button has to be pressed as quickly as possible every time a lighted arrow appears, not unless an auditory tone is played. This test possibly scrutinizes a person’s ability to inhibit an action.
“The finding that there was little difference on the Stop-Signal Task between smokers and non-smokers was a surprise,” commented the study’s senior author, Edythe London, a professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA. “That suggested to us that the motor response of smokers may be maintained through some kind of compensation from other brain areas.”
Before the fMRI test, experts employed the Heaviness of Smoking Index (HSI) to measure the level of nicotine dependence in the smoking group. The HIS supposedly analyzes the amount of cigarettes a teen smokes in a day and how soon after waking he or she takes the first smoke. It was pointed out that higher the HIS, lower may be the activity in the prefrontal cortex. In spite of the reduced levels of activation, the smoking group and the non-smoking group performed roughly the same with respect to inhibition on the Stop-Signal Task.
The study is published in the current online edition of the journal Neuropsychopharmacology.