Nicorette be damned! Quitting smoking is easy…if you’ve had a stroke. Naqvi et al. report that stroke-induced damage to the insula associates with smoking cessation in today’s issue of Science.

The insula lies in the pocket separating the temporal lobe from the parietal lobe and is thought to provide emotional context for sensory information. Sixteen of nineteen smokers who suffered strokes that affected the insula quit smoking immediately. Smokers who sustained damage to the insula were more likely to quit than smokers who had sustained damage to other brain regions. Although several of the patients with insular damage also sustained damage to the putamen, which is part of the striatum thought to be involved in learning drug use behaviors, no other brain region associated with smoking cessation in the stroke patients.

Do smokers with insular damage lose pleasure in smoking? After smoking cessation, none of the patients with insular damage reported losing pleasure in eating or drinking, suggesting that they had not lost motivation or the ability to experience pleasure. Do these patients lose other habits? Unfortunately, the authors did not address this possibility.

These findings suggest that the insula is important in experiencing the need to smoke and is therefore a target for smoking cessation therapy. Considering the insula’s proximity to language centers, surgical lesion of the insula is certainly not advisable. However, targeted pharmacological therapy might some day help smokers quit. According to the authors, the efficacy of smoking cessation programs might be determined by imaging insular activation.

Despite my best efforts to stop it, my most productive planning always occurs in the last five minutes of a yoga class. Relax my mind? I don’t think so! What goes on in the brain when we let our minds wander? Mason et al. report that a network of brain structures is active during daydreaming in a recent article in Science.

The authors had people do repetitive (i. e. boring) tasks, like memorizing and rehearsing the same short list of words forward and backward, for 30 minutes each day. The subjects reported that their minds wandered more during this task than when they were given a new task to do. On the fifth day, the subjects did the same task in an MRI machine. The authors identified regions of the brain that were active during this literally mind-numbing activity relative to those that were active when participants worked on a novel task. Then they correlated the activity of these brain regions to the participants’ daydream frequencies. BOLD signal in the medial prefrontal cortex, cingulate, precuneus, right superior frontal gyrus and the left and right insula associated with daydreaming. In addition to daydreaming, the authors believe that these brain regions might be important in ‘housekeeping’ functions or might cause people to be aware of their daydreams.

Why do we daydream? I’ll look that up once I stop thinking about a beach vacation…

Several sources, including news@nature and the Washington Post, reported today that relative to the early 1990s, the average blood level of folate in women is declining. Folate deficiency is associated with neural tube defects during fetal development. So women of child-bearing age are encouraged to take folate supplements even if they are not pregnant or actively trying to get pregnant. Incidence of neural tube defects has declined by approximately 25%, presumably because we are all taking folate.

So why are folate levels declining? It’s not clear, but officials from the U. S. Centers for Disease Control and Prevention have several ideas. Obese individuals metabolize folate differently than thin people and may need to consume more folate than their thin counterparts. Because obesity is on the rise, that may explain the decline in average folate levels. Alternatively, diet trends may be to blame. In the U. S., the Food and Drug Administration requires that enriched flour used in cereals and breads be fortified with folic acid. But in 2003, the Atkins diet craze encouraged us all to trade in our Cheerios for steaks. Now diet gurus are encouraging people to eat whole grains, which unlike their processed counterparts, are not supplemented with folic acid.

So, women should consume far more folate. That is, unless you remember this bizarre news item from last spring, reporting that each generation of obese pregnant mice fed folate and other methyl donors had increasingly heavier offspring.