Q. My husband and I are both accountants. Every year at tax time I seem to tire faster. He says it’s all in my head. Is it really?

A. Yes, most likely. Although male and female brains are more alike than they are different, there are some differences. For example, the corpus callosum, the largest band of horizontal connecting fibers, is smaller in the male brain. This contributes to lateralization; in other words, the male brain can concentrate its thinking efforts in one portion of the cerebrum. A larger corpus callosum in the female brain is believed to contribute to a more global type of processing. The entire cerebrum must be revved up to run any part of it thereby utilizing more metabolic energy. Practically and theoretically this may mean that when men and women are given the same mental task, all else being equal, the female brain may tire more quickly.

Other factors could contribute to your fatigue, as well, however. For example: spending large amounts of time performing tasks outside your natural brain lead, inadequate diet, lack of sleep, stressors in your lifestyle, physical illness, or trying to keep up all household tasks in addition to accounting duties.