Baby Girls Seem To Have More Complex Brain Activity Than Boys, Finds Study

The team suspects the variation between the sexes might be due to "underlying differences in how the nervous system develops in boys and girls".

Brain activity in baby girls seems to be more complex than that in baby boys, a new study has found. For the research, Joel Frohlich at the University of Tubingen in Germany and his colleagues used an imaging technique called magnetoencephalography (MEG) to measure the magnetic fields produced by the brain's electrical currents in fetuses and babies to sound stimuli. The team found that the complexity of signals in the brain seems to decrease as the nervous system develops in fetuses and babies - and does so significantly faster in males compared with females.

According to New Scientist, the researchers used MEG in 43 third-trimester fetuses and 20 babies, aged between 13 and 59 days old. The sound stimuli consisted of various arrangements of beeps. One sequence was made up of four beeps, each lasting 200 milliseconds and separated by 400 millisecond intervals. This was played to the fetuses via a "sound balloon" squeezed between the pregnant person's abdomen and the MEG sensors.

The team then recorded their magnetic brain activity upon hearing the sound stimuli. They calculated several different measures that reflect the complexity of the MEG signal, using algorithms that determine, for example, how difficult it is to process.