A number of non-human species have been found to make specific vocal sounds that are meaningful to others of their species. An imaging study investigating such sounds in macaque monkeys has found that the regions of the brain that are activated when the monkeys hear such meaningful vocalizations correspond to the same regions that we know as the 'language centers' in the human brain. This suggests that these communication centers in the last common ancestor of humans and macaques were recruited for language purposes during human evolution.

Scientific American reports on a recent study that found that autistic males have fewer neurons in the amygdala -- a region that could be described as the 'emotional center' of the brain -- than non-autistic males. Interestingly, previous studies have found that autistic boys develop adult-size amygdala many years earlier than other males. The fact that the volumes are the same, but the number of neurons is so much less, is certainly intriguing.