Different Behaviors, Different Brains?


Individual Variation

domestic cats
bird song
human development
hermaphroditic fish
crayfish aggression

Alzheimer's and other Pathologies

& Sexual Orientation

Bibliography & Links

Human Brain Development

(thanks to the Jim Borgman's Zits cartoon at this site)

Large changes in the brain do not just occur during infancy. It has been shown that, as this site indicates, there is a "brain spurt" just before puberty, with lots of new gray matter -- the part of the brain responsible for thinking. During the rest of adolescence, much of the new gray matter goes away. Which parts remain depend on the nature of a teen's activities. Adolescence is in many ways a fresh start for the brain, a chance to hardwire the brain for the rest of life. "Use it or lose it," is the simplified principle, as teenagerss design their brains for the future with the choices they make now.

Brain development is refined during adulthood according to one's life experiences. This means that the experiences that may shape one person's brain to function in particular way will be different from the experiences that affect someone else. For example, one research team found that the brain regions controlling the finger movements of experienced string musicians were more sophisticated than the same brain regions of adults who did not play string instruments! In a similar manner, the recurring, everyday experiences of each adult-whether they are a professional musician, skilled gardener, expert mathematician, expressive artist, or surgeon-alter their brain's organization and functioning in small but important ways. Because experience influences brain development throughout life, each of us has a brain that is similar to everybody else's-but is also individually tailored to our personal interests, skills, and experiences.

Click here to download an article (by Erin Clifford, in the "Harvard Brain") about the brain's ability to reorganize in response to some change in input from internal or external sources.

Remember-- all of these changes in the brain are also accompanied by SIGNIFICANT behavior changes. While a five month old cries for food, a five year old tugs on his father's sleeve until he gets a snack. While an eight day old baby is only just learning who her mother is, an eight year old expresses her love for her mother with hugs and kisses.

Hmmm... so, humans develop at a slow pace, changing behavior as they go. In addition, their behavior may change the development of certain connections in the brain. The next step is to question whether there are rapid brain and behavior changes? For that, we're best off going back to some animal examples for a little while...

Let's look at rapid brain/behavior changes in fish and crayfish