The Human Brain - part 2

Five(?) senses

When we think about senses we usually mean: sight, hearing, taste, smell and touch. However, according to wikipedia there are few additional senses such as: nociception (pain), thermoception(temperature), and equilibrioception(balance and acceleration), proprioception (kinesthetic sense) and “other internal senses”. I believe that names of first, second and third senses are self-explanatory. The fourth sense provides us with information on the relative positions of the parts of the body, e.g. when you try to touch your nose with your fingertip.

Stimulus processing

Each sense provides our brain with some kind of stimulus which is then processed. But we still don’t know how it works exactly. According to logic, each sense should be governed by its own region in brain, but some research clearly shows that auditory and visual information is processed together before the combined signals reach the brain’s cortex. It means that these two different types of signals are combined before brain can “think” about it. It is also explanation why when we are looking at some puppet show e.g. (click) we automatically associate the voice and mouth of the dummy.

My own experience shows that there is similar correlation with smell and taste. Ask yourselves, how often bad smelling food was in fact delicious? Or how often you haven’t something because its smell was bad?

Brain capability of adaptation

Take a look a the MRI below.

What you see is brain, to be more specific a half of brain of an 10 yo. German girl. She is a medical phenomena. Doctors are stunned that despite of absence of her right hemisphere (since her birth) she is capable of living normal life. Moreover her left hemisphere possessed functions of her right, missing, hemisphere. And what is more fascinating she have left and right visual fields. Normally each hemisphere is responsible for the opposite visual field, so the right hemisphere is responsible for left visual field. In other words her sight should be severly damaged.

Déjà vu

So. What is déjà vu? (no, I don’t mean matrix failure ;)). Generally it is anomaly of memory that gives impression that an experience is “being recalled”. One of theories states that déjà vu occurs when there is asynchronous in memorization of an experience. It happens when one hemisphere gets information slower than the other. In other words, one hemisphere is experiencing something that other already experienced.

Assuming that this theory is true. Do you think that “German girl” (mentioned above) will ever experience déjà vu?