2	The Role of Biology in Psychology

IN 2012, JACK OSBOURNE (Figure 2.1), the 26-year-old son of Ozzy and Sharon Osbourne, celebrated the arrival of his daughter Pearl. Just two weeks later, he noticed a disturbing problem with his vision. He told People magazine (July 9, 2012) about an experience he had at a gas station: “I was talking to the attendant, and all of a sudden a black dot appeared in my vision…. I was like, ‘That’s weird.’ The next day I woke up and the dot had turned into a cigar shape.” Jack’s vision kept getting worse, until he could barely see out of his right eye. After a series of tests, doctors determined that Jack was in the early stages of multiple sclerosis.

 

Multiple sclerosis (MS) is a disorder of the nervous system that is typically diagnosed in people between ages 20 and 40. MS affects the brain and the spinal cord, so that movements become jerky and people lose the ability to coordinate their actions. Gradually, the ability to move, see, and think all become severely impaired. MS affects about 2.5 million people throughout the world. It is incurable, but in some forms of the disease the symptoms are now manageable.

The symptoms of MS make clear that our nervous system is critical for thinking normally and behaving normally. The nervous system consists partly of nerve cells, also known as neurons. MS limits the ability of neurons to send signals to each other and to receive each other’s signals. To picture how a neuron operates, imagine the plastic around a wire, such as the cord from a lamp or an appliance. The plastic insulates the wire, allowing electrical current to run to the lamp so it can turn on. Without that insulating layer, electricity will never reach the lamp. One part of the neuron, like the lamp cord, is covered by a fatty layer that enables the neuron to transmit signals to other neurons and other parts of the body. In MS, the fatty layer deteriorates, and normal communication between neurons is short-circuited.

To learn about psychology, you need to understand how neural communication enables us to think and behave. You also need to see how both nature and nurture affect these processes. We cannot understand thought and behavior without understanding our underlying biological processes.