The identity theory
The identity theoryThe identity theory, also known as reductive materialism, is one of the views
Churchland uses to describe mind-brain correlation. Churchland believes that
the mental states of the body are one and in the same (double aspectism) with
brain states. They are the same because the biochemical actions produced in
brain states (release of serotonin and acetylcholine) have direct interaction with the mental states (mood disorders such as depression). With the help of
psychological and physiological evidence the identity theory can be better
supported. It has not yet been proven but following along with the symptoms,
diagnosis, and treatment of biochemical disorders of the brain the identity theory has a strong case towards becoming reality.
Reductive materialism is known to be the reducing of mental activity into physical activity. In its simplest form thoughts are just states of the brain. This is basically a similar form of Descartes line, "I think, therefore I am" or vice versa.
Churchland first tries to parallel the identity theory with sound and light. "We now know that sound is just a train of compression waves traveling through the air..." (BR323). Society does know or has some common sense notion of how sound travels, yet we still consider it just "sound". Even though we are not automatically thinking when we here a sound, "it is waves traveling through air", we are aware to the fact that is how sound travels. This parallelism is intertheoretic reduction; taking an older version of reductive materialism and using it to help explain a newer version, Churchland's identity theory.
Neural activity and neuroscience play a major role in the identity theory. "...the correct account of human-behavior-and-its-causes must reside in the physical neurosciences" (MR324). Neurosciences and cognitive psychology
have been used together to explain brain states and mental states correlation.
"And those behavior-controlling internal operations are precisely what the
neurosciences are about" (BR324). Neuroscience is described as being
behavior that which is a result of neural activity in the brain (i.e. consciousness). This consciousness is a result of neural activity in the brain producing thoughts and then behavior.
The identity theorist resides on simplicity to describe mental/brain states "...from the neural dependence of all known mental phenomena..." (TL325). Once thought of as mental disorders, forms of depression are now recognized as brain disorders. Understanding the biochemical determinants and the function of the brain has helped to draw this conclusion. Biochemical changes in the brain cause a person to fall into a depressed state. These brain states are the release of low levels of the chemical serotonin. Serotonin is a chemical in the brain that controls much of the mental state (learning and memory function) with impulses between neurons. This brain state simultaneously affects the mental state or behavior of a person who shows signs of depression. Such signs are inability to fall asleep at night, frequent panic attacks, loss of concentration, and thoughts of suicide or even attempted suicide.
Depression has also been linked with the low chemical release of the
neurotransmitter (chemical messenger) acetylcholine in the brain, which affects
memory capabilities in the mental state. These chemical releases can be
controlled with the aid of medication which alter the releases of these chemicals serotonin and acetylcholine.
Medication such as Zoloft, Imipramine, Xanax and Clonopin help to alter
the brain states. Once the medication has taken effect and the brain states are
under control, the mental states (thoughts) have been altered as well. It is very hard to explain without using some doctor's DSM-IV book but the effects the
brain/neural transmitters have on the mental states of a person are in fact the
same. The thought's under the mental state are changed solely because of the
altering of the brain state. In other words reductive materialism is at work!
Concentration levels have increased and a calmness has overcome the fear and
guilt in the mental states brought on by the brain state's biochemical releases.
Another form of a brain state-controlling device is an electronic device
known as a transcutaneous electronic nerve stimulator. This is used to control
the mental states of pain. It sends electronic currents to the brain which in turn send pain-inhibitors affecting the mental states. Once again this shows that "our behavior appears to have its basic causes in neural activity" (TL325).
Reductive materialism by Churchland's definition is simply the reduction of mental phenomena into physical phenomena, and vice versa making them the same. This identity theory holds much ground in the psychological and
physiological forms as well. The example of depression is just one of many
claims that can be taken into consideration for the plausibility of the identity
theory. This brain disorder was used because of the personal involvement that I
have with it. Mental and brain states are one and in the same idea due to the
fact that I am experiencing these effects due to obsessive-compulsive disorder
and high anxiety which I am being treated for. Mental and brain states are
reduced into one with the occurrence of biochemical releases simultaneously
changing thoughts and behavior.