Chapter 7 - Physiological approach to personality Flashcards
What does the case of Elliot, and others, tell us about the physiological approach to personality?
That the body and mind are intimately connected. Personality resides, somehow, in our neurological pathways - and damage to these will alter personality.
Dr. Antonio Damasio, a neurologist at the University of Iowa wrote a book on his fascinating case study of “Elliot” (1994). Recount Elliot’s condition.
Elliot, a successful businessman, was discovered to have a brain tumor just above his eyes, behind his forehead. He therefore had to remove parts of his prefrontal cortex. All of his cognitive functions seemed to have remained normal or above normal after his operation. He however soon turned out to have problems reasoning, making bad judgements, did not feel emotion, his life changed drastically.
What is the most normal personality change due to brain damage?
Normally brain damage is in the frontal lobes, and this often results in impulsivity and lack of self-control.
How would the physicologically orientet personality psychologist explain someone’s introversion?
That the person has an overly sensitive nervous system.
Mention the most commonly used measures in physiological personality research:
- Electrodermal activity (skin conductance)
- Cardiovascular activity
- Brain activity
- Other measures like immune system functioning and hormone levels.
What do we measure when we do tests on Electrodermal Activity?
We’re measuring the amount of water in our skin, especially in the areas where there are high concentrations of sweat glands (i.e. the hands). This is an indication of autonomic activity, how active our autonomous nervous system is. More specifically, the sympathetic nervous system.
Explain the method of electrodermal activity measuring.
Two electrodes are placed on the palm of one hand. A very low voltage of electricity is then put through one electrode into the skin, and the researcher measure how much electricity is present at the other electrode. The difference in the amount of electricity that is passed into the skin at one electrode and the amount detected at the other electrode tells researchers how well the skin is conducting electricity. The more sympathetic nervous system activity there is, the more water is produced by the sweat glands, and the better the skin conductance.
Which personality trait is associated with nonspecific electrodermal responding?
Neuroticism and anxiety (Cruz & Larsen, 1995). A person who is rated as high in anxiety and neuroticism appears to have a sympathetic nervous system that is in a state of chronic activation.
Why is heart rate (BPM - beats per minute) interesting to researchers?
A rise in BPM tells you that the body is preparing for action.
What is cardiac reactivity?
How much peoples heartbeat increases during difficult tasks. Cardiac reactivity is associated witht he Type A Personalit - a behavior pattern characterized by impatience, competitiveness and hostility.
A study by Canli and colleagues (2001) looked at the personality through and fMRI scanner. What did they do and what did they find?
They presented 20 negative or 20 positive emotional images. They found personal difference in the degree of brain activation in response to the positive and negative images. These differences correlated with personality traits. Neuroticism correlated with increased frontal activation to the negative images, and extraversion correlated with increased frontal brain activation to the positive images.
H. J. Eysenck was a pioneer in explaining personality with physiology. What was his theory?
He proposed that introverts are characterized by higher levels of actrivity in the brain’s ascending reticular activating system (ARAS) than are extraverts. The ARAS is a structure in the brain stem thought to control overall cortical arousal. In the 1960s, the ARAS was thought of as a gateway through which nervous stimulation entered the cortex. If the gate was somewhat closed, then the resting arousal level of the cortex would be lower, and if the gate was more open, then the resting arousal level would be higher.
What is Hebb’s (1955) theory of “optimal level of arousal”?
By optimal level of arousal, Hebb meant that a level that is just right for any given task.
Eysenck included Hebb’s theory in his own physiological explanation of the extraversion-introversion dimension. How?
He hypothezised that introverts had a higher baseline arousal than extraverts, causing them to be more restrained and inhibited. This turned out not to be true, and Eysenck revised with arousal theory. A good deal of evidence now suggests that the real difference between introverts and extraverts lies in their arousability (not their baseline arousal).
Jeffrey Gray has proposed an influential alternative biological theory of personality (Gray, 1972, 1990), called reinforcement sensitivity theory. What does it say?
Based on brain function research in animals, Gray has constructed a model of human personality based on two hypothesized biological systems in the brain. The first is the behavioral activation system (BAS), which is responsive to incentives, such as cues for reward and regulates approach behavior. The other system is the behavioral inhibition system (BIS), which is responsive to cues for punishment, frustration and uncertainty.
