Chapter 7 Personality

behavioral activation system

BAS. in gray's reinforcement sensitivity theory, the system that is responsive to incentives, such as cues for reward, and regulates approach behavior. when some stimulus is recognized as potentially rewarding, the BAS triggers approach behavior. this system is highly correlated with the trait of extraversion.

behavioral inhibition system

BIS. in Gray's reinforcement sensitivity theory, the system responsive to cues for punishment, frustration, and uncertainty, the effect of BIS activation is to cease or inhibit behavior or to bring about avoidance behavior. this system is highly related to neuroticism.

reinforcement sensitivity theory

Gray's biological theory of personality. based on the recent brain function research with animals, gray constructed a model of human personality based on two hypothesized biological systems in the brain: the behavioral activation system (which responds to incentives, such as cues for reward, and regulates approach behavior) and the behavioral inhibition system (which is responsive to cues for punishment, frustration, and uncertainty)

optimal level of arousal

Hebb believed that people are motivated to reach an optimal level of arousal. if they are underaroused relative to this level, an increasing in arousal is rewarding, conversely, if they are overaroused, a decrease in arousal is rewarding. by optimal level of arousal, Hebb meant a level that is "just right" for a given task.

harm avoidance

In cloninger's tridimensional personality model, the personality trait of harm avoidance is associated with low levels of seretonin. people low in seretonin are sensitive to unpleasant stimuli or to stimuli or events that have been associated with punishment or pain. consequently, people low in seretonin seem to expect that harmful and unpleasant events will happen to them, and they are constant vigilant for signs of such threatening events.

free running

a condition in studies of circadian rhythms in which participants are deprived from knowing what time it is (meals are served when participants ask for them) when a person is free running in time, there are no time cues to influence behavior or biology.

sensation seeking

a dimension of personality postulated to have a physiological basis. it refers tot he tendency to seek out thrilling and exciting activities and to take risks and avoid boredom.

norepinephrine

a neurotransmitter involved in activating the sympathetic nervous system for fight or flight.

serotonin

a neurotransmitter that plays a role in depression and other mood disorders. drugs such as prozac, zoloft, and paxil block the reuptake of seretonin leaving it in the synapse longer, leading depressed persons to feel less depressed.

dopamine

a neurotransmitter that seems to be associated with pleasure. dopamine appears to function something like the reward system and has even been called the "feeling good" chemical.

alpha wave

a particular type of brain wave that oscillates 8 to 12 times a second. the amount of alpha wave present in a given time period is an inverse indicator of brain activity during that time period. the alpha wave is given off when a person is calm and relaxed. in a given time period of brain wave recording, the more alpha wave activity present the more we can assume that that part of the brain was less active.

impulsivity

a personality trait that refers to lower self control, especially in the presence of potentially rewarding activities, the tendency to act before one thinks, and a lower ability to anticipate the consequences of one's behavior.

cortisol

a stress hormone that prepares the body to flee or fight. increases in cortisol in the blood indicate that the animal has recently experienced stress.

ascending reticular activating system (ARAS)

a structure of the brain stem though to control overall cortical arousal; the structure eysenck originally thought was responsible for differences between introverts and extraverts.

monoamine oxidase (MAO)

an enzyme found in the blood that is known to regulate neurotransmitters, those chemicals that carry messages between nerve cells. MAO may be a causal factor in the personality trait of sensation seeking.

anxiety

an unpleasant, high arousal emotional state associated with perceived threat. in the psychoanalytic tradition, anxiety is seen as a signal that the control of the ego is being threatened by reality, impulses from the ID, or harsh controls from the superego. freud identified three different types of anxiety: neurotica anxiety, moral anxiety, and objective anxiety. According to Rogers, the unpleasant emotional state of anxiety is the result of having an experience that does not fit with ones self conception.

frontal brain asymmetry

asymmetry in the amount of activity in the left and right part of the frontal hemispheres of the brain. studies using EEG measures have linked more relative left brain activity with pleasant emotions and more relative right brain activity with negative emotions.

neurotransmitters

chemicals in the nerve cells that are responsible for the transmission of a nerve impulses from one cell to another, some theories of personality are based directly on different amounts of neurotransmitters found in the nervous system.

novelty seeking

in Cloninger's tridimensional personality model, the personality trait of novelty seeking is based on low levels of dopamine. Low levels of dopamine create a drive state to obtain substances or experiences that increase dopamine. novelty and thrills and excitement can make up for low levels of dopamine, and so novelty seeking behavior is thought to result from low levels of this neurotransmitter.

reward dependence

in Cloninger's tridimensional personality model, the personality trait of reward dependence is associated with low levels of norepinephrine. people high on this trait are persistent, they continue to act in ways that produce reward. they work long hours, put a lot of effort into their work, and will often continue striving after other have given up.

arousal level and arousability

in Eysenck's original theory of extraversion, he held that extraverts had lower levels of cortical or brain arousal than introverts. more recent research suggests that the difference between introverts and extroverts lies more in the arousability of their nervous systems, with extraverts showing less arousability or reactivity than introverts to the same levels of sensory stimulation.

circadian rhythms

many biological processes fluctuate around an approx. 24/25 hour cycle. these are called circadian rhythms. their rhythms in temporal isolation studies have been found to be as short as 16 hours in 1 person and 50 hours in another person.

seneory deprivation

often done in a sound-proof chamber containing water in which a person floats, in total darkness, such that sensory input is reduced to a minimum. researchers use sensory deprivation chambers to see what happens when a person is deprived of sensory input.

electroencephalograph (EEG)

the brain spontaneously produces small amounts of electricity, which can be measured by electrodes placed on the scalp. EEGs can provide useful information about patterns of activation in different regions of the brain that may be associated with different types of information processing tasks.

comorbidity

the presence of two or more disorders of any type in one person.

morningness-eveningness

the stable differences between persons preferences for being active at different times of the day. the term was coined to refer to this dimension. differences between morning and evening types of persons appear to be due to differences in the length of the underlying circadian biological rhythms.