Tuesday, February 3, 2015
Lecture: Physiological Approaches to Personality
Building a theoretical bridge..
-different levels of ﬂuid in our bodies account for differences in personality, location
and sizes of bumps on our heads, our body types. (not proven).
Speciﬁc Conditions or Stimulus (audience) -> personality trait (shyness) ->
psychological response (anxiety) -> physiological response (HR increase) -> behaviour
(avoiding, running away) ex: someone who is extraverted. (they are not going to get the
Common Physiological Measures in Personality Research
1. Electrodermal Activity (AKA skin conductance)
-provides a measure of sympathetic nervous system is active (ﬁght or ﬂight response)
-having two electrodes place on one ﬁnger and one part of the hand (water, greater
-measure trait neuroticism (putting people in different types of settings) corresponds to
psychological reactions to their personality.
Skin Conductance and Self Injury
Nock and Mendes
Emotional Activity: intensity and persistence of emotion to stimuli - thought to be
elevated among those who self injure. (anxiety, stress, sadness, anger, do something
about it to get relief) -> particularly related with negative events or stressful tasks.
Induce stress in two groups and measure skin conductance (one group had a history of
this behaviour and the other group had never done this)
stress induction: matching game in which failure feedback is given even when a
response is correct. (card best matched with)
goal: to determine how long people stay in the game and tolerate distress from negative
failure feedback. -> do some people quit to avoid this?
-top line -> self injury, bottom who had never done this. (those who did, will do so
again because they are more stress prone and have higher skin conductance and
more negative emotional reactivity to stress)
-they also quit the game sooner which also might indicate lower distress tolerance
Tuesday, February 3, 2015
Implications: emotional reactivity and distress tolerance may be key to understanding
self injury. (why is more likely for some people and continue to do it)
2. Cardiovascular Activity
-blood pressure (BP) -> individual variability (arterial walls in the heart are pressured
by blood) - those who are more stress prone may have a higher stress response.
-heart rate (HR) -> expressed in beats per minute (eg. interval between beats) it is a
good indicator of stress and anxiety as well as a cognitive effort (stats or math, by
using more brain activity for this task)
-hypothesize that people may vary! cardiac reactivity -> increase in BP and heart rate
in times of stress.
-chronic reactivity linked with type A personality (constellations of traits that have this
high motivation to achieve, hostility and anger) cardiac disease risk
3. Brain Activity
-EEG (measures brain activity by looking at electrical impulses (electrodes) to
determine areas in the brain that have more activity and put them in situations and
measures those differences in their stress response)
-fMRI (shows images of areas of the brain activity (certain task speciﬁcity and
EX: MRI and Psychopathy (more prone if they are shown certain types of images)
decreased limbic system (experience in responses to emotion) activation when viewing
violent images for those high in psychopathy vs control (who had more activity)
may be used to explain lack of empathy and remorse* -> amygdala and temporal lobe
(emotional responses) and frontal lobe (controls impulses) - trying to develop treatments
involvement in reoffending after release. Hence, the parts of the brain responsible for
emotional processing are under-developed.
TAKE-HOME: how we experience emotions through these kinds of tests.
MRI: other relevant ﬁndings
-neuroticism: correlated with increased frontal brain activation to negative images.
(tends to be stable)
-extraversion: correlated with increase frontal brain activation to positive images.
Physiological Personality Theories & Related Research & Clinical Findings
Eysenks Original Theory
-Ascending Reticular Activating System -> gateway for nervous stimulation of cortex
(resting state, less gateway, open, more gateway)