Harmon-Jones, Gable, P.A.,
Peterson, C.S.
The role of asymmetric frontal
cortical activity in emotion related phenomena. A review and update
Biological Psychology, 84,
451- 462
Greater
left than right neural activity ( defined as reduced alpha power) associated
with positive affect ( approach/no approach) behaviours.
Carotid
Amytal, rTMS, findings interpreted as losing inhibitory influences of the
affected hemisphere. Hemisphere specialisation evidenced by asymmetry in neural
activation, right versus left as the DV, usually assessed by EEG specifically
alpha power (KRO but see Davidson 1988 for the conceptual difference between
hemisphere specialisation and hemisphere activation and how the two need not be
related)
Methodological issues
State
variables-environmental e.g. Time of day and time of year influences on cortisol
levels may explain disparate findings about trait influences.
Manipulations
of emotion, p 454 'some may not evoke
sufficient emotional intensity to engage asymmetrical frontal activations
for all individuals' , ' Moreover, the intermixing of multiple types of
affective stimuli may weaken motivational affects'
Measuring
motivational direction. Motivational direction can be measured by using
behavioral inhibition/activation system scales BIS/BAS of Carver and White
(1994).
Motivational
intensity
can be potentiated by trait, and the opportunity to act. Led to
experiments comparing supine and upright whilst Ps were given insulting
feedback. Frontal activations diminished when supine. This finding has
implications for the choice of technique .. .
, . . . ,
. ,
. ...
,
fMRI ( when Ps need to be supine) and EEG(when they do not).
Gross
& Levinson (blinking associated
with anger due to emotion suppression activity)
Manipulations
Neurofeedback
Used
with AHSD by monitoring theta and alpha levels
In
experimental settings Ps have been trained by 'rewarding' or 'not' with tones
of differing frequency. 32 minutes training per day, feedback every 2 seconds.
One group trained to increase relative right. Then zygomatic and corrugated
monitored while Ps watched films . The
relative right group produced more corrugater.
P453
' this research suggests that asymmetric frontal cortical activity is casually
involved in emotional responses'
Hand
contractions
Hand
and face contractions activate contralateral hemisphere and in turn lead to
spreading activation in that hemisphere and therefore alpha suppression is the
consequence. tested and affirmed by
comparing uni lateral hand contractions (4 mins) then Ps watched a mildly positive approach
-orientated radio editorial while EEG recorded
Then an attitude scale used to measure motivation?
Guilt
'Does
asymmetric frontal cortical activity fluctuate in response to motivational
intensity changes?' ' guilt is hypothesised to serve two functions that operate
in temporal sequence' (Amodio et al , 2007). Guilt first causes a reduction in
approach motivation once one is aware of having committed a social
transgression. This reaction is followed
by an increase in approach motivation when one is presented with an opportunity
to engage in behaviour to repair the transgression.
P458
Motivational intensity cf
valence
Events
vary in their impact ie motivational intensity
Do
positive(valence) affects of any approach motivational intensity cause increase
in relative left frontal activation.
The
Mindset experiment
3
conditions
1. High approach positive valence (the P' s
actions lead to positive outcome)
2. Low approach positive valence ( the positive
is produced by someone else but the P benefits)
3. Neutral
Result
alpha asymmetry 1>2>3
Source
location studies
Using
alpha power as the DV left frontal dorsal lateral is associated with approach
motivation
EEG v fMRI/PET
P
459 'Each technique may assess different populations of neurons. EEG signals
result from very selective areas of current source activity, often
corresponding to small subsets of total synaptic action in tissue volumes and
largely independent of action potentials. PET/fMRI measures, in contrast,
result from activity in areas requiring much hemodynamic/metabolic activity.
For example, cortical stelate cells occupy roughly spherical volumes and their
synaptic sources provide a " closed field" structure which makes them
invisible to the EEG. Although stellar
cells contribute only 15% of the neural population they contribute
disproportionally to cortical metabolic activity. Thus they have a large effect
on fMRI and PET. Other cases yield strong EEG signals and weak fMRI/PET
activity. EEG can be large when only a few percent of neurons in each column
are "synchronously active", if a large-scale synchrony among
different columns produces a large dipole in which individual columns tend to
be phase locked in particular frequencies. In this case, because most neurons
in each intra-column population are relatively inactive, there is minimal
metabolic activity'
Other
P459
'
Posterior cortical regions are asymmetrically involved in emotional perception'
right parietal and right temporal parietal , as measured by alpha power !!!!!!!
Even in sensory areas
p459
'
the research has suggested the importance of delineating emotional experience
from emotional expression and emotional valence from motivational intensity'
