Debra Pizzuto
Neuropsychology
Professor Morgan


Normal Aspects of Human Emotion

Emotions are physiological and psychological responses that 
influence perception, learning and performance.  In 1884, 
Harvard psychologist William James wrote that conscious 
experience follows the bodily reactions, which are more or less 
automatic reactions responding to stimulus in the environment 
(Murray,49).  
Two theories relate to emotion.  James Lange theory, proposed 
that automatic and skeletal reactions happen before our 
response.  This theory has had much criticism.  Injections of 
adrenalin for example, do the same thing to the autonomic 
nervous system, and patients feel as if they are afraid or as if 
they are experiencing a joyous event.  Cannon-Bard theory 
proposed that emotional experience and physiological arousal are 
simultaneous, but independent.  If this were true, intensity 
would not make a difference (Kalat, 326).  Both theories are not 
exactly correct.
Sudden intense stimulus can cause fear in an adult or child. 
Donald Hebb found that there is some learning involved before we 
can identify emotions.  It is what we experience as emotion that 
produces the label we give our response.  Anger and frustration 
aggression are examples that according to hypotheses where 
frustration produces feelings of anger.  Physiologically, fear 
and anxiety are the same, but fear is thought to involve a 
specific physical threat, where anxiety is more general.  Doubt 
thrown on one=s intelligence, religion, or honesty could produce 
some anxiety.  Reactions to stimuli are different for each 
person, depending on relative importance.  Robert Plutchik 
proposed a theory that produced eight basic emotional relations: 
anticipation, anger, joy, acceptance, surprise, fear, sorrow, 
and disgust.  We can also find, he states, these proto types in 
lower animals (Murray, 57).
Emotion always includes specific kinds of somatic responses 
from specific autonomic sympathetic or para sympathetic 
activities.  Perceptions of emotion from somatic responses like 
for fear, rapid heartbeat, anger tenseness of muscles, with 
flushed face, or pleasure, with relaxed muscles and quiet 
breathing are each slightly different in each individual.  
Memory for events is individual.  Often memory can remain as a 
symbol for initial emotional reaction.  Some intrinsic parts of 
higher level functions may no longer require specific emotional 
stimulus to bring them forth(Garoutte,204). Memorized 
perceptions may induce the somatic changes from the original 
stimulus without it being present.  This refers to the 
experience of somatic perceptions associated with fear, anger, 
or pleasure, without any immediate external cause or event 
(Garotte, 205).   


Emotional expression is often ascribed to the limbic 
system. Limbic system functions of forebrain structures are: 
hypothalamus, hippocampus, amygdala, olfactory bulb, septum, 
parts of the thalamus, and cerebral cortex. The right hemisphere 
is thought to dominate for emotional reactions in humans.  All 
limbic structures project onto hypothalamic structures in 
greater or lesser degrees(Eleftheriou,343).  Evidence from tests 
on the sympathetic nervous system with regard to heart rate and 
blood pressure have indicated right side responses.  EEG 
demonstrates increase in theta waves, which indicates stress or 
activity.  These waves increase when alpha waves decrease.  Also 
delta and theta waves are more common among children with 
neurological disorders.  Alpha waves indicate an awake but 
inactive person who is not attending to external stimulus. For 
example, brain waves component with latency of 100msec may be an 
index of selective attention to the external stimulus.  A spike 
of 200msec occurs when unexpected occurance is presented 
(Wittrock, 384).  
Pet scans indicate that reciprocal limbic-cortical 
functions where blood flow increases in paralimbic blood flow 
and decreases in neocortical (dorsolateral, prefrontal, inferior 
parietal)regions.  With recovery from sadness for example, the 
reverse pattern involving the same regions ,limbic metobolic 
decreases and neocortical increases.This activity occurs with 
transient and chronic changes in negative mood (Mayberg et al 
1999).  Neuroscientists have begun to explore intense emotions 
at key times in early life that produce behavioral and long 
lasting physical changes which remain in the brain long after 
the emotion has passed that shape emotional responses later in 
life.  Research indicates that there are distinct patterns of 
brain activity in individuals who are fearful or resilient.  It 
seems that memory depends on self re exciting electrical 
activity in the brain.  Certain regions of the hind brain and 
medial forebrain bundle with changes in the thalamus coming 
later for more learned behavior and still later changes in the 
cerebral cortex. Alexander Forbes in 1922 at Harvard found this 
activity demonstrated in the cuttlefish when they were after 
prey.  The same re exciting chains did not occur in the fish 
when circuit were interrupted or cut(Young,82).  
Scientists have examined the need for special language to 
describe emotion.  Popper in 1972 states that questions of truth 
or validity must be sharply distinguished from all genetic, 
historical, and psychological questions.  Evasion from this 
would be deceptive and dangerous accordingly.  He states further 
that all language is arbitrary and relative (Young,82).


Research correlating emotion processing of normal subjects 
with that of subjects diagnosed with alexithymia, which is a 
desease characterized by a decreased ability to communicate 
feelings, even to identify them, with a cognitive tendency 
toward detail and external events combined with imagination or 
fantacy (Roedema & Simons).  Emotion measured by skin conduction 
responses and self report developed by Lang and associates, with 
EMG responses, targeted frontal areas of the brain not well 
researched yet.  The authors comment in their conclusion that 
there research indicates that further study is needed.
   	There is continual interplay between actions that spring 
from lower regions and the restraints imposed by learned 
responses of the cortex.  In humans, the frontal orbital zone if 
inhibit aggressive behavior.  Where as people with damage in 
this area show generalized disinhibitation and changes in 
affect.    They may show lack of selfcontrol, and violent 
emotional outbursts.  Altered by procedures, amounts of chemical 
activity can produce that same results.  Levels of NA, 
noradrenaline, will produce aggressive behavior in rats where 
they readily kill mice, while dopamine levels are raised.  If 
serotonin is injected, it will depress forms of aggression.  The 
ratio of amine is important in control of aggression(Young,159).  
The amines are transmitters used by nerve fibers to activate 
synapses.  The alarm reaction we experience is activation of the 
adrenal gland in the medulla.  The release of adrenaline 
hormone, is the effect of preparation of the body for action as 
is fight or flight responses.  These are just responses of 
arousal. The same chemicle compound, for example, NE, can be a 
neurotransmitter when it is released in one manner and a hormone 
when it is released in another manner.  Terminology is more 
acceptably called neuroendocrine system. 
The amygdala, located at the base of the brain is 
responsive to aggression and other emotional behavior. Its 
connection to the hypothalamus produces reciprocal connections.  
The amygdala controls endocrine function.  Pituitary gland 
attached to the hypothalamus produces secretions that regulate 
the activity of many hormonal glands whose activity has capacity 
to regulate, sexual hormones, sadness, depression, attack 
behaviors, to name a few.   The relationship between the 
hypothalamus and amygdala studies indicates specific regions of 
response.  Wendt (1963) noted that response from amygdala to 
hypothalamus was concentrated in HVM, nucleus ventro medialis, 
and the anterior hypothalamic area mostly in AHD(III).  It is 
speculate that the hypothalamus modulates and times some 
important functions of control over integration 
(Eleftheriou,337).


Input fibers of neurotransmitters in the corticostriatal 
pathway is glutamate(Sheppard,356).  Thalamostriatal is less 
clear but is likely to be glutamate as well.  Analysis of 
synaptic actions must rely on neostriatal input and output 
pathways by electrical stimulation.  The corticostriatal EPSP is 
mediated by glutamate acting on nonNMDA receptors(Sheppard, 
358).  Stimulus on the thalamus is very similar.  These neuron 
have large numbers of spiny dendrites.  The main axon of the 
dendrite emits several collaterals before leaving the cell body.  
This gives rise to arbortration.  This type of neuron comprises 
about half of the neuron in the basal ganglia(Sheppard,337).  
One of the most prominent features of the neurons in cortical 
regions are spiny neurons.
Neurotransmission for excitation in the cortical regions 
are now known to be glutamate, aspartate, glycine, and taurine.  
L glutamate has emerged as the major excitatory amino acid 
transmitter of the cerebral cortex.
Gaba is the major inhibitory neurotransmitter in the 
cortex.  This has been tested with evoked IPSP.(Conners et 
al.,1988; Douglas et al.,1989).  Antibodies directed at the 
amino acid indicate that about 20% of the neocortical neurons 
synthesize and contain GABA(Naegele and Barnstable, 1989),in 
Sheppards book on synaptic organization.             
It is viewed that synaptic depletion of saratonin levels is 
a cause of depression, that permits the fall of norepinephrine 
levels.  The amygdala and brain stem contain serotonin producing 
cells.  Norepinephrine and acetylcholine are chemically 
antagonistic neurotransmitters involved with muscle 
contractions.  Both act to balance with Ach causing contractions 
and NE inhibiting, making muscles perform dual functions.  They 
act in the same way in the autonomic regulation of heart beat, 
peristaltic movement of the intestines.
Emotion processing in three systems (Simons et al 1999), 
measured two emotion dimensions. Valence and arousal responses 
were consistent in self report, physiological and overt 
behavioral responses.  

Martin=s text, Human Neuropsychology has provided one with 
a brief overview of complex networks of the central nervous 
system.  He has also evidenced that left hemisphere is 
associated with positive emotional experience and the right 
hemisphere with negative emotional response.  Memory of 
emotional experience is  is superior for expression of emotion,  
while the right hemisphere is superior for recognition and 
perception of emotion.
Though most studies are focused on vision inputs, there are a 
few relating that initial emotion responses are measured in 
blind subjects.



	References
Garotte, B. (1981).  Survey of functional Neuroanatomy.  
Greenbrea, CA: Jones Medical Publications.

Eleftheriou, B.E., Ed. (1972).  The Neurobiology of the 
Amygdala.  New York, NY: Plenum Press.

Kalat, J.W. (1998).  Biological Psychology.  Pacific Grove, 
CA: Brooks Cole. pp.322-334.

Lazarus, R.S., Ed. (1964).  Foundations of Modern Psychology.  
Englewood Cliffs, NJ: Prentice Hall.

Martin,N.G. (1989).  Human Neuropsychology.  London, England: 
Prentice Hall Europe.

Roedema, T.M. & Simons, R.F. (1999).  Emotion processing 
deficit in alexithymia. Psychophsiology, 36, 379-387. 
 
Simons et al. (1999). Emotion processing in three systems: 
the medium and the message.  Psychophysiology, 36, 619-627.
 
Wittrock, M.C., Ed. (1980).  The Brain and Psychology.  Los 
Angeles, CA: Academic Press.

Young,J.Z. (1978).  Programs of the Brain.  Great Britain: 
Oxford University press. NY:  

Copyright © 1999, Dr. John M. Morgan, All rights reserved - This page last edited 13 - December, 1999
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