Download Neuroscience

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How do we understand the brain?
“I change you as you unfold and you change me as I unfold”
Beebe (2002) as cited in Gerhardt 2004.
Objectives:
• Describe the functions and part of the brain that hold our
emotional memory.
• Explain why the brain is different from other organs.
• The importance of experience dependent development.
• Understand the brain in terms of emotion, learning and
memory.
• Different types of memory
• What can happen when the brain is damaged –Can it change
who we are?
• Understand the autonomic nervous system.
• How we experience emotion.
• How does all of this have anything to do with how we relate
to each other.
YOU ARE YOUR SYNAPSES. THEY ARE WHO YOU ARE.
CELL BODY
Receive information
through Dendrites
Myelin sheath
Send
messages
through the
AXON
Nucleus
Synapses
Neural synchrony is the simultaneous / synchronous oscillations of
membrane potentials in a network of neurons connected with electrical
synapses (gap junctions). It is considered by some theorists to be the
neural correlate of consciousness. (Stufflebeam 2009)
Neural Plasticity
‘The brain’s capacity for change’.
•Only a few years ago, researchers considered
our brains lost their plasticity in adolescence
or early adulthood.
•the human brain is a lifetime work in progress
that retains plasticity - the capacity to change
- as long as the ‘owner’ is still alive’
• This gives great hope to people who suffer
certain types of brain injuries as it suggests
the brain will adapt to accommodate the
damaged area.
Hippocampus
Amygdala
AMYGDALA - part of the limbic system
CO-ORDINATES THE FEAR RESPONSE
Temporal Lobe
AMYGDALA
AMYGDALA IS IMPORTANT IN VIGILANCE, THREAT DETECTION AND DETERMINING
MEANING AND IMPORTANCE OF STIMULI (Making sense of stimuli).
According to Scaer (2005) the brain is:
A plastic, fluid and ever-changing
electrical /chemical /structural system
that generates new synapses and neurons
and discards old ones in response to
sensory input from changes in the
environment (p. 16).
Some facts about the brain:
•
more complex than we can imagine
•
all current theories are inadequate
•
Many of the “facts” known now will be proven false
•
Our knowledge consists of a network of hypotheses and
partial facts
•
Experience dependent
•
New connections are formed between neurons
•
Hippocampus (which serves explicit memory) new neurons
may be formed and existing ones discarded based on the
nature of experience.
•
Brain shrinks or expands and become more or less functional
based on experience (Scaer, 2005).
• The brain is designed to automate
behaviours because of its inefficiency
and ability to regard every situation as
new.
• An important factor in creating learning
and memory is the state of arousal in
which learning happens and then how
we regulate it. The alert state is the
optimal state for learning and encoding.
The mind on the other hand is:
• a perceptual experience
• generated by a complex set of synapses, neurons,
and neurochemicals states
• determined by genes, instinct and experience,
that is capable of developing and directing novel
behaviour
• the mind reflects, problem solves and incorporates
conscious information from experience
• the mind develops future self-protective and
avoidant behaviours that promote survival (Scaer,
2005 p.20).
EXPERIENCE-DEPENDENT DEVELOPMENT
•
The brain is an organ of adaptation and different from
other bodily organs.
•
The maturation of the cortex, especially the prefrontal
cortex, is essentially postnatal.
•
At birth, humans are some of the most immature
of
beings.
•
70% of cortical neuronal material is constructed after birth
as a result of interactions with the environment – this is
experience-dependent development.
•
Experience
dependency
maximises
the
environment-
organism fit and demands great parental investment
Explicit Memory (Declarative Memory)
• Later developing – matures with hippocampal and cortical
structures
• Hippocampus is critical to the formation of declarative
memory
• Contextualised within episodic and autobiographical
narratives.
• Known memory source – Memory of facts (semantic) and
events (episodic)
• Declarative, Organised by language, Related to visual
images.
• Identity/social information, Social rules, norms,
expectations
Implicit Memory (Non-Declarative)
• Early developing – Highly Functional at Birth – 18 months.
• Right-hemisphere bias
• Amygdala centred/OMPFC
• Context free regarding time, space and self-awareness/no
source attribution
• Emotional
• Sensory- Motor and Visceral
• Procedural Learning, Emotional responses, behavioural
patterns and skills, habits.
• Attachment schema
• Transference
• No conscious recollection
Lost Memory
A Model of the injury sustained by Phineas Gage.
The Autonomic Nervous System
Brain structures and hormones influence the emotions we feel.
 Darwin/Freud –
(observation).
emotion
understood
as
emotional
expression
–
 James/Lange Theory (1800’s) we experience emotion in response to
physiological changes in the body. One perceives frightening stimulus and
reacts and as a consequence of the body’s reaction to the situation one
becomes afraid. Physiological changes of increased heart rate and muscle
activity.
Danger perceived
SEE A SNAKE
- we flee
HEART RATE UP
- then we feel fear.
FEEL AFRAID
 Cannon/Bard Theory (1900’s) opposed James – Lang Theory. Emotional experience
can occur independently of emotional expression. The frightening stimulus leads to
feelings of fear first then we react.
Danger perceived
SEE A SNAKE
- feel fear
FEEL AFRAID
- we flee.
HEART RATE UP
T
H
E
S
T
R
E
S
S
R
E
S
P
O
N
S
E
Hippocampus
Amygdala
A - Brain response associated with the perception of self and others actions.
B – Earlier response for perception of one’s own actions as compared to the
perception of the actions of others.
These composite MRI brain scans show the distribution of active
areas in the brain of males (left) and females (right) during a verbal
task involving rhyming. In males, activation is more lateralized, or
confined, to the left hemisphere, whereas in females, activation is bilateralized, that is, occurring in both hemispheres of the brain.
The Social Brain
“As we learn more about the synaptic
mechanisms of memory we learn more about the
neural basis of self” (p. 173).
“That the self is synaptic can be a curse – it
doesn’t take much to break it apart. But it is also
a blessing, as there are always new connections
waiting to be made. You are your synapses. They
are who you are” (p. 324).
Joseph LeDoux (2002)
The Emotional Brain.
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Subject: Meet-up Presentation