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THIRD EDITION
PSYCHOLOGY
from inquiry to understanding
CHAPTER
3
Biological
Psychology
BRIDGING THE LEVELS OF
ANALYSIS
Slides prepared by Matthew Isaak
Copyright © 2014, © 2011, © 2009 by Pearson Education, Inc.
All Rights Reserved
Learning Objectives
LO 3.1
LO 3.2
LO 3.3
LO 3.4
LO 3.5
Distinguish the parts of neurons and what
they do.
Describe electrical responses of neurons
and what makes them possible.
Explain how neurons use
neurotransmitters to communicate with
each other.
Describe how the brain changes as a result
of development, learning, and injury.
Identify what roles different parts of the
central nervous system play in behavior.
Understanding Psychology: from Inquiry to Understanding, Third Edition
Lilienfeld | Lynn | Namy | Woolf
Learning Objectives
LO 3.6
LO 3.7
LO 3.8
LO 3.9
Clarify how the somatic and autonomic
nervous systems work in emergency and
everyday situations.
Describe what hormones are and how they
affect behavior.
Identify different brain-stimulating, recording, and -imaging techniques.
Evaluate results demonstrating the brain's
localization of function.
Understanding Psychology: from Inquiry to Understanding, Third Edition
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Learning Objectives
LO 3.10 Describe genes and how they influence
psychological traits.
LO 3.11 Explain the concept of heritability and the
misconceptions surrounding it
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Lecture Preview
• Nerve cells and communication in the
brain
• The central and peripheral nervous
systems
• The endocrine system: glands and
hormones
• Mapping the mind: the brain in action
• Nature and nurture
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Biological Psychology
LO 3.1 Distinguish the parts of neurons and what they do.
• Neuroscientists have made huge strides
in understanding how the brain works.
• Bridging the gap between the nervous
system and our behavior allows us to
span multiple levels of analysis.
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Neurons
LO 3.1 Distinguish the parts of neurons and what they do.
• Neurons are brain cells that specialize
in communication.
• There are around 85 billion neurons,
with around 160 trillion connections
between them.
• Oddly shaped compared to other cells
in the body, they have a number of
specific features.
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Neuronal Components
LO 3.1 Distinguish the parts of neurons and what they do.
• Cell body (soma)
– Center of neuron; builds new cell
components
• Dendrites
– Branchlike extension that receive
information from other neurons
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Neuronal Components
LO 3.1 Distinguish the parts of neurons and what they do.
• Axons
– "Tails" of the neuron that spread out
from the cell body and transmit
information
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Figure 3.1
A Neuron with a Myelin Sheath.
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Neuronal Components
LO 3.1 Distinguish the parts of neurons and what they do.
• Axon terminal
– Knob at the end of the axons that
contains synaptic vesicles filled with
neurotransmitters
• Neurotransmitters (NTs)
– Chemical messengers that allow
neuron-to-neuron communication
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Neuronal Components
LO 3.1 Distinguish the parts of neurons and what they do.
• Synapse
– Space between neurons through which
NTs travel
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Figure 3.2
The Axon Terminal.
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Glial Cells
LO 3.1 Distinguish the parts of neurons and what they do.
• There are as many glial cells as
neurons in the brain. Several types:
– Astrocytes are the most abundant and
increase reliability of neuronal
transmission.
– Ogliodendrocytes promote new
connections and produce the myelin
sheath around axons.
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Electrifying Thought
LO 3.2 Describe electrical responses of neurons and what makes them possible.
• Neurons respond to NTs by generating
electrical activity.
• When there are no NTs acting on a
neuron, it is at the resting potential.
• When there is enough of a charge
inside the neuron (threshold), an
action potential will occur.
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Action Potentials
LO 3.2 Describe electrical responses of neurons and what makes them possible.
• Abrupt waves of electric discharge
triggered by a change in charge inside
the axon
• This is the neuron "firing," an all-ornone response.
• Originate near cell body and travel
down the axon to the axon terminal,
triggering NT release
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Figure 3.3 The Action Potential. When a neuron is at rest there are positive and negative ions on both sides
of the membrane. During an action potential, positive ions rush in and then out of the axon. This process recurs
along the axon until the axon terminal releases neurotransmitters.
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Action Potentials
LO 3.2 Describe electrical responses of neurons and what makes them possible.
• Neurons can fire 100 to 1,000 times
per second.
• In between firings, there is a very brief
absolute refractory period.
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Neurotransmission
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
• Inside neurons, communication is
electrical, but between neurons, it is
chemical via NTs.
• When released, NTs bind with the next
neuron's receptor sites.
• This process is halted by reuptake,
when NTs go back into the axon
terminal.
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Figure 3.5
The Lock-and-Key Model of Neurotransmitter Binding to Receptor Sites.
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Neurotransmission
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
• Some NTs excite the nervous system,
whereas other NTs inhibit the nervous
system.
• Each NT has specific roles and functions
in brain and behavior.
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Types of Neurotransmitters
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
• Glutamate and GABA are the most
common NTs in the central nervous
system.
• Glutamate is excitatory and increases
the chance neurons will communicate;
GABA is inhibitory.
• Acetylcholine (Ach) influences
arousal, selective attention, sleep, and
memory.
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Types of Neurotransmitters
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
• Monoamines contain only one amino
acid.
– Norepinephrine (NE) and serotonin
influence arousal.
– Dopamine plays a role in our response
to rewarding experiences.
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Types of Neurotransmitters
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
• Neuropeptides have specialized
functioning (like endorphins for pain
relief).
• Anandamides bind to the same
receptors as THC and influence eating,
motivation, memory, and sleep.
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Psychoactive Drugs
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
• Psychoactive drugs impact mood,
arousal, or behavior by acting as
agonists or antagonists for NTs.
• Agonists – increase NT activity
• Antagonists – decrease NT activity
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Agonists and Antagonists
LO 3.3 Explain how neurons use neurotransmitters to communicate with each other.
Agonists
• Opioids – mimic
endorphins
• Alcohol, Xanax –
stimulate GABA
receptors
• Prozac, Paxil –
block serotonin
reputake
Antagonists
• Antipsychotics –
block dopamine
from receptors
• Botox – blocks ACh
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Neural Plasticity
LO 3.4 Describe how the brain changes as a result of development, learning, and injury.
• Plasticity – nervous system's ability to
change over time
• Neurons change in four ways during
development:
– Growth of dendrites and axons
– Synaptogenesis
– Pruning
– Myelination
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Neural Plasticity
LO 3.4 Describe how the brain changes as a result of development, learning, and injury.
• During learning, long-term
potentiation occurs and makes
synapses perform better.
• There is only limited recovery following
brain injury or serious illness.
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Neural Plasticity
LO 3.4 Describe how the brain changes as a result of development, learning, and injury.
• Stem cell therapies may someday
encourage plasticity after injury or
degeneration.
• Neurogenesis – creation of new
neurons – does occur during adulthood.
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The Brain-Behavior Network
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Sensory information comes into—and
decisions come out of—the central
nervous system (CNS).
• The nerves outside the CNS are called
the peripheral nervous system
(PNS).
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LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
Nervous System
Central Nervous
System
Peripheral Nervous
System
Somatic
Brain
Autonomic
Spinal cord
Sympathetic
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Parasympathetic
Figure 3.8
The Nervous System Exerts Control over the Body.
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Central Nervous System
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• The CNS is divided into distinct systems
based on location and function.
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Figure 3.9
The Human Brain: A Simple Map.
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Cerebral Cortex
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• The forebrain is the most developed
area of the human brain, giving us our
advanced intellectual abilities.
• Consists of two cerebral hemispheres
corrected by the corpus callosum
which allows communication between
them.
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Figure 3.10
The Cerebral Hemispheres and the Corpus Callosum.
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LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• The majority of the forebrain is
composed of the cerebral cortex.
• It can be divided into four lobes, each
associated with a different function.
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Figure 3.11
The Four Lobes of the Cerebral Cortex.
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Frontal Lobes
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Oversee and organize most other brain
functions (executive functioning)
• The body is mapped onto the motor
cortex.
• The prefrontal cortex is responsible
for thinking, planning, and language.
– Broca's area – important in speech
comprehension
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Parietal Lobe
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Contains the somatosensory cortex,
which is sensitive to touch, pain, and
temperature
• Helps track objects' locations in space
• Communicates information to the
motor cortex every time we reach,
grasp, or move our eyes
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Figure 3.12 Representation of the Body Mapped onto the Motor and Sensory Areas of the Cerebral
Cortex. The brain networks with the body in a systematic way, with specific regions of both the motor and
primary sensory cortex mapping onto specific regions of the body.
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Temporal Lobe
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• The lower part of the cerebral cortex, it
plays a role in hearing, understanding
language, and storing autobiographical
memories.
• Contains the auditory cortex and
Wernicke's area, responsible for
speech comprehension
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Occipital Lobe
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Lies at the rear of the brain and is
specialized for vision
• When sensory information enters the
brain, it first goes to that sense's
primary sensory cortex, then to the
association cortex.
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Basal Ganglia
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Forebrain structure that helps control
movement
• Allows us to perform movements to
obtain rewards and reinforcement
• Damage can contribute to Parkinson's
disease
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Limbic System
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• The emotional center of the brain that
also has a role in smell, motivation, and
memory
• Thalamus relays information from the
sense organs to primary sensory cortex
• Hypothalamus regulates and controls
internal bodily states; controls the
pituitary gland
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Limbic System
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Amygdala plays key roles in fear,
excitement, and arousal
• Hippocampus plays a role in spatial
memory; damage causes inability to
form new memories
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Figure 3.14 The Limbic System. The limbic system consists mainly of the thalamus, hypothalamus,
amygdala, and hippocampus.
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Brain Stem
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Connects the cerebral cortex and spinal
cord
• Performs some basic bodily functions
• Serves as a relay station between the
cortex and rest of nervous system
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Figure 3.15
The Brain Stem. The brain stem is located at the top of the spinal cord, below the cortex.
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Brain Stem
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Midbrain contributes to movement,
tracking of visual stimuli, and reflexes
triggered by sound
• Reticular Activating System
connects the forebrain and cerebral
cortex and plays key role in arousal
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Hindbrain
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• Cerebellum plays a predominant role
in our sense of balance and enables us
to coordinate movement and learn
motor skills
• Pons connects cortex to cerebellum
and triggers dreams
• Medulla regulates breathing,
heartbeat, and other vital functions
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Spinal Cord
LO 3.5 Identify what roles different parts of the central nervous system play in behavior.
• The thick bundle of nerves that conveys
signals between the brain and the body
• Sensory nerves carry information
from body to the brain; motor nerves
carry information from brain to the rest
of the body.
• Also contains interneurons, which
allow reflexes to happen
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Peripheral Nervous System
LO 3.6 Clarify how the somatic and autonomic nervous systems work in emergency and everyday
situations.
• Somatic nervous system conveys
information between the CNS and the
body, controlling and coordinating
voluntary movement
• Autonomic nervous system controls
the involuntary actions internal organs
and glands
– has two divisions: sympathetic and
parasympathetic
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Peripheral Nervous System
LO 3.6 Clarify how the somatic and autonomic nervous systems work in emergency and everyday
situations.
• Sympathetic division is engaged
during a crisis or after actions requiring
"fight or flight"
• Parasympathetic division controls
rest and digestion
• When one is activated, the other is
inactive.
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Figure 3.17 The Autonomic Nervous System (Female Shown). The sympathetic and parasympathetic
divisions of the autonomic nervous system control the internal organs and glands.
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Endocrine System
LO 3.7 Describe what hormones are and how they affect behavior.
• Consists of glands that release
hormones, molecules that influence
particular organs
• Also influence emotions and stress
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Figure 3.18
The Major Endocrine Glands of the Body.
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Pituitary Gland
LO 3.7 Describe what hormones are and how they affect behavior.
• Controls the other glands in the body
• Releases hormones that influence
growth, blood pressure, and other
functions
• This includes oxytocin, responsible for
number of reproductive functions and
involved in maternal and romantic love.
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Adrenal Glands
LO 3.7 Describe what hormones are and how they affect behavior.
• Release adrenaline and cortisol
during states of emotional arousal
• Adrenaline boosts energy production in
muscle cells, but restricts it in other
cells.
• Cortisol regulates blood pressure and
cardiovascular function, as well as the
use of proteins, carbohydrates, and
fats.
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Sexual Reproductive Glands
LO 3.7 Describe what hormones are and how they affect behavior.
• Testes in males and ovaries in females
• Both sexes manufacture testosterone
(male sex hormone) and estrogen
(female sex hormone).
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Mapping the Mind
LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques.
• There have been many attempts to
map the mind onto the brain.
• Phrenology was one of the earliest, but
was discredited by the mid-1800s,
mainly due to early neuropsychological
studies of persons with brain damage.
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Mapping the Mind
LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques.
• Electroencephalograph
– Measures electrical activity via
electrodes placed on skull
– Can tell which regions of the brain are
active during specific tasks
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Figure 3.19
Electroencephalograph (EEG).
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Mapping the Mind
LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques.
• Neuroimaging techniques allow us to
see brain structure, function, or both.
• Computed tomography (CT) uses
multiple X-rays to construct threedimensional images.
• Magnetic resonance imaging (MRI)
uses magnetic fields to indirectly
visualize brain structure.
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Mapping the Mind
LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques.
• Positron emission tomography
(PET) measures consumption of
glucose-like molecules to give a picture
of neural activity.
• Functional MRI (fMRI) uses magnetic
fields to visualize brain activity.
• These both measure structure and
function.
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Mapping the Mind
LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques.
• Transcranial magnetic stimulation
(TMS) applies strong and quickly
changing magnetic fields to the surface
of the skull that can either enhance or
interrupt brain function.
– Allows causal determination of
functioning
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Mapping the Mind
LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques.
• Magnetoencephalography (MEG)
measures tiny magnetic fields
generated by the brain.
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Which Area for What Task?
LO 3.9 Evaluate results demonstrating the brain's localization of function.
• Many areas of the brain are associated
with a particular function (localization
of function).
• However, complex tasks often require
numerous parts working together.
• Each region participates in many
functions, so coordination across
multiple brain regions contributes to
each function.
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Which Side Do We Use for What?
LO 3.9 Evaluate results demonstrating the brain's localization of function.
LEFT HEMISPHERE
• Fine-tuned language
skills
• Speech comprehension
• Speech production
• Phonology
• Syntax
• Reading
• Writing
• Actions
• Making facial
expressions
• Motion detection
RIGHT HEMISPHERE
• Course language skills
• Simple speech
• Simple writing
• Tone of voice
• Visuospatial skills
• Perceptual grouping
• Face perception
Many brain functions show lateralization.
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How We Come to Be Who We Are
LO 3.10 Describe genes and how they influence psychological traits.
• We have chromosomes inside each
cell's nucleus that carry genes.
– Humans have 46 chromosomes, 23
from each parent.
• Our genotype is the set of genes we
have, while our phenotype is our
observable traits.
– Genes can be dominant or recessive.
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Figure 3.22
Genetic Expression.
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Behavioral Adaptation
LO 3.10 Describe genes and how they influence psychological traits.
• Some organisms have adaptations that
make them better suited to their
environment.
• They survive and reproduce at higher
rates than other organisms (fitness).
• Those adaptations then have a higher
frequency in the population (evolution
by natural selection).
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Brain Evolution
LO 3.10 Describe genes and how they influence psychological traits.
• Humans and apes last shared a
common ancestor 6-7 million years
ago.
• Since then, human brains have tripled
in size, with the greatest increase in
the cerebral cortex.
• Relative brain size appears to be
associated with intelligent behavior
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Behavioral Genetics
LO 3.11 Explain the concept of heritability and the misconceptions surrounding it.
• Studies the relative impact of nature
and nurture on psychological traits
• Estimates heritability—percentage of
the variability in a trait across
individuals that is due to genes
• Some traits are highly heritable
(height), while others are not (religious
affiliation).
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Behavioral Genetic Designs
LO 3.11 Explain the concept of heritability and the misconceptions surrounding it.
• Scientists use three types of designs to
estimate heritability of traits:
– Family studies
– Twin studies
– Adoption studies
• Determine how much both genes and
environment contribute to a particular
trait
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