Chapter 3: The Biology of Behavior

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Chapter 3 The Biology of Behavior
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• Dualism - The human body and brain are a machine
• The mind is an attribute completely separate, not
  subject to the laws of the universe
• The pineal gland acts as a valve to let in the
  thoughts and emotions into the body

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The Lost Art of Phrenology

• Thomas Willis and Franz Gall
• late 17th century provided detailed descriptions
  of localization of function (really personality
  traits)
• Feel bumps on the head and describe your
  personality

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• Amativeness- produces sexual love
• Combativeness courage to meet danger and
  overcome difficulties tendency to defend, oppose
  and attack
• 7. Secretiveness propensity to conceal
  ideas/emotion
• Ideality desire of excellence absurd enthusiasm

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1862
Broca Production Wernicke comprehension
1874
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The Modern Phrenology
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The Lost Art of Phrenology

• Thomas Willis and Franz Gall
• late 17th century provided detailed descriptions
  of localization of function (really personality
  traits)
• Feel bumps on the head and describe your
  personality

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• Amativeness- produces sexual love
• Combativeness courage to meet danger and
  overcome difficulties tendency to defend, oppose
  and attack
• 7. Secretiveness propensity to conceal
  ideas/emotion
• Ideality desire of excellence absurd enthusiasm

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1862
1874
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The Modern Phrenology
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Methods of Research
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Correlational Methods

• Single Unit Recording
• EEG
• CT
• PET
• MRI
• fMRI
• TMS

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Single Unit Recording

• Single neurons are recorded using
• electrodes implanted into neural tissue
• Electrical activity of Individual neurons
• recorded as waveforms
• In vitro recording vs. In vivo recording
• Single Vs. Clusters
• Tetrodes
• Spatial resolution - 1/100th mm
• Temporal resolution 1-2 ms

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Neural Recording Apparatus

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Electroencephalograpy (EEG)

• Records average electrical activity of thousands
  of neurons via small metal disks placed on the
  scalp
• Event related potentials (ERPs)
• Spatial resolution very poor
• Temporal resolution 1-2 ms
• Only records responses from cortex

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EEG

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Computerized Axial Tomography (CT)

• A series of x-rays reveal the density of brain
  structures
• High - Bone, tissue, blood, CSF - Low
• High density appears white / Low density appears
  black
• Spatial resolution - 1 cm or greater

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Positron Emission Tomography

• Isotopes are injected into the bloodstream and
  emit photons as they decay
• Active regions of the brain will have higher
  concentrations of blood and isotopes
• Spatial resolution 5-10 mm
• Temporal resolution 40 secs or greater

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Magnetic Resonance Imaging (MRI)

• A magnetic field is created around the head and
  radio waves are sent through the magnetic field
• Sensors read signals and tissue density is
  revealed
• This method is excellent for producing high
  resolution images of the brain
• Spatial resolution - 1 mm
• Temporal resolution N/A

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MRI

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functional Magnetic Resonance Imaging (fMRI)

• Reveals functional activation based on
  concentration of oxygen
• Increased oxygen concentration is associated with
  increased functional activation (cognitive
  activity)
• Functional activity, which is measured over time,
  is mapped onto High resolution MRI images
• Spatial resolution 3-7 mm
• Temporal resolution 6 secs

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Transcranial Magnetic Stimulation (TMS)

• Coils applied over the scalp that produce a
  magnetic field when activated
• The magnetic field results in a polarized
  electrical field
• The electrical field disrupts synchronous neural
  activity and yields random firing
• Random firing results in a temporary lesion
• The temporary lesion disrupts functional activity
• This method can only be applied to the cortex

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TMS

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Strengths and Weaknesses

• Single Unit Recording
• high temporal and spatial resolution
• - typically only used in non-human animals
• EEG
• high temporal resolution and good as a
  diagnostic tool
• - poor spatial resolution and only measures
  cortical activity
• CT
• good for diagnostic tool
• - poor spatial resolution and involves
  radiation

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PET measures functional activation - poor
temporal resolution requires radioactive
injection MRI excellent spatial resolution,
good diagnostic tool, doesnt require radiation
- static image and cant be used if you have
metal in your body fMRI fair spatial
resolution and measures functional activation -
poor temporal resolution TMS produces
temporary functional lesions in humans - may
have detrimental long term effects when used on
the same individual. Only useful for cortical
regions.

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Research Methods in Behavioral Genetics
Figure 3.19 Genetic relatedness
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Research Methods in Behavioral Genetics

• Family studies does it run in the family?
• Twin studies compare resemblance of identical
  (monozygotic) and fraternal (dizygotic) twins on
  a trait
• Adoption studies examine resemblance between
  adopted children and their biological and
  adoptive parents

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Figure 3.20 Twin studies of intelligence and
personality
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• Methods for Non-human Animal Research
• Inactivation
• Lesions
• Neural Recording
• Anatomical tracing
• Injection of neuromodulators
• Measurement of neurotransmitters

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Generalize
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Non-Human Animals Models
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The Central Peripheral Nervous System

• Divisions
• Structures
• Functions

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Organization of the Nervous System

• Central nervous system (CNS)
• Afferent toward the CNS
• Efferent away from the CNS
• Peripheral nervous system
• Somatic nervous system
• Autonomic nervous system (ANS)
• Sympathetic
• Parasympathetic

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Sensory
Motor
Afferent toward the CNS Efferent away from
the CNS
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• Pupils Dialate
• Airway Relaxes
• Heart accelerate
• Digestion Inhibited
• Adenal Gland
• epinepherine released

• Pupils Constict
• Airway co ntracts
• Heart decelerates
• Digestion stimulated
• Adrenal Gland

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Triune Brain

• Paul Maclean
• Archipallium brain (reptilian brain)
• Palleomammalian brain (limbic system)
• Neopallium brain (neocortex)

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Triune Brain

• Archipallium brain (reptilian brain)
• The brain stem pons, medulla, reticular
  formation and cerebellum
• Controls basic functions and stereotyped , rigid,
  behaviors breathing, heartbeat, muscles,
  balance, sleep

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Triune Brain

• Palleomammalian brain (limbic system)
• The hippocampus, amygdala, fornix, mammillary
  bodies, parahippocampal and cingulate gyrus
• Contols instinctual behavior feeding, fleeing,
  fighting, sexual beahvior
• The seat of emotion, attention, and the
  production of memory

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Triune Brain

• Neopallium brain (neocortex)
• The cortex
• Responsible for higher cognition
• Language, abstract thought, working
• memory, planning

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Left hemisphere

• 70 to 95 of humans have a left-hemisphere
  language specialization.
• Specializes in such verbal functions as reading,
  writing, comprehension, speech, and verbal
  thinking.
• In general, the left hemisphere is considered
  dominant in analytical, sequential processing of
  verbal information.

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Right hemisphere

• Dominant in spatial and nonverbal perception.
• It is more efficient than the left hemisphere in
  tasks that require spatial orientation and
  perception of shape, depth, and texture.
• Dominant in the expression and identification of
  emotions.

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Corpus Callosum

• A cluster of axons, mostly myelinated, that
  connects the two brain hemispheres.
• As the largest interhemispheric connection, or
  commissure, in the brain, the corpus callosum
  allows the two hemispheres to exchange neural
  information.
• In a surgical procedure used to treat severe
  cases of epilepsy, the surgeon cuts the corpus
  callosum, separating the two hemispheres (the
  split-brain operation).

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Figure 3.14 The cerebral hemispheres and the
corpus callosum
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Thalamus

• Thalamus comprises two lobes, one in each
  hemisphere, connected by a bridge of gray matter
  (the massa intermedia).
• The lateral geniculate nucleus (LGN) receives
  visual information from the eye and projects it
  to the primary visual cortex
• The medial geniculate nucleus (MGN) receives
  auditory information from the inner ear and
  projects it to the primary auditory cortex.
• The ventrolateral nuc. Receives info. from the
  cerebellum and projects it to prim motor ctx.

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(LGN) receives visual
(MGN) receives auditory
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HypoThalamus

• Located on both sides of the below the thalamus
  (hypo means below).
• Through its connection to the pituitary gland,
  the hypothalamus regulates the hormonal system.
• A short stalk (the infundibulum) connects the
  hypothalamus to the pituitary gland, allowing the
  hypothalamus to control the release of hormones
  from the pituitary. (HPA axis)

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Brain Stem
Medualla Life support functions breathing,
heartbeat Reticular Formation involved in waking
and sleeping Pons Almost all white matter
(axons) relays information from spinal cord and
medulla to highr brain regions Cerebellum fine
motor control Motor meory or well learned
behavior
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Basal ganglia

• A group of large subcortical nuclei that surround
  the thalamus (with connections to cortex and
  midbrain)
• Parkinsons disease is caused by degeneration of
  certain dopaminergic neurons that originate in
  the midbrain and extend to the basal ganglia.
• The basal ganglia control skeletal muscle
  movement and eye movements.

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Limbic system

• Subcortical structures that surround the corpus
  callosum and were the earliest parts of the
  forebrain to develop in the course of evolution
• The limbic system plays an important role in the
  regulation of, motivation, emotion, and memory
• The hippocampus, amygdala, fornix, mammillary
  bodies, parahippocampal and cingulate gyrus

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Meninges

• Dura mater - (Hard mother) forms a leathery,
  inelastic bag around the brain and spinal cord.
• Arachnoid - Greek for spider, forms a web of
  fibrous connective tissue
• Pia mater (pious mother) is a gentle, or thin
  membrane that adheres to the surface of the
  brain.

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Ventricles

• A series of interconnected chambers, filled with
  CSF.
• (125 mL replenished every 6 hrs.)
• Choroid plexus special tissue w/in ea.
  Ventricle that produces CSF
• 4 Ventricles
• Lateral ventricles, 3rd and 4th ventricle

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Monday No classWed Neurons and
Neurotransmitters