Introduction to Biopsychology [PSB 4002]

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Introduction to BiopsychologyPSB 4002

• Professor Josh Herrington
• DM 249 305-348-1230
• Jherr033_at_fiu.edu
• website dpblab.fiu.edu

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Big Questions for Biopsychology

• How is the nervous system structured and
  organized? How does the nervous system develop?
• How does the nervous system process and represent
  information about an organisms internal and
  external environment?
• How does the brain change during learning and how
  are memories stored and retrieved? How does the
  brain think?

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Big Questions Continued

• What brain sites and activities underlie emotions
  and feelings?

• What brain regions are involved in language?

• How does consciousness emerge from the
  activities of a nervous system?

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What is inside your head?

• Your cerebral cortex, critical to higher brain
  functions such as speech, thought, complex
  movement patterns, goals and planning, has about
  10 billion neurons (nerve cells)

• Each of these neurons receives connections from
  other neurons at sites called synapses. There are
  roughly one million billion of these connections
  in just in your cerebral cortex

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What is inside your head?

• If you set out to count these connections, one
  connection (synapse) per second, you would finish
  counting 32 million years after you began
  counting.
• Another way of getting a feeling for this
  complexity is to consider that a match heads
  worth of your brain contains about 1 billion
  connections.

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What is inside your head?

• If we consider how the connections between
  neurons might be variously combined, the number
  becomes hyperastronomical 10 followed by
  millions of zeros.
• So we have our first clue as to what makes the
  brain so remarkable, because when one adds the
  chemical factors (neurotransmitters, hormones)
  that influence neurons, we are talking about the
  most complicated material object in the known
  universe.

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Complexity

• Complexity turns out to be difficult to define,
  but there are five attributes that in combination
  seem to be involved
• large number of parts, large number of levels
• large number of interactions among parts and
  levels
• hierarchical organization (of multiple levels)
• non-linearity (not A ? B? C? D)

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Complexity

• and perhaps most important, emergent properties
  (the whole is greater than the sum of the parts)
• emergent properties cannot be predicted based on
  knowledge of the properties of the parts alone
  (example of water, H2O)
• emergence will turn out to be important in how we
  make sense of higher order mental functions, such
  as thinking, dreaming, and consciousness

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A Systems Perspective
The brains job is to facilitate an adaptive
dynamic pattern of interaction among brain, body,
and the world In other words, neural systems are
elements of a larger system that includes the
rest of the organisms body and also its
situation in and interaction with the environment
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Historical Perspective

• Traditional views within psychology, cognitive
  science and philosophy have often characterized
  the mind as an abstract information processor
  largely divorced from the body and the
  environment.

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Introduction to BiopsychologyPSB 4002

• Professor Josh Herrington
• DM 249 305-348-1230
• Jherr033_at_fiu.edu
• website dpblab.fiu.edu

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The Notion of Embodiment

• Proposes that all aspects of perception,
  movement, cognition, and interactions with the
  environment are based on the coupling of a brain,
  in a body, in an environment.
• Embodiment thus refers to bodily interactions
  with the world, which is proposed to be a
  necessary precondition for subjectivity, emotion,
  value and meaning. These interactions are based
  on (and constrained by) the actual shape and
  physical capacities and limits of the body.

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The overall function of the brain is to be well
informed about what goes on in the rest of the
body, about what goes on in itself, and about the
environment surrounding the organism. Regulating
both internal and external stimuli involves the
process of homeostasis. Homeostasis involves (at
the very least) the coupling of a number of
complex systems beyond simply the nervous system.

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The Bidirectional Coupling of Levels

• Meeting the challenge of homeostasis involves
• central nervous system
• autonomic (peripheral) nervous system
• endocrine system
• immune system
• limbic system

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Insight

• Given that the brains primary job is to
  coordinate our dealings with the environment, it
  is only in the context of the brain, body, and
  environment system that the function of the
  brain can be understood

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Neurons

• Like all cells of the body, neurons contain
• 1. nucleus
• 2. cytoplasm
• 3. cell membrane
• However, neurons are specialized to communicate
  with other neurons, muscles, glands, and other
  internal organs. This is achieved via
• 4. axon
• 5. dendrites
• 6. synapses

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Neurons

• Axons are coated (insulated) by
  myelin, improving the flow of electrical events
  from cell to cell

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Neurons

• Nerve cells are arranged in circuits and these
  are arranged in neural networks
• There are three basic types of neurons
• sensory neurons (input)
• motor neurons (output)
• interneurons (integration)

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The Language of the Nervous System

• There are two forms or channels of communication
  between neurons
• electrical action potentials / an all or
  nothing mode
• chemical neurotransmitters / many and modulated

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Introduction to BiopsychologyPSB 4002

• Professor Josh Herrington
• DM 249 305-348-1230
• Jherr033_at_fiu.edu
• website dpblab.fiu.edu

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First Exam

• Exam Date is Friday, January 25th
• Will be combine the terms outlined in the
  textbook (Chapters 1, 3, and 6) with the
  information in the class lectures.
• IF ATTENDANCE IS SATISFACTORY then you will
  receive the lecture notes to help you study one
  week before the exam. You will receive sample
  test questions to help you study.

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emergence

• The manner in which complex phenomena arise from
  a collection of interactions between system
  components
• The outcome is more than the sum of its parts

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• The brain is a complex temporally and spatially
  multiscale structure that gives rise to complex
  molecular, cellular, and neuronal phenomena that
  together form a basis for perception, movement,
  cognition.

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The Language of the Nervous System

• There are two forms or channels of communication
  between neurons
• electrical action potentials / an all or
  nothing mode
• chemical neurotransmitters / many and modulated

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HOW NEURONS COMMUNICATE WITH EACH OTHER CHEMICALLY

• The connection between two neurons is called a
  synapse
• The neurons are not in direct physical contact at
  the synapse but are separated by a small gap
  called the synaptic cleft
• The neuron transmitting to another is called the
  presynaptic neuron
• The receiving neuron is the postsynaptic neuron

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The Synapse Between a Presynaptic Neuron and a
Postsynaptic Neuron
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HOW NEURONS COMMUNICATE WITH EACH OTHER

• A Presynaptic Terminal Releases Neurotransmitter
  at the Synapse

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Development of the Nervous System

• The human genome has approximately 25,000
  genes the brain and spinal cord (CNS) has more
  than 100 billion neurons. Clearly these numbers
  indicate that nervous system development cannot
  be simply genetically determined or prescribed.
  
• Gene expression is certainly involved in all
  aspects of nervous system activity and the
  behavior it supports, but many other factors and
  processes must be at play

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Central Nervous System (CNS)
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• Development is an historical process
• initial conditions are powerful
• one thing leads to another
• what happens before guides and constrains
  what can happen next
• particular pathways taken promote or make less
• likely other pathways becoming available

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• Self-Organization
• Self-organization is the process in which pattern
  at the global level of a system emerges from
  numerous interactions among the lower-level
  components of the system.
• Thus, self-organization is an emergent property
  of the system, rather than imposed on the system
  by a pre-specified program or set of instructions.

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Self-Organization
Example termite mounds
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Introduction to BiopsychologyPSB 4002

• Professor Josh Herrington
• DM 249 305-348-1230
• Jherr033_at_fiu.edu
• website dpblab.fiu.edu

39
First Exam

• Exam Date is Wednesday, January 30th
• Will be combine the terms outlined in the
  textbook (Chapters 1, 3, and 6) with the
  information in the class lectures.
• IF ATTENDANCE IS SATISFACTORY then you will
  receive the lecture notes to help you study one
  week before the exam. You will receive sample
  test questions to help you study.

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Two Key Concepts in Making Sense of Developmental
Processes - self-organization - loss of
degrees of freedom
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What determines the structure and behavior of a
system are particular relational conditions of
the system and the environment over time
Self-organization can be contrasted to the notion
of organization by design. Example A car or a
computer - in order to work, every detail must
function according to a preconceived plan or
design.
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Loss of Degrees of Freedom The emergence of
structure or pattern at any point in a
developmental sequence constrains or limits what
structure or pattern can occur next.
Example moving into a new apartment
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The instructions for development dont reside
or exist anywhere they emerge out of how an
organism lives and interacts with its world
This insight leads us to a key insight in our
exploration of development the minimum unit of
analysis for understanding the nervous systems is
the coupling of a brain, in a body, in a complex
physical and social environment
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Development in utero

• The human ovum is the largest cell in the body,
  roughly 15 times larger than other cells, but it
  is still no larger than a dot, much much smaller
  that the period at the end of this sentence.
• Over about 277 days of gestation, this one
  fertilized cell will become trillions of cells,
  all organized into the various glands, tissues,
  organs, etc. that constitute our brain/body
  system.

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Some perspective How old are you?

• As it turns out, not a straightforward question,
  as the egg that developed following fertilization
  into you was formed when your mother was a fetus
  so, at least from our mothers side of the
  story, you are as old as your mother.
• Human development before birth takes place in
  three stages
• zygote (first 2 weeks following conception)
• embryo (3-8 weeks following conception)
• fetus (8-38 weeks following conception)

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Principles at Play

• Self-organization
• Reducing degrees of freedom
• Sensitive periods
• Developmental cascades

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• This process of prenatal development consists of
  a cascade of many thousands of events a cascade
  is a succession of sequentially interdependent
  events, with each event both triggered/influenced
  by the event(s) preceding it and in turn itself
  acting as a trigger for the next event(s).
• The cascade of prenatal development involves gene
  expression events, chemical events, cellular
  events, and their interactions. No surprise -
  these events are influenced by factors both
  internal and external to the developing embryo or
  fetus.

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Introduction to BiopsychologyPSB 4002

• Professor Josh Herrington
• DM 249 305-348-1230
• Jherr033_at_fiu.edu
• website dpblab.fiu.edu

53
First Exam

• Exam Date is Wednesday, January 30th
• Will be combine the terms outlined in the
  textbook (Chapters 1, 3, and 6) with the
  information in the class lectures.
• IF ATTENDANCE IS SATISFACTORY then you will
  receive the lecture notes to help you study one
  week before the exam. You will receive sample
  test questions to help you study.

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Principles at Play

• Self-organization
• Reducing degrees of freedom
• Sensitive periods
• Developmental cascades

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Key Processes in the Prenatal Development of the
Nervous System

1. Induction cells on the ectoderm form a neural
   tube, induced by cells below it in the mesoderm
2. Proliferation cell division results in an
   incredibly rapid generation of tens of thousands
   of cells per minute (during the last half of
   gestation, over 250,000 cells per minute)

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Key Processes (continued)
3. Migration moving from the neural tube to the
location where the cell will form a part of the
brain and become functional, with help from glial
cells 4. Aggregation similar cells come
together by means of chemical and electrical
gradients produced by surrounding cells
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Key Processes (continued)
5. Differentiation sprouting axon and dendrites
by means of a growth cone 6. Circuit and
Network Formation connecting synapses and axons
and producing neurotransmitters, thereby
establishing channels of communication across the
NS
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Circuit Formation

• During circuit formation, the axons of developing
  neurons grow toward their target cells and form
  functional connections.
• To find their way, axons form growth cones at
  their tip which sample the environment for
  directional cues.
• Chemical and molecular signposts attract or repel
  the advancing axon, coaxing it along the way.

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Key Processes (continued)
7. Cell Death (apoptosis) based on patterns of
activity, experience, and use
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DEVELOPMENT AND CHANGE IN THE NERVOUS SYSTEM

• 8. The next stage of neural development,
  circuit pruning, involves the elimination of
  excess neurons and synapses.
• neurons that are unsuccessful in finding a place
  on a target cell, or that arrive late, or that
  dont get activated, die.

• In the second step of circuit pruning, the
  nervous system refines its organization and
  continues to correct errors by eliminating large
  numbers of excessive synapses.
• synapses are strengthened or weakened depending
  on whether the pre-synaptic neuron and the
  postsynaptic neuron fire together (temporal
  synchrony).

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Prenatal Development of the Nervous
System (summary of eight processes)

• Induction
• Proliferation
• Migration
• Aggregation
• Differentiation
• Circuit formation
• Cell death (apoptosis)
• Circuit pruning

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Prenatal Development
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Introduction to BiopsychologyPSB 4002

• Professor Josh Herrington
• DM 249 305-348-1230
• Jherr033_at_fiu.edu
• website dpblab.fiu.edu

64
First Exam

• Exam Date is Wednesday, January 30th
• Will be combine the terms outlined in the
  textbook (Chapters 1, 3, and 6) with the
  information in the class lectures.
• IF ATTENDANCE IS SATISFACTORY then you will
  receive the lecture notes to help you study one
  week before the exam. You will receive sample
  test questions to help you study.

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Prenatal Development
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Fetal Programming

• The Prenatal environment provides experiences and
  affordances that allow for typical neural
  development

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POSTNATAL DEVELOPMENT IN THE NERVOUS SYSTEM

• patterns of increased connectivity and
  organization, and synchronization of
• activity
• increased number of dendrites, axon branches,
  synapses
• increased brain weight, increased thickness of
  cortex
• increasing degree of mylenation of axons
• all of these processes involve experience and
  activity-dependent competition and selection

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POSTNATAL DEVELOPMENT IN THE NERVOUS SYSTEM

• The neural networks of the brain are made during
  development by cellular movement, extensions, and
  connections increasing numbers of neurons.
• The number of cells being made, dying, and
  becoming incorporated into the nervous system is
  huge. The entire situation is a dynamic one,
  depending on signals, proteins, cell movement,
  divisions, gradients, and cell death, all
  interacting at many levels.

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POSTNATAL DEVELOPMENT AND CHANGE IN THE NERVOUS
SYSTEM

• Stimulation continues to shape synaptic
  construction and reconstruction throughout the
  individuals life.
• Much of the change resulting from experience in
  the mature brain involves reorganization, a shift
  in connections that changes the function of an
  area of the brain.

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Nervous System

• The process of nervous system development is
  cumulative (builds on itself) events occurring
  in one place require that previous events have
  occurred at other places. In other words, brain
  structure and function is
• historical
• situated
• contingent

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Nervous System

• The KEY mechanisms involved in the process of
  nervous system development are
• competition
• selection

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Nervous System

• The notion of experience-dependent development
•  
• -interactions with the environment modify gene
  activity and expression and shape the course of
  nervous system construction and modification

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Postnatal Maternal Care in Rodents
Variations in care lead to variations in
offspring phenotype
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stress responsivity
response to reward
natural variations in maternal care
cognition
High vs. Low levels of licking/grooming
stimulation of pups
social behavior
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Real Time/ Developmental Time

• Real Time firing patterns of diverse neural
  networks cell groups transmit information to
  each other activities of brain regions cohere or
  synchronize it real time (we can now observe this
  with neural imaging technology)
• Developmental Time increasing specification of
  structure increased levels of organization based
  on real time use. The overall cumulative effects
  of activity and experience over time sculpts the
  nervous system.

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