introduction to biopsychology [psb 4002]

Introduction to Biopsychology[PSB 4002]

Professor Robert LickliterDM 294 / [email protected]: dpblab.fiu.edu

mailto:[email protected]

PSB 4002 / INTRODUCTION TO BIOPSYCHOLOGYT TH 12:30 – 1:45 pm / Fall Semester, 2013

Instructor: Professor Robert Lickliter

DM 294 email: [email protected] webpage: http://dpblab.fiu.edu Teaching Associate: Victoria Bein email: [email protected] Instructor’s Office Hours: Tuesdays & Thursdays: 2 – 3:30 pm (DM 294) or by appointment (email or 305/348-3441) Prerequisites: PSY 2020 / Introduction to Psychology (or equivalent)

Required Text: Biological Psychology (3rd edition) by Frederick Toates Prentice Hall Publishers (2011) On-Line Text Supplement: Brain Facts: A Primer on the Brain and Nervous System

Society for Neuroscience (pdf format) (available on the course webpage: dpblab.fiu.edu)

Course Goals: The combined scientific disciplines of behavioral and cognitive neuroscience, physiological psychology, and psychobiology are often referred to as biopsychology. This survey level course is designed to examine a variety of topics in the domain of biopsychology and to explore how their understanding contributes to a better understanding of behavior. These topics include evolutionary theory, organization and development of the nervous system, sensing and moving, maintaining homeostasis, biological rhythms, emotions, learning and memory, thinking and consciousness, and disorders of the brain and behavior. While the primary emphasis of the course will be to develop a better understanding of the complex relationship between the nervous system, the body, and the environment, we will also explore such topics as the roles of evolution and development in nervous system structure and function, the biological foundations of consciousness, and the importance of comparative psychology to advances in biopsychology and the neurosciences.

Course Format and Grading: There are two sources of information you will be responsible for: the class lectures and your assigned textbook readings (they are not the same material).

Your grade in this course will depend on your performance on three midterms and a final exam. The three midterm exams and the final exam will consist of both multiple choice and true/false questions and each exam will count 50 possible points. The final exam will not be cumulative and will essentially be a fourth midterm.

The material to be covered in each exam will include both assigned readings in your text and lecture material presented in class. This means you are responsible for both sources of course information, the assigned readings and the classroom lectures. Your final letter grade in the course will be directly translated from your overall percentage, which will be derived from the total number of points you accumulate across the three midterms and the final out of the possible 200 points.

Important: Since this is a survey level course and we must cover a large amount of material over the semester, the assigned textbook readings and the lecture material presented in class will rarely overlap in their content, so class attendance is necessary for you to do well in the course. No makeup exams will be provided without a valid medical release. Plan to be in class for all four scheduled exams. The date of the exams will be announced at least two weeks prior, and your will receive sample study questions and the lecture powerpoint slides one week prior to each exam. Please arrive to lecture on time (12:30 pm). It is distracting to both the instructor and other students if you arrive after lecture begins. I appreciate how challenging it can be to be “unplugged” for more than an hour – nevertheless, I expect you to turn off your cell phones, social media, etc. and actively participate in the lecture and discussion while you are in the classroom.

Dissuade you of common myths about the human brain

1. you do not use “all” of your brain, only some percentage of it

2.your brain developed according to prewired genetic instructions

3.you can trace a behavior or an emotion or a thought to one specific region of your brain

Big Questions for BiopsychologyBig 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 organism’s internal and external environment?

• How does the brain change during learning and how are memories stored and retrieved? How does the brain “think”?

Big Questions ContinuedBig 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?

What is inside your head?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


• 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 head’s worth of your brain contains about 1 billion connections.


• 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, as well as billions of glial cells that influence neurons, we are talking about the most complex material object in the known universe.

ComplexityComplexity

• 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 levelslarge number of interactions among parts and

levelshierarchical organization (of multiple levels)non-linearity (not A B C D)

ComplexityComplexity• 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

Scientific study of complexity

• Explaining how large numbers of relatively simple entities organize themselves, without the benefit of any central controller, into a collective whole that has structure, creates patterns, and uses information

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

Self-Organization: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.

A Systems Perspective

The brain’s 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 organism’s body and also its situation in and interaction with the environment

Structure fosters complexity

Complexity fosters structure

The Notion of Situated 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. These interactions are based on (and constrained by) the actual shape and physical capacities and limits of the body.

The overall function of the brain is to be well informed about:

1) what goes on in the rest of the body, 2) about what goes on in itself, and 3) what goes on in the environment

This regulatory process is in the service of maintaining homeostasis. This involves (at the very least) the coupling of a number of complex systems beyond simply the nervous system.

The Coupling of Levels

Meeting the challenge of homeostasis involves:

• central nervous system• autonomic (peripheral) nervous system• endocrine system• immune system• limbic system

Important Insight

• Given that the brain’s 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

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

NeuronsNeurons• Like all cells of the body, neurons contain:

1. nucleus2. cytoplasm3. cell membrane

• However, neurons are specialized to communicate with other neurons, muscles, glands, and other internal organs. This is achieved via:4. axon5. dendrites6. synapses

NeuronsNeurons

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

NeuronsNeurons

• Nerve cells are arranged in circuits and these are arranged in neural networks

The Language of the Nervous SystemThe 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

• 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

HOW NEURONS COMMUNICATE WITH EACH HOW NEURONS COMMUNICATE WITH EACH OTHER CHEMICALLYOTHER CHEMICALLY

The Synapse Between a Presynaptic Neuron and The Synapse Between a Presynaptic Neuron and a Postsynaptic Neurona Postsynaptic Neuron

•A Presynaptic Terminal Releases Neurotransmitter at the Synapse

HOW NEURONS COMMUNICATE WITH HOW NEURONS COMMUNICATE WITH EACH OTHEREACH OTHER

•There are three basic types of neurons:

–sensory neurons (input)–motor neurons (output)–interneurons (integration)

Central Nervous System (CNS)Central Nervous System (CNS)

The Development of the Nervous System

Principles at Play

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

The “instructions” for development don’t 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 system is the coupling of a brain, in a body, in a complex physical and social environment

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.

Development of the Nervous SystemDevelopment of the Nervous System•The human genome has approximately 21,000 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

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

Two Key Concepts in Making Sense of Two Key Concepts in Making Sense of Developmental ProcessesDevelopmental Processes:

- self-organization

- loss of degrees of freedom

Self-OrganizationSelf-OrganizationExample: termite mounds

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

• 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 mother’s 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)

Some perspective: How old are you?

• 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.

Developmental Resources

The ingredients of self-organizatiaon

Key Processes in the Prenatal Key Processes in the Prenatal Development of the Nervous SystemDevelopment 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)

Key Processes (continued)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


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

Circuit FormationCircuit 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.


7. Cell Death (apoptosis): based on patterns of activity, experience, and use

DEVELOPMENT AND CHANGE DEVELOPMENT AND CHANGE IN THE NERVOUS SYSTEMIN THE NERVOUS SYSTEM

8. The next stage of neural development, circuit pruning, involves the elimination of excess neurons and synapses

• the developing nervous system refines its organization and continues to correct errors by eliminating large numbers of excessive synapses over time.

Prenatal Development of the Nervous Prenatal Development of the Nervous SystemSystem

(summary of eight processes)(summary of eight processes)

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

Prenatal DevelopmentPrenatal Development

Principles at Play

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

POSTNATAL DEVELOPMENT IN THE NERVOUS SYSTEMPOSTNATAL 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

POSTNATAL DEVELOPMENT IN THE NERVOUS SYSTEMPOSTNATAL DEVELOPMENT IN THE NERVOUS SYSTEM

• The neural networks of the brain are made during development by cellular movement, extensions, and connections

• 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.

POSTNATAL DEVELOPMENT AND CHANGE POSTNATAL DEVELOPMENT AND CHANGE IN THE NERVOUS SYSTEMIN THE NERVOUS SYSTEM

• Stimulation continues to shape synaptic construction and reconstruction throughout an individual’s life.

• Much of the change resulting from experience in the mature brain involves reorganization, a shift in connections that can change the function of an area of the brain.

•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

Nervous SystemNervous 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


Postnatal Maternal Care in Rodents

Variations in care lead to variations in offspring phenotype

natural variations in maternal care

High vs. Low levels of licking/grooming

stimulation of pups

stress responsivity

response to reward

cognition

social behavior

Real Time/ Developmental TimeReal 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.

ENDOCRINE GLANDS

Endocrine SystemEndocrine System

Example: if blood pressure rises, sensors in the kidney detect the rise and set in motion the

various processes that reduce blood pressure.

Endocrine Glands Produce Endocrine Glands Produce Hormones Hormones

• Hormones affect behavior in two primary ways:-1. Organizational effects: influence the developing structure of the organism in long-lasting ways (examples include the effects of estrogen and testosterone on primary and secondary sexual characteristics). Brain reorganization induced by fetal androgens cannot be reversed.

Organizational Effects of Hormones Organizational Effects of Hormones • Sex differences in brain structure: corpus callosum is relatively larger in females

• the suprachiasmatic nucleus of the hypothalamus is relatively larger in males

• hippocampus is relatively larger in males than females

• the left hemisphere of the cerebral cortex is thicker than the right in females; in males, the right cortex is thicker than the left

Hormones Hormones 2. Activational effects: prime the organism

for responding to certain stimuli in real time. Are typically reversible and short-term (examples of oxytocin and prolactin in the expression of maternal behavior in mammals).

introduction to biopsychology [psb 4002]

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