Biopsychology

What makes you, you?

What makes you unique from every other person?

The Mind is what the Brain does

• Specific areas of the brain and specific systems in the body are responsible for– Learning and Memory– Sensing and perceiving – Emotion– Personality– Planning– Attention and arousal– Motivation– Etc.

The building blocks of the brain

The Neuron

The Neuron

• Types of Neurons– Sensory neurons (carry messages from

sense receptors towards the CNS)

– Motor neurons (carry messages from CNS toward muscles and glands)

– Interneurons (carry messages between nerve cells)

The Structure of a Neuron

Neural Communication• Two states

– Resting Potential Negatively charged ions on inside; positively

charged ions on outside; cell is negatively charged on inside relative to outside

– Action Potential Based on summation of excitatory and inhibitory

signals Cell depolarizes; i.e., cell becomes positively charged Voltage change (electrical surge) travels down axon

and causes release of neurotransmitter into the synapse

Neural Communication

• All or None Law– Neurons either fire or they don’t– Require a minimum amount of excitation or

stimulation in order to fire– Once the minimum threshold has been

reached, the neuron will fire

– Regardless of the intensity of stimulation, the neuron will fire with the same intensity

Neural Communication

• If neurons always fire with the same intensity, how do we discriminate intensity of the stimulus?

– The # of neurons stimulated by a single stimulus

– Rate of firing (up to a maximum)

Neural Communication

• Once the neuron fires, it releases its Neurotransmitter into the synapse– Neurotransmitter Chemical messengers that relay

neural messages across the synapse

• Neurotransmitter fits in receptor like a key fits in a lock

• Neurotransmitter either excites or inhibits the post-synaptic cell by binding to its receptors

Neuron Demonstration

Neural Communication

• Methods to stop neural transmission

– Reuptake

– Degradation

– Presynaptic autoreceptors

Seven Important Neurotransmitters

DopamineDopamine

SerotoninSerotonin

AcetylcholineAcetylcholine

GlutamineGlutamine

NorepinephrineNorepinephrine

GABAGABA

EndorphinsEndorphins

DopamineDopamine

Serotonin

Acetylcholine

Glutamine

Norepinephrine

GABA

Endorphins

Normal FunctionNormal Function::

Produces sensations of Produces sensations of pleasure and reward; used pleasure and reward; used

by CNS neurons in by CNS neurons in voluntary movementvoluntary movement

Problems with Imbalance:Problems with Imbalance:

Schizophrenia, Parkinson’s Schizophrenia, Parkinson’s diseasedisease

Substances that Affect:Substances that Affect:

Cocaine, amphetamines, Cocaine, amphetamines, Ritalin, alcoholRitalin, alcohol

Dopamine

SerotoninSerotonin

Acetylcholine

Glutamine

Norepinephrine

GABA

Endorphins

Normal Function:Normal Function:

Regulates sleep and Regulates sleep and dreaming, mood, pain, dreaming, mood, pain,

aggression, appetite and aggression, appetite and sexual behaviorsexual behavior

Problems with Imbalance:Problems with Imbalance:

Depression, certain anxiety Depression, certain anxiety disorders, obsessive-disorders, obsessive-compulsive disordercompulsive disorder

Substances that Affect:Substances that Affect:

Prozac, hallucinogenics Prozac, hallucinogenics (e.g. LSD)(e.g. LSD)

Dopamine

Serotonin

Acetylcholine

Glutamine

NorepinephrineNorepinephrine

GABA

Endorphins

Normal Function:Normal Function:

Controls heart rate, sleep, Controls heart rate, sleep, sexual responsiveness, sexual responsiveness,

stress, vigilance and stress, vigilance and appetiteappetite

Problems with Imbalance:Problems with Imbalance:

High blood pressure, High blood pressure, depressiondepression

Substances that Affect:Substances that Affect:

Tricyclic antidepressants, Tricyclic antidepressants, beta blockersbeta blockers

Dopamine

Serotonin

Acetylcholine

Glutamine

Norepinephrine

GABA

EndorphinsEndorphins

Normal Function:Normal Function:

Pleasurable sensations and Pleasurable sensations and control of paincontrol of pain

Problems with Imbalance:Problems with Imbalance:

Lowered levels resulting Lowered levels resulting from opiate addictionfrom opiate addiction

Substances that Affect:Substances that Affect:

Opiates: opium, heroin, Opiates: opium, heroin, morphine, methadonemorphine, methadone

Plasticity

• Plasticity –

– Ability of the nervous system to adapt or change as the result of experience; sometimes helps the nervous system adapt to physical damage

The Organization of the Nervous System

Nervous systemNervous system

Peripheral nervous Peripheral nervous systemsystem

Central nervous Central nervous system (CNS)system (CNS)

AutonomicAutonomicnervous systemnervous system

SomaticSomaticnervous systemnervous system

SympatheticSympatheticnervous systemnervous system

Parasympathetic Parasympathetic nervous systemnervous system

Divisions of the Nervous System

• Central Nervous System (CNS)–Brain and spinal cord

• Peripheral Nervous System (PNS)–Connects brain and spinal cord with

the rest of the body

Peripheral Nervous System

• Somatic Nervous System– Carries incoming messages from sense organs

– Carries outgoing messages to skeletal muscles; mobilizes voluntary movements

• Autonomic Nervous System– Carries signals from the CNS to the internal

organs

– regulates involuntary functions such as digestion, respiration, heart rate

Autonomic Nervous System

• Sympathetic Division– Mobilized under stress – (e.g., controls 4 F’s)

• Increases heart rate and respiration, increases muscle tension, shuts off digestion

• Parasympathetic Division– Responsible for basic processes or

homeostasis• Slows heart rate and respiration, increases

digestive functioning

Example• Hear rattlesnake

– Somatic NS orients eyes to sound to locate snake

– Sympathetic Division of ANS mobilizes fight or flight response (i.e., blood to skeletal muscles; increases respiration)

– Somatic NS initiates skeletal muscles to escape

– Once escaped, Parasympathetic NS initiates relaxation response

The Endocrine System(the body’s chemical messenger system)

The Endocrine System

• Pituitary gland– Master gland; i.e., produces

hormones that influence the secretions of all other endocrine glands

– Attached to and controlled by hypothalamus

The Endocrine System

• Endocrine glands release hormones into bloodstream; circulate through body until target organ is reached

• Non-stress conditions supports parasympathetic nervous system in maintaining basic processes or homeostasis

• Stress conditions supports sympathetic nervous system through release of epinephrine (adrenaline)

Example Revisited• Hear rattlesnake

– Somatic NS orients eyes to sound– Sympathetic Division of ANS mobilizes fight or

flight response– Somatic NS initiates skeletal muscles to escape– Parasympathetic NS initiates return to resting

state, But, …

– Endocrine system release of adrenaline, explains why you feel edgy for a long time afterward

The Endocrine System

Glands Systems/ Processes regulated

Anterior Pituitary Ovaries and Testes, Milk production, metabolism, stress reactions

Posterior Pituitary Conservation of water, milk secretion, uterus contractions

Thyroid Metabolism, physical growth & development

Parathyroid Calcium levels

Pancreas Glucose (sugar) metabolism

Adrenal glands Fight or flight response, metabolism, sexual desire (especially women)

Ovaries Female sex characs., production of eggs

Testes Male sex characs., sperm production, sexual desire

How Does the Brain Produce Behavior and

Mental Processes?

The brain is composed of many specialized modules that work together to create

mind and behavior

Film on Structures of the Brain

Three Layers of the Brain• Brain stem and cerebellum

– Drive vital functions, such as heart rate, breathing, digestion

• Limbic system– Adds emotions, complex motives, increased

memory abilities

• Cerebrum– Enables reasoning, planning, creating,

problem solving

The Brain Stem and Cerebellum

• Thalamus

• Pons

• Cerebellum

• Medulla

• Brain stem

The Limbic System

• Hypothalamus –Serves as the brain’s blood-testing laboratory, constantly monitors blood to determine the condition of the body

The Limbic System

• Amygdala –Involved in memory and emotion, particularly fear and aggression

The Limbic System

• Hippocampus –Involved in establishing long-term memories

The Cerebrum

• Cerebrum –Topmost layer of the brain; the bulbous cap over the limbic system

• Cerebral cortex –Thin gray-matter covering of the cerebrum; carries on thinking and perceiving

• Cerebral hemispheres –The two walnut shaped halves of the cerebrum, connected by the corpus callosum

W. W

. No r

ton

Phineas Gage

Specialization of the Cerebral Hemispheres

Left Hemisphere Right Hemisphere• Spontaneous

speaking and writing

• Responses to complex commands

• Word recognition• Memory for words

and numbers• Sequences of

movements• Feelings of anxiety• Positive emotion

• Repetitive but not spontaneous speaking

• Responses to simple commands

• Facial recognition• Memory for shapes

and music• Spatial interpretation• Emotional

responsiveness• Negative emotion

Film on Split-Brain