Introductory chapter
Biological psychology = the study of physiological, evolutionary and developmental
mechanisms of behavior and experience.
→ it holds that we think and act as we do because of brain mechanisms and that we evolved
those brain mechanisms because ancient animals built this way survived and reproduced
Our universe has four fundamental forces: gravity, electromagnetism, the strong nuclear
force and the weak nuclear force.
Questions that stand out the most and are the most difficult:
● Why is there something rather than nothing
● How does the mind relate to brain activity (mind-body problem)
A fundamental property = one that cannot be reduced to something else.
→ some state that consciousness is a fundamental property (not likely)
Dorsal view = brain from the top
Ventral view = brain from the bottom
Two types of cells:
● neurons, convey messages to one another and to muscles and glands
● glia, have many functions but don’t convey information over great distances
3 general points to remember:
1. Perception occurs in your brain
2. Mental activity and certain types of brain activity are, so far as we can tell,
inseparable (monism, opposite of dualism)
3. We should always be cautious about what is an explanation and what isn’t
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,4 categories of biological explanations of behavior: physiological, ontogenetic,
evolutionary and functional.
Physiological explanation = relates a behavior to the activity of the brain and other organs.
It deals with the machinery of the body.
Ontogenetic = the origin (genesis) of being; describes how a structure or behavior
develops, including the influences of genes, nutrition, experiences and their interactions.
Evolutionary explanation = reconstructs the evolutionary history of a structure or behavior
and how it evolved from something.
Functional explanation = describes why a structure or behavior evolved as it did.
4 reasons why psychologists study nonhumans:
1. The underlying mechanisms of behavior are similar across species and sometimes
easier to study in a nonhuman species
2. We are interested in animals for their own sake
3. What we learn about animals sheds light on human evolution
4. Legal or ethical restrictions prevent certain kinds of research on humans
Legal standard emphasizes three R’s:
● Reduction, using fewer animals
● Replacement, using computer models or substitutes for animals when possible
● Refinement, modifying the procedures to reduce pain and discomfort
Minimalist = wishes to limit animal research to studies with little discomfort and much
potential value.
Abolitionist = wishes to eliminate all animal research regardless of how the animals are
treated or how much value the research might produce.
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,Chapter 1
Membrane = the surface of a cell, a structure that separates the inside of the cell from the
outside environment.
Nucleus = structure that contains the chromosomes
Mitochondria = structures that perform metabolic activities, providing the energy that the
cell uses for all activities. “powerhouse of the cell”
Ribosomes = the sites within a cell that synthesize new protein molecules.
Endoplasmic reticulum = a network of thin tubes that transport newly synthesized proteins
to other locations.
Soma = cell body; contains the nucleus, ribosomes and mitochondria
Motor neuron = has its soma in the spinal cord, receives excitation through its dendrites
and conducts impulses along its axon to a muscle; efferent
Sensory neuron = specialized at one end to be highly sensitive to a particular type of
stimulation, such as light, sound or touch; conducts information from e.g. skin to spinal cord;
afferent
Afferent axon = brings information into a structure
Efferent axon = carries information away from a structure
Dendrites = branching fibers that get narrower near their ends; receives information at
synaptic receptors from other neurons
Dendritic spines = short outgrowths that increase the surface area available for synapses.
Axon = a thin fiber of constant diameter; conveys an impulse toward other neurons, an
organ or a muscle.
Axons of neurons become covered by myelin, a fatty sheath that acts like insulation to
speed the transmission of neural impulses.
→ with interruptions known as nodes of Ranvier
Presynaptic terminal = here the axon releases chemicals that cross through the junction
between that neuron and another cell.
Interneuron or Intrinsic neuron = when a cell’s dendrites and axon are entirely contained
within a single structure; neurons that connect to brain regions.
Astrocytes = star-shaped glial cells that wrap around the synapses of functionally related
axons to shield it from chemicals circulating in the surround and help synchronize closely
related neurons to send signals in waves.
Tripartite synapse = hypothesis that states that the tip of an axon releases chemicals that
cause the neighboring astrocyte to release chemicals of its own, thus magnifying or
modifying the message to the next neuron.
Microglia = act as part of the immune system, removing viruses and fungi from the brain,
they proliferate after brain damage, removing dead or damaged neurons.
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, Oligodendrocytes = located in the brain and spinal cord; build the myelin sheaths that
surround and insulate certain vertebrate axons and supply an axon with nutrients necessary
for proper functioning.
Schwann cells = in the periphery of the body; build the myelin sheaths that surround and
insulate certain vertebrate axons and supply an axon with nutrients necessary for proper
functioning.
Radial glia = guide the migration of neurons and their axons and dendrites during embryonic
development, when finished they differentiate into neurons and a smaller number
differentiate into astrocytes and oligodendrocytes.
Blood-brain barrier = mechanism that excludes most chemicals from the vertebrate brain.
→ to minimize the risk of irreparable brain damage, the body lines the brain’s blood vessels
with tightly packed cells that keep out most viruses, bacteria and harmful chemicals
→ depends on the endothelial cells that form the walls of the capillaries, outside the brain
such cells are separated but in the brain they are joined so tightly that they block viruses,
bacteria and other harmful chemicals from passage.
→ people with Alzheimer’s disease or similar conditions have shrinked endothelial cells that
cause harmful chemicals to enter the brain.
Active transport = a protein-mediated process that expends energy to pump chemicals
from the blood into the brain (glucose, amino acids, purines, chlorine, a few vitamins and
iron).
Passive transport = no energy is needed; small, uncharged molecules such as oxygen,
carbon dioxide and water cross the blood-barrier passively.
Glucose = a sugar, vertebrate neurons depend on glucose for nutrition.
Thiamine = body needs this vitamin B1 to use glucose, deficiency leads to death of neurons
(Korsakoff’s syndrome).
Messages in a neuron develop from changes in the resting potential.
Inside the cell is more negative than the inside (resting potential)
Action potential (neural firing) = the electrical signal that passes along the axon and
subsequently causes the release of chemicals from the terminal buttons to get a signal
across if the signal of neuron A is strong enough to receive for neuron B.
- -70 mV (resting potential)
- -55 mV (activation threshold)
- +30 mV (activation peak)
- -80 mV ? (restoring to balance)
When a neuron has more negative ions inside than outside → neuron is polarized
Selective permeability = some chemicals (oxygen, carbon dioxide, urea and water) pass
through membranes more freely than others.
Sodium-potassium pump = a protein complex, repeatedly transports three sodium ions out
of the cell while drawing two potassium ions into it; active transport
→ when the membrane is at rest, the sodium and potassium channels are closed.
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