Module 5: The Brain and its Biology
Everything psychological—every idea, every mood, every urge—is biological at its core.
● Psychologists working from a biological perspective study the links between biology and
● Humans are biopsychosocial systems in which biological, psychological, and
sociocultural factors interact to influence behavior.
● The Biopsychosocial approach is not medical but it integrates the Biology of the body
with the environment and the mental processes of the mind
● Psychologists believe that Biology is not the sole determining factor and there is a lot
more complexity involved in understanding the brain and the mind
● There is a constant debate regarding the brain vs the mind
Understanding of the relationship between the brain and mind has evolved over time.
● Plato: Mind located in spherical head
● Aristotle: Mind found in heart (feelings)
● Gall: Phrenology revealed mental abilities and character traits- Phrenology is the study
of the outer structure and what it says about the inside. Gall believed that outer features
like certain bumps, grooves and shapes were representative of personality traits
● Despite initial acceptance of Franz Gall’s speculations, bumps on the skull tell us nothing
about the brain’s underlying functions. Nevertheless, some of his assumptions have held
true. Though they are not the functions Gall proposed, different parts of the brain do
control different aspects of behavior.
Idea of dualism ie are certain entities separate- BRAIN VS MIND
● Can you have a brain without a mind?: Yes (brain death etc)
● Can you have a mind without a brain?: No
● So Yes they are separate but they are inextricably related
● The mind is a separate entity that emerges from the brain
During the past century, researchers discovered
● Nerve cells conduct electricity and communicate through chemical messages across tiny
separating gaps. There is cross communication.
● Specific brain systems serve specific functions and information is integrated to construct
a wide range of experiences. There is localization of function.
● The adaptive brain is wired by experience. The brain possesses plasticity : There has
been this idea that once you damage the brain, that is it and there is no regeneration.
But now we know that that is not true and that the brain has a neurogenesis capacity. It
possible (but slow) to grow new cells and eve easier to form new connections between
Key terms Neuron
● an electrically excitable cell that processes and transmits information through electrical and
● Neurons are the elementary components of the nervous system—the body’s speedy
● These signals between neurons occur via specialized connections called synapses
● Neurons can connect to each other to form neural networks.
All neurons consist of the cell body, axon and dendrites
● The cytoplasmic structure of the neuron
● It contains the nucleus
● Dendrites are thin structures that arise from the cell body
● They are recipients of signals
● It is a special cellular extension that arises from the cell body
● Every neuron has only one axon
● It carries the signal away from the cell body
● It is covered with a Myelin sheath that smooths it out so that that the signal can travel
smoothly and quickly
● Breakdown of myelin can cause multiple sclerosis
Neurons receive signals through branching dendrites and send signals through its axons.
● An electrically driven neural impulse that travels down the axon via an all or nothing process
● A good way to think of this as if there is potential for action in neurons which may or may not
occur depending on whether the signal reaches threshold
● The neuron’s reaction is an all-or-none process. ●