Why Study Brain and Behaviour?
-Behaviour is action, momentarily observable, but fleeting.
1) A growing list of behavioural disorders can be explained and cured by
understanding the brain.
2) The brain is the most complex living organ on earth and is found in many
different groups of animals
3) How the brain produces both behavior and human consciousness is a major
unanswered scientific question.
What is the Brain?
- Brain: Tissue found within the skull.
- Forebrain: prominent in birds and mammals with big brains, including
ourselves. It’s responsible for most of our conscious behaviors.
- Brainstem: source of behavior in simpler animas such fish, amphibians and
retiles. It’s responsible for most of our unconscious behaviors.
- Hemispheres: forebrain has 2 nearly symmetrical halves, called
- Cerebral cortex: outer layer of brain tissue surface composed of neurons.
- Temporal lobe: located at the side of brain and is responsible for functions
of hearing, language and musical abilities.
- Frontal lobe: responsible for executive functions like decision making
- Parietal lobe: located at the top of the skill, behind the frontal lobe and
above the temporal love. Its functions include directing our movements
toward a goal or to perform a task, such as grasping an object.
- Minimally conscious state (MCS): condition in which a person can display
some rudimentary behaviors, such as smiling, or utter a few words but is
otherwise not conscious.
- Traumatic brain injury (TBI): wound to the brain that results from a blow
to the head.
- Persistent vegetative state (PVS): condition in which a person is alive but
unable to communicate or to function independently at even the most basic
- Clinical trial: Approved experiment directed toward developing a treatment.
- Deep brain stimulation (DBS): Neurosurgery in which electrodes
implanted in the brain stimulate a targeted area with a low-voltage electrical
current to facilitate.
- Occipital lobe: Area at the back of each hemisphere where visual processing
- Neurons: most directly control behavior. A specialized “nerve cell” engaged
in information processing.
- Spinal cord: provides most of the connections between the brain and the
rest of the body. - Central nervous system (CNS): the brain and the spinal cord that together
mediate behavior. It’s central because it’s physically located to be the core of
the nervous system and because it is the core structure mediating behavior.
- Peripheral nervous system (PNS): all the neurons in the body located
outside the brain and spinal cord; provides sensory and motor connections
to and from the central nervous system.
- Embodied consciousness: hypothesis that the movements that we make
and those that we perceive in others are essential features of our conscious
In the 1920s, Edmond Jacobson did an experiment, where people practiced “total”
relaxation and were later asked what the experience was like. They reported a
condition of “mental emptiness” as if the brain had gone blank.
Findings from these lines of research suggest that the CNS needs ongoing sensory
stimulation from the world and from its own body’s movement if it is to maintain its
What is Behavior?
“Behavior consists of patterns in times”. These patterns can be made up of
movements, vocalizations, or changes in appearance, such as the facial movements
associated with smiling. Thinking is also a behavior that forms patterns in time.
The behavioral patterns of some animals are relatively fixed: most of the behaviors
are inherited ways of responding. The behavioral patterns of other animals are both
inherited and learned. If all members of a species display the same behavior under
the same circumstances, that species has probably inherited a nervous system
evolved to produce that relatively fixed behavioral patterns automatically. In
contract, if each member of a species displays a somewhat different response in a
similar situation, that species has inherited a much more flexible nervous system
that is capable of changes in behavior due to learning.
Generally, animals with smaller, simpler nervous systems have a narrow range of
behaviors dependent on heredity. Animals with complex nervous systems have
more behavioral options that depend on learning. We humans believe that we the
animal species with the most-complex nervous system and the greatest capacity for
learning new responses.
Complexity emerges in part because new nervous-system structures are added to
old ones and that is why the sucking response of newborns are inherited eating
patterns in humans.
Perspectives on Brain and Behavior:
- Psyche: synonym for mind, an entity once proposed to be the source of
human behavior. Aristotle argued it’s responsible for life, and its departure
from the body results in death. - Mind: Proposed nonmaterial entity responsible for intelligence, attention,
awareness and consciousness. Mind is an anglo-saxon word for memory and
when psyche was translated into English it became the mind.
- Mentalism: the philosophical position that a person’s mind, or psyche is
responsible for behavior is called mentalism, meaning “of the mind”.
- Dualism: the philosophical position that two entities, a mind and a body,
- Mind-body problem: the problem of how a nonmaterial mind and physical
brain might interact.
Descartes suggests that the mind resides in a small structure in the center of the
brain, the pineal body (now called the pineal gland), which is located beside fluid
filled cavities called ventricles. Today we understand that the pineal glad plays a
role in behavior related to biological rhythms, but it does not govern human
Darwin and Materialism:
- Materialism: the idea that rational behavior can be fully explained by the
workings of the brain the rest of the nervous system, without any need to
refer to an immaterial mind.
- Natural selection: Darwin’s theory for explaining how new species evolves
and existing species change over time.
Mendel deduced that heritable factors, which we now call genes, are related to the
various physical traits displayed by the species
- Species: group of organisms that can interbreed
- Genotype: Members of a species that have a particular gene or combination.
The unequal ability of individual organisms to survive and reproduce is related to
the different genes that they inherit from their parents and pass on to their
Darwin’s theory of natural selection has 3 important implications for the study of
the brain and behavior:
1) Because all animal species are related, so too must be their brains.
2) Because all species of animals are related, so too must be their behavi