Lecture 6 th
September 24 2013
Chapter 3 The Biological Basis of Behaviour
Nervous system is a communication network that serves as the foundation for all psychological activity. It consists
of billions of nerve cells or neurons. It comprises two systems- central nervous system and peripheral- defined by
both anatomy and function.
→ Central Nervous System (CNS)
Central nervous system is central to the body’s structure and workings. It is composed of the brain and spinal
cord. Nearly all functions of the CNS are performed by the brain.
Different parts do different things VS. entire brain acts in unison
1800 1900 1930 1940 2000
Phrenology. Scientists Amachine Researchers focused on Measuring the electrical
Anatomists tried were able to that could people who suffered activity in brain became
to understand explain the record the from specific brain one of the most important
personality traits electrical broad damages to investigate techniques used in brain
brain-behaviour research and it is
and mental impulses patterns of
abilities by and electrical relationship. Dr. developed further in
measuring the neurotrans activity in Penfield worked with recent years.
bumps on the mitters the brain epilepsy patients, used Ex: EEG, computerized
human skull. was electrical stimulation tomography, MRI, and
Scientists were developed. and made important PET scans.
contributions to the -provide us information
able to examine about brain structure,
the nerve cells. area.
-help us map brain activity
Now, we know that the brain consists of highly specialized areas mostly for physical activities, but different areas
coordinate for even routine mental operations.
TMS video** Trans-cranial magnetic stimulation. Use to understand brain activity related to behaviour, we
can modify the brain and increase or decrease activity in some parts of the brain.
Magneto-encephalogram video** captures the electric activity.
→ SpecializedAreas of the Brain
As we move upward, the functions of the brain structures go from regulation of basic processes
to the control of more complicated and complex mental processes.
-attached to the spinal cord,
-in charge of highly vital functions including blood circulation,
breathing, regulating reflexes.
-connects brainstem with cerebellum.
-contains several cell bodies involved with sleep and arousal. Cerebellum:
-critical to the coordination of movement and physical balance.
-segment between hindbrain and forebrain.
-Dopamine-releasing neurons originate from midbrain, so it is indirectly related to
the performance of voluntary movements.
-contains other network of neurons known as reticular formation, which mainly
contributes to regulation of sleep and arousal.
Hindbrain and midbrain are evolutionarily older part of the brain. Newer, larger and more complex region of our
brain is the forebrain.
-integrates and directs sensory info (except smell) to correct
location in the cortex.
-the smell is the oldest and most fundamental of the senses, so
it has a direct route to the cortex.
-while the brain is resting during the sleep, thalamus shuts the
gate on incoming sensations.
-governs biological drives related to survival: fighting, fleeing,
feeding and mating.
-controls the autonomic nervous system. It is responsible for
regulating the vital functions- body temperature, blood pressure, glucose level.
-controls the master gland of the body, pituitary gland, which by
releasing hormones into bloodstream controls all other glands.
-the structure in the brain most closely aligned to