Psy100 Lecture 6
Tuesday October 5, 2010
Psychology Student Association - psa.utoronto.ca
The Pre-Frontal Cortex
Mind and life institute
Key Outcomes: people can permanently adjust their neuroanatomy, people
can make themselves much happier and emotionally stable than previously
believed and people can affect even low-level processes
The brain changes continuously
“Our brains’ connections are refined and retuned with every experience of
our lives.” The brain is constantly evolving. Plasticity is amazing but the
limits are unknown.
Only recently have we begun to appreciate our brains’ incredible plasticity or
ability to change
Certainly, age is a factor
Current huge questions concern the outer limits to which people can learn to
manipulate their own neural functioning and the benefits gained. Practical
questions concern how to create a more brain-healthy society.
Brain areas can even recruit systems normally devoted to other tasks
Example: cut off a finger: that part of the sensory cortex will start to receive
signals from the other fingers: enhanced sensitivity
Example: if blind, the sensory cortex corresponding to the Braille-reading
finger expands; sense of touch starts to get processed by the visual cortex.
In essence, this is how our sensorimotor cortices evolved in the first place.
The Split Brain
The two hemispheres of the brain are actually two mini-brains connected by
a bundle of fibers, the corpus collosum
In 1930s-1950s, cutting the corpus collosum became all the rage, to help
people with epileptic seizures and other disorders. Amazingly, these people
seemed pretty normal but clever psychologists discovered ways of
communicating separately with the now-independent hemispheres
Experiments: when asked to point to the item that was seen, the left hand
(RH) pointed to the image seen by the right hemisphere. It’s a very simple
People rely on the left hemisphere for what they have to turn into words.
Figure 4.17, 4.19 -
A patient can have emotional reactions to stimuli without being able to
verbalize what he/she saw.
Left hand and eye= right brain
Right hand and eye= left brain The mind is what the