Biopsychology
Localisation of functions in Evaluation
the brain
Case study evidence Phineas Gage had accident as metre length pole went through
Gage’s left cheek, taking a portion of his brain with it most of his
left frontal lobe. The damage to his brain had left a mark on his
personality as he had turned from someone who was calm and
reserved to someone who was quick-tempered and rude. This is
a strength as it suggests that the frontal lobe may be responsible
for regulating mood
Brain scan evidence of Petersen used brain scans to demonstrate how Wernicke’s area
localisation was active during a listening task, and Broca’s area was active
during a reading task, suggesting that these areas of the brain
have different functions. Another study revealed that semantic
and episodic memories reside in different parts of the prefrontal
cortex. This is a strength because there now exists a number of
highly sophisticated and objective methods for measuring
activity in the brain, which provide evidence of localisation of
brain function
Neurosurgical evidence Psychologist reported on 44 people with OCD who had
undergone a neurological procedure. At post-surgical follow up,
after 32 weeks, a third had met the criteria for successful
response to the surgery and 14% for partial response. This is a
strength because the success of procedures like this strongly
suggests that symptoms and behaviours associated with serious
mental disorders are localised
Plasticity When the brain has become damaged and a particular function
has been lost, the rest of the brain appears able to reorganise
itself in an attempt to recover the lost function. There are
several documented cases of stroke victims being able to recover
those abilities that were seemingly lost as a result of the illness.
This is a weakness because this shows that the brain is much
more flexible than it is claimed to be in localisation of function,
as it can prove to repair and make up for a loss of function
Plasticity and functional Evaluation
recovery of the brain after
trauma
Practical applications Understanding the processes involved in plasticity has
contributed to the field of neurorehabilitation. Following injury
to the brain, spontaneous recovery tends to slow down after a
number of weeks, so physical therapy may be required to
maintain improvements in functioning. Techniques may include
movement therapy and electrical stimulation of the brain to
counter the deficits in cognitive functioning that may be
experienced following a stroke. This is a strength because it
shows that although the brain may have the capacity to ‘fix itself’
to a point, this process requires further intervention if it is to be
completely successful
, Negative plasticity The brain’s ability to rewire itself can sometimes have
maladaptive behavioural consequences. Prolonged drug use has
been shown to result in poorer cognitive functioning as well as
an increased risk of dementia later in life. Also, 60-80% of
amputees have been known to develop the experience of
sensations in the missing limb as if it were still there. These
sensations are usually unpleasant, painful, and are thought to be
due to cortical reorganisation in the somatosensory cortex that
occurs as a result of limb loss
Age and plasticity Functional plasticity tends to reduce with age. The brain has a
natural tendency for reorganisation in childhood as it is
constantly adapting to new experiences and learning. It was
demonstrated 40 hours of golf training produced changes in the
neural representation of movement in participants aged 40-60.
Using fMRI, the researchers saw reduced motor cortex activity in
the novice golfers compared to a control group, suggesting more
efficient neural representations after training. This is a strength
as it shows that neural plasticity does continue throughout the
lifespan
Support from animal studies Early evidence of neural plasticity and functional recovery was
derived from animal studies. Psychologists involved sewing one
eye of a kitten shut and analysing the brain’s cortical responses.
It was found that the area of the visual cortex associated with
the shut eye was not idle but continued to process information
from the open eye. This further empirical evidence supports
plasticity, making the theory more reliable
Split brain research into Evaluation
hemispheric lateralisation
Demonstrated lateralised Sperry’s work into the split-brain research lots of findings. The
brain functions main conclusion is that the left hemisphere is more geared
towards analytic and verbal tasks whilst the right is better at
performing spatial tasks and music. The right hemisphere can
only produce basic words and phrases but contributes emotional
content to language. Research suggests that the left hemisphere
is the analyser whereas the right hemisphere is the synthesiser.
This is a strength because it is a key contribution to our
understanding of brain processes, and increases the scientific
credibility
Strengths of the methodology The experiments involving split-brain individuals made use of
highly specialised and standardised procedures. The image
projected would be flashed up for 1/10 of a second, meaning the
individuals would not have time to move their eye across the
image and so spread the information across both sides of the
visual field to both sides of the brain. This allowed Sperry to vary
aspects of the basic procedure and ensured that only one
hemisphere was receiving information at a time. This is a
strength because he was able to develop a very useful and well-
controlled procedure, meaning that it ensures reliability as it can
be replicated
Issues with generalisation Sample of people was so small that it cannot be generalised to
the general public. There were only 11 people who took part in
Localisation of functions in Evaluation
the brain
Case study evidence Phineas Gage had accident as metre length pole went through
Gage’s left cheek, taking a portion of his brain with it most of his
left frontal lobe. The damage to his brain had left a mark on his
personality as he had turned from someone who was calm and
reserved to someone who was quick-tempered and rude. This is
a strength as it suggests that the frontal lobe may be responsible
for regulating mood
Brain scan evidence of Petersen used brain scans to demonstrate how Wernicke’s area
localisation was active during a listening task, and Broca’s area was active
during a reading task, suggesting that these areas of the brain
have different functions. Another study revealed that semantic
and episodic memories reside in different parts of the prefrontal
cortex. This is a strength because there now exists a number of
highly sophisticated and objective methods for measuring
activity in the brain, which provide evidence of localisation of
brain function
Neurosurgical evidence Psychologist reported on 44 people with OCD who had
undergone a neurological procedure. At post-surgical follow up,
after 32 weeks, a third had met the criteria for successful
response to the surgery and 14% for partial response. This is a
strength because the success of procedures like this strongly
suggests that symptoms and behaviours associated with serious
mental disorders are localised
Plasticity When the brain has become damaged and a particular function
has been lost, the rest of the brain appears able to reorganise
itself in an attempt to recover the lost function. There are
several documented cases of stroke victims being able to recover
those abilities that were seemingly lost as a result of the illness.
This is a weakness because this shows that the brain is much
more flexible than it is claimed to be in localisation of function,
as it can prove to repair and make up for a loss of function
Plasticity and functional Evaluation
recovery of the brain after
trauma
Practical applications Understanding the processes involved in plasticity has
contributed to the field of neurorehabilitation. Following injury
to the brain, spontaneous recovery tends to slow down after a
number of weeks, so physical therapy may be required to
maintain improvements in functioning. Techniques may include
movement therapy and electrical stimulation of the brain to
counter the deficits in cognitive functioning that may be
experienced following a stroke. This is a strength because it
shows that although the brain may have the capacity to ‘fix itself’
to a point, this process requires further intervention if it is to be
completely successful
, Negative plasticity The brain’s ability to rewire itself can sometimes have
maladaptive behavioural consequences. Prolonged drug use has
been shown to result in poorer cognitive functioning as well as
an increased risk of dementia later in life. Also, 60-80% of
amputees have been known to develop the experience of
sensations in the missing limb as if it were still there. These
sensations are usually unpleasant, painful, and are thought to be
due to cortical reorganisation in the somatosensory cortex that
occurs as a result of limb loss
Age and plasticity Functional plasticity tends to reduce with age. The brain has a
natural tendency for reorganisation in childhood as it is
constantly adapting to new experiences and learning. It was
demonstrated 40 hours of golf training produced changes in the
neural representation of movement in participants aged 40-60.
Using fMRI, the researchers saw reduced motor cortex activity in
the novice golfers compared to a control group, suggesting more
efficient neural representations after training. This is a strength
as it shows that neural plasticity does continue throughout the
lifespan
Support from animal studies Early evidence of neural plasticity and functional recovery was
derived from animal studies. Psychologists involved sewing one
eye of a kitten shut and analysing the brain’s cortical responses.
It was found that the area of the visual cortex associated with
the shut eye was not idle but continued to process information
from the open eye. This further empirical evidence supports
plasticity, making the theory more reliable
Split brain research into Evaluation
hemispheric lateralisation
Demonstrated lateralised Sperry’s work into the split-brain research lots of findings. The
brain functions main conclusion is that the left hemisphere is more geared
towards analytic and verbal tasks whilst the right is better at
performing spatial tasks and music. The right hemisphere can
only produce basic words and phrases but contributes emotional
content to language. Research suggests that the left hemisphere
is the analyser whereas the right hemisphere is the synthesiser.
This is a strength because it is a key contribution to our
understanding of brain processes, and increases the scientific
credibility
Strengths of the methodology The experiments involving split-brain individuals made use of
highly specialised and standardised procedures. The image
projected would be flashed up for 1/10 of a second, meaning the
individuals would not have time to move their eye across the
image and so spread the information across both sides of the
visual field to both sides of the brain. This allowed Sperry to vary
aspects of the basic procedure and ensured that only one
hemisphere was receiving information at a time. This is a
strength because he was able to develop a very useful and well-
controlled procedure, meaning that it ensures reliability as it can
be replicated
Issues with generalisation Sample of people was so small that it cannot be generalised to
the general public. There were only 11 people who took part in
