Betsy Edwards Psychology A
Discuss ways of studying the brain. (16 marks)
Functional magnetic resonance imaging (fMRI) scans are specialist MRI scans that measure brain
activity whilst a person is completing a task or responding to a stimulus. They can detect the blood
oxygenation of different regions of the brain, and therefore their relative activity levels; this is because
of the haemodynamic response, whereby more active regions of the brain require more blood flow to
meet their oxygen demand. Neural activity can be visually displayed on an activation map.
Electroencephalograms (EEGs) measure general neural activity by recording the patterns of
firing neurons in the brain. EEG data can then be statistically analysed to produce event-related
potentials (ERPs); these show the brain’s electrophysiological responses to specific stimuli. By
superimposing multiple scans relating to the same stimulus, extraneous activity can be removed, leaving
only the neural activity relevant to the stimulus (which would have been the same in each scan).
Post-mortem examinations involve studying the brain after death to determine whether certain
observed behaviours during the patient’s lifetime can be linked to abnormalities of the brain. This may
involve comparing the brain to a neurotypical brain.
A strength of EEGs is that they have practical applications in identifying abnormalities, e.g.
arrhythmic patterns of neuron activity within the brain may indicate epilepsy. The high temporal
resolution of EEGs make them a better diagnostic tool than other methods of studying the brain. For
example, there is around a five-second time lag between neural activity and on-screen imaging in fMRI
scans, meaning neural responses faster than one second may be missed. Therefore, the value of EEGs is
strengthened by their use in clinical diagnosis, allowing health problems to be identified and – thereafter
– treatment options to be explored.
A strength of post-mortem examinations is that they have helped contribute to our
understanding of how functions of the brain are localised. For example, post-mortem examinations of
patients with Broca’s aphasia allowed us to conclude that the Broca’s area is responsible for speech
production. However, post-mortems are passive studies with questionable precision, and the presence
of many confounding variables – such as age and cause of death – may mean conclusions are not
generalisable universally. Therefore, fMRI scans may provide more valid conclusions about localisation
of function, as they clearly show which brain regions are active during certain tasks and have high spatial
resolution; this also allows for valuable practical applications, for example cingulotomy treatments for
cases of severe OCD.
A strength of post-mortem examinations is that areas deep within the brain can be investigated.
This is not the case for EEGs and ERPs, where the electrical signals occurring in deeper regions cannot be
detected by the electrodes attached to the scalp. This means that potentially post-mortem examinations
are more beneficial to the study of biopsychology, as more regions of the brain – such as the
hypothalamus – can be investigated.
Word count: 182 + 285
Discuss ways of studying the brain. (16 marks)
Functional magnetic resonance imaging (fMRI) scans are specialist MRI scans that measure brain
activity whilst a person is completing a task or responding to a stimulus. They can detect the blood
oxygenation of different regions of the brain, and therefore their relative activity levels; this is because
of the haemodynamic response, whereby more active regions of the brain require more blood flow to
meet their oxygen demand. Neural activity can be visually displayed on an activation map.
Electroencephalograms (EEGs) measure general neural activity by recording the patterns of
firing neurons in the brain. EEG data can then be statistically analysed to produce event-related
potentials (ERPs); these show the brain’s electrophysiological responses to specific stimuli. By
superimposing multiple scans relating to the same stimulus, extraneous activity can be removed, leaving
only the neural activity relevant to the stimulus (which would have been the same in each scan).
Post-mortem examinations involve studying the brain after death to determine whether certain
observed behaviours during the patient’s lifetime can be linked to abnormalities of the brain. This may
involve comparing the brain to a neurotypical brain.
A strength of EEGs is that they have practical applications in identifying abnormalities, e.g.
arrhythmic patterns of neuron activity within the brain may indicate epilepsy. The high temporal
resolution of EEGs make them a better diagnostic tool than other methods of studying the brain. For
example, there is around a five-second time lag between neural activity and on-screen imaging in fMRI
scans, meaning neural responses faster than one second may be missed. Therefore, the value of EEGs is
strengthened by their use in clinical diagnosis, allowing health problems to be identified and – thereafter
– treatment options to be explored.
A strength of post-mortem examinations is that they have helped contribute to our
understanding of how functions of the brain are localised. For example, post-mortem examinations of
patients with Broca’s aphasia allowed us to conclude that the Broca’s area is responsible for speech
production. However, post-mortems are passive studies with questionable precision, and the presence
of many confounding variables – such as age and cause of death – may mean conclusions are not
generalisable universally. Therefore, fMRI scans may provide more valid conclusions about localisation
of function, as they clearly show which brain regions are active during certain tasks and have high spatial
resolution; this also allows for valuable practical applications, for example cingulotomy treatments for
cases of severe OCD.
A strength of post-mortem examinations is that areas deep within the brain can be investigated.
This is not the case for EEGs and ERPs, where the electrical signals occurring in deeper regions cannot be
detected by the electrodes attached to the scalp. This means that potentially post-mortem examinations
are more beneficial to the study of biopsychology, as more regions of the brain – such as the
hypothalamus – can be investigated.
Word count: 182 + 285
