Evaluate ways of studying the brain (8 marks)
FMRI:
An advantage of FMRI is that it is non-invasive. Unlike other scanning techniques, for example
Positron Emission Tomography (PET), fMRI does not use radiation or involve inserting instruments
directly into the brain and is therefore virtually risk-free. This matters because it should allow more
patients/participants to undertake fMRI scans which could help psychologists to gather further data
on the functioning human brain and therefore develop our understanding of localisation of function.
However, one limitation of fMRI scans is that they have poor temporal resolution. Temporal
resolution refers to the accuracy of the scanner in relation to time: or how quickly the scanner can
detect changes in brain activity. fMRI scans have a temporal resolution of 1-4 seconds which is worse
than other techniques (e.g. EEG/ERP which have a temporal resolution of 1-10 milliseconds). This
matters because psychologists are unable to predict with a high degree of accuracy the onset of
brain activity making conclusions about neural activity difficult.
EEG:
An advantage of the EEG is that it has good temporal resolution. Temporal resolution refers to the
accuracy of the scanner in relation of time: or how quickly the scanner can detect changes in brain
activity. EEG scanners take readings every millisecond, meaning it can record the brain’s activity in
(nearly) real time. This matters because it leads to an accurate measurement of electrical activity in
the brain and provides a high degree of accuracy when examining the onset of brain activity allowing
psychologist to make accurate conclusions in relation to the timing of neural activity.
However, one disadvantage of EEG is that this technique has poor spatial resolution. Spatial
resolution refers to the smallest feature (or measurement) that a scanner can detect and is an
important feature of brain scanning techniques. Greater spatial resolution allows psychologists to
discriminate between different brain regions with greater accuracy. EEGs only detect the activity in
superficial regions of the brain. This matters because EEGs are unable to provide information on
what is happening in the deeper regions of the brain (such as the hypothalamus), making this
technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm.
Outline one difference between fMRI and EEG (2 marks)
One key difference between fMRI and EEG is that fMRI measures blood flow when a person
performs a task and creates a dynamic (moving) 3D map of the brain; WHEREAS, EEG
measures electrical activity through electrodes attached to the scalp producing a graph of
electrical activity.
One key difference between fMRI and EEG is the spatial resolution (the smallest feature the
scanner can detect). fMRI scanners have a spatial resolution of 1-2mm; WHEREAS, EEG
scanners can only detect electrical activity in superficial general regions of the brain,
producing waves which are graphed and not a 3D map.
Outline one difference between EEG and ERP (2 marks)
EEG measures electrical activity through electrodes attached to the scalp while the
participant is in a general state (e.g. sleeping); WHEREAS, ERP looks at brain activity related
to a specific stimulus that is presented to the participants.
, One issue with both fMRI and EEG is the inability to show causation. fMRI scans do not provide a
direct measure of neural activity. fMRI scans simply measure changes in blood flow and therefore it
is impossible to infer causation (at a neural level). Likewise, the issue with EEG is that electrical
activity is often detected in several regions of the brain simultaneously. Consequently, psychologists
are unable to conclude whether particular brain regions are associated with specific functions (in the
case of fMRI) and which area/region the electrical activity took place (in the case of EEG) making
solid cause and effect conclusions impossible.
Outline fMRI and EEGS:
FMRI: is a brain scanning-technique that measures blood flow in the brain when a person performs a
task. fMRI works on the idea that the neurons in the brain which are the most active, use the most
energy. Deoxygenated and oxygenated haemoglobin have different magnetic qualities. An fMRI
scanner can detect these different magnetic qualities and can be used to create a moving 3D map of
the brain.
EEG: measures electrical activity through electrodes attached to the scalp. EEG scanners work on the
idea that information is processed in the brain as electrical activity in the form of action potentials or
nerve impulses. small electrical charges are detected by the electrodes that are graphed over a
period of time, indicating the level of activity in the brain. EEG can be used to detect illnesses like
epilepsy and to diagnose other disorders that affect brain activity, like Alzheimer’s disease.
Outline the role of the motor area in the brain. (3 marks)
The role of the motor area is to control voluntary motor movement by sending signals to
muscles in the body.
Furthermore, the role is to control the muscles on the opposite side of the body, so the left
hemisphere controls muscle movements on the right, and vice versa for the right
hemisphere.
The regions of the motor area are arranged in a logical order, for example, the region that
controls finger movement is located next to the region that controls the hand, arm and so
on.
FMRI:
An advantage of FMRI is that it is non-invasive. Unlike other scanning techniques, for example
Positron Emission Tomography (PET), fMRI does not use radiation or involve inserting instruments
directly into the brain and is therefore virtually risk-free. This matters because it should allow more
patients/participants to undertake fMRI scans which could help psychologists to gather further data
on the functioning human brain and therefore develop our understanding of localisation of function.
However, one limitation of fMRI scans is that they have poor temporal resolution. Temporal
resolution refers to the accuracy of the scanner in relation to time: or how quickly the scanner can
detect changes in brain activity. fMRI scans have a temporal resolution of 1-4 seconds which is worse
than other techniques (e.g. EEG/ERP which have a temporal resolution of 1-10 milliseconds). This
matters because psychologists are unable to predict with a high degree of accuracy the onset of
brain activity making conclusions about neural activity difficult.
EEG:
An advantage of the EEG is that it has good temporal resolution. Temporal resolution refers to the
accuracy of the scanner in relation of time: or how quickly the scanner can detect changes in brain
activity. EEG scanners take readings every millisecond, meaning it can record the brain’s activity in
(nearly) real time. This matters because it leads to an accurate measurement of electrical activity in
the brain and provides a high degree of accuracy when examining the onset of brain activity allowing
psychologist to make accurate conclusions in relation to the timing of neural activity.
However, one disadvantage of EEG is that this technique has poor spatial resolution. Spatial
resolution refers to the smallest feature (or measurement) that a scanner can detect and is an
important feature of brain scanning techniques. Greater spatial resolution allows psychologists to
discriminate between different brain regions with greater accuracy. EEGs only detect the activity in
superficial regions of the brain. This matters because EEGs are unable to provide information on
what is happening in the deeper regions of the brain (such as the hypothalamus), making this
technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm.
Outline one difference between fMRI and EEG (2 marks)
One key difference between fMRI and EEG is that fMRI measures blood flow when a person
performs a task and creates a dynamic (moving) 3D map of the brain; WHEREAS, EEG
measures electrical activity through electrodes attached to the scalp producing a graph of
electrical activity.
One key difference between fMRI and EEG is the spatial resolution (the smallest feature the
scanner can detect). fMRI scanners have a spatial resolution of 1-2mm; WHEREAS, EEG
scanners can only detect electrical activity in superficial general regions of the brain,
producing waves which are graphed and not a 3D map.
Outline one difference between EEG and ERP (2 marks)
EEG measures electrical activity through electrodes attached to the scalp while the
participant is in a general state (e.g. sleeping); WHEREAS, ERP looks at brain activity related
to a specific stimulus that is presented to the participants.
, One issue with both fMRI and EEG is the inability to show causation. fMRI scans do not provide a
direct measure of neural activity. fMRI scans simply measure changes in blood flow and therefore it
is impossible to infer causation (at a neural level). Likewise, the issue with EEG is that electrical
activity is often detected in several regions of the brain simultaneously. Consequently, psychologists
are unable to conclude whether particular brain regions are associated with specific functions (in the
case of fMRI) and which area/region the electrical activity took place (in the case of EEG) making
solid cause and effect conclusions impossible.
Outline fMRI and EEGS:
FMRI: is a brain scanning-technique that measures blood flow in the brain when a person performs a
task. fMRI works on the idea that the neurons in the brain which are the most active, use the most
energy. Deoxygenated and oxygenated haemoglobin have different magnetic qualities. An fMRI
scanner can detect these different magnetic qualities and can be used to create a moving 3D map of
the brain.
EEG: measures electrical activity through electrodes attached to the scalp. EEG scanners work on the
idea that information is processed in the brain as electrical activity in the form of action potentials or
nerve impulses. small electrical charges are detected by the electrodes that are graphed over a
period of time, indicating the level of activity in the brain. EEG can be used to detect illnesses like
epilepsy and to diagnose other disorders that affect brain activity, like Alzheimer’s disease.
Outline the role of the motor area in the brain. (3 marks)
The role of the motor area is to control voluntary motor movement by sending signals to
muscles in the body.
Furthermore, the role is to control the muscles on the opposite side of the body, so the left
hemisphere controls muscle movements on the right, and vice versa for the right
hemisphere.
The regions of the motor area are arranged in a logical order, for example, the region that
controls finger movement is located next to the region that controls the hand, arm and so
on.
