Brain Imaging Techniques, Neuroplasticty and Localisation

Question 1

What are brain imaging techniques?

Answer 1

Brain imaging techniques are methods used in psychology to examine the human brain, allowing researchers to see where specific brain processes take place.

Question 2

What is an fMRI (Functional Magnetic Resonance Imaging)?

Answer 2

• A noninvasive test used to measure brain activity.
• fMRI creates detailed images of the brain during a specific experimental time period by looking at blood flow in the brain.

Question 3

What is the aim of Fisher et al’s 2005 study?

Answer 3

To investigate the neural mechanisms associated with the attraction system (romantic love)

Question 4

Procedure of Fisher et al’s study?

Answer 4

Fisher used fMRI scanning to see the brain activity of participants when they were shown images of their loved one, compared to a photo of a “neutral” friend.

Question 5

What did Fisher find in their study?

Answer 5

The fMRI showed increased activity in the dopamine rich areas associated with reward, motivation and goal orientation when they looked at photos of their lover.
Increased activity in brain regions include the right mid-insular cortex and the right posterior cortex.

Question 6

What can be concluded from Fisher’s study?

Answer 6

The fMRI brain scan helped us to understand that romantic love is associated with subcortical dopaminergic pathways in the reward system and that romantic love is primarily a motivation system, which leads to various emotions rather than just one specific emotion.

Question 7

What are the strengths of Fisher’s study?

Answer 7

It can evaluate brain function safely, non-invasively and effectively. The images produced are very high resolution (as detailed as 1 mm).

Question 8

What are the limitations of Fisher’s study?

Answer 8

• Expensive
• It can only capture a clear image if the subject stays completely still
• Results can be difficult to interpret
• Researchers can only look at blood flow in the brain, not activities of individual nerve cells (neurons), which are critical to mental function - limits the information that can be gained by the scan.

Question 9

What is an MRI (Magnetic Resonance Imaging)?

Answer 9

MRIs detect pulses of energy emitted from hydrogen atoms in body tissue to obtain an image that maps the relative distribution of the atoms.

Question 10

Aim of Maguire et al’s 2000 study?

Answer 10

To investigate the structural changes and function of the hippocampus in the brains of London taxi drivers.
According to Maguire, the role of the hippocampus is to facilitate spatial memory, in the form of navigation.

Question 11

Procedure of Maguire et al’s study?

Answer 11

16 right-handed male taxi drivers who had undergone an intensive training programme on how to navigate the city were recruited. Their average experience was 14.3 years, ranging from 1.5 years to 42 years. All taxi drivers had healthy medical profiles. The control group consisted of 50 healthy right-handed males who did not drive taxis.

Question 12

Findings of Maguire et al’s study?

Answer 12

It was found that the posterior hippocampi of taxi drivers were significantly larger than the control subjects and the anterior hippocampus were significantly smaller.

Question 13

Conclusions of Maguire et al’s study?

Answer 13

Quasi-experiment, therefore no cause-effect inferences can be made. An alternative explanation could be that people with larger grey matter volumes are naturally deposited to choose professions that depend on navigational skills

Question 14

Strengths of Maguire et al’s study?

Answer 14

• No health risks

- Many controls, such as age, experience and right-handedness

Question 15

Limitations of Maguire et al’s study?

Answer 15

• Expensive
• All male participants - generalisability low
• Low ecological validity

Question 16

What is the aim of Draganski et al’s 2004 study?

Answer 16

To find out whether the human brain is able to change the structure in response to environmental demands with the use of MRIs.

Question 17

What is the procedure of Draganski et al’s study?

Answer 17

Sample: self-selected/ volunteer
Participants were randomly allocated into 2 groups: jugglers & non-jugglers. They made sure none of the participants had any experience with juggling. The first brain scan was performed at this point.
The juggler group spent 3 months subsequently learning a classic juggling routine with 3 balls. The second brain scan was then performed.
The participants spent another 3 months where they were asked not to practice any juggling. The third brain scan was then performed.
The control group (the non-jugglers) just lived their daily lives and had their brains scanned the same time as the juggler group.

Question 18

What were the findings of Draganski et al’s study?

Answer 18

There were no differences prior in the brain scan results of the two groups prior to the start of the experiment.
The second brain scan showed that the juggler group had significantly more grey matter in some areas of the cortex, most notably, the mid-temporal areas in both hemispheres. These areas are known to be implicated in the coordination of movement. The third scan showed that these differences decreased, but the jugglers still had more grey matter than they did in the first scan.

Question 19

What can be concluded from Draganski et al’s study?

Answer 19

By learning a simple juggling routine, certain areas of your brain grow. However, with failure to practice, these areas shrink back, but not to the original size.

Question 20

What is localisation?

Answer 20

Localisation of function is the idea that areas of the brain are responsible for certain functions, that behaviour, thoughts and emotions are controlled by the brain in specific locations.

Question 21

What is Broca’s area?

Answer 21

Broca’s area is the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production.

Question 22

What was the aim of Broca’s 1861 study on Tan?

Answer 22

To test his theory that damage to a specific part of the brain (the frontal lobe) was responsible for problems with speech by studying his patient, Tan’s brain.

Question 23

Procedure of Broca’s study?

Answer 23

Broca studied a patient over a number of years (as it was a longitudinal study), known as “Tan,” because it was one of the few sounds he could make.
After Tan died, Broca conducted a post-mortem autopsy on this patient (and several others) to figure out what part of the brain caused his or similar conditions.

Question 24

Findings of Broca’s study?

Answer 24

After performing the autopsy, he now had evidence that damage to a specific area of the brain was responsible for the loss of ability to produce coherent speech. This area became known as Broca’s area. The effects of damage to this part of the brain can most easily be observed in the speech of stroke victims, many of whom are temporarily or permanently unable to produce language, a condition known as Broca’s aphasia.

Question 25

Conclusions from Broca’s study?

Answer 25

Broca concluded that Broca’s area is responsible for an impairment of language in a person. Through this study, new understanding and research had arised of localised functions of different parts of the brain, as a result of this finding from early research into the brain by scientists such as Broca.

Question 26

Strengths of Broca’s study?

Answer 26

• Longitudinal study which was able to see the long term effects of the accident such as the changes overtime.
• Method triangulation which allowed for the data collected to be more supported which allows for a higher internal validity.

Question 27

Limitations of Broca’s study?

Answer 27

• Case study - unable to replicate
• Due to lack of technology at the time, no brain scans were available until after his death, no way of knowing for certain how the brain operated when he was alive

Question 28

What is Wernicke’s area?

Answer 28

It is located in the temporal lobe on the left side of the brain and is responsible for the comprehension of speech.

Question 29

Aim of Wernicke’s 1874 study?

Answer 29

Like Broca, Wernicke wanted to investigate another speech/language and comprehension disorder, in which he believed, resulted from a different area than Broca’s area responsible for the comprehension of speech.

Question 30

Procedure of Wernicke’s study?

Answer 30

Wernicke worked in a similar fashion to Broca, by noting behaviour and conducting post-mortem autopsies to locate brain damage after patients had died, particularly in stroke victims.

Question 31

Findings of Wernicke’s study?

Answer 31

After performing the autopsies, Wernicke concluded that there was a section of the brain which was responsible for the comprehension of speech. The area later became known as Wernicke’s area. Individuals with this type of aphasia might have problems understanding the speech of others or might substitute wrong words into planned phrases. He now had evidence that damage to Wernicke’s area was responsible for the loss of ability to comprehend and understand speech, but still being able to speak.

Question 32

Conclusions from Wernicke’s study?

Answer 32

Through this study, Wernicke concluded that Wernicke’s area is responsible for an impairment of comprehending/understanding language.

Question 33

Strengths of Wernicke’s study?

Answer 33

Through studies like Wernicke and Broca’s, it became clear that specific parts of the brain were responsible for specific human activities and behaviour.

Question 34

Limitations of Wernicke’s study?

Answer 34

However, it was still very difficult to find ways to investigate this further, as cases like these were usually rare. Furthermore, people could not be operated on as it is deemed to be unethical.

Question 35

Aim of Kim and Hirsch’s 1997 study?

Answer 35

To find out if the age at which a second language is learnt affects where it is ‘stored’ in the brain.

Question 36

Procedure of Kim and Hirsch’s study?

Answer 36

Kim and Hirsch gathered 12 fluently bilingual study subjects for the study. The subjects were categorised equally into 2 groups: those who had learnt both languages early in life and those who learnt their second language later in life.
The subjects were asked to engage in a silent internal monologue about the previous day and an advanced brain imaging technology called functional magnetic resonance imaging (fMRI) was used to take images of their brain while they did this.
They were then asked to repeat this monologue separately in both languages.

Question 37

Findings of Kim and Hirsch’s study?

Answer 37

The fMRI scans showed that in Wernicke’s area, there was little to no separation of activity based on the age of language acquisition. However, in Broca’s area, languages acquired in adulthood were spatially separated from native languages.
For someone who learned a second language later in life, (teenage years or adulthood) a different spot within Broca’s area would be activated when they used their second language. On the other hand, for those who had learned two languages as a child, their native and second languages tend to be represented in common areas in Broca’s area.

Question 38

Conclusions of Kim and Hirsch’s study?

Answer 38

It is not clear why child and adult language acquisition are different but they speculated that the brain uses different strategies for learning languages depending on age.
After the passage of early childhood, Broca’s area may become less malleable and “not subsequently modified”.

Question 39

Strengths of Kim and Hirsch’s study?

Answer 39

• The task is a common everyday task

- High ecological validity

Question 40

Limitations of Kim and Hirsch’s study?

Answer 40

Small sample size, limited generalisability

Question 41

What is neuroplasticity?

Answer 41

Neuroplasticity is the ability of the brain to change throughout the course of life, through the making and breaking of synaptic connections between neurons.

Question 42

How does Maguire et al’s study link into neuroplasticity?

Answer 42

Difference in the distribution of grey matter: taxi drivers had more grey matter in the posterior hippocampus and less in the anterior hippocampus. The opposite was true for non-taxi drivers. Alternative explanation could be that people with larger grey matter volumes are naturally deposited to choose professions that depend on navigational skills.

Question 43

What is the aim of Merzenich et al’s 1984 study?

Answer 43

To study the cortical representation of the hand in 8 adult owl monkeys.

Question 44

Procedure of Merzenich’s study?

Answer 44

Sensory inputs from all the fingers were mapped into the cortex by inserting electrodes in the cortical area known to be responsible for sensation from the hand. Different fingers were stimulated. By recording which electrode responded to the stimulation, researchers could map which area controlled which digit. The owl monkeys’ middle fingers were then amputated. 62 days later, the monkeys’ cortex was remapped.

Question 45

Findings of Merzenich’s study?

Answer 45

Areas which had controlled now amputated digits were taken over by the adjacent digits (i.e. areas that controlled fingers 2 and 4 had expanded to control finger 3 as well.

Question 46

Conclusions of Merzenich’s study?

Answer 46

Supports the theory of neuroplasticity. There was re-specialisation of brain matter responsible for one digit, so that it became responsible for other, adjacent units.

Question 47

Limitations of Merzenich’s study?

Answer 47

Ethics - permanent physical damage and harm.