2.1 Localisation

Define

Localisation of function is a concept in neuroscience that refers to the idea that different regions of the brain are responsible for specific cognitive and behavioural functions.

Explain: Key Processes

• This theory suggests that different areas of the brain are specialised for different tasks, such as vision, hearing, language, movement, and emotion.

• There are different types of localisation, including strict, weak, and relative localisation.

• Weak localisation refers to the idea that different brain regions contribute to different aspects of a function rather than a single function being entirely confined to one region.

Explain: How it Works

• The human brain is the central organ of the nervous system, consisting of the cerebrum, cerebellum, and brainstem.

• It controls and coordinates all bodily functions, including movement, sensation, thought, memory, and emotion.

• Damage to specific regions of the brain can lead to deficits in the corresponding function.

Explain: Theoretical Support

• The concept was first proposed by Paul Broca and Carl Wernicke in the 19th century, who observed that damage to specific regions of the brain resulted in language and speech deficits.

• Further research has confirmed that different regions of the brain are indeed specialised for different functions.

Link

• Localisation of function is essential for understanding how the brain supports cognitive and behavioural processes.

• The transition from invasive methods (e.g., post-mortem examinations) to non-invasive neuroimaging techniques has made the study of brain function much safer and more effective.

Overview

• Localisation of function is essential for understanding how the brain supports cognitive and behavioural processes.

• The transition from invasive methods (e.g., post-mortem examinations) to non-invasive neuroimaging techniques has made the study of brain function much safer and more effective.

Aim

To determine the potential role of biological factors on flashbulb memories

Method

Quasi Experiment

Design

Independent Measures

Sampling Strategy

Purposive (24 participants)

IV

Downtown or Midtown Manhattan

DV

Activation of the amygdala

Procedure 1

participants placed in an fMRI
Words placed on screen

Summer or September along with words

Procedure 2: Rate

After recall, participants were asked to rate memories:

Vividness
Confidence in accuracy
Arousal
Detail

Procedure 3

Participants were also asked to write down personal memories

Control

Summer recall was used as a baseline

Findings 1: FBM

• Only half of the participants actually reported having ‘flashbulb memories’

Findings 2: Proximity

• Those who reported flashbulb memories also reported they were closer to the attacks.

• Also included more specific details in their written memories

Findings 3: DT or MT

Downtown = higher activation of the amygdala when attack recalled than when summer recalled

Midtown = similar activation of the amygdala when recalling both events

Conclusion 1

Strength of amygdala activation shown to correlate with flashbulb memories

Close personal experience = critical in engaging neural mechanism that produce flashbulb memories

Evaluation: (strengths)

• Demand characteristics are not possible = increased internal validity

Evaluation: (weaknesses)

• Correlational = no cause and effect

• high artificial environment = low ecological validity

• Small sample size and culturally biased = research shows individualistic cultures are more likely to have flashbulb memories than collectivistic = hard to generalize

For a ERQ about localisation, which study should be used with Sharot el al. (2007)

Maguire et al.

Maguire et al. year

2000

Aim

To investigate whether the brains of London taxi drivers would be somehow different due to their deep city knowledge and extensive driving hours in London

Method

Natural Experiment

Design

Independent Measures

Single Blind

Sampling Strategy

Purposive; 16 right-handed London taxi drivers/50 right-handed males who did not drive taxis.

Selection Criteria

• Completed the ‘knowledge’ test

• Had their license for a least 1.5 years

IV

Whether they were a London taxi driver or not

DV

Mass and Distribution of Grey Matter in the Hippocampus

Procedure: 1

Data from MRI measured using two different techniques:

VBM - to measure density of GM

Pixel counting - counting pixels to measures area

Findings: Pixel Counting

Pixel counting = posterior hippocampi taxi - significantly larger

anterior hippocampi significantly smaller

Findings: VBM

Volume of right posterior hippocampi - correlate with time spent as taxi driver

Findings: 3

No differences observed in other parts of the brain

Conclusion

Maguire argues: demonstrates hippocampus may change in response to environmental demands

Conclusion: 2 - anterior posterior

Posterior Hippocampus - involved when previously learn spatial info used
Anterior hippocampus - encoding new environmental layouts

Evaluation: Methodological Strengths

Ethically sound - MRI no health risks

Coded brains scans= blind analysis - avoiding researcher bias

Evaluation: Methodological Weaknesses

Quasi-experiment - no cause-and-effect