Ways of Investigating the Brain

• What are techniques used for investigating the brain often used for?

  Medical purposes
• What is scanning often used to investigate?

  Localisation
• What does fMRI measure while a person is performing a task?

  Brain activity
• What type of images does fMRI produce?

  3D images
• How does fMRI detect brain activity?

  By changes in blood oxygenation and flow
• What is a key advantage of fMRI regarding radiation?

  It does not rely on the use of radiation
• What is a significant drawback of fMRI in terms of cost?

  It is expensive compared to other techniques
• What is the temporal resolution of fMRI?

  It has poor temporal resolution
• What is the time-lag associated with fMRI images?

  About 5 seconds
• What does EEG record?

  Tiny electrical impulses from the brain
• What do EEG recordings represent?

  Brainwave patterns from neuron actions
• Why are EEGs often used by clinicians?

  To identify neurological abnormalities
• What is a key advantage of EEG technology?

  Extremely high temporal resolution
• What conditions have EEGs been useful in diagnosing?

  Epilepsy
• What is a limitation of EEG signals?

  They cannot pinpoint exact neural activity
• What do event-related potentials measure?

  Brain responses to specific events
• How are event-related potentials derived?

  From statistical analysis of EEG data
• What is a key advantage of event-related potentials?

  They provide much more specificity
• What is a drawback of event-related potentials methodology?

  Lack of standardisation between studies
• What is the purpose of post-mortem examination?

  To link behaviors to brain abnormalities
• Who are likely subjects for post-mortem examinations?

  Individuals with rare disorders
• What did Broca and Wernicke rely on for their studies?

  Post-mortem studies
• What is a key ethical issue with post-mortem examinations?

  Informed consent may not be obtained
• What is a potential problem with observed brain damage?

  It may not link to observed deficits
• What are the strengths and weaknesses of fMRI?

  Strengths:

  • Non-invasive and risk-free
  • High spatial resolution
  • Clear images of brain activity

  
  

  Weaknesses:

  • Expensive compared to other techniques
  • Poor temporal resolution (5-second lag)
• What are the strengths and weaknesses of EEG?

  Strengths:

  • High temporal resolution (1 millisecond)
  • Useful for diagnosing conditions

  
  

  Weaknesses:

  • Generalised information
  • Cannot pinpoint exact neural activity
• What are the strengths and weaknesses of event-related potentials?

  Strengths:

  • High specificity in measuring neural processes
  • Excellent temporal resolution

  
  

  Weaknesses:

  • Lack of standardisation in methodology
  • Difficulty in eliminating extraneous data
• What are the strengths and weaknesses of post-mortem examinations?

  Strengths:

  • Provides early understanding of brain processes
  • Useful for linking brain structure to behavior

  
  

  Weaknesses:

  • Ethical issues regarding consent
  • Damage may not relate to observed deficits
• What is a strength for fMRIs as a way to Investigate the Brain?

  • Does Not Rely on the Use of Radiation
  • If administered correctly, it is virtually risk-free, non-invasive and straightforward to use
  • It also produces images that have very high spatial resolution and provides a clear picture of brain activity
  • This means that fMRI can safely provide a clear picture of brain activity
• What is a limitation for fMRIs as a way to Investigate the Brain?

  • Expensive
  • fMRI is expensive compared to other neuroimaging techniques
  • It has poor temporal resolution, as there is around a 5 second time-lag behind the image on screen and the initial firing of neuronal activity
  • This means that fMRI may not truly represent moment-to-moment brain activity
• What is a strength for EEGs as a way to Investigate the Brain?

  • Diagnosis of Conditions
  • EEGs have been useful in studying stages of sleep and in the diagnosis of conditions, such as epilepsy
  • Unlike fMRI, EEG technology has extremely high temporal resolution and today’s EEG technology can accurately detect brain activity at a resolution of a single millisecond
  • This shows the real-world usefulness of the technique
• What is a limitation for EEGs as a way to Investigate the Brain?

  • Unable to Pinpoint
  • The main drawback of EEGs is the generalised nature of the information received
  • The EEG is also not useful for pinpointing the exact source of neural activity
  • Therefore, it does not allow researchers to distinguish between activities originating in different but adjacent locations
• What is a strength for Event-Related Potentials as a way to Investigate the Brain?

  • Specificity
  • Event-related potentials bring much more specificity to the measurement of neural processes than could ever be achieved using raw EEG data
  • As event-related potentials are derived from EEGs, they have excellent temporal resolution
  • This means that event-related potentials are frequently used to measure cognitive functions and deficits
• What is a limitation for Event-Related Potentials as a way to Investigate the Brain?

  • Lack of Standardisation
  • Critics have pointed to a lack of standardisation in event-related potentials methodology between different research studies, which makes it difficult to confirm findings
  • A further issue is that extraneous material must be completely eliminated in order to establish pure data
  • This is a problem because it may not always be easy to achieve
• What is a strength for Post-Mortem Examination

  as a way to Investigate the Brain?

  • Early Understanding of Key Processes in the Brain
  • Broca and Wernicke both relied on post-mortem studies in establishing links between language, the brain and behaviour before neuroimaging was possible
  • Post-mortem studies were also used to study HM’s brain to identify the areas of damage, which could then be associated with his memory deficits
  • This means that post-mortem examinations continue to provide useful information
• What is a limitation for Post-Mortem Examination

  as a way to Investigate the Brain?

  • Ethical Issues
  • Observed damage to the brain may not be linked to the deficits under review but some other unrelated trauma or decay
  • Additionally, participants may not have been able to provide informed consent and yet post-mortem research has been conducted regardless
  • This challenges the usefulness of post-mortem studies in psychological research