research methods additional reading

Question 1

Electroencephalography (EEG) strengths

Answer 1

• Luck (2014)- excellent temporal resolution. EEG, especially through event-related potentials (ERPs), allows researchers to track brain responses to specific stimuli in real-time, which is crucial for understanding processes like perception, attention, and decision-making
• Michel & Murray (2012): Compared to other brain imaging techniques like fMRI or MEG, EEG is relatively inexpensive and portable, which allows for broader applications in diverse settings, including field studies and bedside monitoring

Question 2

Electroencephalography (EEG) limitations

Answer 2

-Nunez & Srinivasan (2006): the inverse problem in EEG (inferring sources of brain activity from scalp recordings) is mathematically ill-posed, making it difficult to pinpoint the origin of neural activity accurately
- Grech et al., (2008): EEG is most sensitive to activity in the cortex and less effective at detecting signals from deeper brain structures like the hippocampus or thalamus.

Question 3

Magnetoencephalography (MEG) strengths

Answer 3

• Baillet (2017): MEG can localize activity to within millimeters when combined with anatomical MRI, making it superior to EEG in spatial precision for neocortical sources
• Hari & Salmelin (2012): MEG offers millisecond-scale temporal resolution, allowing researchers to track dynamic neural processes with great precision- ideal for sensory motor and cognitive processes

Question 4

Magnetoencephalography (MEG) limitations

Answer 4

• Gross et al., (2013): MEG data require sophisticated source localization algorithms and modeling (e.g., beamforming, minimum norm estimates), which demand expert knowledge and computational resources
• Okada & Kyuhou (1997): MEG is primarily sensitive to neural currents oriented tangentially to the scalp, typically in the sulci, and is largely insensitive to deep brain structures (e.g., hippocampus, brainstem).

Question 5

MRI strengths

Answer 5

• Van Essen (2013): MRI provides exceptional spatial resolution (sub-millimeter in high-field scanners), making it ideal for detailed anatomical imaging of brain structures
• McRobbie et al., (2017): MRI uses strong magnetic fields and radio waves—avoiding ionizing radiation—which makes it suitable for repeated use and safe for most populations

Question 6

fMRI strengths

Answer 6

-Logothetis (2008): fMRI offers high spatial resolution (typically 1–3 mm), allowing researchers to localize brain activity with fine anatomical detail
- Huettel et al., (2014): Unlike techniques such as EEG or MEG, fMRI can image the entire brain, including deep structures such as the thalamus, basal ganglia, and hippocampus.

Question 6

MRI limitations

Answer 6

• Huettel et al., (2014): MRI, particularly fMRI, has a temporal resolution in the range of seconds, which is insufficient for capturing rapid neural dynamics
• Power et al., (2012): MRI is sensitive to head motion, which can severely degrade image quality—particularly problematic in children or clinical populations.

Question 7

fMRI limitations

Answer 7

-Ekstrom (2010): fMRI does not measure neural firing directly. Instead, it relies on changes in blood oxygenation (the BOLD response), which is a delayed and indirect proxy for neuronal activity.
-Poldrack (2006): Functional activation patterns do not directly equate to cognitive processes. The BOLD signal reflects complex interactions between neurons and vascular systems, making it difficult to draw firm conclusions about causality or function.

Question 8

PET strengths

Answer 8

• Volkow (2009): PET allows for direct measurement of neurotransmitters, receptors, and metabolic processes by using radioligands specific to biological targets
• Raichle (1998): PET provides whole-brain imaging, including subcortical and deep brain structures, which may be challenging for other modalities like MEG or TMS

Question 9

PET limitations

Answer 9

• Phelps (2000): PET’s slow signal dynamics limit its application for studying fast-changing cognitive states or neural oscillations.
• Cherry (2001): PET involves the injection of radioactive substances, which limits its use in vulnerable populations (e.g., children, pregnant individuals) and in longitudinal studies

Question 10

Transcranial magnetic stimulation (TMS) strengths

Answer 10

• Walsh & Cowey (2000): TMS can transiently disrupt or enhance brain activity, allowing researchers to draw causal conclusions about the function of specific brain areas.
• Illmoniemi & Kicic (2010): TMS can be delivered with millisecond precision, allowing researchers to investigate the timing of neural processes and brain–behavior relationships.

Question 11

transcranial magnetic stimulation (TMS) limitations

Answer 11

• Hamada (2013): Anatomical differences (e.g., skull thickness, cortical folding) and brain state can influence TMS effects, reducing reproducibility. Variability in response to TMS protocols highlights the need for individualized calibration in research and therapy.
• Wagner et al., (2007): TMS can only reach superficial cortical regions (~1–2 cm depth), limiting its use in studying deep brain structures like the amygdala or hippocampus. The spatial spread of TMS can lead to unintended stimulation of adjacent regions, complicating interpretation.