Chapter 15 Flashcards
(27 cards)
What did phrenologists believe they could do by examining the skull?
Understand the brain by examining bumps on the skull.
What is the goal of modern brain imaging?
To observe brain structure and function from outside the skull.
What traditional method linked structure to function in the brain?
Studying patients’ behavior and brain structure postmortem.
What are the limitations of postmortem lesion studies?
Lesions may disconnect brain regions, plasticity may occur, and lesions rarely affect only one precise area.
What does PET stand for?
Positron Emission Tomography.
What does PET measure?
Changes in local cerebral blood flow using radioactive tracers.
What is the main disadvantage of PET?
Requires injection of radioactive substances.
What does MRI stand for?
Magnetic Resonance Imaging.
What does MRI provide?
High-resolution structural images of the brain.
What is diffusion tensor imaging (DTI) used for?
Mapping white matter tracts in the brain.
What does fMRI measure?
Blood-Oxygenation-Level-Dependent (BOLD) signal.
What causes the BOLD signal in fMRI?
Differences between oxyhaemoglobin and deoxyhaemoglobin during neural activity.
What happens to blood flow during increased neural activity?
It increases, leading to a higher concentration of oxyhaemoglobin.
Why is the BOLD signal important?
It reflects synaptic activity, making it useful for functional localization.
How are fMRI tasks typically designed?
Using two similar tasks where only one activates the process of interest.
What is subtraction imaging?
Subtracting brain images during two tasks to isolate specific activity.
What is event-related fMRI?
fMRI that measures brain activity from events lasting 1–2 seconds.
What software is commonly used in fMRI analysis?
Statistical Parametric Mapping (SPM).
What happens when viewing a moving checkerboard in an fMRI?
The primary visual cortex (V1) is activated.
What brain area processes color?
Area V4.
What brain area processes motion?
Area V5.
What does V5 receive input from?
V2 and the pulvinar; information flow is managed by the posterior parietal cortex (PPC).
What is effective connectivity?
Analysis of how different brain regions interact during complex tasks.
What surprising finding was made regarding memory in early fMRI studies?
The medial temporal lobe did not routinely show activity in long-term memory tasks.
