Lecture 1: Resting-state physiology and cognition Flashcards
What is cognitive neuroscience?
The combined study of mind and brain that aims to improve diagnosis and treatment of brain-disorders (also A.I.)
Explain Positron Emission Tomography (PET) imaging (think of what is actually measured/detected).
Radioactive material is injected (e.g. FDG). Since the brain uses sugar, FDG will accumulate in brain areas that are metabolically active. The decay of FDG gives off a neutron and a positron. The positron hits an electron which falls apart into 2 gamma rays, which is detected by a computer.
What is temporal resolution?
Temporal resolution refers to how closely the measured activity corresponds to the timing of the actual neuronal activity (when).
What is spacial resolution?
Spatial resolution refers to how accurately the measured activity is localised within the brain (where).
In brain imaging, when looking at specific neuroreceptors, it’s possible to make use of PET. How?
This can be done by developing radiolabelled ligands for those receptors (don’t learn by heart).
What is meant by the fact that traditional task-dependent PET studies rely on subtraction?
The metabolism of the brain is huge (20% of the whole body). Therefore, when comparing different performed tasks in a PET image, it’s hard to distinguish the differences. When subtracting images from different tasks from each other, you can develop a more clearer picture where it’s visible what differences in active brain areas there are between tasks.
Fill in (Wernicke’s/Broca’s):
Speaking words activates …. area, whereas thinking about words activates … area.
Speaking words activates Wernicke’s area, whereas thinking about words activates Broca’s area.
What is functional MRI (fMRI)?
fMRI makes use of the oxygen transport in the brain. When a brain area becomes active, it will receive oxygenated blood within seconds. This is called the hemodynamic respons and since oxygenated and deoxygenated hemoglobin have different magnetic properties, the hemodynamic response can be measured by fMRI.
95% of the brain shows task-related activity. What does this mean?
That there’s localization (specific active brain areas), but task-related activity is also dependent on the entire brain.
fMRI and PET initially didn’t capture signs of background activity in the brain when a subject was doing nothing and so provided an inaccurate picture of neural activity (old view). What’s the new view?
Research has shown that the brain maintains a high level of activity even when at rest. Some activities, like reading or other routine tasks require minimal additional energy (up to 5%).
There are also brain areas that show a decrease in activity when performing a specific task. What is typical about these areas?
That these areas correspond with a high-resting state metabolism.
What is an advantage of resting-state neuroimaging?
The ability to assess the functional integrity of many brain networks in a short amount of time and with a task instruction that almost all subjects, including children and patients, can perform.
What’s interesting about brain areas that show task-dependent decrease?
They are connected with each other through strong neural fibers. In fMRI, these areas show correlated BOLD signals during rest.
What are default mode network (DMN) areas?
Brain areas that decrease their activity during a specific task performance.
What are tasks that do result in activation of these default mode networks?
Tasks that have to do with yourself:
- Recalling autobiographical memory
- Envisioning future
- Thinking in another one’s perspective (theory of mind)
- Moral decision making
A smartphone app can be used to investigate the probably correlation between daydreaming and DMN. What was the result of this study (don’t learn by heart)?
5000 participants installed an app that on a daily basis randomly asked questions like “how are you feeling right know”, “what are you doing right know” and “are you thinking about something other than what you’re currently doing?”. The conclusion was that 47% of patients daydreamed, which caused less happiness.
What was the first validated questionnaire to quantify thoughs and feelings during rest?
The Amsterdam Resting-State Questionnaire (ARSQ)
Just have a look at this model of resting-state thoughts and feelings based on factor analysis.
Ok
So based on the model of resting-state thoughts and feelings, some correlations between one thing and the other can be made. What does this figure state?
That discontinuity of mind (how long you can hold on to certain thoughts -> e.g. constantly changing?) correlates with comfort. The more discontinuity of mind (quick change in thoughts) correlates with less comfort.
So based on the model of resting-state thoughts and feelings, some correlations between one thing and the other can be made. What does this figure state?
That comfort and theory of mind don’t correlate with each other. This means that being comfortable doesn’t have anything to do with being able to take over someone else’s perspective.
So based on the model of resting-state thoughts and feelings, some correlations between one thing and the other can be made. What does this figure state?
That planning and theory of mind correlate with each other. This makes sense, since planning usually has something to do with other people as well. So the more you are able to take over someone’s perspective, the better you are in planning.
