W5: Using Neuroscience to Understand Self-Control and Health Flashcards
What is self control (3)
Ability to override thoughts, emotions, and behaviors
However, self-control seems to be limited…
After coping with stress, subsequent control impaired
How do we know these processes occur (stress and fatigue impact our ability to self-control?) - self-control failure
(4)
- fMRI
- EEG
- Fatigue/stress manipulations (last week)
- Cue reactivity
fMRI (2)
Scans measure the radio-frequency waves emitted by hydrogen atoms when they are subjected to a strong magnetic field
Gives detailed structure of the brain and can indirectly measure activity through changes in blood flow that accompany activity
fMRI
After activity in the brain (4)
- Increase in oxygen consumption in the area of the brain active
- There is increased blood flow to the oxygen-deficient area
- Wherever this increase is found, we assume that part was active
- BOLD (Blood Oxygen Level Dependent) response
EEG - (5)
- Records combined activity from many neurons using electrodes
- Good temporal resolution but poor spatial resolution
- Instant neural activity
- Vague idea where it is coming from
- Best used to detect changes in emotions, motivation, or arousal (since it is instant)
EEG data has rhythms - (3)
- EEG data is composed of distinct frequencies or patterns that happen in a given time (measured in hertz or Hz)
- The greater Hz, the more frequency of “events” which are typically just “ups and downs” in the data
- Certain mental processes occur during certain frequencies
Alpha activity in EEG
Relaxed, but awake
Brain at rest
Used to determine what part of the brain is active
EEG data a combination of frequencies!
Diagram
Measuring motivation - Difference in activity between the left and right frontal lobes (3)
- Assessed via alpha frequencies
- Lower alpha in left frontal = approach (reward) - motivated to seek reward in environment
- Lower alpha in right frontal = avoidance (inhibition) - going to have deliberate decision making and make healthy decisions
Schmeichel et al. (2019) - measuring motivation procedure (4)
Manipulated stress/fatigue - Restricted writing task
Had stress manipulated group (restricted writing task) and control (free writing task
Participants viewed positively, neutral or negative images
Measured approach (reward) motivations via EEG while viewing images
Schmeichel et al. (2019) - measuring motivation results
- Those in restricted writing condition (stress) did have greater activity in left frontal lobe when viewing positive images compared to those in control condition
Schmeichel et al. (2019) - measuring motivation conclusion - (4)
- Stress increases motivations towards rewarding stimuli (positive images)
- Supports theoretical model of self-control
- Stress increases motivation towards positive, rewarding stimuli
- Shifts in motivation undermine inhibition and self-control
Petzel et al. (2019) - Measuring motivations procedure (5)
- Measured likelihood of dependence (alcohol sensitivity)
- Manipulated stress/fatigue
- Restricted writing task
- Participants viewed alcohol versus neutral images (waterbottle)
- Measured approach (reward) motivations via EEG while viewing images
Petzel et al. (2019) - Measuring motivations results - (1)
- Those with lower alcohol sensitivity (more dependent on alcohol) in stress condition had higher activation in the left frontal lobe (reward) when viewing alcohol compared to those who are less dependent on alcohol and no stress condition
Petzel et al. (2019) - Measuring motivations conclusion - (5)
- Stress increases motivations towards rewarding stimuli (alcohol)
- Effects strongest for at-risk or vulnerable groups
- Potential alcohol abuse
- Low tolerance to alcohol
- Supports theoretical model of self-control
