Social Zeitgeber & Chronotype Flashcards
Explain the pressures on timing of:
Producer - Consumer
Predator - Prey
Parasite - Host
Commensalism
Producer - Consumer:
- Producer needs to when to spread seeds
- Consumers need to know when predators are out (when dangerous to eat)
Predator - Prey:
- Prey same as consumer
- Predator needs to know when food available
Parasite - Host:
- Parasite would rely on host’s immune system and behavioural timing
Commensalism:
- Ability of 2 organisms to co-exist
- Similar to parasite-host but both benefit
How is sociality important for bees and humans?
- Working together more important than being on own (Sociality more important than biological clock)
Bees:
- Selection occurs at hive level (depends on how queen passes genetic material down to worker bees)
- Hive is like entire organism
Humans:
- Need certain times of day to go to work, school, etc
Social Zeitgeber
- Reflects pressure from population to adapt the individual temporal program to a common program for the population
- There’s a distribution of circadian phase but people decide on common times to interact socially
Chronotype
Preference of when to do activities in the day vs actual timing of activities
- Based on self-assessment
- Usually doesn’t align for activity done alone vs in a group
What can you assess to determine someone’s chronotype?
1) Relative preference for morning vs evening activities
- Morningness-eveningness questionnaire (MEQ)
2) Phase angle of entrainment
- Munich chronotype questionnaire (MCTQ)
3) Account of the various rhythms of physiology
- Ask spouse or equivalent when they think you perform activities
Why shouldn’t you ask a chronobiologist on your chronotype?
Why is it so complex?
Chronotype is intuitice
- Self-assessment most accurate
We need to know how to correct for circadian misalignment
- Many factors that can make up a chronotype (personality, expression of circadian clock, etc)
Internal desychrony experiment
Ppl lived in bunkers, reported when activities done
- Found humans have bio clock running at 25 hours
- 24.8 hours for body temp
- 33 hours for sleep
In absence of light/dark cycle, period of sleep/wake and body temp can become as long as 48 hours
- Relationship between sleep/wake and body temp cycles
Do people’s preferences correlate more on activities on weekend or weekday?
Weekend
What happens when your body temperature is low?
What does it depend on?
Become groggy, typically at night
Depends on when you prefer to sleep and how long you’ve been awake for
What human factors drive self-assessments of ability/performance?
Cognitive:
- Executive control (inhibitory control) worse at non-optimal time of day
- Memory (working memory span) increases throughout day for eveningness and decreases for morningness
Emotional:
- Morningness tend to rate more positive affect
- Eveningness tend to display greater tendency for higher depression scores and suicide
Physical:
- Some physical activity appear better at one’s optimal time of day
- Linked to increased enjoyment, motivation, affective response
Social jet lag
Effect on sleep
Timing discrepancy between one’s rhythm and chronotype, and social clocks
- But adequate and good quality sleep is necessary for maintaining optimal, cognitive, physical, and emotional health
Sleep tends to be shorter and earlier on weekdays, which causes sleep rebound on weekends
What does the MCTQ do that the MEQ doesn’t?
Makes you think deeper about your habits to produce more realistic responses
- Ex: Sleeping habits on weekdays vs weekends
MEQ more of just scenarios
Older vs Younger adults executive function experiment
Tested thru recall of items on list
- Older adults did better in morning (tend to be morning type)
- Younger adults did better in evening (tend to be evening type)
Chronotype goes from eveningness to morningness as you age
What does the University if Toronto Inventory if Morningness Eveningness measure?
Correlations with UTime and MEQ vs MCTQ
Measures on how much cognition, emotion, and physicality is involved in responses
- Questions on situations that the person might encounter
Stronger correlations w/ MCTQ (esp in emotion)
- MEQ mainly correlated w/ cog performance
- Automatic responding increases when inhibitory function us low
