PSY260 - 13. Time Memory

Question 1

Time Memory

Answer 1

Bees +other animals remember time of day they discovered food (food anticipation)
Marmosets learn which box will contain food, but assume restricted to 1 time of day

Question 2

Time Memory

Answer 2

Hamsters + mice learn where find food/receive foot shock + what time of day will happen
Human beings have distinct times of day they will perform specific tasks/actions

Question 3

Time Memory

Answer 3

ability to learn + remember time of day when things happen
implicitly remember time of day
food not available all day long - remember time accessible

Question 4

Time Memory

Answer 4

do a dance to communicate info to sister bees
never taught to them explicitly
we have various devices that tell us the time
don’t think about it - you know it

Question 5

Episodic memory

Answer 5

autobiographical, places individual at scene of memory (it is your memory, and you know that you were there)
time is critically important for episodic memory

Question 6

Episodic memory

Answer 6

don’t know if animals simply learned association/know it’s happening, if they have episodic memory
animals behave in tests that indicates they might be using episodic memory
we don’t know how they are accessing that memory

Question 7

Episodic-like memory

Answer 7

memory of what/when/where but no concrete evidence of autobiography

Question 8

Explicit time memory

Answer 8

time of day discriminative cue + part of context that must be learned
explicit: avoid chamber at 2, not at 6, get shock in afternoon, not at night

Question 9

Implicit time memory

Answer 9

time of day not discriminative cue

memory implied by response of subject

Question 10

Implicit time memory

Answer 10

train at 1 time, no info about what happens at another time, yet perform at time of day trained, not any other time

Question 11

Implicit time memory

Answer 11

Animals automatically register time of day that significant conditions occur
Animals expect recurrence of condition at same time on subsequent days
measurement of learning depends on when you measure memory

Question 12

Implicit time memory

Answer 12

has to be significant for animals, not for humans

if tested at diff time of day, might conclude that it hasn’t learned

Question 13

Conditioned Place Preference or Avoidance

Answer 13

Day 1: Pre-exposure (10 minutes)
animals allowed access to both chambers
no preference

Question 14

Conditioned Place Preference or Avoidance

Answer 14

Days 2-9: Conditioning (5 min/day, 1 time of day) - animals confined to single chamber on each day - Chamber is alternated each day - reward is paired with ONE chamber
teach them to prefer a chamber - time not discriminatory
next day give nothing in other context at same time

Question 15

Conditioned Place Preference or Avoidance

Answer 15

Day 10+: Testing (20 minutes)
animals allowed access to both chambers
tested at a clock time which either matches/doesn’t match training time

Question 16

Post-training context preference: animals trained at CT 13 (late day) with wheel reward

Answer 16

test at same time: preference for paired context

no significance preference at diff time of day

Question 17

Post-training context preference: animals trained at CT 04 (early day) with wheel reward

Answer 17

paired at early day: show significant preference at early day
no significant preference in late day
takes energy + risk to go foraging for food: so organisms assess likelihood of getting reward + go out when they have experienced reward before

Question 18

Conditioned Place Avoidance

Answer 18

mild footshock
strong avoidance same chamber 24 hours
don’t show strong avoidance at 32 hours, 40 hours
comes back at 48 h
avoidance occurs every 24 hours at same time of day

Question 19

Passive avoidance

Answer 19

Performance of passive avoidance depended on matching of time of training + time of testing, regardless of time of training.

Question 20

Passive avoidance

Answer 20

1 training experience
rodent placed in start box with bright light, door to dark box
wires allow researcher to put footshock, rat wants to go to dark
immediately after footshock goes to light

Question 21

Passive avoidance

Answer 21

takes longer for animal to go back into dark
strong 12 + 24 hour components in response
learning expressed at 24 hour intervals

Question 22

CPA time stamp persists in arrhythmic SNC-lesioned hamsters

Answer 22

The time CPA stamp rhythm, like CPP, not based on SCN biological clock
oscillator governs time
lesion has no effect on learning

Question 23

Passive avoidance at 2 shock levels in the mouse

Answer 23

apply footshock sufficient to induce fear responses, you don’t see rhythm
experience so bad it won’t go back into the dark at any time
reduce the intensity - longer time to go back when on time
will go back early/late
fear conditioning induced at 1 amp
this is anxiety conditioning

Question 24

Passive Avoidance

Answer 24

scn lesion shows no effect on learning

still remember time of day they learned

Question 25

Conclusions

Answer 25

Animals learn time of day significant conditions occur – even when timing not explicit condition of task
don’t need to know what happens at other time of day

Question 26

Conclusions

Answer 26

The underlying oscillator set rapidly – at time of stimulation
biological clock not directly involved in learning
SCN (biological master clock) not required for time memory

Question 27

Conditioned place avoidance

Answer 27

time of day is critical - physiological changes, wake/sleep
ability to recall explicitly learned info have preference for learning at certain time of day
before puberty - prefer day, after puberty - prefer evening

Question 28

Conditioned place avoidance

Answer 28

training animal to avoid footshock at particular time of day
after 5 + 18 days, still remember time of day
trained at 11, when they’re active

Question 29

Conditioned place avoidance

Answer 29

they remember at 3, don’t avoid it at 11
after 5 days, they seem to forget, lots of variability
after 18 days, they have completely forgetten

Question 30

Conditioned place avoidance

Answer 30

appear to forget, but test them later in day, find they remember
train these animals late in day, they remember for at least 18 days
train in the middle of day, seem to forget after a couple of days

Question 31

Conditioned place avoidance

Answer 31

test them later, they show that they remember
avoided at training time in 5 days
after 5 days, trained at day less diff behaviour than other times
they remember at 11 days, but they get time wrong, they perform just as well at time of day as ones trained at 11

Question 32

Shifting Clock

Answer 32

Wheel Running
animals run, measure how much they run every 6 seconds
nocturnal animal runs at the dark
timing of light cycle shifts + animal changes its timing

Question 33

Shifting Clock

Answer 33

18 days later, what time of day they avoid footshock
now that we shifted timing, they avoid few hours later when they think it’s 11
this internal clock associated with light + dark

Question 34

Shifting Clock

Answer 34

trained at day, shifted at opposite direction, still show avoidance behaviour at same time
clock doesn’t pay attention to light/dark
no matter what always at 11, no need for light cycle

Question 35

Shifting Clock

Answer 35

train at inactive time, response time has shifted over to beginning of its activity
clock is set when animal learns something so days later, animal will anticipate when condition happens again
absence of reinforcement, no sense in remembering time

Question 36

Shifting Clock

Answer 36

time of day shows anticipation is time of day when begin to be active whe it’s most likely to encounter the danger/reward, when it is motivated to forage

Question 37

Summary

Answer 37

Performance on context learning tasks depends on synchrony betw times of training + testing

Question 38

Summary

Answer 38

phenomenon doesn’t require suprachiasmatic nucleus

Question 39

Summary

Answer 39

assumes it’s not gonna occur at another time of day

central clock that produces circadian clock

Question 40

Conclusions

Answer 40

Brain mechanisms involved in learning + memory are rhythmic, + time of conditioning is registered by setting of intrinsic rhythm

Question 41

Conclusions

Answer 41

Time of day memory does not provide “when” used to define episodic memory
all of these systems are rythmic (nucleus accumbens)

Question 42

Conclusions

Answer 42

when something important happens, oscillators change timing, set by experience
hippocampus pays attention to what, where + when it happens

Question 43

Conclusions

Answer 43

does this by changing oscillator timing
don’t hold time in same storage system as other attributes of environment because timing changes over few days
when changes all the time

Question 44

Conclusions

Answer 44

episodic memory order of episodes + understanding order they occur
time of day memory is transient, not like episodic like memory