Episodic-like Memory and other Behavior in Scrub Jays
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Episodic-like Memory and other Behavior in Scrub Jays. Lecture 7 Psych 1090. I’ve done things a bit differently in this lecture…. assigning only a review paper for the earlier material. and giving the details in the lecture. What is episodic memory?. unique, personal, past experience.

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I’ve done things a bit differently in this lecture…

assigning only a review paper for the earlier material

and giving the details in the lecture

What is episodic memory?

  • unique, personal, past experience

  • recalled in terms of a time frame or temporal-spatial relation

  • thus tells ‘what’, ‘when’, and ‘where’

  • not expected in nonhumans

Explanation in terms of other forms of human memory:

  • Procedural memory

  • inaccessible to conscious recall

  • examples are some motor skills, or simple classical (Pavlovian) conditioning

  • Declarative memory

  • involves propositional material, symbols

  • used to guide inference, reasoning, true/false statements

Declarative memory is subdivided:

  • semantic memory

  • factual knowledge of the world

  • what one knows from books, etc.

  • episodic memory

  • factual knowledge of past experience

  • what one knows from living one’s own life

According to Tulving and Marlowitsch, episodic memory is

  • unique to each episode

  • allows recall of past experiences rather than facts

  • develops later in children; is impaired faster in age than semantic memory

  • related to unique cortical activity

Supposedly, animals remember facts (semantic memory) but not personal experiences (episodic memory)

plenty of evidence to show that animals remember that ‘x indicates y’, or ‘if x, do y”,

but not necessarily ‘when I saw x, I then remember doing y’

The point may seem trivial, but it’s not.. personal experiences (episodic memory)

The difference is in knowledge that is assumed to represent the way the world works for everyone (semantic memory)

And knowledge that is understood to represent only what one has personally experienced (episodic memory)

Which brings up another issue: personal experiences (episodic memory)

Some researchers argue that to understand that an experience is personal, a being must have full consciousness….

an attribute that is generally denied to animals.

To get around the argument that a being must be conscious in order to have personal memories—i.e., to have episodic memory—we can simply agree

to define episodic-like memory as retrieval of “what”, “where” AND “when”

Thus the issue of personalization and of self-projecting past to future

And of assuming that others experience life similarly

Such a definition puts emphasis on the ‘episode’ aspect of episodic memory, and is one that can be tested in animals

Note that other types of memory that have been studied may past to futureseem to involve time, but are not truly episodic….

For example, animals trained on delayed match-to-sample or delayed nonmatch-to-sample

may seem to be recalling previous, personal events….

That is, being shown a red sample at time T and then, at T+20 seconds, being shown red and green samples,

they have learned—via trial and error—that they get rewarded

only for matching or not matching the original sample shown at time T

One could argue that the animals are responding based on personal, event-based memories…..

They may, however, simply be choosing or avoiding the most familiar object….

Which really has nothing to do with ‘episodes’

Specifically…. personal, event-based memories…..

There is a distinct difference between

  • recognizing something as ‘familiar’


  • a specific recollection of where and when it has been seen before

Another example…. personal, event-based memories…..

The difference between knowing a face is familiar


remembering that you saw this person last Saturday night at the bar in Harvard Square

But many animals likely demonstrate some kind of episodic memory in nature….

Nest parasites, like cuckoos, must keep track of the location and state of nest-building and egg laying in their hosts

so as to know when to drop their eggs

And because recently researchers found that cuckoos will destroy the nests of hosts who dump their eggs…

Some connections might be made in terms of personal experience for both hosts and cuckoos…

But probably the best example are food-caching birds… destroy the nests of hosts who dump their eggs…

As we learned last lecture

They store thousands of food items in the autumn in thousands of locations, and recover them over the course of several winter months

And even though the scrub jays that are used by Clayton et al.

don’t cache nearly as much as the nutcrackers and pinyon jays

they do cache some food, and for times a bit longer than chickadees

To connect to episodic memory: al.

  • information guiding recovery is based on a single, past, personal memory

  • retrieval requires precise spatial data

  • birds need to remember the order of caching to prevent spoilage

  • birds need to remember precisely what was stored in which cache to prevent spoilage

To get clear data on such behavior, Clayton and Dickinson performed a series of experiments with scrub jays

Birds were allowed to cache wax-worms (perishable and preferred) and peanuts (non-perishable and liked) in visually distinct sites in the laboratory

Sites were ice cube trays with Lego blocks in varied patterns…

Birds were divided into two groups, Degrade and Replenish performed a series of experiments with scrub jays

Birds in the “Degrade” group were given the chance to cache peanuts and wax worms in two different trays

and then recover at both 4 hours and 124 hours, and to learn that the worms would be horrid after 124 hours

They then were tested by being allowed to cache and recover the two different foods at the two intervals

But now the experimenters removed all the food items before recovery,

so birds couldn’t possible smell the degraded worms….

The researchers found that after 4 hours, the birds preferred to visit the sites where they had cached the worms…

but went to the peanut sites after 124 hours

suggesting that they knew precisely what was where and the time delay

But maybe the birds just remembered which caches they had already emptied…

Or maybe they just more rapidly forgot worm sites…

i.e., maybe some evolutionary rather than memory process was at work…

So the researchers worked with the Replenish group already emptied…

who never learned that the worms degraded

because the researchers put in fresh ones before allowing recovery at 124 hours

When tested with all food removed, these birds preferentially went to the worm sites, at both 4 and 124 hours

Thus the behavior of prioritizing which food to recover was learned, and not some genetic instinct…

And was nice preliminary evidence of episodic-like memory

But this design still didn’t examine whether the birds in “Degrade”

understood more than “time makes worms decay”

…i.e., just that something about the time at which they stored the various foods was important

So now the birds could store both foods (nuts and worms) in one tray at one time

then a few days later could again store both foods in another tray

and after a short interval after the last caching, were allowed to recover

So, in order to get worms and nuts appropriately (avoid yucky worms)

they had to remember which tray was cached when

And not just better memory for nicer food

And they succeeded on that task

To tease this out even further, the researchers designed another experiment

in which the birds got to store the different foods at different times,

and then recover them at the same later time

  • were made to wait 120 hours

  • and then were allowed to cache the other type of food in the other side of the tray….

  • the type of food altered with respect to time in two different sets of trials

Test: predict worms side of the tray at first

Peanut, then Worm





120 h

4 h

Worm, then Peanut

Test: predict nuts





120 h

4 h

Birds with side of the tray at firstexperience with degraded worms

chose worms at a significantly higher rate than peanuts when the worms were cached last

and peanuts at over twice the rate when the worms were cached early and likely degraded

Interestingly….and critically….birds with side of the tray at firstno experience with degraded worms chose the worms in both cases—

that is, they just chose on preference

not as to what was likely to have happened to the worms

Thus: side of the tray at first

  • The peanut-side preference shown by the Degrade group was not simply due to differential forgetting of worm caches

  • the preference to search for worms 4 hrs after caching and peanuts 120 hrs after caching does not reflect a genetic predisposition, because it was learned

But what if the birds were trained on something totally counter-intuitive….

That worms were yuckky after a couple of hours

But somehow were ok after a few days?

Test: predict nuts counter-intuitive….

Peanut, then Worm





120 h

4 h

Worm, then Peanut

Test: predict worm





120 h

4 h

And the birds acted as predicted counter-intuitive….

functioning on the basis of what they had learned about worms

And it wasn’t what they learned during the test phase

because they acted OK from trial 1

Moreover, the birds’ behavior was not just a matter of familiarity of the tray

that is, somehow associating tray with the issues

because the tray exposure was the same for each type of caching

The switch by the birds in the Degrade group familiarity of the tray

requires the birds to recognize a particular cache site

in terms of both its content and the relative time that has elapsed between caching and recovery

The birds HAD to recall information about familiarity of the tray

  • what (worms vs. peanuts) was cached

  • where it was cached (right vs. left)

  • when (4 hrs vs. 120 hrs)

Too…the information was acquired on the basis of a single, trial-unique personal experience

That is….something getting quite close to episodic memory

Note the result cannot be explained by the simple rule trial-unique personal experience

“search the side of the tray in which food was stored most recently, regardless of food type”….

birds couldn’t use recency, because each food was cached at the same time in different trials

Researchers next wanted to make sure that the birds remembered

not only which sites have been depleted (data from experiments by Kamil and Balda that we discussed)

but also exactly WHAT was recovered

not just the choice of spoiled vs. unspoiled, remembered

but also what might be more appealing at a particular time….

which relies on a very personal memory for what has been consumed recently

not just always go for “X” if it’s fresh

So, they tested whether what they fed the birds just prior to recovery would affect what they recovered….

and also made them remember where the different foods were stored in two different trays….

The trials are quite complicated!

(1) cache P in one side of each tray to recovery would affect what they recovered….

(3) 3 hrs later, allowed to recover P from one tray and K from the other













A few mn

(2) cache K in one side of each tray

(4) Prefeed bird P, see what it does















Assumption is that bird that is full of peanuts to recovery would affect what they recovered….

will choose the kibble, and remember where the kibble still was…

even after additional time delay

Of course, during test, all food was removed by the experimenter to prevent any odor or disturbance cues

So birds should not rely on a scent or preference for food

but on satiation

Note that birds have to INTEGRATE information as to experimenter to prevent any odor or disturbance cues

  • what it cached where

  • what it recovered where

  • what was same/different from what it had just eaten

9 of 12 birds upheld the prediction of feeding from the tray experimenter to prevent any odor or disturbance cues

that held food different from what it had just eaten

Birds made twice as many searches to the place where there was intact different food

as to where there was intact same food experimenter to prevent any odor or disturbance cues

birds made very few searches to depleted sites

And this did not depend on training about “good” or “bad” types of food

Three main conclusions from these data experimenter to prevent any odor or disturbance cues

  • Birds encode info about what they store in a site

  • Birds can update their memory as to whether they have depleted one of two sites, even if they essentially bated them simultaneously

  • Birds can integrate these two bits of information

Now, those of you who have been mulling about the peanut/mealworm study may have realized a possible flaw in the experimental design…

Maybe the birds just have a differential memory for remembering stuff that spoils versus stuff that does not….

rather than remember when stuff was cached… peanut/mealworm study may have realized a possible flaw in the experimental design…

In other words….

Birds that experienced degradation not only learned something about what is good to eat when

But also that, in general, it’s best to remember where peanuts are stored because they are a more reliable source of food

So don’t ‘clog’ memory with information about degradable mealworms….

Thus researchers had to figure out a way around that problem…..

They did so by replicating the experiments with crickets instead of worms…

Crickets degrade more slowly than worms,

so the researchers could see if birds progressively recovered crickets more slowly as the days went by

Thus, if birds were just not bothering to remember where a degradable food was cached

and they didn’t like the degradable crickets as much as the degradable worms

but they liked the crickets only as much as the peanuts

they should start skipping the crickets immediately degradable food was cached

If, instead, they remembered crickets as well as peanuts,

and when they cached

they should go for the cricket for the first day or so after caching and stop after about 3 days…

Interestingly, almost none of the 6 birds involved went for peanuts on the first three days

By day 5, all 6 birds went to peanuts first…..

The birds seemed to make a categorical decision as to change their behavior around day 4

Thus, it could still be that the birds were not directing a lot of resources to remembering crickets

or had some kind of ‘intermediate’ range memory in which they stored information about degradable food

compared to long-range memory for nondegradable items.

So, the idea was to give the Degrade birds staggered caching and then see what the birds did on progressive days….

Cache day 1

Cache day 2

Cache day 3










Recover day 4

Recover day 5

Recover day 6










This time, tho’, some birds were givendegraded crickets on Day 3

Before and then see what the birds did on progressive days…., remember, crickets were still pretty good on Day 3…

If they really remembered what they cached and when

they would go for peanuts on day 6 in the last tray that was cached

only if they experienced degraded crickets on day 3

But if they were the group that had not had rummy crickets on Day 3 for the first two trays,

they should still go for crickets on day 3

because crickets were usually good until day 4

And, to make sure that the birds just now didn’t decide that any cached crickets were worthless,

they were given good crickets on a Day 1 recovery trial

The idea was to see if the researchers could tweak the encoded information….

Showing that the information was indeed encoded that any cached crickets were worthless,

and not just that crickets were relegated to a specific memory bin

Most of the birds that got degraded crickets on Day 3 for trays 1 and 2 did search for peanuts on Day 3 for tray 3….

In general, the birds had encoded some kind of semantic memory about the state of crickets over time (i.e., that they degrade in a few days)

And then integrated this information with respect to where and when they had cached the crickets…..

And they were able to update their general semantic knowledge of the world based on new information….

These data fit with the ethology of the scrub jays, who cache items under varying conditions….

and thus must determine the effects of, e.g., a hot spell on their caches

So, these data suggest that birds fulfill the criteria for episodic memory:

What, When, Where

But is this behavior identical to that of humans, as Suddendorf and Busby question?

We still do not know….

We don’t know if the birds are simply reacting on the basis of semantic memory….

That is, on some version of ‘this is just how the world works’

versus some understanding that the situations are specific to themselves or allow them to project ahead….

Specifically, one can argue that the birds have each remembered a set—albeit a very complex set—of facts and integrated these facts….

Thus demonstrating an extremely high level of complex cognitive processing

What is needed is to show that the animal remembers a remembered a set—albeit a very complex set—of facts and integrated these facts….specific episode

that is, “where I was and what I was doing on September 11, 2001”….

And not just a collection of facts that allow me to solve a problem…

because what you were doing was dissociated from the events remembered a set—albeit a very complex set—of facts and integrated these facts….

Is there any way to get around that problem?

Possibly, by designing experiments in which a bird has to separate out its own experiences from that of other birds..

This strategy isn’t perfect remembered a set—albeit a very complex set—of facts and integrated these facts….

because it still can’t separate out the bird as a dispassionate observer from what is going on around it

But it is a start in the right direction

Researchers realized that scrub jays will steal from one another’s caches…..

And that as a precaution, some jays will re-cache items

if their initial caching is observed by other jays….

So maybe researchers could work with that knowledge to see if they could ‘personalize’ the birds’ memories

And also see if the birds could project their knowledge to the future

So, one group of birds watched another group cache, and then was allowed to pilfer….

Another group of birds never had this experience of being allowed to pilfer….

although they could watch caching

Both sets of birds were then allowed to cache in the presence of a competitor….

Both sets of birds were then given the opportunity to re-cache their hoards in private….

Pretty much only those that had pilfered other birds’ stores did re-cache

These data begin to suggest that birds do have memories that, if not specific to themselves,

at least suggest some sense of attribution to others….

Specifically….”if I pilfered another birds’ hoard whom I watched, someone watching me may pilfer mine”

Of course, one can always come up with alternative explanations….

Something a bit less mentalistic….any ideas???

Well…it seems that birds are acting as tho’ if they do something, all other birds will do the same thing….

that is, generalization

Such behavior does not really impute intentionality or personal experience….

What one would really have to show is that birds recognize specific individuals

and that these individuals are indeed pilferers…

and react only in the presence of a bird that they have reason to expect will pilfer their food….

not simply react on a generalized basis

Testing this with respect to actual knowledge is difficult

But possibly testing it with respect to the birds having some idea

of what a potential pilferer may or may not be able to see might work

Some evidence exists for ravens

If other ravens are around some idea

the storer will wait until those birds are distracted or have moved away

or will make false caches and false recaches

or store behind barriers

But, again, are the birds acting as if they really have a “Sally-Ann” sense of theory of mind

or are they also working on a sort of generalization of “this is what should be done in this circumstance”

without fully knowing why?

One can set up an experiment in which the storer sees who is stealing some of its cache

And determine if the storer will then respond in a way that suggests it knows something about this specific competitor

compared to how it treats food stored in private

So, storers had three trials where they could store in private

And three trials where they knew that one potential pilferer was watching

In each case, two trays were available, at different ends of their cage

The same potential pilferer saw all three trials private

Interestingly, storers also sometimes cached outside of the trays, but experimenters removed those caches

Experimenters also noted how much was eaten

Then, in the presence of the storer, the pilferer was given one tray

while the other tray was out of reach of both birds (trays marked w/ Legos)

And pilferers could eat a cache or re-cache it in same or different site

In contrast, after the storer had stored in private one tray

the trays were observed by both birds, but no one could reach either tray

thus observation time for all four trays was equal

Then the storer, now in private, got back two trays one tray

  • two trays had been cached in private and seen by both birds

  • two trays had been cached in public, both seen by both birds, but only one accessible to the pilferer

What did storer do?

For whatever reason, birds cached a bit more when being observed

Pilferers got about 50% of what had been stored when they could access a tray

But overall, about the same number of items were left for recovery… remember, 3 unpilfered trays

The original storers didn’t differ in how much they ate or checked their caches when they got the trays back in the two conditions

But they did re-cache more items in the trays that the pilferers had observed than in trays stored in private

They discriminated the particular trays that the pilferer had observed

And, interestingly, they took food out of the observed trays more often…

Stuffing it in sites in the cage that could not be accessed by the pilferer at all

They also ate a lot more after being in trials in which the observer ate some of their caches

Here they weren’t just observed, but actively saw their caches being pilfered,

which is a fairly strong condition

In a separate study on other cachers, the Grey jay observer ate some of their caches

This species would cache in front of a nutcracker because nutcrackers don’t pilfer

but wouldn’t cache in front of Stellar jays that do

None of these observational studies, however, deal with social effects

In the wild, many of these birds have social hierarchies that affect who has access to food

And may affect caching if good sites are limited

In a 2005 paper (Dally, Clayton, and Emery, social effectsBehaviour) looked at caching in an aviary in which there existed a social hierarchy

They found that the alpha pair would cache more than the beta pair

And that the alpha pair knew where each other cached and didn’t care who recovered the cache

But the alpha pair seemed to defend their caches from the other birds

And when the alphas were removed, the betas then became the alphas

And took over the caching

Probably the subordinate birds knew they could not defend cache sites from the domiants

And basically just gave up on it

The effect might, however, have to do with being in an aviary…

In the wild, the subordinate might need to cache more…. cache sites from the domiants

Here, the birds were basically well-fed and limited only slightly

Might be a totally different story in the wild w/ limited food available and the need to steal and cache

In yet another 2005 study ( cache sites from the domiantsAnimal Behaviour, Dally, Emery and Clayton) looked at positional factors in social settings

Here birds had a choice of where to store under conditions of being watched or not

sites were either close or far

If the bird had a general theory of just storing as far away from any possible observer

it would always use the far tray

Even if, in this case, the bird saw a screen being pulled down between it and a neighbor

If, however, it was sensitive to the condition of not being viewed

It should cache randomly in the two possible trays

The expt would show whether the bird was really aware of what the other bird could see

Now, this time the birds did not see anyone eat their food before the trays were removed

And they had successive trials so that they could learn what was happening to their hoardes

Which could all affect results

Again, for whatever reason (maybe fear of pilfering?) more food was cached when the birds were observed

And more food was put in the far tray when the birds were observed

suggesting that being observed had an effect

More food from the near trays were re-cached during recovery food was cached when the birds were observed

Note that in the three hours in between caching and recovery, the screen was installed

So the storers had no idea what had happened to their trays

This condition is quite different from the one in which the storers saw the pilferers go to work

But the fact that the storers re-cached in private suggests that they knew that by caching all the stuff initially in the far space wouldn’t be good either

Although this might suggest a sort of awareness, it may not storers saw the pilferers go to work

Could just be a simple idea of trying to avoid being near a conspecific during caching

And moving stuff away from the site it was at…

What if you put non-cacheable food near the observer? storers saw the pilferers go to work

Would the bird go near the observer?

What if you played with the details of where the observer could be?

Birds happily ate in view of the observer storers saw the pilferers go to work

So they weren’t simply avoiding another bird

And their behavior during caching wasn’t just due to avoiding the other bird

In terms of playing with the spacing, the experimenters set up the cages so that the birds could see one another in a limited way

and sometimes the observer was stuck on one side or the other

but the storer could move

Up close, pilferer can see only one site up the cages so that the birds could see one another in a limited way

No matter which side the potential pilferer was on up the cages so that the birds could see one another in a limited way

The storer cached in the far and unseen location

Interestingly, the caches were moved more often when the potential pilferer could move about

And sometimes the birds would cache in view and then recache several times

As if the confuse the pilferer as to where the item was….

Of course, the cacher could just be dithering here

Another problem is that the unseen site is always the further one away….

So we still don’t know if the bird is acting upon what it thinks is the sight of the potential pilferer

Or it just wants to store in a far location….

Hence, another setup: further one away….

Seen and unseen are now equi-distant

Here jays could also cache totally in private further one away….

But, for whatever reason, they did not!

But when they were viewed, they put more in the out-of-sight tray than the one in-sight

But, this still could be some kind of ‘out of sight, out of mind’ behavior….

What is needed is a system in which the pilferer can be seen by the storer

But the storer knows it is unseen

In yet another study, jays seemed to understand which bird was the observer and react appropriately

So, for example, it didn’t care if its partner saw a cache (all in the family)

But did react if a dominant saw it cache…

And the experimenters had problems because some birds stopped caching at all in the presence of observers

And birds would respond differently when birds that observed recovery were not birds that observed caching

So the birds seemed to attribute some knowledge to the observer

Or at least some memory of the observer and some memory of what might have happened in a related situation….

We are getting closer and closer to some kind of TOM

But it’s always difficult to know for sure

In terms of planning, however, a recent paper ( what might have happened in a related situation….Nature, 2007, 445: 919-921) does show clever behavior on the part of the jays….

First experiment involved ‘planning for breakfast’ to see if birds would provision themselves depending upon their knowledge of the future

Powdered nuts what might have happened in a related situation….

No food

Later in day, learned that they could eat in B, too, but just powdered nuts

Then they were given whole nuts in B in the evening…. what might have happened in a related situation….

They put more nuts in C than A

Ostensibly to compensate for lack thereof

But to make sure the birds weren’t simply associating caching and hunger

The experiment was repeated with nuts in A and kibble in C

And then they were given both nuts and kibble in B

And they put kibble in A and nuts in C

Showing some level of planning

Overall, the data demonstrate incredible abilities that were not thought to exist in any nonprimate other than humans and apes, much less in a bird!

Which, of course, brings up the monkey paper…..what about other nonprimates?

Now, of course, rhesus monkeys do not normally cache…

It does not make ecological sense

Most of their food is perishable other nonprimates?

And most of the time it is not limited in any real way

So that the idea of worrying about caches is not likely

What may be true for monkeys, however, other nonprimates?

is when a particular tree is fruiting

with respect to a particular location in the forest

Maybe this is less precise, or is seasonal…but could be episodic

So, although monkeys might not be the best possible subjects other nonprimates?

There might be some reason why they might have something like episodic memory….

But will this task show it?

Monkeys had two different foods, one yummy and one less so other nonprimates?

They could then go back after either a long or a short delay

Both foods were available after short delay; only less yummy food after a long delay

Would they learn, over training, other nonprimates?

which food would be available after different delays?

Note how this differs from the jays…

in what is available

Learning that something just disappears over time can be seen as just someone else eating it up if you don’t get to it first

which is a subtle difference from something that has to do with time per se

And this task used some monkeys with hippocampal lesions… seen as just someone else eating it up if you don’t get to it first

Now we know that the hippocampus involves spatial memory

But some areas of the hippocampus also seem to be involved with episodic memory

or possibly, as we saw in the last lecture, the connections between the hippocampus and other parts of the brain…

One idea is that the “where” and “when” of the “what-where-when” may be closely tied together….

which might explain corvid success on both sets of tasks

So, monkeys had three foraging sites, one empty and two w/ foods of differing appeal…

In training, the placement of the sites vary between, but not within, sessions

So monkeys had to forget between sessions (time not given) and remember within session placement

Although there is no report of within-session timing, it sounds as tho’ it was just a few minutes between runs….

Enough to pull monkeys to cage, cover w/ tarp, and re-bait the sites

We are not told the time delay between sessions…

But this time delay is sounds as tho’ it was just a few minutes between runs….crucial…

Because it sets up what delay the monkeys expect during which the expected sites have been altered!

The assumption is 24 hrs, given that food preference tests were given on a 12 trial/day basis

Monkeys were considered ‘trained’ if they went to preferred food on the last 3 of 4 runs in a session….

They acquired what is known as a ‘learning set’

where they learn a task, and small variations on the task are learned successively more rapidly

Then they were tested…. preferred food on the last 3 of 4 runs in a session….

They went into the room, had, again, a unique set of placements

had the chance to learn where the good food had been hidden

Both the controls and lesioned animals quickly learned to find treat

They also learned to avoid the less tasty food preferred food on the last 3 of 4 runs in a session….

So at least for these very short delays (a few minutes) within sessions

lesions had no effect on how well the animals remembered the two sites

Then they were tested after each of the ‘study’ trials preferred food on the last 3 of 4 runs in a session….

Now with first 1 hr and then 25 hr delays

After a 1 hr delay, the monkeys were allowed into the site preferred food on the last 3 of 4 runs in a session….

Nothing had changed

Researchers noted which food was chosen first, but monkeys had to visit both sites to end a trial

After choosing the good food, the marker was removed to encourage choice of the second site

After 25 hrs, the monkeys went back into the experimental room

Nothing had changed in the placement, UNLIKE the previous training phase

Now, however, the good food was degraded to be yuckky

Now remember, each test trial consisted of 8 runs for the animals to learn where the foods were

Then one run an hour later and another run 25 hrs later

Each monkey had 30 of these test trials; not sure of the time between test trials

The experimenters expected that, with time, the monkeys would stop going to the preferred food after the 25 hr delay….

Remember, the jays learned that worms got yuckky after 4 days

But the monkey data didn’t quite work out that way….

First of all, the monkeys didn’t bait the areas themselves would stop going to the preferred food after the 25 hr delay….

Second, the sites changed initially from one day to the next

So after a 25 hr break, they may have expected the room to look different….

But now, sometimes, instead of seeing a different setup would stop going to the preferred food after the 25 hr delay….

which they had learned meant some trial-and-error choice

they saw a familiar pattern…

How easy would it be to learn to ignore that????

We would stop going to the preferred food after the 25 hr delay….know that reversals are tough to acquire

And that’s what the monkeys had to learn…

So it’s likely there was a lot of interference going on

The lesioned monkeys more often examined unbaited sites would stop going to the preferred food after the 25 hr delay….

suggesting that they indeed had a poorer memory for the location of any kind of food…good or bad

Toward the end of the paper, the authors admit that their training might have skewed the results

But they then discount the possibility…for what seem to be odd reasons

The point is that the continued shifting of the sites for the animals during training blurs the situation

What IS an episode for them?

Unlike the Clayton studies, the monkeys were trained in a particular way, then tested with a ‘glitch’

and then were expected to figure out a correlation that was obvious to the researchers

but one that would not necessarily be obvious to an individual experiencing the task

Too, although Clayton couldn’t put every control in every experiment

each experiment was a consistent whole, with no claims as to having controlled for every variable

Although one could see the work as really on large paper instead of several individual ones…

These studies, of course, get into the realm of questioning what it is that the animals actually do know…

and, of course, what they “know” that they “know’’…i.e., metacognition

The suggestion is that metacognition is necessary for episodic memory

But do you need to know that you know that worms degrade? what it is that the animals actually do know…

Metacognition might be more important in the pilfering study…

in terms of getting to a kind of theory of mind behavior

But none of these cases are clear

An animal might know what food is hidden where and whether it is still good…

but not know HOW or WHY they know it…

No reasoning would be involved, just some memory returning when visiting the area

Humans use language to declare this information… it is still good…

How can we get at it in animals that have no, or only very limited, interspecies communication skills?

Some studies purportedly allow monkeys to state if they do or do not remember the answer to a task…

But in reality the animals reporting of uncertainty just allows them a third choice when a first choice doesn’t surface quickly

It may not be any more conscious than any other type of choice they are given

Some researchers—Suddendorf—argue that episodic memory is really a means of future planning

using the past to project to the future

How would that help us understand animals?

Clearly the jays store for the future and monkeys do not… is really a means of future planning

But that doesn’t get to the idea of whether the jays’ behavior is a mixture of instinct and knowledge

or self-awareness of what is individually needed

Would seem that the jays’ actions in preparing for the contingency of another animal pilfering

might actually tell us more than the caching behavior itself

Wouldn’t it be great to ask Jay A where he thought Jay B would search after A re-cached?

The implication is that Jay A thinks Jay B will look in the old site and be fooled

Otherwise why would Jay A re-cache?

But Jay A re-caches in sight of Jay B;

Such would seem to be a silly behavior, and thus researchers make an argument for “confusion”

But is Jay A really pondering such an outcome, or just kinda freaking out and maybe trying to find a slightly better hiding place?

or hoping B will lose interest?

The take-home message is basically the cleverness of the birds and the need for truly complicated experiments in order to uncover their cleverness