Episodic-like Memory and other Behavior in Scrub Jays
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Transcript of Episodic-like Memory and other Behavior in Scrub Jays
Episodic-like Memory and other Behavior in
Scrub Jays
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?What is episodic memory?
unique, personal, past unique, personal, past experienceexperience recalled in terms of a time recalled in terms of a time frame or temporal-spatial frame or temporal-spatial relationrelation thus tells ‘what’, ‘when’, and thus tells ‘what’, ‘when’, and ‘where’‘where’ not expected in not expected in nonhumansnonhumans
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..
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:
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-likeepisodic-like memory as retrieval of
“what”, “where” AND “when”
Such a definition puts emphasis on the ‘episode’ aspect of episodic memory, and is one that can be
tested in animals
Thus the issue of personalization and of self-projecting past to
future
And of assuming that others experience life similarly
Note that other types of memory that have been studied may seem 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
They may, however, simply be choosing or avoiding the most
familiar object….
One could argue that the animals are responding based
on personal, event-based memories…..
Which really has nothing to do with ‘episodes’
Specifically….
There is a distinct difference between
recognizing something as ‘familiar’
and
a specific recollection of where and when it has been seen before
Another example….
The difference between knowing a face is familiar
and
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…
They store thousands of food items in the autumn in thousands
of locations, and recover them over the course of several winter
months
But probably the best example are food-caching birds…
As we learned last lecture
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:
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
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
Or maybe they just more rapidly forgot worm sites…
But maybe the birds just remembered which caches they
had already emptied…
i.e., maybe some evolutionary rather than memory process was
at work…
So the researchers worked with the Replenish group
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”
…i.e., just that something about the time at which they stored the
various foods was important
understood more than “time makes worms decay”
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 trayand 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 they succeeded on that task
And not just better memory for nicer food
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
Birds were thus allowed to cache one type of food in one side of the tray at first
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
Peanut, then Worm
Worm, then Peanut
P
P
P
W
W
WP
dW
120 h
120 h
4 h
4 h
Test: predict worms
Test: predict nuts
Birds with experience 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 no
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:
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?
Peanut, then Worm
Worm, then Peanut
P
P
P
dW
W
dWP
W
120 h
120 h
4 h
4 h
Test: predict nuts
Test: predict worm
And the birds acted as predicted
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
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
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
birds couldn’t use recency, because each food was cached at the same time in different trials
“search the side of the tray in which food was stored most recently, regardless of food
type”….
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,
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!
AA
B
B
A
(1) cache P in one side of each tray
P
KP
KP
P
(2) cache K in one side of each tray
(4) Prefeed bird P, see what it does
(3) 3 hrs later, allowed to recover P from one tray and K from the other
B
A
/P
P K
K
K
B /
/
/
A few mn
KP
P
Assumption is that bird that is full of peanuts
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
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
Birds made twice as many searches to the place where
there was intact different food
that held food different from what it had just eaten
as to where there was intact same food
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 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….
In other words….
Birds that experienced degradation not only learned
something about what is good to eat when
rather than remember when stuff was cached…
But also that, in general, it’s best to remember where
peanuts are stored because they are a more reliable source of
foodSo 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
If, instead, they remembered crickets as well as peanuts,
and when they cached
they should start skipping the crickets immediately
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
Recover day 6
Recover day 5
Recover day 4
Cache day 3
Cache day 2
1 2 3
31 2
P
PP
PPC CC
dCdC ? ?
This time, tho’, some birds were given degraded crickets on Day
3
If they really remembered what they cached and when
Before, remember, crickets were still pretty good on Day 3…
they would go for peanuts on day 6 in the last tray that was
cachedonly 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
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….
and not just that crickets were relegated to a specific memory
bin
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:
But is this behavior identical to that of humans, as Suddendorf
and Busby question?
We still do not know….
What, When, Where
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
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…
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..
because what you were doing was dissociated from the
events
This strategy isn’t perfect
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,
Specifically….”if I pilfered another birds’ hoard whom I watched,
someone watching me may pilfer mine”
at least suggest some sense of attribution to others….
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
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
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
traywhile 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
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
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
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,
Behaviour) 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….
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 (Animal Behaviour, Dally, Emery
and Clayton) looked at positional factors in social
settingsHere 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
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
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?
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
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
No matter which side the potential pilferer was on
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:
Seen and
unseen are now
equi-distant
Here jays could also cache totally in private
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 observersAnd 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 (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
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….
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
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,
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
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
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,
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…
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 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….
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
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
Now with first 1 hr and then 25 hr delays
After a 1 hr delay, the monkeys were allowed into the site
Nothing had changed
Researchers noted which food was chosen first, but monkeys had to visit both sites to end a
trialAfter 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….
But the monkey data didn’t quite work out that way….
Remember, the jays learned that worms got yuckky after 4
days
First of all, the monkeys didn’t bait the areas themselves
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
which they had learned meant some trial-and-error
choicethey saw a familiar pattern…
How easy would it be to learn to ignore that????
We 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
sitessuggesting 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?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…
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…
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