118 Final

Learning, a behavioral mechanism

Learning/memory have received the most study in psychology and neuroscience

how are phenotypes/behaviors passed down?

genes & environment --\> developmental programs --\> mechanisms (ex. perceptual) --\> behavioral capacities --\> lifetime reproductive success --\> next generation

how does learning occur psychologically?

information from world --\> perceptual processes --\> learning (short term acquisition

what does learning include?

- nonassociative (habituation & sensitization)
- associative (ex. Pavlovian)
- cognitive (configural & episodic; ex. building rules)

what processes affect behavior that aren't learning?

- motivation
- affect
- arousal
- attention

need to control for these when studying learning

Pavlovian Conditioning

A type of learning in which a neutral stimulus acquires the ability to evoke a response that was originally evoked by another stimulus
- bell alone can elicit a response (CS)
- prepare for biologically-meaningful things (maximize reward, minimize punishment)

Documented CS-US associative learning.

Why does CS elicit CR?

- Associative Learning OR

- Nonassociative Effects (have to control for)
\--- CS habituation effects
\--- CS sensitization effects
\--- US sensitization effects/Pseudoconditioning

hypotheses exist not due to learning

CS habituation effects

Repeated presentation of a CS can decrease a response elicited by the CS
- Ex. A sound stimulus may initially cause an orienting response that goes down over repeated stimulations.

CS sensitization effects

Repeated presentation of a CS can increase a response elicited by the CS
- Ex. A loud sound that elicits a startle response. Repeating the sound could sensitize the subject, leading to an increased startle response

US sensitization effects/Pseudoconditioning

Exposure to a particularly-arousing US can increase the probability that other stimuli would elicit some response, even in the absence of CS--\>US pairings
- Repeated exposure to a food US that induces salivation can cause a light to also induce salivation.

Pavlovian control conditions

experimental: acquisition (expose CS--\>US, test CR)
- demonstrates associative learning

controls:

CS only (expose CS, test cr)
- want to rule out CS habituation & sensitization; if CS only and less responding, can say due to learning

US only (expose US, test cr)
- want to rule out US sensitization

explicitly unpaired (CS/US separated in time, test cr)
- can rule out CS habituation & sensitization, US sensitization
- same amount of CS exposure and US exposure, just separated in time
- has become preferred method to study conditioning

learning in mollusks

- Pavlovian conditioning in Aplysia
- Second-Order Conditioning (SOC) in slugs
- Octopuses learn to manipulate environment (instrumental learning)

Pavlovian conditioning in Aplysia

can we Pavlovian condition the withdrawal reflex?
- CS \= tapping of siphon, US \= shock
- without shock, withdrawal reflex would decrease (control should show habituation)
- had paired (experimental), US alone, unpaired, and CS alone groups

paired group showed a very big gill withdrawal response when shock was paired, afterwards tapping alone elicited an adaptive/exaggerated response after learning (sensitization - if I'm about to get shocked, withdraw gills)
- see minimal change in US alone and unpaired groups, habituation in CS alone group

aplysia can do pavlovian conditioning

Second-Order Conditioning (SOC) in slugs

got a CS (carrot) paired with an aversive-tasting US (quinidine), then potato flavor associated with carrot flavor
- in a preference test, potato taste preferred less than chow
- control unpaired-paired (carrot not associated with quinidine) and paired-unpaired (potato not associated with carrot) groups --\> see no preference between potato and chow
- paired-unpaired and experimental group (first-order conditioning) show aversion to carrot

Octopuses learn to manipulate environment (instrumental learning)

Instrumental learning (trial-and-error) to open lid of a jar containing food
- can manipulate their environment to achieve a reward (will eventually figure it out)

learning in arthropods

- Classical conditioning of proboscis extension in the honeybee
- Blocking of proboscis extension in honeybee
- Individual diffs in latent inhibition of PER in honeybees
- Discrimination learning in honeybees
- Within-compound associations in honeybees
- Maze learning in honeybees

insects

Classical conditioning of proboscis extension in the honeybee

proboscis extension (stick out proboscis to get food)
- proboscis will not extend when odor CS (ex. banana) is given prior to conditioning (no CR)
- pair odor with sucrose (something proboscis will extend for)
- bees will then stick out proboscis for odor

Blocking of proboscis extension in honeybee

- learn stimulus A is associated with sucrose (A --\> sucrose) in phase 1, learn A+X --\> sucrose in phase 2, see a blocking effect when proboscis extension to X is tested

- in control group that learned N --\> sucrose in phase 1 and A+X --\> sucrose in phase 2, do see more of a proboscis extension to X at test

blocking effect

Learning about one association (CS1 --\> US) in first phase blocks learning about X in CS1 + X --\> US
- X doesn't give any new information

Individual diffs in latent inhibition of PER in honeybees

• Latent inhibition is the retarded acquisition of a CR to a CS that has been preexposed (made familiar) prior to being paired with the US

• Honey bee colonies need both scouts (look for food) and recruits (help collect food)
\--- Scouts should learn to ignore familiar odors at faster rate than recruits (more likely to find new food sources with novel scents)

• Thus, scouts should show stronger LI than recruits
\--- give 40 presentations of odor for 4s; then, this odor and a novel odor were both paired with a sucrose US
\--- both show LI, but scouts show more LI than recruits (less responding to familiar scents)

Second-Order Conditioning

conditioning where a CS is paired with a stimulus that became associated with the US in an earlier procedure

CS1 --\> US
CS2 --\> CS1

CR to both CS1 and CS2

CS-pre exposure effect (latent inhibition)

pre-exposure to the CS without pairing with a reward can prevent or slow down subsequent learning of associations involving that CS
- pre-exposure to a cue slows future learning
- you learn less about familiar cues than novel cues

Discrimination learning in honeybees

free-flying bees have to choose one of two choices (two-alternative forced choice)
- pair sucrose with blue side, see how many bees will go back to the blue side (predictive of sucrose) over the orange side
- 95% of bees prefer blue side

if we switch it, associating yellow with sucrose, bees will learn the reversal
- bees actually better at reversal learning than original (high transfer rate) --\> may be making a rule (more trials, will get faster)

seems homoplastic, but mechanisms may be homologous

Within-compound associations in honeybees

Within-compound associations can form between stimuli that occur at the same time
- Basis of perceptual learning, object-object learning, binding of different features of an object in memory
- ex. associate multiple features of a coffee cup together to combine into the object

phase 1: compound conditioning (all bees exposed to both conditions)
- Orange + Jasmine -\> Sucrose
- Yellow + Lemon -\> Sucrose

phase 2: differential conditioning (use one component of each previous condition)
- Jasmine -\> Sucrose
- Lemon -\> No Sucrose

will phase 2 learning change preferences for phase 1 stimuli that weren't altered?
- yes, bees preferred orange taste over yellow taste
- formed association between CSs impacted by learning in phase 2

Maze learning in honeybees

can put bees through mazes; instrumental
- pathway marked by green tape and bees can learn it well (seem to learn an association of following the tape--if tape is rearranged, changes colors, or taken away after learning, bees will also follow)
- bees can learn without tape, just not great at it

can learn radial arm maze as well
- food cup with or without food at end of each arm, want animals to only enter arms they haven't been in before (memory)

learning in nematodes

- Pavlovian Conditioning in C. elegans

Pavlovian Conditioning in C. elegans

will turn around if touched while swimming
- CS: plates coated with Na+ or Cl-
- had an appetitive condition where the CS (one of the ions) was paired with food (E. coli) US
\--- control groups with naive, US only, and unpaired; half the experimental got Na+ pairing, half got Cl- pairing
- had an aversive condition where the CS (one of the ions) was paired with garlic US (aversive)

test by putting on a plate with both ions on it; *will approach CS+ in appetitive conditions and avoid it in aversive conditions*

learning in flatworms

- Aversive conditioning in Planarian
- Total Recall in Planaria

Aversive conditioning in Planarian

planarian have a CNS, but can grow back head after it being cut off
- each worm placed in a trough of water, get a 3s light that turns on (CS), then a 1s shock (US); 50 pairings a day
- measured whether they contract body during the CS (light), and they do (compared to the unpaired group)

Total Recall in Planaria

wanted to know whether previously-shown conditioning depends on planarian having a brain (appetitive)
- worms were fed or not in a textured petri dish (CS: texture of petri dish)
- then, worms were decapitated (14 days to regrow)
- since planarian like to be on the edges and dislike light, measured how quickly they would go out to the center to eat (after making association then being decapitated)
\--- latency to eat

found that both non-decapitated and decapitated planarian that were conditioned ate faster
- showed memory is not being stored in the head neurons, or was restored when regrown

learning in cnidarians

- Aversive conditioning in Sea Anemone

Aversive conditioning in Sea Anemone

get a light (CS) paired with shock (US)
- control groups that get light or shock only, or random light/shock unpaired
- contracts in response to shock; by trial 50, contracting a lot to the CS (light)

can learn that light predicts shock

Appetitive learning in plants?

touched the stamens of flowers either every 15 minutes, every 45 minutes, or not at all
- tested, if they touched stamen once, how many stamens would fall off (change in number of stamens dropped or retained from beginning)
- group that was never touched had many stamens fall off during test, groups with training saw less fall off (15 min group less than 45 min group)
- controlled with plant that wasn't touched during test just seeing how many fell off naturally

suggests plants have some type of functional learning

levels of learning phenomena

- psychological (ex. S-\>S learning)
- neurobiological (ex. coincidence detectors: cerebellum/amygdala)
- neurochemical (ex. synaptic receptors: NMDA)
- cell-molecular (ex. second messenger systems)

are learning mechanisms homologies or homoplasies?

similar learning phenomena in vertebrates and invertebrates
- very few things are homologous
- pressures have produced different mechanisms of learning; there are more homologies at the lower levels (ex. molecular) than higher
- if it's truly homologous, needs to be the same at all levels

Vertebrate, mollusk, and arthropod CNSs evolved independently (no shared brain homologies)
- Similarities in psychological and neurobiological learning mechanisms due to the evolution of independent brain systems (homoplasy)
- Cell-molecular systems, however, are conserved among vertebrates and arthropods.
\--- Likely evolved very early and thus are a synapomorphy (homology) shared among all extant animals

Coincidence Detectors: homoplasy or homology?

Different coincidence detectors (regions that get information about both CS and US) within an individual are similar due to homoplasy
- seen in fear & appetitive conditioning in the amygdala
- seen in eye-blink conditioning in the cerebellum (Purkinje cells)

Appetitive conditioning in the honeybee brain: homoplasy or homology?

Different coincidence detectors across species are similar due to homoplasy
- in humans, coincidence detector for appetitive conditioning is the amygdala
- bees don't have an amygdala (mushroom body/Kenyon cells)

Homology at Cell-Molecular level

no homologies at all levels
- but, there can be homologies at the cell-molecular level (second messengers)
- cAMP --\> PKA --\> CREB (produce structural changes; this pathways shared by many species, important in cerebellum, amygdala, mushroom body)

Goals of Comparative Psychology

1) Determine whether similarities among species are the result of evolutionary homology or homoplasy.
- cell-molecular level could be homologies, but everything else is homoplasies

2) Search for species differences in learning and cognitive processes that may be attributed to evolutionary divergence in mechanisms
- ex. Species differences in spatial memory in birds & phylogenetic history of emotional processes in learning (frustration/disappointment)

Species differences in spatial memory in birds

species differences in learning and cognitive processes that may be attributed to evolutionary divergence in mechanisms

- Chickadees (food-hoarding) birds perform better on spatial memory tasks than juncos (non-food-hoarding), but both species perform equally on non-spatial memory tasks (like memory for color)

might be due to differences in salience of spatial cues

Phylogenetic history of emotional processes in learning (rats & successive negative contrast)

Elliott (1928) experiment on Successive Negative Contrast (SNC) in a complex maze with rats \= "disappointment"
- have to do a complex T maze with either sunflower seed or bran mash (preferred) at the end
- rats will do better with preferred rewards; when changed to all sunflower seeds, group that previously got bran mash will perform worse than other grow to show disappointment

successive negative contrast

A negative contrast effect in which exposure to a large positive reward decreases the subsequent positive reaction to a smaller positive reward than would ordinarily be observed
- will go lower than if they had gotten the reward from the beginning
- positive contrast: animals will work harder for better rewards

successive negative contrast is only found in...

mammals

Hypotheses about divergent behaviors

When different learning phenomena are found in different species, there are two possible explanations (either due to learning or non-learning factors)

1. The underlying mechanisms of learning have diverged.

2. Differences may be due to divergence in non-learning mechanisms that affect behavior
\--- contextual factors like sensory/perception detection (ex. sight), motivation/emotion (ex. hunger), motor control --\> control for these

Comparative Methodology

1) Control by equation: Try to equate contextual factors across species.

2) Control by systematic variation: Compare the functional relationships between variables across species

Control by equation

Try to equate contextual factors across species (trying to control for contextual variables)
- less helpful; ex. reinforce rats and turtles with three pellets at end of runway --\> comparing learning of rats and turtles

If rats learn the task faster, why? (problems with control by equation)
- Rats are better learners
- 3 pellets are more motivating to a rat than a turtle
- Levels of food deprivation are not equated (rat is hungrier, hard to control)

Impossible to compare two species in absolute terms

Control by systematic variation

Compare the functional relationships between variables across species
- Instead of asking whether the rat learns the runway faster than the turtle, ask whether the runway task depends on the same set of variables in rats and turtles
- Ex. acquisition may improve in both species as size of reinforcer increases, though absolute levels of reinforcement may produce differences in learning rats between species.

Two examples:
1. Comparative analysis of serial list learning.
2. Determinants of generalization of instrumental responding in rats and pigeons

Serial Position Effect

our tendency to recall best the last and first items in a list
- Present list of items (e.g., words) to subject one at a time
- Ask subject to recall or recognize as many words as they can (Ebbinghaus)

if tested immediately after list, produces a recency effect
- testing after a delay, produces a primary effect

primacy, recency, and testing time have a similar impact on multiple species (Wright)

Serial Position Effect across species (Wright 1985 Study)

humans were given a set of four images (animals got travel slides) and tested at various time points with either one of the images they had seen (same) or a different image
- same \= move left; humans got points, pigeons got grain, monkeys got juice
- tested either immediately or after some delay

results:
- all species (pigeons, monkeys, and humans) showed primacy and recency effects
- all species showed recency effect with immediate testing, primary effect with delayed testing, and showed both with medium delay
- time scale shrunk in animals than humans (took longer)

recency effect

tendency to remember words at the end of a list especially well

primacy effect

tendency to remember words at the beginning of a list especially well

Interference mechanisms of working memory across species (serial position effect)

Suggests working memory process is homologous for all three species
- short retention interval (tested immediately) \= retroactive interference (recent memories clogging up others) --\> recency effect
- long retention interval \= proactive interference (more solid in LTM) --\> primacy effect
- medium retention interval \= retroactive & proactive interference --\> show both primacy and recency effects (usually true)

Determinants of generalized instrumental responding (experiment: visual target generalizability)

Train rats and pigeons to approach and stand under a visual target (a white circle) projected onto the floor of an arena
- an empty floor with images that can be projected onto the floor; animals have to stand on visual target for reward
- have to stay in the light for longer on each successive trial to get reward (dwell time)
- Pigeons were able to sit and wait (dwell) for the reinforcer for longer durations than could rats
\--- could be due to differences in nature: pigeons eat food while exploring; when rats find food, run off with it to eat

how do animals generalize responding? (usually bell curve of generalization)
- Stimuli varied systematically in color, size, intensity, and texture. The white circle of 100% size was the training stimulus
- On each non-reinforced probe test trial, subject was presented with 5 targets simultaneously. First choice was recorded on each trial --\> since none are original stimulus, which will they choose?
\--- found that pigeons liked to select for similarities in brightness and size
\--- rats were generally poorer at visual discrimination (couldn't see to discern patters, also attuned to brightness and size)

How do animals learn new behaviors?

Thorndike:
- Cat puzzle-box experiments.
- Stimulus-response (S-R) associative learning.
- Law of Effect: Subject learns to make a response, R, when R is followed by reinforcement.
- According to Thorndike, the subject does NOT learn about the reinforcer, only to make an R in stimulus context S
- "when I'm in this situation, do this response"
- believed most new learning was due to new S-R associations (disagreed with learning through insight) --\> but, not the only way animals learn

Kohler disagreed, said learning through insight/bursts

Kohler & insight (logical inference) in chimps

German cognitive psychologist objected to Thorndike's simple trial-and-error mechanism of learning.
- Studied "insightful" behavior in Chimpanzees.
\--- chimps saw banana hanging from string, started stacking boxes to reach banana (novel reasoning)

Insight:
- A novel solution to a problem.
- Inferring relationships beyond one's prior experience (but based on prior experience)

insight in pigeons (Epstein)

pigeons solving same problem as chimps

Epstein trained two instrumental responses:
1. Push box to a green spot randomly placed at base of chamber wall.
2. Step onto a box fixed in place and peck at a plastic banana hanging from the ceiling.

Tested with a suspended banana and a moveable box at the side of the chamber.
- pigeon can solve this problem, but some debate whether this was really insight

What do the differences in Kohler's and Epstein's data demonstrate?

demonstrates the tension between the cognitive perspective and behaviorist perspective of animal cognition research
- pigeons and chimps have to have extensive background experience, otherwise cannot do task (might not be insight)

what constitutes higher cognition?

- Learning
- Memory
- Perception
- Spatial behavior
- Timing
- Counting
- Emotion
- Problem solving
- Categorization
- Concept learning
- Causal reasoning
- Language

not easily explained through basic learning mechanisms/simple associations

Behaviorism

(Thorndike, Watson, Skinner) - mind as a black box

said all learning is learning new stimulus -\> response reflexes
- Reinforcement is necessary for learning.
- Little or no reference to mentalistic terms (non-cognitive/Freud)

Tolman and the advent of cognition

earliest person that liked the empiricism of behaviorism, but thought behavior was more complex than simple S-R reflexes

Suggests rats acquire cognitive map of spatial layout of the maze even without food reinforcement
- Rats running complex T-mazes (got fed at goal or not)
\--- in the behaviorist view, shouldn't be learning without a reward
\--- day 11: started to give food to half of group he didn't before; did better than group who got food from beginning
- Form a cognitive map of their environment
\--- if you remove the barriers, will run a more efficient route: novel shortcuts and detours - hallmarks of the cognitive map

called this "latent learning" (shown with motivation)
- proves S-R theory wrong (sudden use of previous knowledge)

can pigeons make a cognitive map?

Touchscreen procedure for spatial learning (pigeons good at pecking lights when they turn on)

- In Phase 1: Landmark (LM) X and LM A were presented on computer screen that contained a response grid; A was always two clicks to the left of X until pigeons form X--\>A association (X -\> A)

- An Phase 2: LM A directed pigeons where to search to locate a hidden "goal" (A -\> Goal); always one to the right of A

are they learning that the position to the right of A is food? Or, are they learning a cognitive map?
- Test by presenting LM X alone--pigeons can predict where Goal will be (X -\> A + A -\> G \= X -\> Goal)
- pigeons are making a cognitive map (expectation-mediated behavior), disproving S-R learning

what do spatial inferences indicate?

Seen in the touchscreen study of pigeons, indicate that:
- Details of an experience are encoded as representations during a learning experience.
- Associatively-acquired representations can be integrated into a larger framework (i.e., a structure or map) from which novel relationships can be derived.
- Novel relationships (ideas) support novel behaviors

what has been studied in animal cognition?

Study of cognition in animals has become a more systematic endeavor.

Goal is to understand the types of cognitive behaviors and the mechanisms that underlie these behaviors

A few examples:
- Cognitive maps (e.g., spatial maps)
- Causal inference
- Mental imagery (ex. daydreaming)
- Social cognition and Theory of Mind (TOM)

principles behind associative learning's evolution

1. Causal relations are neither arbitrary nor accidental.

2. Events stand in causal relation because of the physical laws of the universe.

3. Sensitivity to these relations (our ability to understand causality) is critical for survival and reproductive fitness

Therefore, associative learning mechanisms are adapted to be sensitive to the causal texture of a species' ancestral environment

But, do animals also represent an associative relation as causal?

Associative or Causal Learning

In Pavlovian conditioning, is the dog learning...
- a bell-food association? (associative model)
- that the bell causes food? (causal model)

Two ways to acquire causal knowledge

Bottom-up:
- Build smaller associations between events that occur together (to make things like maps)
- Pavlovian & Instrumental conditioning

Top-Down:
- Represent associative relations as causal.
- Build causal model from associative input.
- Experimentally test hypotheses about causal structure

types of causal structures

causal chain: Cause 1 (light) --\> Cause 2 (tone) --\> Effect (food)

common effect: two separate causes --\> effect

common cause: one cause --\> effect 1 & effect 2

example:
- smoking causes yellow teeth which causes lung cancer
- smoking and yellow teeth cause lung cancer
- smoking causes both yellow teeth and lung cancer

can test causal models with interventions (experimental method)--ex. manipulating yellow teeth

Do animals understand Interventions?

Different causal inferences can be made when an effect is merely observed compared to when the effect is the result of an intervention (allows animals to actually cause the causes)

Are rats capable of causal reasoning about their interventions?
- one group gets events that occur according to common cause model (light causes tone and food)
\--- light -\> tone and light -\> food, what will rat do when it hears the tone vs. causes the tone?
- one group gets events that occur according to causal chain model (tone -\> light -\> food)
\--- tone -\> light and light -\> food
- unpaired controls: get tone alone, learn light -\> food, observe tone

differ in the order of the light and the tone
- test: have rat hear tone or cause the tone (via lever press)
\--- in common cause group, if they hear the tone, they should predict food, but shouldn't predict food if they cause the tone
\--- in causal chain group, should predict food in both cases
- this is what we see (by measuring mean nose pokes as proxy for expecting food)

this difference can't be explained by purely associative frameworks

rats & causal interventions

Suggests rats understand their own agency.

This understanding goes beyond instrumental learning because inferences cannot be based on prior training history.

Open Questions:
- How do rats acquire understanding of agency?
- Can rats use this knowledge to investigate causal maps of the world (i.e., can they experiment)?


What other aspects of human causal understanding are found in rats?

Test mental imagery using ambiguous cues (rats)

Will the image/imagination of a visual cue influence responding the same as if the visual cue were actually present?

To test this, Fast & Blaisdell:
- Paired two lights during training
\--- An association would form between them
- Then presented only one light at test while the other light was covered by an opaque metal shield (can't see anymore)

Will the rat imagine that the covered light is on?
- Will animals respond as if the other light is on?

Training on compound/element Discrimination

used patterning:
- two lights: A & B
- some animals get positive patterning: A-/B-/AB+ (no sucrose if only one of cues is on, but get sucrose if both are on); linear
- or negative patterning: A+/B+/AB- (non-linear)

mice are able to learn this discrimination between a compound and its elements (better at positive patterning)

now, either cover light B or put cover between the lights (control for new thing \= generalization decrement)
- cover B and test A:
\--- when A is on, if mice think B is not on, positive patterning group should not press lever, negative patterning group should
\--- when A is on, if mice think B is on, positive patterning group should press lever, negative patterning group should not
\--- four groups total (either positive or negative, B covered or uncovered)

results:
- in positive patterning, when B is covered, act like they think B is off (don't press)
- in negative patterning, when B is covered, act like they are unsure/ambigious (inhibited pressing)

implications of rats & mental imagery

This is but one example of evidence for mental imagery in an animal.

Collectively, research so far suggests mental imagery can be found in rats and pigeons, and of course in people.

Are animals with mental imagery also self aware? Do they have a consciousness like we do? How many levels of intentionality can they process?
- can rats understand what other rats are expecting?

Can they take the intentional stance to practice deception? What else do they think about? Can they be deluded?

Daniel Dennett's levels of intentional stance

1 - individual has no beliefs about minds

2 - Individual has beliefs about its own mind (self awareness)

3 - individual has beliefs about others' beliefs (true TOM)

animals & theory of mind (background)

Do animals have a TOM?
- Prerequisite would seem to necessitate self awareness (first level intentionality)
- TOM: to be aware that others have conscious minds (subject knows it has a mind and that others have their own minds and thoughts)

Mirror use as a test of self awareness

Does the animal know it's seeing itself?

"Self awareness" in a bored ape?

Chimpanzees show evidence of "self awareness" as assessed with the mark test developed by Gallup (respond to marks put on them in the mirror)

magpie & self-recognition in mirror

magpies have good memories
- placed a mark on their upper chest (so it couldn't be seen)
- mark would be either yellow/red or black (which couldn't be seen on black plumage) --\> control
- saw how much birds pecked after seeing it in mirror (was raised with orange marks and having a mirror)

Face scraping of marked area in fish (given mirror)

guppy got a red dot on neck, measured how often they scraped throat
- scraped at mark on throat when saw it in the mirror

how do we diagnose a theory of mind?

humans aren't born with theory of mind
- Sally-Anne task: used to track development of TOM in children. TOM requires the ability to separate one's own's beliefs from the beliefs of another. Thus, to have TOM, the child should recognize that Sally would believe the marble to be in the basket, even though the child knows that the marble is in the box
- until age 4, humans will say box

communication & theory of mind

what kind of representation does a signaller have?
- Monkey A sees a leopard and gives an alarm call, Monkey B runs into the trees

Why does A call?
1. (S-R) the leopard elicits alarm calling by A
2. (A has intentions) A wants B to run to the trees
3. (A has a theory of mind) A wants B to believe there is a leopard

does A want B to think A sees a leopard?

A false belief task for apes

gorilla runs onto screen and bothers human caretaker, then hides in one of two hay bales
- will the monkey look where it thinks the human will look?
- even if the monkey moves hay stacks, chimps will still look where they think the human will look first (based on eye tracking)

Can chimps tell who can see them (perspective taking)?

Will chimp beg for food from a person who can see him/her, and not a person who can't?
- Chimps did not discriminate between seeing vs. blinded person.
- But they could figure out the difference if presenter was facing away vs. toward them

could be since, during training, only got rewards from people facing them

food competition in chimps & grabbing food

Chimpanzees don't naturally share, but typically compete for food
- if both submissive and dominant monkey are given food, dominant will usually get both
- if only the submissive can see the second food, will it take it instead of the dominant? (realizing the dominant cannot see it)

the submissive in the condition where the food is hidden to the dominant chimp will more often take the hidden food

Reptile Cognition

Old research found reptiles to be pretty stupid. But they used old methods of control by equation which may be inappropriate.
- take 2 animals in exactly same task to measure behavioral differences -\> may be due to other species differences

New research is challenging this view, such as by testing reptiles in a more species appropriate manner, including testing them at much warmer temperatures!
- Working memory in a radial maze in a turtle.
- Anole lizards learn new strategies to retrieve hidden prey.
- Monitor lizards learn to open a device containing live mice. They get better with repeated trials (just like Thorndike's cats in the puzzle box).
- Suggests that phylogenetic distribution of flexible cognition is more widespread

Working memory in the turtle

using a radial arm maze, it seems turtles can successfully do the task

Ontogeny (individual development) recapitulates Phylogeny

in development, we tend to go through developmental stages that look like our evolutionary ancestors
- Developmental process provides clues to evolutionary history
\--- for instance, gill slits and tails in humans
- things that develop later generally evolved more recently

Big 6: mice, chicks, frogs, fruit flies, zebrafish, nematodes

recapitulation theory
- this theory has kind of been abandoned (doesn't look like adults of ancestors)

The Ontogenetic (developmental) Niche

the environment to which a developing organism is adapted

The environmental challenges a developing animal faces can be quite different than those of an adult.
- High mortality during infancy
- Physical capacities are rapidly developing
- There is much to learn

Many adaptations are specific to developmental environments.
- Tail & gills in amphibian tadpoles
- Suckling reflex in mammal infants

will often go away with development

Development in placentals

The womb is a unique environment adapted to foster development of embryo to fetus.
- warm, protecting
- supplies nutrients, removes waste, e.g., respiration
- sensory stimulation (aids sensorimotor development)
- *some learning can occur in the womb*

To study learning in the rat fetus:
- Uterus is removed from dam and placed in a saline bath.
- Fetus then removed from the uterus.
- Fetus exposed to stimuli and it's responses are recorded.
- E.g., placing a nipple near its mouth causes the fetus to wipe at its face.

Pavlovian conditioning in fetal rats

Appetitive learning
- Rat fetus unconditionally wipes at its face when presented with irritating orofacial stimulation
- wiping response to nipple significantly suppressed after paired training (nipple --\> milk)

Aversive learning
- Rat fetus unconditionally becomes active when presented with lemon (sucrose --\> lemon)
- Activity after sucrose presentation significantly increased in paired condition

Babies learn in the womb

1. Habituation to novel sounds when repeated (non-associative learning)

2. Foods the mother eats lead to food preferences after birth (Pavlovian learning)

3. Mothers read "Cat in the Hat" to fetus while pregnant. After birth, babies learned to suck an artificial nipple at correct speed when reinforced with a recording of the mother's voice reading "Cat in the Hat", but not when reinforced by the mother's voice reading a novel story (instrumental learning)

Development of learning in rat pups and babies

Most developmental research uses rats and humans

Simple learning
- habituation

Pavlovian conditioning
- aversive & appetitive conditioning
- conditioned suppression
- second-order conditioning
- latent inhibition

Instrumental conditioning
- simple instrumental conditioning
- discriminative control of instrumental conditioning
- successive negative contrast (SNC)

Habituation of leg flexion in neonatal rats

Mild electric shock applied to leg - causes flexion. Flexion response decreases with repeated stimulation (and show dishabituation)

Habituation at longer ISIs declines with age (3 says, 6 days, 10 days, 15 days)

Suggests sensitization mechanisms develop later than habituation mechanisms.

Ontogeny recapitulates phylogeny (sensitization may have developed later evolutionarily)

Pavlovian conditioning in rat pups

Appetitive - cedar odor -\> milk
- increases mouth movements in presence of cedar

Aversive - saccharin -\> LiCl (gastric malaise)
- decreases amount of saccharin consumed

Instrumental conditioning in rat pups

Instrumental conditioning: Response-Outcome pairings change frequency or strength of response

touch paddle -\> infusion of milk into the mouth (reward)
- increases paddle touching

Conditioned suppression in infant rats

When do rats learn and remember fear?

Rats trained at PND (post natal day) 11-22, then tested 32 days later.

Conditioned fear was retained in rats trained at PND 17 and older
- won't remember conditioned fear until 17 days

going down is more learning (suppression)

Conditioned suppression

Suppression of ongoing behavior (e.g., lever pressing for food) produced by the presentation of a CS that has been conditioned to elicit fear through association with an aversive US.

Role of amygdala in fear conditioning

When do rats learn and remember fear?

Conditioned fear was retained in rats trained at PND17 and older
- need hippocampus

Amygdala not developed until PND 6 (coincidence detector for fear conditioning)

When do rats learn and remember fear?

development of the ability to fear condition
- Rat pups receive a fear conditioning experience (pairing an odor with shock) on a specific day of development, and conditional responding is measured at some point in the future
- Their preference or aversion for the odor is measured as an index of learning

found that if rats learned an odor-shock pairing on PND 9, developed a preference for that odor
- even after PND 9, if learned then or before, keep preference later (PND 12)
\--- early learning experience will block amygdala from creating aversion with odor-shock pairings later on
- but training on PND 10 or 11, see aversion
- in line with amygdala development

using glucose measures (active brain regions take more glucose) shows amygdala is not activated by odor-shock pairings at PND 8 (when preference develops), but is activated at PND 12
- with amygdala \= aversion, before amygdala \= preference

what drives preference towards typically aversive stimuli in early learning in rats?

animals received training and testing either at PN6 or PN12

Animals received either odor-stroke (maternal behavior) conditioning (appetitive) OR odor-shock conditioning (aversive)

What does this reveal?
- At PN6, animals develop a preference to anything paired with stimulation, whether that stimulation is good (stroking) or bad (shock)
- At PN12, animals develop an aversion to shock but no learning to the stroke (as it is no longer rewarding at that age)
- If not the amygdala, what is helping drive this learning?

Norepinephrine (NE) release in response to stimulation

in infants, almost everything that happens is either good or it kills them --\> fear conditioning might not be useful that young

How does preference/aversion learning early on impact adult behavior?

Male rat pups receive an aversive conditioning experience (pairing an odor with shock) on a specific day of development (so they would develop a preference)

As adults, they give male rats access to females with control scents or the shock-paired odor

Mounting attempts and intermission (how good they are at sex) are measured in the presence of each odor-scented female

found that if they developed a preference for the odor as pups (shock pairings prior to PN10), they will still prefer that odor as an adult and be more likely to engage in sexual behavior with females who smell like the paired odor

early preference learning biases later behavior (especially sexual)