Animal Learning - PSYC1011

Learning

Learning

The acquisition of knowledge or skills through experience, typically resulting in a change in behavior and the brain's ability to adapt to the environment.

Mental Health Disorders

Disorders that affect an individual's thoughts, emotions, and behavior, including anxiety disorders, phobias, PTSD, and other conditions. Learning plays a role in these disorders and can affect how individuals perceive and interact with the world.

Non-Associative Learning

A type of learning where an animal's behavior, physiology, or brain changes following repeated exposures to a stimulus. It includes habituation, which is a decrease in response to a repeated stimulus, and sensitisation, which is an increase in response to a repeated stimulus.

Habituation

A type of non-associative learning where an animal's response amplitude or frequency decreases as a result of repeated experience with a specific stimulus. It allows the animal to ignore familiar stimuli and focus on new information.

Is also most common type of learning.

Sensitisation

A type of non-associative learning where an animal's response amplitude or frequency increases as a result of repeated experience with a stimulus. It is not stimulus-specific and can occur with strong stimuli, such as electric shock.

Pavlovian Conditioning

A form of associative learning where an animal learns that one stimulus predicts another stimulus. It involves the pairing of an unconditioned stimulus (US) with a conditioned stimulus (CS), resulting in a conditioned response (CR) to the CS.

Instrumental Conditioning

A form of associative learning where an animal's behavior is reinforced or punished based on its consequences. It involves the contingency between a response and an outcome, and can be influenced by factors such as contiguity, schedule of reinforcement, and delay of reinforcement.

Extinction

The decrease in the amplitude or frequency of a conditioned response (CR) as a result of non-reinforced presentations of the conditioned stimulus (CS). It involves the learning of a new association that the CS no longer predicts the unconditioned stimulus (US).

Spontaneous Recovery

The recovery of a conditioned response (CR) when the conditioned stimulus (CS) is tested after a delay

Continuity of species - Darwin

The concept that species change over time through the process of natural selection. It emphasizes that all organisms are connected through a common ancestry, with new species arising from existing ones. This theory challenges the idea of fixed species and supports the understanding of evolution.

Finding of Mutschler et al (2010)

After 40 mins of exposure to a piano piece, the arousal and amygdala activation gets lower and lower as time goes on, people adapt and get bored

Finding of Gandhi et al (2021)

Participants with autism don’t habituate over time - they are learning about the world in a different way

Finding of Benito et al (2018)

Those who had received CBT for their OCD

Found that single best predictor of treatment success in all aspects of treatment success was habituation in fear response

Finding of Holz et al (2021)

Measured neural response to emotional faces in the amygdala.

Babies come into lab with their mum, amount of maternal stimulation (playing with kid, giving love) was determined

Less habituation in those diagnosed with ADHD

Amount of maternal stimulation affected habituation ONLY for those in high-risk families, so maternal engagement can protect someone who comes from a high risk family

Bedecarrats et al (2018)

Adult group of Alysia, who got 5 electric shocks to their tail and then get 5 more 24 hours later, test how long their tails withdraw for.

Other group not shocked.

Give RNA from shocked animals and control groups to untrained animals.

1st experiment: Shocked animals withdraw for 10 extra seconds

2nd experiment: Animals given trained RNA, despite never experiencing the shocks had a near identical reaction.

(memories are transferrable)

Associative relationships

Learned relationships between events linked in time/space.

Boileau et al (2006)

Measured brain response to amphetamine, adults given 3 doses each

Brain continues to be more fired up after each dose

Way more dopamine release after each time

Olssen & Phelps (2007)

One stimulus (blue square on computer screen) predicted shock while a different stimulus predicted no shock. The one that predicts shock is referred to as the CS+, and the other is the CS-

CS+ starts to elicit a state of fear (through skin conductance response increase), along with more activation in the amygdala

Observational (vicarious) learning

Learning that occurs simply from watching another

Huddling Behaviour - Brunjes & Albert

10 day old and 15 day old rats placed in a circular chamber with rats and gerbils.

10 day old rats just wanted a warm body and did not differentiate between rats and gerbils.

Older rats preferred rats.

Alberts and May

Investigated whether transition in Brunjes & Albert was due to “nature” or was it due to “experience”.

Some rats left smelling normal, others were sprayed with “wild musk”.

Baby rats raised with wild musk or normal musk.

Suggests the transition from physiological to filial huddling is because of Pavlovian condition, as rats were conditioned by smell.

Fillion & Blass (builds off Alberts & May)

Rats raised with mum who smells normal or with an artificial odour.

Then placed in chamber with female rat at 100 days old.

Rats ejaculate quicker when the rat that they mate with smells like mum.

(ew)

Sullivan - olfactory learning

She pairs an odour CS with mild electric shock US in rats. Then measures odour preferences

Tested rats of 6, 12, 20

At older ages, they avoid the odour that is paired with shock.

At younger ages, loved the electric shock and kept going for CS

Tiffany Field’s experiment - Massage therapy in premature human infants

Over 30% higher survival rate for babies that were massaged than not.

Birbaumer et al - Criminality & Psychopaths

Psychopaths will experience the same pain as normal people, but not the same skin conductance response or activation in the amygdala and the orbitofrontal cortex

Tottenham et al (2019)

• 3-5 year old children tested

• Trained with a one shape, that would predict an aversive, loud scream; this stimulus is referred to as CS+

• Different shape that does not have scream is the CS-

• Some trained alone, some with parent

• Left in a room, with two “arms”

• When kids were not trained with their parents, they preferred the CS-

• 55% of the time, kids trained with their mother preferred the CS+

Gao et al (2010) - Pavlovian conditioning and criminality

Children who grew up to be convicted of serious crimes did not exhibit the fear response to the CS+, there was no increase in skin conductance

Why does animal perform the instrumental response? Ostlund & Balleine, 2009

Presented animals with two foods, click a lever for type of food.

They would purposely devalue certain foods by giving way too much.

• Good evidence to assess that the animal is pressing the handle in order to get an outcome.

• Showed 10 vs 40 of training, overtrained group still want same food after devaluation, shows that habits are less sensitive to the reward value of the outcome

There are a range of factors that influence instrumental conditioning. Ostlund & Balleine, 2009

• Delay between response and outcome

  • Huamns tend to tolerate longer delay (fortnightly income)

• Schedule of reinforcement

Partial reinforcement schedule - two types

Interval and ratio

Both can be either fixed or variable

Stress-enhanced fear learning - Nishimura

• Animals getting shocked or not

• After delay, animals placed into a completely different context and both are shocked once

The ones initially shocked have a much higher association of that environment with fear

Poulos et al - stress-enhanced learning

• Gave infant rats early life stress with repeated shocks

• Gave a single shock when they were adults

Babies forget they have been shocked due to infantile amnesia, but that early stressful experience still led to increase when they were shocked again as adults

“Natural” Individual differences in fear expression? - Graham and Richardson

• Trained adult rats to fear a context

• Some are terrified after a single shock

• Some “learn” nothing → no reactions

• These two groups different in level of FGF2 in the hippocampus, which is really important for neural development and neuroplasticity

• Illustrates individual differences despite having extremely similar life experiences

Goosens et al (2007) → Examined the effects of exposure therapy on spider phobia

Amygdala is super fired up before the therapy of seeing spiders, and then levels down to those who are not afraid of spiders

Reinstatement

Recovery of responding when subject is tested after a non-signalled US presentation

Enhancement of extinction/exposure therapy

One approach → Reduce anxiety (i.e. give an axiolytic)

What three factors are necessary for pavlovian conditioning?

Surprise

Contingency

Contiguity

Renewal

• Recovery of responding when subject is tested in a context different from that where extinction occurred

→ Shows learning of CR is contextually modulated

Enhancement of extinction/exposure therapy?

• One approach would be to reduce anxiety → give an axiolytic

• However, if we accept that extinction (i.e. exposure) is new learning, then maybe we need to give something that ehances learning