Biological Imitation

What is NOT imitation

o Not the passive and faithful echoing of an arbitrary demonstration achieved in a single, immediate attempt.

o Mimicking – copying the form of acts without any representation of their goal. (birds, rats)

o Pavlovian Conditioning

o Matched Dependant Behavior – use of demonstrator’s behavior as a discriminative stimulus for the same or similar behavior, without knowing that their behavior was similar to that of the demonstrator.

More of Not Imitation

o Stimulus Enhancement – observing an action can influence the degree to which the observer attends to certain physical components of the problem situation, facilitating independent acquisition by the observer of a successful technique.

o Emulation Learning – Observer duplicates the results of other individual’s behavior, but not the specific way to achieve them.

o Response Facilitation – selective enhancement of motor responses: watching a conspecific performing an act increases the probability of an animal doing the same. Only for actions already in repertoire.

True Imitation

o Generates new behavior on the basis of observation rather than experience

o Active process of abstraction and reconstruction.

o Attempt to learn is purposeful, goal-directed

o Learns Form as well as Goal

True Imitation (2)

o May be most powerful and efficient of the social learning processes

o Has special status because it is viewed as involving symbolic mental processes

Metarepresentations

• Theory of Mind

• Mindreading

• Pretense

Theory of Mind

o To have a ToM: to believe that mental states play a causal role in generating behavior and infer the presence of mental states in others by observing their appearance and behavior.

• Theory of Mind = mentally represent the mental representations of others

o Concerns Content of representations: Think about self and others in terms of Mental States

Theory of Mind (2)

o Have mental state concepts such as• Believe Know• Want See

– and use these concepts to predict and explain behavior.

• Relevant because imitation is thought to involve the ascription of purposes or goals by the imitator to the model.

• However, it is possible that imitation occurs without a Theory of Mind on the part of the imitator (eg mimicry, associative learning).

Mindreadingo Basis: animal communication signals may be designed to

fundamentally manipulate others to the signal-sender’s ultimate genetic advantage,

o which in turn leads to selection pressures for protagonists to become more skilled at discerning the true state of mind of the signalers: mindread!

o “Ability to recognize states of mind (mental states) in oneself and/or others.”

o Ability to translate between one’s own and another

individual’s intentional or representational state – “cognitive empathy.”

Pretense

o Imitators copy the actions in demonstrations, but not the results.

• Pretend play in children points to the origins of the child’s developing of a Theory of Mind;

– psychological operation of Metarepresentation = Theory of Mind.

Metarepresentation

2 representations– First order: program / action-plan, drives the

actions of the model– Second order: in imitator, replicates the model’s

1st order representation.

o Can say that secondary representations are intrinsic to imitation: that the basis of secondary representation is the ability to coordinate multiple models, which represent different situations.

Metarepresentation (2)

o BUT in human children, the ability to imitate develops much earlier than either pretense or mindreading!

• So maybe imitation is cognitively linked to mindreading and pretense,

• on the principle that each incorporates a facility in self-other representation, but imitation is a simpler and developmentally prior achievement.

Infant Imitation o Must consider both the Cognitive and Social domains

o There are questions of perception and control.

o Robust across contextual changes – learn here, do there; imitative learning is flexible.

o Goal-directed: infants gradually correct their imitative attempts.

– Creative error example: adult protrudes tongue to one side, infant protrudes tongue and turns head!

Neonatal Imitation Debate: Meltzoff & Moore

• Organ identification: during initial phase of imitation, before actual movement, babies may quiet the rest of their body and just wiggle the tongue.

• Body parts and movement patterns are recognized and imitated: tongue for tongue, lip for lip.

• The later observed decline in facial movement is a result of motivational change: babies become too distracted to Just protrude their tongues anymore.

Neonatal Imitation Debate:Susan Jones

Tongue Protrusion in neonates is motivated by interest in visual display and exploration, Not imitation!

• Infants produce tongue protrusion when their interest is aroused by any visual display

• Most infants find tongue protrusion more interesting and arousing to watch than mouth openings.

• Infants move their tongues when they are interested because interesting sights motivate exploratory behavior, and the only exploratory behavior infants are capable of is tongue movement. TP ceases once infants can reach for objects.

Why Infant Imitation is Important

o Imitation is one of the most sensitive tools available for investigating the foundations of infants’ understanding of people.

o Tells us about perception, and links between perception and action.

o Provides information about infants’ notion of self, other, and the mappings between the two.

o Provides first opportunity for infants to make the connection between the visible world of others and the infants’ own internal states.

Infant Imitation (2)

o Recognization of Being Imitated o Infant plays more, looks more at person imitating him/her.– Will test an adult by changing the ‘game,’ throwing a curve ball once

in a while to see if the adult is paying attention (9+ months).

o Identifying Peopleo Infants use Functional Criteria – gestural signatures

o Ex: 1st adult plays A with infant, then goes away, and then 2nd adult comes and tries to play B

• If infant has kept visual track and therefore Knows that 2nd adult is not 1st adult, infant will switch immediately to game B.

• If infant did lose visual contact with 1st adult, infant will try to play A, to ascertain if adult is still 1st adult.

Developmental Consequences of Reciprocal Imitation Games

o Infants gain a sense of what his or her felt acts look like.

• Imitation games provide an opportunity to the infant to see both self and other as producers of intended acts instead of merely of equivalent surface behaviors.

Autism

o Autistics perform significantly poorer than controls on imitation of both body movements and actions involving objects.

• “Early capacities involving imitation, emotion-sharing, and theory of mind are primarily and specifically deficient in autism. Further, these three capacities involve forming and coordinating social representations of self and other at increasingly complex levels via representational processes that extract patterns of similarity between self and other.” – imitation plays a primary constructive role in the generation of

theory of mind, pretence, and other capacities. (Rogers & Penrose, 1991)

Primates

• Chimpanzees and Orangutans demonstrate imitative capabilities

• Monkeys are Not good at imitation.

• Apes are thought to be true imitators, but we don’t have much data on them.– Learning may be importantly handled by apprenticeship, – While Imitation serves self-teaching functions.

• Most of the work done in non-human primates can be explained by non-True types of Imitation.

Deception

• Most deception, especially in non-human primates, can be explained by – associative learning– chance– inference about observable features rather than mental

states.

• Examples– Female carnivorous baboon– Chimpanzee-trainer interaction– Vervet monkeys’ false leopard call

Mirror Neurons

• 2nd category of F5 visuomotor neurons

• Visually activated when a monkey observes a goal-directed action with either hand or moutho Tools and emotional gestures do not activate mirror

neurons.

o Majority only become active during the observation of a single type of action

o Ex: Grasping, placing, manipulating.o Precision grip

o Finger prehension,

o Whole-hand prehension

Resonance Mechanisms

o Motor neurons of higher centers always discharge in association with a particular movement, but will also discharge in the absence of overt motor behavior.

o It is not a command, but an internal representation of the motor behavior they code.

• Resonance: internal motor representation of the observed event which, subsequently, may be used for different functions, among which is imitation.

Low Level Mechanisms

and Response Facilitation o Mostly in the superior parietal lobule.

o 2 fundamental types of releasing signals– Objects of certain size, shape, color– Movements by conspecifics

• Is a fundamental way in which the behavior of groups of animals acquires coherence. (Birds flocking)

o Infant imitation differs from Response Facilitation in that infants do perform deferred imitation – the behavior does not disappear with disappearance of the releasing signal.

• It is very difficult to refrain from imitating observed movements. Ex: boxing match.

Evidence for Low Level Mechanisms

and Response Facilitation o Motor Evoked Potentials recorded from arm and hand

muscles when observing meaningless intransitive arm movements and grasping movements: increased upon observation of arm and hand movements – no goal needed.

o Cortical 15-25 Hz rhythmic activity: usually suppressed during movement execution, also significantly diminished during movement observation.

o EEG: observation of human movements, but NOT objects or animals, desynchronizes EEG patterns of precentral cortex. – Desynch of primary motor cortex more likely due to arrival of action

potentials originating from premotor areas than from a direct visual input to the primary motor cortex.

o Echopraxia: impulsive tendency to imitate other’s gestures. Reflexive.

High-Level Resonance Mechanism,

Emulation, and True Imitation

o Left inferior frontal gyrus (Broca’s Region)

• Firing of F5 codes the motor representation of the action, not the movements forming it.

Hypothesis: activity of F5 mirror neurons mediates action understanding.

• Purpose of F5 is to generate a representation of what another individual is doing.

• Meaning of an observed action can be recognized because of similarity between observed and acted representation.

• Emulation: allows observer to retrieve most relevant information, the action goal.

• Mirror neurons constitute first step: action-goal understanding.

True Imitation

results from interplay of the

two levels of resonance.

o High-level resonance describes the Goal

o Low-level resonance describes the Form