Week 1 - Intro & theories

why is language important?

it is related to several later outcomes

• educational attainment

• health

• incarceration

how many children in the UK don’t have books?

3.8 million (national Literacy trust, 2011)

McCormack et al., 2010

case study - Ewan wouldn’t talk to others that didn’t understand him but would start talking when they talked to him first.

Norbury et al., 2016

2 children per reception class have clinically significant language deficits (no gender difference)

consequences of a language impairment

• more social, emotional and behavioural problems

• lower academic progress

what is a hypothesis?

A testable prediction
• Based on some previous
knowledge or observation
• “what happened?”
• Describes, explains

what is a theory?

• comprehensive explanation

• based on a large body of evidence

• explains why/how

• describes, explains and predicts future behaviour

explain Jorge Cham’s scientific method

• observe natural phenomena

• formulate hypothesis

• test hypothesis 

• modify hypothesis

• repeat

• establish theory based on repeated validation of results

what is the role of theories?

• guide experimental design

• guide interpretation of results

what are the 5 qualities of good theories?

• logically sound

• testable

• consistent with data

• parsimonious (as simple as possible, but not simpler)

• general and unified (brings many ideas together into one theory)

what are the benefits of models for testing theories?

• they force researchers to be explicit about input and how learning is defined

• they allow a deeper look at what has changed

• can create predictions that can be tested to advance a theory

• can test things that are not feasible with children due to time and ethics

explain the nature/nurture continuum (Gerken, 2008)

a scale of language development theories from most to least related to human genetics

what is interactionism?

the idea that a child learns from both nature and nurture (they come with a predisposition and the environment/input provides the rest)

explain dynamic systems theory (DST)

• behaviour is made from many complex, interacting parts within a system (“soft assembly”)

• not one single element that controls development

• behaviour is the result of many elements interacting through time

• interaction of parts changes over time - behaviour can become more stable/habitual/predictable

key points for triggering (Gerken, 2008)

• specificity - language is distinct from other cognitive domains

• what can be learned - children should not learn language-like patterns that don’t occur in language

• learning speed - some things can be learned from single encounters

• errors - errors should reflect possible languages

keys points of linguistic hypothesis theory (Gerken, 2008)

• specificity - language is distinct from other cognitive domains

• what can be learned - children should not learn language-like patterns that don’t occur in language

• learning speed - learning can be rapid but is based on input

• errors - errors should reflect incorrect hypotheses about the input

keys points of general purpose hypothesis testing (Gerken, 2008)

• specificity - learning language should resemble learning in other cognitive domains

• what can be learned - children can learn language-like patterns that do not occur in language

• learning speed - learning can be rapid but is based on input

• errors - errors should reflect incorrect hypotheses about the input

key points for associative learning (Gerken, 2008)

• specificity - learning language should resemble learning in other cognitive domains

• what can be learned - children can learn language-like patterns that do not occur in language

• learning speed - learning should be gradual and based on input

• errors - errors should reflect the statistics of the input

what role does time play in dynamic systems theory

• development in continuous in time

• time scales can be years, months, days, etc.

• accounts for both “real time” changes (seconds, mins) and “developmental time” (months, years)

• behaviour is a product of a child’s history, current environment, current task

what are nested timescales?

learning is the culmination of a child is doing the moment, their recent past, and developmental history

challenges of testing children

• task can’t be too easy/hard

• can’t be too long

• children under 4 are biased to answer ‘yes’ (Cameron-Faulkner, Lieven & Theakston, 2007)

• children are susceptible to inadvertent cues (Grow & LeBlanc, 2013)

• children are biased to chose novel objects (Horst et al., 2011)

• can only learn up to 3-4 words a day (Bion et al., 2013)

• you have to ‘guess’ what children are thinking

why do many studies use novel (pseudo) words?

to avoid a priori associations/knowledge

explain the intermodal preferential looking task (Hirsh-Palek & Golinkoff, 1996)

• children sit on lap on parent and are shown two screens (sometimes one)

• attention will be centred

• children are filmed

• children will hear a spoken sentence about one of the images and then their looking can be assessed to see if they look at the correct one

• tells us about how a child understands the sentence

explain looking tasks

• training phase - looked at familiar objects and then novel objects

• test phase - two things presented on the screen and then heard speech relating to one of the objects

• eye-tracking to see whether they looked at the correct object

switch task (Fennell & Byers-Heinlein, 2014)

• train a child with two images with certain words (habituation)

• switch the words and images so they are incorrect

• child should (hopefully) spend more time looking at the incorrect match

what is a forced-choice task?

• 2AFC/3AFC etc. (alternative forced choice)

• making children pick one word/object from a collection in response to a question/request

communicative development inventory (CDI)

• used to make sure not all children of higher language abilities are in the same condition

• used to make sure that they do/don’t know the word(s) being used in the experiment

• MacArthur-Bates CDI: words and gestures/words and sentences

peabody picture vocabulary test 

• standardised vocab test for 3y - 16y 11m

• 4 alternative photos

• point to/say number of picture that matches a word

what is a corpus?

• a collection of real words, utterances and sentences

• often it is a transcription of children and parents speaking, reading, playing etc.

• sometimes it is a list of words found in books of a certain level 

• example: CHILDES (child language data exchange system)

what is mean length of utterance (MLU)

• the average meaning units (morphemes) per utterance

different task demands (Gordan & McGregor, 2014)

• referent selection task (comprehension, recognition memory, manual response)

  • provide multiple objects and then ask for one specific object

• production task (recall memory, verbal response)

  • provide an object and ask for the word form (i.e. name)

explain the dot task (Gordon & McGregor, 2014)

• a form of production task

• allows a child to give a manual response instead of a verbal response

• place objects on the dots and then later ask the child which dot refers to which object

comprehension vs production

comprehension precedes production (Caselli et al., 2012)