Chapter 15 - Language & Lateralization

Communication

Movement of info from one place to another

Occurs when a signal conveys info

• Other animals communicate but do not use language

Language

Rule-bound arrangement of symbols (spoken, written, etc.) which are use to convey a vast range of thoughts, actions, & concepts

It is:

• Dynamic (changes over time

• Arbitrary (no inherent relationship between a word & its meaning

• Grammatical (follows a series of rules that dictate structure & usage)

Phoneme

Most basic sound of speech

Morpheme

Most basic unit of meaning

• In some languages, most phonemes are words

• In others, morphemes can include distinct, stand-alone words & things like prefixes & suffixes

Words

Distinct, meaningful units of language, made of at least one morpheme

• no widespread agreement on definition of “word” that applies to all languages

Lexicon

Full set of words belonging to a given language

Grammar

System of rules that governs how words are used

Syntax

Rules about the organization of words into sentences

Semantics

Method by which we draw meaning from groups of morphemes & words

BF Skinner’s Explanation for Language Development

Reinforcement

Parents & other caregivers provide feedback in response to vocalizations

• If feedback is positively reinforcing, the vocalization reoccurs

Noam Chomsky’s Explanation for Language Development

Innate Grammar

Exists in many languages a fundamental structure determined by universal rules

• Brain comes into world already knowing what to look for, thus facilitating acquisition of given language

Evidence for Skinner’s Explanation

Many researchers have attempted to teach basic language to non-human species, primarily birds & non-human primates

Idea: If non-humans can learn language, then language is not innate to humans

EX: Washoe & Loulis; Sarah (Chimps) , Koko (Gorilla) , Kanzi (Bonobo) , Alex (Parrot)

Sarah the Chimp

Learned symbols to represent different concepts → presented with apple as well as symbol for apple & asked to describe them

• She described the symbol the same way she described the apple

  • Round, Stemmed, & Red → despite symbol being a blue triangle

Evidence for Chomsky’s Explanation

Early in development, babies will start to babble → many parents assume it’s them trying to communicate, but → they babble whether someone is present or not

• babies raised in ASL homes will “babble” using hand signs instead of vocal babbles

Babbling is likely a natural developmental process during which babies practice phoneme formation w/ mouth & vocal cords

Critical Period for Language

Penfield & Roberts

Time window that constrains language learning & development

• Based idea on observation that early-life brain injury has less impact on language than similar injuries in adults

Second languages learned after the age of 10 very rarely reach native-level fluency

Case Study: Genie

Severe childhood neglect & isolation → never learned to speak until after being rescued

Learned Faster: Individual word meaning (particularly complex descriptors: color & #), Grammatical rules (plurality), & Conceptual Interrogatives (How, Why, When)

Learned Slower: More complex grammatical rules (tense) & Syntax (sentence structure)

Synaptic Pruning

Widespread reduction in synaptic connections that continues into early adulthood

Brain continues to develop & grow for first few years if life

• At age 2, toddler brains begin process of synaptic pruning

  • Bulk of pruning happens by age 10

Theorized that pruning process represents “critical period” for language development

Language must be learned before the necessary pathways are pruned