Lecture 4 - Language and the brain

Question 1

What is the social brain hypothesis (Dunbar 1998)?

Answer 1

social complexity drives primate cognition

Question 2

What is the cultural intelligence hypothesis (Van Schaik et al 2011)?

Answer 2

co-evolution of cognition and culture

Question 3

Foraging brain hypothesis?

Answer 3

• new research comparing 140 primate species suggests diet not sociality better predicts brain size expansion in primates
• specifically eating fruit and extractive foraging

Question 4

Brain size in genus homo?

Answer 4

• homo habilis (first member of the genus homo) show evidence of Broca’s area
• homo erectus = larger brains and bigger body size
• brain size doubles between homo Erectus and Homo sapiens

Question 5

Brain evolution and language?

Answer 5

• rapid increase in homo brain size during a period of dramatic climate change
• Homo sapiens were likely to be the first linguistic species
• language cannot be time stamped as it’s a very gradual process with many blocks already in place

Question 6

What is the mirror neuron system?

Answer 6

• discovered by Rizolatti and colleagues in 1992
• mirror neutrons match observed and executed actions
• ‘monkey do, monkey see’
• they are implicated in language, imitation , action learning, action understanding and empathy

Question 7

What is the Gestural theory of language evolution?

Answer 7

• Corvallis (2010) argues that language evolved ‘hand to mouth’ starting with gestures

Question 8

How do mirror neutrons contribute to language?

Answer 8

• they are active during speech perception
• they contribute to complex control systems in low level ways

Question 9

What is the left hemisphere of the brain responsible for?

Answer 9

• analysis of sequences
• comprehension/ production of speech and language
• logic, reasoning, analysis

Question 10

What is the right hemisphere of the brain responsible for?

Answer 10

• visual-spatial skills
• processing space and geometrical shapes including faces
• organising a narrative
• understanding speech rhythm and intonation (prosody) = they way we speak
• recognising and expressing emotions of speech
• music

Question 11

Split brain?

Answer 11

• epileptic activity can spread from 1 hemisphere to the other through the corpus callosum
• in the 1950s-60s epilepsy was treated by severing the corpus callosum

Question 12

What did research from Sperry and Gazzangia find?

Answer 12

• left hemisphere = read and verbally communicate
• right hemisphere = identify visuospatial info, could not linguistically communicate
• only processing occurring in the left hemisphere could be described
• also found evidence of hemispheric neural plasticity

Question 13

What is Broca’s area?

Answer 13

• important region for language production
• located in the left inferior frontal cortex

Question 14

What is Broca’s aphasia?

Answer 14

• is caused by lesions to Broca’s area
• causes problems in language production
• speech = non fluent, laboured and hesitant
• comprehension = relatively intact
• partial paralysis of the body

Question 15

What is Wernicke’s area?

Answer 15

• important region for language comprehension
• found in the temporoparietal junction of the posterior temporal lobe

Question 16

What is Wernicke’s aphasia?

Answer 16

• caused by lesions to Wernicke’s area
• problems in language comprehension
• speech is fluent but meaningless
• patients cannot repeat words or sentences and cannot recognise speech sounds
• no paralysis

Question 17

What is a problem of bilingualism?

Answer 17

• verbal skills of bilinguals are generally weaker than those of monolingual speakers (Bialystock et al. 2013)

Question 18

What are some benefits of bilingualism?

Answer 18

• show better executive control (Bialystock et al. 2013)
• executive control = cognitive skills like inhibition, attention and working memory

Question 19

Joint activation?

Answer 19

• there is neural evidence of joint activation of both languages during bilingual linguistic processing even when focused on 1 language
• bilinguals must select the language from competing options and selectively attend (Krollet et al. 2006)

Question 20

Bilingualism and mental flexibility?

Answer 20

• fMRI research shows bilingualism leads to grey matter changes
• e.g. Michelle et al. 2004 found that Italian-English bilinguals had higher grey matter density in left inferior parietal regions than English monolinguals
• Peal & Lambert 1962 said that bilingual people have mental flexibility and a more diversified set of mental abilities

Question 21

How do you assess bilingualism?

Answer 21

• is difficult and depends on factors such as age and duration of exposure
• children may be bilingual but not biliterate