Language across the adult lifespan

Question 1

What are the changes associated with aging that may be related to language?

Answer 1

1. Cognitive decline: General decline in function of the brain.
2. Sensori-motor decline: Decline in sensory and motor systems that cause difficulty interpreting spoken and written language, as well as producing speech.

Question 2

What are the white matter tracts involved in language?

Answer 2

1. Arcuate fasciculus
2. Extreme capsule

Question 3

What structural changes in the brain occur due to ageing?

Answer 3

• Decreased grey matter volume (especially in lateral pre-frontal cortex and hippocamus)
• Decreased synaptic density
• Decreased white matter integrity (especially tracts linking fronto-temporal areas)

Question 4

What functional changes are observed with age?

Answer 4

• Decline in:
  1. Speed of cognitive processing (e.g. pattern spotting…)
  2. Working memory (e.g. digit span…)
  3. Long-term memory (e.g. free recall…)
• No decine in semantic knowledge (e.g. vocabulary, conceptual representation…)

Question 5

What is the relationship between language and other cognitive functions with ageing?

Answer 5

• Decline in language is not an isolated phenomenon.
• Language in closely interlinked with other cognitive functions, so decline in those functions will indirectly lead to decline in language.

Question 6

How does decline in visual processing affect language?

Answer 6

When reading, the words need to be seen in order for further processing to take place. Decline in eye-sight will cause decline in ability to see words.

Question 7

How does decline in auditory processing affect language?

Answer 7

Words in speech need to be heard in order to be interpreted correctly.

Question 8

How does decline in working memory affect language?

Answer 8

In order to interpret whole sentence correctly (both spoken and written), words at the beginning need to be held ‘in mind’ when end reached. Decline in working memory impairs this ability.

Question 9

How does decline in attention affect language?

Answer 9

Defects in attention may make it difficult to focus on spoken/written language, thus making it difficult to process.

Question 10

How does decline in long-term memory affect language?

Answer 10

Meanings of words and semantics are stored in LTM and may be affected by decline (although not oberved), making it difficult to interpret language.

Question 11

How does decline in problem solving & decision making affect language?

Answer 11

Both skills are needed to interpret ambiguous sentences.

Question 12

How does decline in learning affect language?

Answer 12

Learning is very important in acquisition of new vocabulary.

Question 13

How does hearing loss impair language processing?

Answer 13

1. Interpretation errors: Higher frequency sounds (e.g. “s” at end of plural words) are not detected. This may lead to interpretation errors.
2. Allocation of resources: More processing power needs to be dedicated to interpreting words in sentences properly, at the cost of other cognitive functions (e.g. memory), leading to impairment of those aspects.

Question 14

What language abilities are not impaired with age?

Answer 14

1. Vocabulary: Knowledge of word meaning
2. Spelling: Detection of correct spelling in tact, but retrieval impaired
3. Syntax: Ability to interpret the meaning of sentence based on order of words

Question 15

What language abilities are impaired with age?

Answer 15

1. Sensory loss (hearing, vision)
2. Limited comprehension due to working memory decline
3. Word finding difficulties

Question 16

What is the “General resource theory” behind age-related language decline?

Answer 16

• There are finite cognitive resources that are shared by all cognitive processes involved in language processing (inc. memory, interpretation, word finding…).
• In aging, atrophy of the brain results in decrease in size of general resource pool available to cognitive processes.
• Decline in sensory function means that more resources are dedicated to interpretation than say working memory.
• Decline in language is observed as a limitation by working memory.

Question 17

What is the “tip-of-tongue” phenomenon?

Answer 17

Individual is able to describe the meaning of the word they require, but are unable to actually find the word.

Question 18

What is “Node Structure Theory” for vocabulary

Answer 18

• Vocabulary is stored in 2 distinct parts:
  1. Semantics: Meaning of words
  2. Phonological: Sound of words, divided into 2 further levels:
• Lexical: Sound of words themselves
• Phonemes: Sounds of individual components

Question 19

What is a possible explanation for the “tip-of-tongue” phenomenon?

Answer 19

• Node Structure Theory states that the semantic part of vocabulary has much stronger connections than phonological part, so phonological part more vulnerable to degradation.
• Within phonological part, stronger connections are established if the words are used more regularly.
• With age, there is degradation in phonological part, especially in words not regularly used, resulting in inability to find the words despite knowing meaning.

Question 20

What is the possible explanation for the perservation of language function with ageing?

Answer 20

• Usually, language processing is restricted to dominant hemisphere in young adults.
• In older adults, decline of brain structure results in deficit in language processing ability of dominant hemisphere.
• There may be recruitment of functionally equivalent areas in the non-dominant hemisphere to compensate for functional loss in dominant hemisphere.

Question 21

What are the characteristics of “elderspeak”?

Answer 21

1. Exaggerated intonation
2. Slower speech rates
3. Repetition and elaboration
4. Shorter sentences, simpler syntax