A.

Genetics and Stuttering

1.

It all started when.......

2. 

Genetics primer

a.

What are genes? (picture from National Health Museum)

b.

Genes generate a "product"

c.

Chromosomes (pic of all) (chromosome 1)

3.

How Scientists do genetic research

a.

Family pedigrees (segregation analysis) (example pedigree from National Health Museum)

b.

"Gene hunting" (gene mapping from National Health Museum)

4.

Family pedigree research on stuttering

a.

Newcastle Upon Tyne study 1964

b.

Kenneth Kidd and his team - 1970s & 1980s

c.

Ambrose, Cox, and Yairi - 1990s

5.

Biological gene research on stuttering

a.

Film:  "Genetics of Stuttering:  Discovery of Causes"

b.

Genome Research & GNPTG and GNPTAB on chromosome 12  (Drayna)

c.

Update on genetics research...  (Drayna)

d.

All of the chromosomes with possible genes linked to stuttering:

6.

Where does genetic research lead us?

a.

Clinical value of genetic information

b.

Genes control things

c.

Scott A look at genetic and neurological correlates     

B. 

Brain Organization and Dysfunction

1.

Excessive Right Hemisphere Activity

a.

Hemisphere involvement in speech-language is not all-or-nothing

b.

In a nutshell: PWS show excessive and atypical activity in the right hemisphere when talking and when processing speech & language

c.

Neural bases of stuttering - Kroll & De Nil              anterior cingulate cortex

d.

Atypical cerebral laterality:  Neural risk for stuttering - Foundas       

e.

Foundas' work with the planum temporale   planum temporale

 2.

Stuttering and the basal ganglia - Alm            basal ganglia

a.

Characteristics of stuttering in common with other basal ganglia disorders

b.

Go signals

c.

In a nutshell: Brain has 2 parallel premotor systems; both can provide go signals under different conditions

d.

The details

 3.

What about PWS and no family history of stuttering? Neurological incidents as background factors - Alm      

C.

Auditory Processing

1.

Observations that led to development of theory

2.

Firsts tests: masking noise

a.

Shane 1955 - psychological explanation

b.

Subsequent observations re: motoric changes in speech production

3.

DAF - began with observations that PWS are often fluent when shadowing or echoing someone

a.

New hypothesis born: stuttering results from deficit in auditory feedback loop

b.

Not all PWS become fluent with DAF DAF and stuttering - Foundas

D.

Summarizing Organic Theories of Stuttering

E.

Putting it All Together