1. A Phonetic Category Learning Road Trip
Chris Heffner
Blair Linguistics Club

2. Categories: Example
How do categories work? Introduce NIH vs. NSF – the difference between these categories is behaviorally relevant.

3. Rule-Based Theories of Category Learning
California
Surfer hair
Up for anything
Fusion everything …
Minnesota
Blond hair, blue eyes
Exceedingly gregarious
Anti-flavor …
Florida
Bronzed or wrinkled skin
Retired and/or tourism
Cuban food …
Maryland
Constantly wearing Maryland flags
Probably a fed
Crab forever! …
Rule-based account – abstract generalizations are compared via a series of rules. A researcher might satisfy most (thought not all) criteria for one category or the other, and would be judged to be a member of that category

4. Exemplar-Based Theories of Category Learning
Exemplar-based account – categories are made up of the specific memories one has for the individuals in each category. No abstraction is performed. A researcher might be classified as an NIH researcher because they remind someone more of the NIH researchers they know than the NSF researchers.

5. Dual-System Theories of Category Learning
Rules
Exemplars

6. Category Learning in Language
Is a /ta/ or a /da/?
Rule-Based
Exemplar-Based
/t/ = VOT > 35 ms
/d/ = VOT < 35 ms da ta da ta da ta

7. Methods: Materials [ç] – palatal [x] – velar 1 2 3 4 5 6 7 8 9 10
Continuum between [ç] and [x] with 10 steps. Created using linear combination. 1 2 3 4 5 6 7 8 9 10

8. Methods: Procedure x450 (maximum)
Brief outline of experiment. Total of about 450 trials maximum (~20 minutes, not for principled reasons), but participants could end early if they have at least 90% of continuum items correct. Participants first heard a sound, and were asked to push keyboard buttons corresponding to the red, yellow, or red categories. They then got feedback.
x450 (maximum)

9. Methods: Conditions [ç] [x]
What counts as correct? 3 continuous conditions, 3 discontinuous conditions.

10. Results: Time to Learn 27 2
Compare learning rates across conditions. Note that continuous (top three) and discontinuous (bottom three) conditions seem to differ in success. 7 8 15

11. Dual-System Model: Implications
Rule-based
Exemplar-based

12. Destination One: Germany

13. Germany: Rationale

14. Germany: Background

15. Germany: Results

16. Destination Two: Michigan

17. Michigan: Rationale

18. Michigan: Background
Stuttering is associated with differences in dopamine circuitry in the brain (Giraud et al., 2008; Lu et al., 2010; Wu et al., 1997), which has been computationally modelled as a part of the underlying etiology of stuttering (Civier et al., 2013)
Stroke and other injuries to the basal ganglia can result in stuttering (Ciabarra et al., 2000; Tani & Sakai, 2011)
“The core dysfunction in stuttering is suggested to be impaired ability of the basal ganglia to produce timing cues for the initiation of the next motor segment in speech.” (Alm, 2004, p. 325)
Stuttering may be associated with some differences in language processing and production other than its diagnostic symptoms, such as past tense marking (Bauman et al., 2012)

19. Michigan: Results

20. Destination Three: Ohio

21. Ohio: Rationale

22. Ohio: Previous Methods
(Gabay et al., 2015)
Ohio: Previous Methods
SMART + what is a good result in SMART?

23. Ohio: My Methods

24. Ohio: Background (Maddox et al., 2013)
Category learning over the lifespan

25. Conclusions
Germany: surprising similarities between English and German speakers
Michigan: kids who stutter seem to be impaired on rule-based learning
Ohio: what will happen with varied age groups?

26. Thank You!