biased learning of long-distance assimilation and dissimilation
TRANSCRIPT
2. Methodology Experimental design: Three phases Example s3muli
Practice: Exposure to six cvcv-Lv stem-suffix pairs in two tenses
Training: 192 triplets with trisyllabic stems and suffixed forms (-li, -ru) • Suffix liquids can trigger alternation in preceding stem • Permutations of 3 binary parameters define 8 experimental groups,
differing only in the encountered patterns of stem-suffix interaction: • Trigger-target interaction: Harmony vs. Dissimilation • Trigger-target distance: Short-range (cvcvLv-Lv) vs. Medium-
range (cvLvcv-Lv) • Evidence at other distance level: Faithful non-alternation (rich
stimulus) vs. No relevant stems included (poor stimulus) • An additional Control group did not hear any stems with liquids
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➤
“Past tense” – toke…toke-li; “Future tense” – mebi…mebi-ru
Stimuli (4 different voices) presented over headphones and repeated aloud
Testing: Stem followed by two realizations of suffixed form (2AFC task) • Choice between harmonic and disharmonic liquid sequence • 32 trials for stems at each of three trigger-target distances (96 total) • Short- (cvcvLv), Medium- (cvLvcv), and Long-range (Lvcvcv)
➤
Examples of test trials (harmonic vs. disharmonic choices): dotile…dotile-li or dotire-li; tukiri…tukiri-ru or tukili-ru (Short-range) teriti…teliti-ru or teriti-ru; bilegi…bilegi-ru or biregi-ru (Medium-range) linode…linode-li or rinode-li; renitu…lenitu-li or renitu-li (Long-range)
4. Summary Pa6erns of learning and generaliza3on Analysis
• Mixed-effects logistic regression model over binary response data (N = 10,185; log-likelihood = –4,940.5)
• Including Group × Distance interaction greatly increased fit • Reported p-values and odds ratios (relative to Control group) shown in
graphs were extracted from the fitted model
Future research • General reluctance to extend alternations to highly salient word-initial
position (cf. Becker, Nevins & Levine 2012)
• What is the proper characterization of the “transvocalic” relation? (Syllable-adjacency? Consonant-tier adjacency? Onset-tier adjacency?)
• Can learners discover (or infer) phonotactic assimilation/dissimilation patterns that involve blocking by intervening segments of certain kinds?
• Computational properties (complexity, learnability) of possible/attested vs. impossible/unattested patterns (e.g. Heinz 2010, Lai 2012)
cvcvLv-Lv cvLvcv-Lv Lvcvcv-Lv
S-Harm + ! ? ? S-Harm-M-Faith + ! – ? M-Harm ? + ! ? M-Harm-S-Faith – + ! ? S-Diss + ! ? ? S-Diss-M-Faith + ! – ? M-Diss ? + ! ? M-Diss-S-Faith – + " ?
3. Results
References Hansson, Gunnar Ólafur. 2010. Consonant harmony: long-distance interaction in phonology. Berkeley: University of California Press.
Heinz, Jeffrey. 2010. Learning long-distance phonotactics. Linguistic Inquiry 41(4): 623–661. Lai, Y. Regine. 2012. Domain specificity in learning phonology. University of Delaware dissertation. McMullin, Kevin and Gunnar Ólafur Hansson. In press. Locality in long-distance phonotactics: evidence
for modular learning. Proceedings of NELS 44. GLSA Publications, University of Massachusetts. Rose, Sharon, and Rachel Walker. 2004. A typology of consonant agreement as correspondence. Language
80(4):475–531. White, James C. 2014. Evidence for a learning bias against saltatory phonological alternations. Cognition
130:96–115.
Becker, Michael, Andrew Nevins and Jonathan Levine. 2012. Asymmetries in generalizing alternations to and from initial syllables. Language 88(2): 231–268.
Bennett, William. 2013. Dissimilation, consonant harmony, and surface correspondence. Rutgers University dissertation.
Finley, Sara. 2011. The privileged status of locality in consonant harmony. Journal of Memory and Language 65:74–83.
Finley, Sara. 2012. Testing the limits of long-distance learning: learning beyond a three-segment window. Cognitive Science 36:740–756.
Acknowledgements Workshop on Learning Biases in Natural and Ar3ficial Language Acquisi3on, LAGB Annual Mee3ng, Oxford, 2014
(Poster downloadable at http://tinyurl.com/HanssonMcMullin-LAGB2014)
This research was supported by SSHRC Insight Grant 435–2013–0455 to Gunnar Ólafur Hansson and a UBC Faculty of Arts Graduate Research Award to Kevin McMullin. Special thanks to Carla Hudson Kam and the UBC Language and Learning Lab, as well as to Jeff Heinz, Alexis Black, James Crippen, Ella Fund-Reznicek and Michael McAuliffe.
Short-range harmony groups:Learning?
Test-item type = Short-range (cvcvLv-Lv)
Pro
port
ion
harm
ony
resp
onse
s ([
l…l]
or [r…
r])
Control S-Harm S-Harm-M-Faith
0.00
0.25
0.50
0.75
1.00
* *(p < 0.01) (p < 0.0001)
O.R. = 2.88 O.R. = 12.88
Medium-range harmony groups:Learning?
Test-item type = Medium-range (cvLvcv-Lv)
Pro
port
ion
harm
ony
resp
onse
s ([
l…l]
or [r…
r])
Control M-Harm M-Harm-S-Faith
0.00
0.25
0.50
0.75
1.00
* *(p < 0.0001) (p < 0.05)
O.R. = 4.12 O.R. = 2.23
Short-range harmony groups:Generalizing OUT to medium-range?
Test-item type = Medium-range (cvLvcv-Lv)
Pro
port
ion
harm
ony
resp
onse
s ([
l…l]
or [r…
r])
Control S-Harm S-Harm-M-Faith
0.00
0.25
0.50
0.75
1.00
n.s. n.s.(p ≈ 0.18) (p ≈ 0.13)
O.R. = 1.55 O.R. = 1.65
Medium-range harmony groups:Generalizing IN to short-range?
Test-item type = Short-range (cvcvLv-Lv)
Pro
port
ion
harm
ony
resp
onse
s ([
l…l]
or [r…
r])
Control M-Harm M-Harm-S-Faith
0.00
0.25
0.50
0.75
1.00
* *(p < 0.0001) (p < 0.01)
O.R. = 3.64 O.R. = 2.76
All harmony groups:Generalizing OUT to long-range (word-initial position)?
Test-item type = Long-range (Lvcvcv-Lv)
Pro
port
ion
harm
ony
resp
onse
s ([
l…l]
or [r…
r])
Control S-Harm S-Harm-M-Faith M-Harm M-Harm-S-Faith
0.00
0.25
0.50
0.75
1.00
*n.s. n.s. n.s.(p ≈ 0.37) (p ≈ 0.13) (p < 0.01) (p ≈ 0.11)
O.R. = 1.34 O.R. = 1.64 O.R. = 2.45 O.R. = 1.68
Short-range dissimilation groups:Learning?
Test-item type = Short-range (cvcvLv-Lv)
Pro
port
ion
dish
arm
ony
resp
onse
s ([
r…l]
or [l…
r])
Control S-Diss S-Diss-M-Faith
0.00
0.25
0.50
0.75
1.00
* *(p < 0.0001) (p < 0.0001)
O.R. = 8.54 O.R. = 10.66
Medium-range dissimilation groups:Learning?
Test-item type = Medium-range (cvLvcv-Lv)
Pro
port
ion
dish
arm
ony
resp
onse
s ([
r…l]
or [l…
r])
Control M-Diss M-Diss-S-Faith
0.00
0.25
0.50
0.75
1.00
* .(p < 0.001) (p ≈ 0.062)
O.R. = 3.07 O.R. = 1.84
Short-range dissimilation groups:Generalizing OUT to medium-range?
Test-item type = Medium-range (cvLvcv-Lv)
Pro
port
ion
dish
arm
ony
resp
onse
s ([
r…l]
or [l…
r])
Control S-Diss S-Diss-M-Faith
0.00
0.25
0.50
0.75
1.00
n.s. n.s.(p ≈ 0.36) (p ≈ 0.26)
O.R. = 1.34 O.R. = 1.45
Medium-range dissimilation groups:Generalizing IN to short-range?
Test-item type = Short-range (cvcvLv-Lv)
Pro
port
ion
dish
arm
ony
resp
onse
s ([
r…l]
or [l…
r])
Control M-Diss M-Diss-S-Faith
0.00
0.25
0.50
0.75
1.00
* n.s.(p < 0.0001) (p ≈ 0.95)
O.R. = 3.97 O.R. = 1.02
All dissimilation groups:Generalizing OUT to long-range (word-initial position)?
Test-item type = Long-range (Lvcvcv-Lv)
Pro
port
ion
dish
arm
ony
resp
onse
s ([
r…l]
or [l…
r])
Control S-Diss S-Diss-M-Faith M-Diss M-Diss-S-Faith
0.00
0.25
0.50
0.75
1.00
n.s. n.s. n.s. n.s.(p ≈ 0.48) (p ≈ 0.59) (p ≈ 0.27) (p ≈ 0.17)
O.R. = 1.25 O.R. = 1.19 O.R. = 1.43 O.R. = 1.57
EVIDENCE ENCOUNTERED IN TRAINING DATA
GROUP SHORT-RANGE (cvcvLv-Lv)
MEDIUM-RANGE (cvLvcv-Lv)
Control ∅ ∅
S-Harm harmony ∅
S-Harm-M-Faith harmony non-alternation
M-Harm ∅ harmony
M-Harm-S-Faith non-alternation harmony
S-Diss dissimilation ∅
S-Diss-M-Faith dissimilation non-alternation
M-Diss ∅ dissimilation
M-Diss-S-Faith non-alternation dissimilation
1. Introduc:on Locality rela3ons in consonant harmony Explaining the typological universal
Only two locality types are attested (Rose & Walker 2004; Hansson 2010): • Transvocalic: interaction in …CVC… only (“syllable-adjacent”?) • Unbounded: interaction in relevant …C…C… pairs at any distance
Implicational universal: Interaction at some beyond-transvocalic distance entails interaction in transvocalic contexts (as well as all further distances). For example, strictly beyond-transvocalic harmony is unattested.
Hypothesis 1: All nonadjacent dependencies originate historically in transvocalic contexts. The unattested locality patterns are synchronically possible (and learnable) in principle, but diachronically inaccessible.
Hypothesis 2: The unattested patterns are synchronically disfavoured or impossible; an inductive bias restricts the hypothesis space available to learners (and/or the heuristics for navigating this space).
Ar3ficial language learning Dissimila3on vs. harmony Finley (2011, 2012), using poverty-of-stimulus paradigm:
Adult English subjects exposed to sibilant harmony suffix alternation in medium-range cvCvcv-Cv contexts generalize this to unseen shorter-range (transvocalic) cvcvCv-Cv and longer-range Cvcvcv-Cv contexts.
Replicated with different design (see §2 below) for sibilant harmony and liquid harmony (McMullin & Hansson in press; this poster)
Bennett (2013): Dissimilation = avoidance of (similarity-driven) surface correspondence relation. Predicts typological mismatches for consonant harmony vs. dissimilation along various dimensions • Strictly beyond-transvocalic (rather, “beyond-syllable-adjacent”)
dependency should be possible for dissimilation, but not assimilation • Empirical support for this hypothesis is rather weak (Sundanese?)
Rich-‐s3mulus vs. poor-‐s3mulus training We extend this line of investigation along two dimensions:
Ø Learning of nonadjacent consonant dissimilation alternations Ø Training on “rich-stimulus” learning data: overt evidence of
absence of interaction at certain distances
Including evidence of non-interaction allows the training data to instantiate locality patterns that are unattested (and impossible?) • Do learners coerce such patterns into their formally simpler, attested
counterparts? (cf. Lai 2012, White 2014)
Biased Learning of Long-‐Distance Assimila:on and Dissimila:on Gunnar Ólafur Hansson and Kevin McMullin
University of Bri3sh Columbia
Short-range (cvcvLv stems)
e.g. pokuri
Medium-range (cvLvcv stems)
e.g. giluko Harmony pokuli-li…pokuri-ru giluko-li…giruko-ru Dissimilation pokuri-li…pokuli-ru giruko-li…giluko-ru Non-alternation pokuri-li…pokuri-ru giluko-li…giluko-ru No liquids tikemu…tikemu-li…tikemu-ru