1. Brain response to Intonational Phrase structure
is purely prosody-driven
Barbara Leone-Fernandez1, Rita Jerónimo2, Shuang Lu3, Susana Correia1,
Marina Vigário1, Kai Alter4 & Sónia Frota1
1Universidade de Lisboa, 2ISCTE-IUL/CIS, Lisboa,
3Renmin University of China, 4Newcastle University/University of Oxford

2. Introduction
Phrase-level prosody plays a crucial role in language processing
Lexical access (e.g., Christophe et al. 2004)
Syntactic ambiguity resolution (e.g., Millotte et al., 2007; Speer et al., 2011)
Artificial grammar learning (e.g., Langus et al., 2012)
It also plays a fundamental role in language development
Prosodic bootstrapping approach (e.g., Jusczyk 1997; Christophe et al., 2008; Hohle 2009)
Prosodic boundaries used to constrain lexical segmentation and guide syntactic parsing, especially Intonational Phrase boundaries (IPB)

3. Introduction
Intonational phrase boundaries (IPB) cue speech chunks, which typically coincide with major syntactic boundaries (e.g. sentence, clause, topic, parenthetical)
Cues to IPB, and their weighting, may vary across languages (Seidl 2007, Wellmann et al. 2012)
Pitch change (rise, fall, reset)
Pre-boundary lengthening
Pause
Although there is no one-to-one correspondence
From Frota (2014: 13)
Fig.1. [the students]IP [as far as we know]IP [have got good marks]IP

4. Introduction Syntax-prosody mapping Major syntactic boundaries
From Frota (2014: 18)
Syntax-prosody mapping
Major syntactic boundaries
Phonology (length, weight, balance…)
IPB
Set of acoustic cues
Fig.2. [the Brazilian girl’s megalomaniac boyfriend]IP [V OBJ]IP
IPBs tend to coincide with
From Frota (2014: 13)
Fig.1. [the students]IP [as far as we know]IP [have got good marks]IP

5. Introduction
Event-related brain potentials (ERPs) are a useful tool for the on-line examination of auditory sentence processing
And thus to investigate the processing of Prosodic Boundaries
Fig.3. From

6. Introduction
Event-related brain potentials (ERPs) are a useful tool for the on-line examination of auditory sentence processing
And thus to investigate the processing of Prosodic Boundaries
The Closure Positive Shift (CPS) is the ERP component that indexes the perception of IPB (Steinhauer et al. 1999, Pannekamp et al. 2005; Boegels et al., 2011, for a review)
Fig.4

7. Introduction
The nature of the CPS has been under debate (in adult and developmental studies)
It is triggered by prosodic information only, given that it is found in utterances with reduced semantic, syntactic and phonemic content (jabberwocky, hummed – Pannekamp et al. 2005) > Reflects the processing of the prosodic form
It is driven by IPBs that reflect syntactic boundaries, since an adult-like effect (no pause) depends on children’s syntactic abilities > Indicates the processing of prosodic and syntactic information (Mannel & Friederici, 2011; Mannel et al., 2013)
Cross-linguistic differences in IPB cues. The CPS is not (just) a response to the pause cue, at least for adults (Steinhauer et al., 1999; Mannel & Friederici, 2009) > Argues against the interpretation that it simply reflects sentence continuation after speech silence

8. Introduction
The nature of the CPS has been under debate (in adult and developmental studies)
Very few studies have addressed the arguably purely prosodic nature of the CPS
In particular in the absence of the pause cue
Considering the contribution of the nuclear contour (the melody on the most prominent word, typically the last prosodic word before the boundary) and of the pre-boundary lengthening cues
Despite the fact that it remains unclear which aspects are necessary to elicit a CPS

9. Present study
Investigates the CPS as a marker of IPB perception in European Portuguese (EP)
Relevant prosodic features of EP > IPB especially prominent:
sparse pitch accent distribution (most IP-internal prosodic words unaccented)
pitch movements mostly confined to IP edges
– last stressed syllable of the IP bears the nuclear pitch accent
– boundary syllable bears the boundary tone
pre-boundary lengthening only at the IP edge (from the last stressed syllable)
IPB especially prominent in EP prosodic phrasing
Frota (2000, 2014)

10. Goals Directly address the debate on the nature of the CPS
Pause
Syntax
Goals
Prosody
Directly address the debate on the nature of the CPS
Using delexicalized stimuli with no syntactic (and semantic) information
Using stimuli without the pause cue
Varying the position of the nuclear syllable with respect to the boundary
If the CPS is prosody-driven in EP
The elicitation of a CPS in response to an IPB in delexicalized utterances
The CPS response modulated by the distribution of prosodic boundary cues: A more pronounced (and later) CPS response when the nuclear syllable and the boundary syllable overlap, than when the nuclear syllable precedes the boundary syllable

11. Method Participants Stimuli and Experimental design
Twenty-four healthy, right-handed, native EP speakers (17 women, age range: years, mean age: 27 years)
Stimuli and Experimental design
Nine pairs of SVO sentences naturally produced by a native EP speaker:
[SVO] – no IPB / [S]IP [VO] – with IPB
All CV syllables in each sentence replaced by /ba/, /na/, /mi/, /ti/, /pu/, /lu/ using MBROLA manipulations (occasional codas replaced by /S/)
54 (9x6) sentences with IPB (WB); 54 with no IPB (NB)
The manipulation removed all the semantic/syntactic information, but preserved all the prosodic information of the original sentences. IPB location not triggered by syntax (Elordieta et al. 2005)

12. Method
Nuclear syllable penultimate or final in the IP (penult or final stress)
NO BOUNDARY (NB)
/na/
WITH BOUNDARY (WB)
Fig.5
Fig.6
[A nananana nana na nana] (NB, penult)
A rapariga brinca na sala ‘The girl plays in the room’
[Asna nanana nana na nana] (NB, final)
Este cangurú brinca na sala ‘This kangaroo plays in the room’
[A nananana]IP nana na nana (WB, penult)
A rapariga brinca na sala ‘The girl plays in the room’
[Asna nanana]IP nana na nana (WB, final)
Este cangurú brinca na sala ‘This kangaroo plays in the room’

13. Main acoustic cues for the IPB
Method
Table 1. Acoustic analysis: Pitch range (Hz) and duration (ms) for the target syllable in the NB and WB conditions
Pitch range Duration
Nuclear contour Pre-boundary
(Boundary tone) lengthening
Main acoustic cues for the IPB

14. Method
Procedure
Experiment lasted ∼20min: 108 sound stimuli delivered aurally in pseudo-randomized order with an inter-stimulus-interval of 2000ms. E-Prime was used.
Stimuli were presented in 3 blocks. Block sequence was randomized.
Participants were instructed to avoid eye blinking and other body movements during stimulus presentation
To minimize eye movements, an eye image was displayed in the center of a monitor before each sentence onset

15. Method EEG recordings and analysis
30 cap-mounted active Ag/AgCl electrodes (Neuroscan)
500Hz, LF0.05Hz, HF40Hz, Notch50Hz
ANOVAs: IPB (NB, WB), ML (Fz, FCz, Cz, CPz, Pz)
time-window ms
ML (5) IPB (NB,WB)
AP (2) x Hem (2) x IPB (NB,WB)
ANOVAs: IPB and Nuclear syllable
time-window ms time-window ms
Penultimate syllable: ML (5) IPB (NB,WB) Final syllable: ML (5) x IPB (NB,WB)
Penultimate syllable: AP (2) x Hem (2) x IPB (NB,WB) Final syllable: AP (2) x Hem (2) x IPB (NB,WB)
ANOVAs for the midline electrodes were performed considering the two conditions (NB and WB) and electrodes (Fz, FCz, Cz, CPz, Pz) as factors. Further analyses included the lateral sites with Hemisphere (left, right) and location (anterior, posterior) as factors.

16. Results
With R, t-contrasts from onset to the end (.05)
(around 450ms from the boundary=end of boundary syllable)
Figure 7.
Visual inspection of the average ERP responses revealed a positive shift that peaks between 1250 and 1500ms from sentence onset

17. Results
Table 2. ANOVAS for mean amplitudes in the TW from sentence onset
A significant main effect of condition over all scalp, but more centrally distributed.
Both distribution and latency relative to IPB in line with previously described CPS responses.

18. Results IPB and Nuclear syllable
Penultimate syllable, i.e. no overlap with boundary syllable (‘rapariga’)
Final syllable, i.e. overlap with boundary syllable (‘canguru’) NB NB WB WB
CPS
( ms
from the onset)
CPS
( ms
from the onset)
IPB x AP: F(4,92)=5.51, p<0.01, ɳ2=0.19
IPB: F(1,23)=10.34, p<0.01, ɳ2=0.31
CPS response was stronger and later when nuclear syllable and boundary syllable overlapped, than when the nuclear syllable preceded the boundary syllable

19. Discussion
We addressed the debate of whether the CPS is, or not, purely prosody- driven
Using delexicalized stimuli with no syntactic (and semantic) information, obtained from natural EP sentences where IPB location is not triggered by syntax
IBP cues: No pause. Pitch (nuclear contour) and duration (pre-boundary lengthening)
Varying cue distribution: spread (nuclear boundary syllables); overlap (nuclear=boundary)

20. Discussion
We addressed the debate of whether the CPS is, or not, purely prosody- driven
A CPS was identified in response to the IPB
The CPS response was modulated by the distribution of prosodic boundary cues
Our findings demonstrate that brain responses to IPB are prosody-driven
Implications for prosodic bootstrapping accounts in language acquisition: prosody-first view, with prosodic bootstrapping of syntactic boundaries (e.g., Morgan & Demuth, 1996; Seidl & Cristia, 2008; Wellmann et al., 2012)
Not pause, not syntax

21. Obrigada!
Thank you!
Thanks to all the participants, and to Simão Cortês, Ana Chainho and Ana Alexandra Malho for their help with data collection
Funding: FCT – Portugal, EXCL/MHC-LIN/0688/2012

22. References
Christophe, A., Peperkamp, S., Pallier, C., Block, E., & Mehler, J. (2004). Phonological Phrase boundaries constrain lexical access I. Adult data. Journal of Memory and Language, 51, 523–547
Frota (2014). The intonational phonology of European Portuguese. In Jun (ed.) Prosodic Typology II. Oxford: OUP. 6-42
Höhle (2009). Bootstrapping mechanisms in first language acquisition. Linguistics, 47(2):
Langus A., Marchetto, E., Bion, H. R. A., & Nespor, M., (2012). Can prosody be used to discover hierarchical structure in continuous speech? Journal of Memory and Language, 66: 285–306
Männel, C., Schipke S. C., & Friederici, A. D., (2013). The role of pause as a prosodic boundary marker: Language ERP studies in German 3- and 6-year-olds. Developmental Cognitive Neuroscience, 5: 86-94
Pannekamp, A., Toepel, U., Alter, K., Hahne, A., & Friederici, A. D., (2005). Prosody-driven sentence processing: an event-related brain potential study. Journal of Cognitive Neuroscience, 17(3): 1-15
Männel & Friederici, (2011). Intonational Phrase structure processing at different stages of syntactic acquisition. Developmental Science 14(4):
Steinhauer, K., Alter, K., & Friederici, A. D., (1999). Brain potentials indicate immediate use of prosodic cues in natural speech processing. Nature Neuroscience 2:
Wellmann, C., Holzgrefe, J., Truckenbrodt., H., Wartenburger, I., & Höhle, B., (2012). How each prosodic boundary cue matters: evidence from German infants. Frontiers in psychology, 3
Bӧgels, S., Schriefers, H., Vonk, W., & Chwilla, D., J. (2011). Prosodic Breaks in Sentence Processing Investigated by Event-Related Potentials. Language and Linguistics Compass 5/7, : 424–440, /j x x

23. Experimental Design Puniltimate Stress Syllable Original sentence:
A rapariga brinca na sala
Replaced sounds :
(ba): A babababa baba ba baba
(lu): U lulululu lulu lu lulu
(mi): I mimimimi mimi mi mimi
(na): A nananana nana na nana
(pu): U pupupupu pupu pu pupu
(ti): I titititi titi ti titi
Ultimate Stress Syllable
Original Sentences
Este canguru brinca na sala
Replaced sounds :
(ba): Ashba bababa baba ba baba
(lu): Ushlu lululu lulu lu lulu
(mi): Ishmi mimimi mimi mi mimi
(na): Ashna nanana nana na nana
(pu): Ushpu pupupu pupu pu pupu
(ti): Ishti tititi titi ti titi

24. Method
Nuclear syllable penultimate or final in the IP (penult or final stress)
NO BOUNDARY (NB)
/na/
WITH BOUNDARY (WB)

25. Results
Table 3. ANOVAS for mean amplitudes by nuclear syllable position, from sentence onset
Penultimate syllable
ms time window
ANOVA
HEMxDMLxAPxIPB
Amp (μV, mean)
F and p values
Main effect of IPB
F(1,23)=2.25, p=.14
Interaction IPBxAP
Frontal: NB, WB
NB=0.48, WB=0.94
F(4,92)=5.51, p<.05
t(23)=-2.89, p hocb .<.05
Final syllable
ms time window
ANOVA
HEMxDMLxAPxIPB
Amp (μV, mean)
F and p values
Main effect of IPB
Mean values NB, WB
NB=0.04, WB=1.02
F(1,23)= , p<.001
Interaction IPBxAP
F(4,92)=2.91, p=.07
Posthoc – hochberg correction

27. IPB
CPS_R NS BS
stress

28. IPB
CPS_R
NS=BS
stress