LATERALIZATION OF
PHONOLOGY
DAY 22 – OCT 18, 2013
Brain & Language
LING 4110-4890-5110-7960
NSCI 4110-4891-6110
Harry Howard
Tulane University
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Brain & Language - Harry Howard - Tulane University
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Course organization
• The syllabus, these slides and my recordings are
available at http://www.tulane.edu/~howard/LING4110/.
• If you want to learn more about EEG and neurolinguistics,
you are welcome to participate in my lab. This is also a
good way to get started on an honor's thesis.
• The grades are posted to Blackboard.
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REVIEW
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Hickok & Poeppel’s model on the brain
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Mirror neurons
Example of a F5 mirror
neuron selectively
discharging …
(A) during observation
of a grasping
movement done by
the experimenter
and
(B) during monkey
grasping
movements.
Arrows denote the onset
of the movement.
Six trials are shown for
each condition.
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LATERALIZATION OF
PHONOLOGY
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10/17/11
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Review of prosody
• Prosody is the quality of spoken language that provides its melodic
contour and rhythm, features which help the hearer to decode
syntactic and lexical meaning as well as emotional content.
• Prosody differentiates, say, the neutral statement of fact “It’s my fault”
from the sarcastic question-like rejoinder “It’s MY fault?”.
• Such distinctions are produced by variation in three parameters,
which are borne in turn by three qualities of sound waves,
respectively:
sound waves
prosody
fundamental frequency
pitch
intensity
stress
timing
duration
As a first approximation, we can say that the RH is sensitive to
pitch/fundamental frequency, while the LH is sensitive to higher
Brain & Language - Harry Howard - Tulane
frequencies, e.g. formants.
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University
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Prosody and the RH
• It has been known since the 1970s that the right hemisphere
dominates in the perception of prosody. Initial evidence thereof were
the descriptions of lesions in the right hemisphere resulting in a
pattern of aprosodias (deficits either in the expression or
understanding of prosody) analogous to the well-documented pattern
of left hemisphere lesions resulting in the various aphasias.
• With respect to production, the speech of patients with right
hemisphere lesions has been characterized as monotonous and
unmodulated. For instance, Ross & Mesulam (1979) report a patient
who had difficulty disciplining her children because they could not
detect when she was upset or angry. She eventually learned to
emphasize her speech by adding "I mean it!" to the end of her
sentences.
• With respect to perception, studies such as that of Tucker, Watson &
Heilman (1977) asked people to identify semantically-neutral
sentences that were intoned to convey happiness, sadness, anger, or
indifference. Patients with RHD were impaired on both identification
and discrimination of such affective meanings, in comparison to both
healthy controls (NBD) and LHD.
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Names for RH prosodic impairments
• Auditory affective agnosia (Heilman, Scholes & Watson
1975)
• Aprosodia (Monrad-Krohn 1947, Ross 1981, 1993)
• Dysprosody (Monrad-Krohn 1947, etc. p. 77)
• ‘Prosodic impairments’
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Research on RH prosodic impairments
• Assumptions that have guided research
• RH prosodic deficits occur with intact sensorimotor & linguistic
processes.
• Emotional prosody is more affected than linguistic prosody.
• RHD patients have problems in interpreting emotional material
in other domains, such as facial expression and stories and
scenes.
• Prosodic comprehension deficits were thought to be unique to
RHD.
• Drawbacks
• Subjects selected on
basis of unilateral hemispheric damage
and not prosodic deficits > subjects may or may not have
prosodic deficits
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Emotional prosodic deficits with RHD
• Perception
• Impaired in discriminating emotions conveyed by a single hummed
vowel.
• Impaired in discriminating emotions after filtering to remove semantic
content.
• Comprehension
• Reduced ability to discriminate and identify mood in neutral sentences
presented without supporting context on the basis of prosodic contour.
• Reduced ability to identify mood in sentences in which the meaning is
incongruent with prosodic contour.
• Production
• “… a flattened, monotone pattern that is characterized by attenuated
variation in stress, duration, and fundamental frequency.” (Duffy 1995)
• Problems in matching prosodic contour to emotional content.
• Reduced reliance on pitch variation to convey emotions.
• Increased reliance on semantic information to convey emotions.
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Hypotheses about emotional prosodic
deficits
• Similarity to depression
• result of alterations in subjective emotional experience;
• but coming out of depression does not cure prosodic deficit.
• General disturbance in encoding emotional behavior
• co-occurs with reduced expressiveness of gestures and facial
expressions.
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Kinds of linguistic prosody
• Lexical and phrasal prosody, see next 2 slides.
• Sentence type and prosodic contour.
• Contrastive (or emphatic or focal) stress.
• Determining whether two sentences are identical based
on any of these stress patterns.
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Lexical prosody (CAPS mark stressed syllable)
• Noun vs. verb in English (±15)
• CONvert
vs. conVERT
• Thai, a tone language
• naa with a rising pitch tone means “thick”
• naa with a falling pitch tone means “face”
LHD (but not RHD) affects both of
these rules
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Phrasal prosody
• Compound noun rule
• noun phrase:
• adjective+noun:
hot DOG (a dog that is hot)
HOTdog (a frankfurter)
• noun+noun:
SHEEPdog (a breed of dogs)
• Stress retraction
• After eating fourTEEN, CAKES did not tempt him.
• After eating FOURteen CAKES, he threw up.
LHD (but not RHD) affects both of these rules
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Contrastive (or emphatic or focal) stress
[clausal prosody]
• Examples
• The horses were racing from the BARN.
• The HORSES were racing from the barn.
LHD (but not RHD) affects this
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Sentence type and prosodic contour
• Types
•
declarative: fall in pitch at end
•
•
I eat chocolate.
interrogative: rise for yes-no question (a); fall for interrogative
pronoun (b)
a) Do you eat chocolate?
b) What do you eat?
•
imperative: even pitch throughout; rise in intensity at end
•
Eat chocolate!
 RHD (but not LHD) reduces accuracy and
variation in pitch
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Summary
LH (preserved in RHD)
• lexical stress
• CONvert ~ conVERT
• tone languages
• phrasal stress
• noun compounding
• stress retraction
• clausal stress
• contrastive stress
RH (preserved in LHD)
• emotional prosody
• sentence type
• declarative, interrogative,
imperative
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NEXT TIME
Q6
Theories of lateralization
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