Preterm birth has a negative effect on the dorsal and ventral streams, and other white matter pathways. Damage to these microstructures affects language comprehension, visual cognition, visuospatial working memory, and visually-guided actions. Prematurity may also affect speech production, the ability to understand words, and auditory-motor integration.

1. Prematurity
Affects the
Integrity of the
Dorsal and
Ventral Streams
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1
(Blaikie, 2007)

2. Dorsal and Ventral Streams
Play Important Roles in Language Comprehension
• The dorsal path is believed to subserve
auditory-motor integration.
• Medial temporal lobe (MT/V5) major
projection travels through the posterior
cingulate and retrosplenial (BA 29) area.
• The ventral path is more involved in the
semantic and syntactic aspects of language
comprehension.
(Hickok and Poeppel, 2007; Friederici, 2012 in Northam, et al., 2012; Pesi, 2012)
2ozella.brundidge@gmail.com 4/8/2017

3. In their study of visual and visuocognitive
development (of preterms at birth and at 6-7
years of age), Atkinson and Braddick (2007)
identified developmental vulnerability in the
dorsal stream in children born very
premature (<32 weeks gestation).
Visual Event-Related Potential Technology Revealed a Relationship
between Prematurity and Dorsal Stream VulnerabilityVisual Event-Related Potential Technology Revealed a Relationship
between Prematurity and Dorsal Stream Vulnerability
(Creative Commons Attributions, 4.0, 2015)
(Atkinson & Braddick, 2007)
3ozella.brundidge@gmail.com 4/8/2017

4. Ventral and Dorsal Streams
are the Two Major Pathways of
the Brain
anterior
temporal target (area TE)
4
(Kravitz, Saleem, Baker, & Mishkin, 2011)
Visual Areas (V1, V2, V4)
Anterior temporal target (area TE)
Posterior inferior temporal cortex (TEO)
Posterior cingulate cortex (PCC)
Retrosplenial cortex (RSC)
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5. Dutton’s @2003) Diagrame of Dorsal and ventral stream within Infants brain
5
Dutton, 2003 in Ortibus, De Cock, Lieven, & Lagae, 2011
Cortical Area Function
Frontal/
Cognitive
Executive planning unit Abstract
Frontal/
Somatosensory
Fast eye movement -
Frontal/
Motor
Motor cortex –
arms & legs
Movement
Parietal/
Cognitive
Motion and attention Planning
unit
Spatial/
Visual
Motion Detect
movement
Occipital/
Visual
Lower image Image
processing
Temporal/
Cognitive
Image, words, shapes Store, routes
faces
Frontal
Temporal
Parietal
Occipital
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6. The Dorsal Stream has Anatomic and Functionally
Distinct Pathways that Originate in the Occipital Striate Cortex
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(Kravitz, Saleem, Baker, & Mishkin, 2011)
Parieto-Prefrontal
Pathway
Spatial Working
Memory
Parieto-Premotor
Pathway
Visually-Guided
Actions
Targets the Premotor Cortex
Parieto-Medial
Temporal Pathway
Navigation
Targets the Medial Temporal Lobe –
Directly (and through the Posterior
Cingulate and Retrosplenial Areas)
SupportsSupportsSupports
Targets the Parietal Lobe
distinct pathways emanate from the
posterior parietal cortex
(2011, Fig. 1c)
V1=Striate Cortex
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7. Neurocognitive Working Model of Cerebral Visual Perception
• Visual stimuli arrives in the occipital striate cortex, which
is the primary visual processing area (V1). Lower level
cognitive visual processing occurs here.
• V1 directs visual stimuli to bundles of white matter axon
fibers to the
Inferior temporal lobe – the Ventral “What” stream
Posterior parietal lobule – the Dorsal “How” stream
(Schmolesky, 2007)
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8. Visual Processing Pathways: Ventral-Recognition vs. Dorsal-Action
(BA 17)
(BA 18)
(BA 19)
(MT/V5)
(Dubuck, 2002; Lloyd, 2007)
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9. The Cortical Organization of Lexical/Word Knowledge along the
Ventral and Dorsal Streams
(Gow, 2012)
Ventral Lexicon
(Hearing Vocabulary)
Dorsal Lexicon
(Speaking Vocabulary)
Inferior Parietal Region
including the
Supramarginal gyrus
Serves as an interface between
phonetic and articulatory
representations
Posterior Superior Temporal Sulcus
and the
Middle Temporal Gyrus
A Dual Lexicon Model of Spoken Language Processing
Serves as an interface
between phonetic and
semantic representations
There are four temporal phonological clusters which courses along the superior temporal sulcus, from the most
anterior part of auditory center, through the planum temporale, the middle part of the auditory center, and then
up to the supramarginal gyrus – This “auditory-motor loop” (Vigneau, et al., 2006) joins the dorsal route.
9ozella.brundidge@gmail.com 4/8/2017

10. Wernicke’s Area Dual Stream Model is Closely Associated with
Auditory Processing
10
Auditory Ventral Stream Auditory Dorsal Stream
two cortical modules
auditory word-form area
in the
an ‘‘inner speech area’’
in the
• Associated with Phonological reading and
inner speech functions
• Regulation of speech production
• Optimized for sensorimotor integration
• Spatial processing
• Vocal repetition
• Monitoring of self-produced speech and the
correction of speech motor programs
• Optimized for object (or pattern)
recognition
• Closely associated with auditory
comprehension
DeWitt & Rauschecker, 2013; Hickok & Poeppel, 2007 in
2013; Rauschecker & Scott, 2009 in 2013; Wise et al., 2001
in 2013; (Kümmerer, et al., 2013) ozella.brundidge@gmail.com 4/8/2017

11. Heschl’s
Gyrus
BA 41
Brodmann
Area 42
(Dehaene, et al., 2010; Frey & Fisher, 2010; Robson, Matthew, & Ralph, 2005; Upadhyay, et al., 2008 in Friederici, et al., 2009; Baron, n.d.)
Wernicke’s
Area
BA 22
Auditory Center
Sensory Auditory Perception and Processing
White matter connective tissue provides pathways which link auditory information to the Wernicke’s areas across the
left superior temporal gyrus.
Auditory Center
Meaningful
Strings
Auditory
discrimination
Acoustic
changes
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12. Wernicke’s Area and the Ventral Stream’s Complimentary Role in
Language Comprehension
Fibers within the ventral stream appear
to collect semantically and syntactically
processed linguistic information from
the Wernicke’s area (posterior STG)
and surrounding temporal lobe areas
transporting neurotransmitters
(information carriers) to the frontal lobe.
(Hickok and Poeppel, 2007; Friederici, 2012 in Northam, et al., 2012)
(Pesi, 2012)
Wernicke’s area
Posterior
Middle
Temporal
Gyrus
12
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13. (Hickok and Poeppel, 2007; Friederici, 2012 in Northam, et al., 2012; Pesi, August 11, 2012)
Fibers of the Dorsal Stream Involved with Speech Production
13
The Dorsal Stream is
believed to Subscribe
Auditory-Motor Integration

14. The Dorsal Pathway for Language: A Composite of the Middle Longitudinal
Fasciculus and the Superior Longitudinal/Arcuate Fasciculi System
Saur and colleagues’ (2008) speech repetition and auditory sentence
comprehension imaging study revealed the structural pathway of the language
system.
• White matter fibers from the middle temporal lobe’s middle longitudinal
fasciculus are connected to the auditory center.
• The auditory center and the posterior superior temporal gyrus (Wernicke’s area)
fiber bundles course together, via the dorsal route along the arcuate/superior
longitudinal fasciculi system.
• The bundle arches around the caudal end of the Sylvan language fissure.
• From there the bundle of fibers course through white matter fibers in the parietal
lobe, making their final connections at the frontal lobe’s premotor BA 6 region –
both the frontal operculum and dorsal premotor areas.
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(Saur, et al., 2008) ozella.brundidge@gmail.com 4/8/2017

15. Intra-Hemispheric Language Pathways
15
(Ventral Pathway) (Dorsal Pathway)
Connection between
anterior temporal lobe
and inferior frontal lobe
Connection between
superior temporal lobe and
premotor cortical areas
Figure 1. Language-relevant white matter pathways and regions of vulnerability in the preterm brain –
Structural MRI and diffusion-tractography analyses of intra-hemispheric tracts image (Northam, et al., 2012).
Language impairment was
not related to abnormalities
of the AF or its sub-segments
Uncinate Fasciculus/
Extreme Capsule
Language impairment was
associated with volume
reductions bilaterally in the
ventral language pathway
(p. 3783)
(AF)
Arcuate Fasciculus
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16. Dorsal & Ventral Streams Communication Networks
Relationship between Auditory Discrimination, Sound-Meaning, and Articulation
Fig. 1. (A) Hickok and Poeppel’s (2000) framework for functional anatomy of language includes
interaction between both ventral and dorsal streams (2000 in Hickok & Poeppel, 2004).
STG
(bilaterally,
asymmetric)
pMTG/pITG
p. Sylvian fissure @
Parietal–Temporal
boundary
p. Inferior Frontal
Gyrus (BA 44) &
dorsal Premotor
area
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17. Left Inferior Temporal Gyrus
Name Visual
Objects
Ventral
Pathway
Primary Visual and
Secondary Visual areas
(V1/V2)
Inferior Temporal Gyrus
Object Recognition
White matter
track leading from
to
Visual
Reading
Semantic Language
Pathway
Second white
matter track
Left
Middle and Inferior
Temporal Gyri
Parieto-Temporal
Junction
(Saur, Kreher, Schnell, Kummerer, Kellmeyer, Vry, Umarova, et
al., 2008; Weems & Reggie, 2006)
Sound-to-Meaning
Interface
MTG/ITG Ventral Stream
Serves as a
Widely Distributed
Conceptual
Representations
by Mapping Sound-Based
Representations of Speech
to
along the
(2008)
17
ITG
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18. Integration of Verbal Information along the Superior Temporal Gyrus
An antero-posterior flux of
processing starts by a
phonological analysis and
travels posteriorly in the STG
to the planum temporale
Next, the stimulus is processed
in the semantic area dedicated to
auditory processing (pSTG) to
be converted in an amoral
format
Information enters into
syntactic analysis in the
posterior STS
Then, conceptual
analysis is performed
within the angular gyrus
(Vigneau, et al., 2006; DeWitt & Rauschecker, 2013)
Phonological Processing in aSTG
Semantic Processing in pSTG
Syntactic Processing in pSTG
Conceptual Analysis in AG
18
The “auditory” ventral
and “inner speech”
dorsal streams of the
Wernicke’s area are in
the posterior STG.
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19. Higher Cognitive Vision Recruit
Visual Areas outside the Primary Visual Cortex (V1)
• Lateral geniculate nucleus (LGN) is located in
the Thalamus and connected to the visual cortex
• Medial Temporal Gyrus/V5 (MT/V5) area
perceives motion.
• Information in ventral stream travels through the
inferior temporal cortex (BA 20) and MTG
• V2, V3, V4, and MT/V5 are extrastriate tissue
located in the visual association areas, where
higher order learning occurs
Lower level visual processing occurs in V1
(Fulton, 2013; Lloyd, 2007; Ball, et al., 2012)
19ozella.brundidge@gmail.com 4/8/2017

20. Graphophonological
Route
Lexicosemantic
Route
(Jobard, Crivello, & Tzourio-Mazoyer, 2003)
Auditory Center
BA 41 & 42
Broca’s
Opercularis
(BA 44) part
of the IFG
STG
Region -
Wernicke’s
(BA 22)
Supramarginal
gyrus
(BA 40)
IFG Inferior frontal gyrus
STG Superior temporal gyrus
MTG Middle Temporal gyrus
ITG Inferior temporal gyrus
BA Brodmann area
Left Lateral
Language Structures
Arcuate
Fasciculus
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21. Graphophonological
Route
Lexicosemantic
Route
Coactivation of
Secondary Structures
Visual
Word
Form Area
(VWFA)
Basal ITG
(BA 20)
Posterior MTG
(BA 21)
(Jobard, Crivello, & Tzourio-Mazoyer, 2003)
Semantic
Areas
Broca’s
Triangular part of
IFG (BA 45)
Ventral Stream
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IFG Inferior frontal gyrus
STG Superior temporal gyrus
MTG Middle Temporal gyrus
ITG Inferior temporal gyrus
BA Brodmann area

22. Fractional Anisotropy (FA) is a Measure of Fiber Track Organization
22
• FA values indicate the degree to which water diffusion is restricted along
one axis relative to all the others, revealing white matter organizational
structure.
• FA is a measure of
- axonal integrity and microstructural connectivity
- the degree of elongation of the diffusion tensor
• Perpendicular diffusivity (λꞱ) and parallel diffusivity (λǁ) are estimated
by fitting the diffusion measurements of each voxel to the diffusion tensor
model.
(Constable, Ment, Vohr, Kesler, Fulbright, Lacadie, Delancy, et al., 2008; Vestergaard, et al., 2011; Basser, Mattiello, &
LeBihan, 1994 in 2011; Beaulieu, 2002 in 2011; Lubsen, et al., 2011)
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23. Diffusion Tensor Imaging (DTI) studies revealed
Widespread Decrease in Fractional Anisotropy (FA)
Values and Microstructural Differences in White
Matter Tract Organization in Premature Children.
(Lubsen, et al., 2011; Constable, Ment, Vohr, Kesler, Fulbright, Lacadie, Delancy, et al., 2008, Figure 4)
23
Increased connectivity between
the left Wernicke’s area and the
supramarginal gyri bilaterally
during a semantic language task
16 year old preterms (32
weeks gestational age
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24. Beginning at 40 weeks Gestational Age Significant
Right-Hemispheric Structural Changes occur in Language Areas
Using voxel-based DTI, Aeby and
colleagues (2012) found that the
right temporal sulcus and the
right occipitotemporal gyrus
experience major maturation and
structural changes beginning at 40
weeks gestational age.
(Aeby, Van Bogaert, David, Balériaux, & De Tiège, 2012) 24ozella.brundidge@gmail.com 4/8/2017

25. Reduced Activation in the Right Arcuate Fasciculus (AF) in
Language Impaired Preterm Adolescents
A comparison of language impaired versus
unimpaired preterm groups showed a
significant reduction of the right direct
arcuate fasciculus in the language impaired
group [(9.29 cm3(1.9) verses unimpaired
group 10.82 cm3 (2.3)], along with a trend
for reduction in the [9.6 cm3 (2.9) verses
11.1 cm3 (2.6) in the left hemisphere.
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(Northam, Liegeois, Tournier, Croft, Johns, Chong, Wyatt, et al., 2012)
Tsang, et al., 2009
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26. End of
Prematurity Effects
the Integrity of the
Dorsal and Ventral
Streams
26
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