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Motion processing in MT+ and structural connectivity in SPEM and MT+ [Elektronische Ressource] / vorgelegt von Qing Mao

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73 pages
Universitätsklinik, Radiologische Klinik, Medizin Physik an der Albert-Ludwigs-Universität Freiburg im Breisgau Motion Processing in MT+ and Structural Connectivity in SPEM and MT+ INAUGURAL-DISSERTATION zur Erlangung des Medizinischen Doktorgrades der Medizinischen Fakultät der Albert-Ludwigs-Universität Freiburg i.Br. Vorgelegt 2010 von Qing Mao geboren in Henan, China Dekan Prof. Dr. Dr. Hubert Erich Blum 1. Gutachter Prof. Dr. Jürgen Hennig 2. Gutachter Prof. Dr. Irina Mader Jahr der Promotion 2010 Acknowledgements This thesis would not have been possible without the assistance of many people whose contributions I gratefully acknowledge. My deepest gratitude is to my advisor, Prof. Dr. Jürgen Hennig for the encouragement, guidance and support of this thesis. I am also very grateful to I am especially grateful to Dr. Sabine Ohlendorf (Freiburg/Münich) for making this thesis possible and for her generous guidance and support, I learned very much from her! I am grateful to my colleagues Dr. Pierre Leven, Dr.Kuanjin Lee, Dr. Thomas Lange, Dr. Hsulei Lee, Benjamin Zahneisen Thimo Grotz and Dr. Daniel Gallichan,for correcting this dissertation, and Dr.
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Universitätsklinik, Radiologische Klinik, Medizin Physik
an der Albert-Ludwigs-Universität Freiburg im Breisgau





Motion Processing in MT+ and Structural Connectivity in
SPEM and MT+


INAUGURAL-DISSERTATION
zur
Erlangung des Medizinischen Doktorgrades
der Medizinischen Fakultät
der Albert-Ludwigs-Universität
Freiburg i.Br.


Vorgelegt 2010
von Qing Mao
geboren in Henan, China
























Dekan Prof. Dr. Dr. Hubert Erich Blum
1. Gutachter Prof. Dr. Jürgen Hennig
2. Gutachter Prof. Dr. Irina Mader
Jahr der Promotion 2010 Acknowledgements

This thesis would not have been possible without the assistance of many
people whose contributions I gratefully acknowledge.
My deepest gratitude is to my advisor, Prof. Dr. Jürgen Hennig for the
encouragement, guidance and support of this thesis. I am also very grateful to
I am especially grateful to Dr. Sabine Ohlendorf (Freiburg/Münich) for making
this thesis possible and for her generous guidance and support, I learned very
much from her!
I am grateful to my colleagues Dr. Pierre Leven, Dr.Kuanjin Lee, Dr. Thomas
Lange, Dr. Hsulei Lee, Benjamin Zahneisen Thimo Grotz and Dr. Daniel
Gallichan,for correcting this dissertation, and Dr. Marco Reisert and Susanne
Schnell for their suggestions and guidance in the fiber tracking study. I also
grateful to Constantin Anastasopoulos who gave me lots of suggestion in fiber
tracking, and I owe a special note of gratitude to my former colleague Rainer
Bögle (Freiburg/Munich) who supported me in many issues such as the
smooth pursuit experiment as well as dissertation corrections, and Kun Zhou
(Freiburg/Beijing) who invested considerable effort in the stimulus program.
Furthermore my special thanks go to Ms Laurence Haller, Prof. Dr. Kurt
Fritzsche in Psychosomatic Medicine und Psychotherapy Department of
Freiburg University Hospital and his wife, Mrs. Geneviève Plasson. They gave
me a lot of care in the past one and half years.
I would like to express my gratitude to all colleagues of the Medical Physics
Department who made it possible to work in a very open and friendly
atmosphere.
I owe my deepest gratitude to my wife and my parents, and the other family
members, this thesis would not have been possible without their persistent
support and encouragement.
And last but not least, I appreciate all subjects in my study, thereby offering
the opportunity to carry out this study.
Abbreviation
BA Brodmann Area
BOLD Blood Oxygen Level Dependency
CBF Cortical Blood Flow
CBV CorticalBlood Volum
EEG Electroencephanlography
EPI Echoplanar Imaging
EOG Electrooculography
FEF Frontal Eye Fields
FST Fundus area of Superior Temporal
FS Fiber Tracking
fMRI functional Magnetic Resonance Imaging
FEW Family Wise Error
GLM General Linear Model
GM Grey Matter
HRF Haemodynamic Response Function
IPL Inferior Parietal Lobule
IPS rietal Sulcus
LGN Lateral Geniculate Nucleus
LIP Lateral Intraparietal area
LOC Lateral Occipital Complex
MNI Montreal Neurological Institute
MR Magnetic Resonance
MST Middle Superior Temporal
MT Middle Temporal
MT+ Middle Temporal Complex
pCG posterior Cingulate Gyrus
PCU Precuneus
PET Positron Emission Tomography
PIP Posterior Intraparietal area
PMd dorsal Premotor Cortex PPC Posterior Parietal Cortex
RF Radio Frequency
ROI Region Of Interest
SC Superior Colliculus
SEF Supplementary Eye Fields
SMA supplementary Motor Area
SnPM Statistical non Parametric Mapping
SPEM Smooth Pursuit Eye Movements
SPL Superior Parietal Lobule
SPM Statistical Parametric Mapping
STS Superior Temooral Sulus
V1 Primary visual area
V2 Visual area2
V3 Visualarea 3
V4 Visual area4
VIP Ventral Intraparietal area
WM White Matter

Chapter 1. General Introduction..................................................................................... 1
1.1 Basic features of MT+ and its subregions ................................................................ 2
1.1.1 MT+ ................................................................................................................... 2
1.1.1.1 MT+ location .............................................................................................. 2
1.1.1.2 MT+ properties ........................................................................................... 2
1.1.2 MT...................................................................................................................... 3
1.1.2.1 MT localization 3
1.1.2.2 MT properties.............................................................................................. 3
1.1.3 MST ................................................................................................................... 4
1.1.3.1 MST localization......................................................................................... 4
1.1.3.2 MST properties 5
1.2 Smooth pursuit eye movements................................................................................ 6
1.2.1 SPEM introduction............................................................................................. 7
1.2.2 Pursuit-related activity recorded other parts of the cortex................................. 7
1.2.3.1 Frontal eye fields (FEF).............................................................................. 8
1.2.3.2 Supplementary eye fields (SEF) ................................................................. 9
1.2.3.3 Posterior parietal cortex (PPC) 10
1.3 Optic flow ............................................................................................................... 11
1.3.1 Optic flow introduction.................................................................................... 11
1.3.2 Optic flow processing in the cortex ................................................................. 11
1.3.3 Optic flow processing in humans..................................................................... 12
1.4 fMRI........................................................................................................................ 13
1.4.1 BOLD introduction .......................................................................................... 14
1.4.2 Approaches to fMRI data analysis................................................................... 15
1.5 Structural connectivity determination by means of DTI based fiber tracking........ 15
1.5.1 Fiber tracking................................................................................................... 16
1.5.2 Combining fiber tracking with fMRI............................................................... 17
1.6 Aim of this study..................................................................................................... 17
Chapter 2: Bold activation response of MT+ subregions to optic flow stimulations at
different locations of the visual field ............................................................................. 18
2. 1 Materials and methods ........................................................................................... 18
12.1.1 Subjects............................................................................................................ 18
2.1.2 Eye movement measurements.......................................................................... 18
2.1.3 MR Imaging..................................................................................................... 19
2.1.4 Visual stimulation ............................................................................................ 20
2.1.4.1Visual stimulation patterns ........................................................................ 20
2.1.5 fMRI methods .................................................................................................. 22
2.1.5.1 fMRI data analysis .................................................................................... 22
2.1.5.2 CARET analysis........................................................................................ 24
2.2 Results..................................................................................................................... 25
2.2.1 Eye Movement results...................................................................................... 25
2.2.2 fMRI results ..................................................................................................... 25
2.2.2.1 BOLD activation response to optic flow at different locations of the visual
field ....................................................................................................................... 25
2.2.2.2 Activations resulting from optic flow stimulation at different locations.. 26
2.2.2.3 Spatial relationship of cortical area........................................................... 28
2.3 Discussion............................................................................................................... 31
2.3.1 Upper and lower visual fields stimulation ....................................................... 33
2.3.2 Vertical and horizontal visual fields stimulation ............................................. 34
2.3.3 Peripheral and central visual field stimulation................................................. 34
Chapter 3: Regions of cortical response to SPEM and motion, and the possible
structural connectivity in SPEM and motion sensitive cortex.................................... 36
3.1 Materials and methods ............................................................................................ 36
3.1.1 Subjects............................................................................................................ 36
3.1.2 Eye movement measurements.......................................................................... 36
3.1.3 MR Imaging..................................................................................................... 37
3.1.3.1 MR Imaging of SPEM .............................................................................. 38
3.1.3.2 MR Imaging of visual motion processing in MT+ ................................... 38
3.1.3.3 MR Diffusion Tensor Imaging.................................................................. 39
3.1.4 Visual Stimulation ........................................................................................... 39
3.1.4.1 Visual stimulation of SPEM ..................................................................... 40
3.1.4.2 Visual motion stimulation of MT+ ........................................................... 40
23.1.5 fMRI data analysis ........................................................................................... 41
3.1.6 Possible structural connectivity revealed by fiber tracking ............................. 42
3.1.6.1 Definition of ROIs seed ............................................................................ 42
3.1.6.2 Analysis of possible structural connectivity by fiber tracking.................. 43
3.2 Results..................................................................................................................... 43
3.2.1 Eye movement results...................................................................................... 43
3.2.1.1 Results of SPEM....................................................................................... 43
3.2.1.2 Result of stimulation of motion sensitive MT+ ........................................ 44
3.2.2 fMRI results ..................................................................................................... 44
3.2.2.1 Cortical activation of SPEM ..................................................................... 44
3.2.2.2 Cortical activation of visual motion stimulation....................................... 47
3.2.3 Possible structural connectivity between SPEM areas and MT+ complex...... 50
3.3 Discussion............................................................................................................... 52
3.3.1 SPEM and motion sensitive cortex.................................................................. 52
3.3.1.1 SPEM ........................................................................................................ 52
3.3.1.2 Functional role of MT+ in SPEM ............................................................. 53
3.3.1.3 FEF and SEF function in SPEM ............................................................... 53
3.3.1.4 PPC function in SPEM.............................................................................. 54
3.3.2 Motion processing in the area MT+................................................................. 54
3.3.3 Structural connectivity in SPEM and motion sensitive cortices...................... 54
3.3.3.1 Fiber tracking in MT+............................................................................... 54
3.3.3.2 Fiber tracking in PPC................................................................................ 55
3.3.3.3 Fiber tracking in FEF and SEF 55
3.3.3.4 Fiber tracking in the functional context of MT+ ...................................... 55
Chapter 4: Abstract ........................................................................................................ 57
Chapter 5: References .................................................................................................... 59
3Chapter 1. General Introduction
A seemingly simple task like walking in an empty corridor without hitting the wall
becomes very difficult when asked to do so blindfold (Berg 2000). Toddlers, who
have just learned to walk, tip over when the walls of a movable room are set into
motion (Stoffregen et al. 1987). It is clear that visual motion plays an important
role in those activities. As for visual activation, optic flow is the pattern of apparent
motion of objects, surfaces and edges in a visual scene caused by the relative
motion of an observer (an eye or a camera) with respect to the scene. Motion
estimation and video compression have developed into a major aspect of optic
flow research (Lee 1980).
Motion-sensitive regions, especially in the primate (e.g. human or monkey) brain,
have been described in the posterior part of the medial temporal gyrus adjacent to
the superior temporal sulcus MT+ (human homologue of the monkey middle
temporal and medial superior temporal parietal area MT/MST). The MT+ area is
characterized by its high proportion of direction-selective and motion-sensitive
neurons, direct input from primary visual cortex, retinotopic representation of the
entire contralateral hemifield, and heavy myelination (Dubner and Zeki 1971; Zeki
1974; Ungerleider and Desimone 1986a; Ungerleider and Desimone 1986b;
Maunsell and Van Essen 1987). Areas MT and MST contain many neurons
sensitive to the direction of motion of the stimulus either in the frontal plane, in
depth, or in both (Dubner and Zeki 1971; Maunsell and van Essen 1983; Tanaka
et al. 1986; Ungerleider and Desimone 1986a; Ungerleider and Desimone 1986b).
Neurons in some of these areas are also known to be sensitive to binocular
disparity (Zeki 1974; Maunsell and van Essen 1983a; Maunsell and Van Essen
1983b; Maunsell and Van Essen 1987; Newsome et al. 1988), and neurons in
different portions of MST play a role in visuomotor processing (Newsome et al.
1988; Komatsu and Wurtz 1988a; Komatsu and Wurtz 1988c; Kaas and Morel
1993; Cusick et al. 1995; Stepniewska and Kaas 1996; Felleman et al. 1997). MT
1and MST are reciprocally connected to more peripheral portions of V2 and V4,
enabling the extraction of motion information (Ungerleider 2005).
In many studies retinotopic activation of primary visual areas has been
investigated (Vanni et al. 2006). The processing of the location of visual motion in
MT+ remains largely unclear since retinotopic mapping of MT+ in human single
subjects was only partially successful (Huk et al. 2002). Therefore, a general
conclusion of human retinotopic mapping of MT+ and its subregions is still difficult
to get. Functional responses in the MT+ complex and its subregions to visual
motion stimulations at different locations of the visual field, and the relationship of
motion sensitive cortical areas to other cortical areas in terms of structural
connectivity are still unclear.
Based on previous studies (Ohlendorf et al. 2007; Ohlendorf et al. 2008), we
investigate the BOLD activation response of the motion sensitive MT+ complex
and its subregions to optic flow stimulations at different locations of the visual field
and the possible structural connectivity between cortical smooth pursuit eye
movement areas and the motion sensitive areas, by means of fMRI and DTI
based fiber tracking.
1.1 Basic features of MT+ and its subregions
1.1.1 MT+
1.1.1.1 MT+ location
The area MT+ is situated in posterior superior temporal sulcus (STS) (Allman and
Kaas 1971; Kaas and Morel 1993; Huk et al. 2002). In human brain, MT and MST
comprise the dominant part of MT+ (V5 in human brain) (See Fig. 1.1).
1.1.1.2 MT+ properties
There is a controversy about whether the motion sensitivity observed in the area
MT+ is established by local circuits in this area or whether it is determined earlier
in visual processing (Hatakeyama et al. 2010). A peculiarity of primates is that
directionally selective ganglion neurons are absent in the primate retina (Hawken
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