<p></p><p><span style="font-size: 1rem;">Networks are built of nodes and connections;
nodes are highly connected and highly central neocortical regions in the brain that are responsible for the integration of
information, globally (across many networks) &nbsp;(Van
den Heuvel &amp; Sporns,
2011). Some nodes are more densely connected than others, some less. Rubinov and Sporns (2010) identified different
nodes as different kinds of hubs, based upon their level of participation in th</span><span style="font-size: 1rem;">eir respective networks, or communities, as well as their level of connectedness to other modules.&nbsp;</span><br></p><p><span>Networks self-organize in such a way that allows a dynamic homeostasis between &nbsp;excitatory and inhibitory states, this is called "self-organized criticality" in physics.</span></p><p><span>We have many brain imaging modalities, of which EEG is the primary tool for neurotherapists and neurologists. However, its important you know all the other modalities, how they are used, and the mechanism of action they are tracking in the brain.&nbsp;</span></p><p><span>Here is an explaner video that covers, PET scan, CAT scans, MRI, and fMRI.</span></p><p><span><a href="https://www.youtube.com/watch?v=N2apCx1rlIQ">Neuro Imaging</a><br></span></p><p>And here is a video on how we came to understand networks via EEG</p><p><a href="https://vimeo.com/443180276">Thatcher on Networks</a><br></p>

<h3><a name="_Toc28940480">Resting State Networks</a></h3>

<p>There are thought &nbsp;to be 20 fundamental
&nbsp;networks in the brain (Laird, et al, 2010}, which made of "brain hubs." &nbsp;Hubs, or high density
nodes, are highly connected and highly central neocortical
&nbsp;hub regions
in the brain that are responsible for the integration of information, globally (across
many networks). &nbsp;"Rich clubs" are the most densely connected
hubs. There are at least 12 highly
connected, bi-hemispheric &nbsp;hubs, which lie in the precuneus, superior frontal&nbsp; and superior parietal
cortex, as well as the subcortical hippocampus, putamen, and thalamus.</p>

<p>"[T]hese
brain regions play a central
role in the overall network &nbsp;organization. These nodes participate
&nbsp;in multiple &nbsp;communications &nbsp;and are central, densely connected, and of short paths to one another
(Sporns et al., 2007; van
den Heuvel et al., 2010}.</p>

<p>Rich clubs are very similar
to the substation system in power grids. The subs are there to facilitate the transmission of power, disseminating loads at appropriate &nbsp;intervals to conjoining substations, allowing
for the ease of transmission and the prevention &nbsp;of system failure. Whether or not a rich club is present in a network&nbsp;
can provide details
about that network,
in terms of the level
of resilience, hierarchical ordering, and specialization. The fewer rich clubs as nodes would reflect a more specialized network.</p>

<p>Disturbances in the hubs connectivity &nbsp;and structure &nbsp;is partly responsible for neuropathology. Failure of a hub can
have a severe effect on the level of global communication efficiency of a network,
due to its central role in the network (Albert
et al., 2000; Callaway et al., 2000;
Zhou and Mondragon, 2004). Studies have suggested connectome &nbsp;abnormalities in a wide range
of neurological and psychiatric brain disorders, for example, Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, schizophrenia, and autism, with each disorder
affecting brain communication efficiency and capacity in a different
manner (Bosboom et al.,&nbsp;<span style="font-size: 1rem;">2009; Stam et al., 2009;
Lynall et al., 2010; van den Heuvel et al., 2010; Verstraete et al., 2010; Zalesky et
al., 2011).</span></p><h4><span style="font-size: 1rem;"><a name="_Toc28940481"><b>Module decomposition of provincial and connector hubs and the major networks of the brain. Images from Van del Heuvet M.P. &amp; Sporns, 0. (2011). Rich club organization of the human connectome. The journal of neurosciences, 3(144). 15775-15786.</b></a></span></h4><p style="text-align: center; "><span style="font-size: 1rem;">&nbsp;<img src="@@PLUGINFILE@@/Networks.png" alt="NETWORKS" width="700" height="729" style="text-align: center; " class="img-responsive atto_image_button_middle"></span></p><p><span style="font-size: 1rem;"><a name="_Toc28940481" style="color: rgb(55, 71, 79); font-family: &quot;Open Sans&quot;; font-size: 1.715rem; background-color: rgb(255, 255, 255);"><br></a></span>&nbsp;</p><p></p>

<br><p></p><p></p><p style="text-align: center;"><span style="font-size: 1rem;">&nbsp; &nbsp;&nbsp;</span><img src="@@PLUGINFILE@@/NETWORKS%20.jpg" alt="Resting Networks" width="600" height="441" class="img-responsive atto_image_button_middle" style="font-size: 1rem; text-align: center;"></p><p style="text-align: center;"><br></p><h3><div><h3><a name="_Toc28940482" style="color: rgb(55, 71, 79); font-size: 1.715rem; background-color: rgb(255, 255, 255);">Resting State Networks</a><br></h3>

<p></p><p><br></p><h5><div>

<p>The resting-state networks are built &nbsp;on the long
fibrous white &nbsp;matter tracts &nbsp;that &nbsp;create the fundamental
structures of the brain. There are 14 major &nbsp;resting-state networks, these
are the default mode network (DMN), &nbsp;dorsal atten-tion network (DAN),
ventral &nbsp;attention network (VAN), right &nbsp;frontoparietal network
(rFPN), left &nbsp;frontoparietal net- work &nbsp;(IFPN), language network
(LN}, cingula-opercular network (CON), auditory network (AN), ventral
&nbsp;somata- &nbsp;motor network (VSN), dorsal somatomotor network (DSN),
visual foveal network (VFN), visual peripheral net- work (VPN), medial
&nbsp;prefrontal network (MPN), and lateral prefrontal network (LPN).</p>

<p>&nbsp;<span>Within resting state networks, low&nbsp;
frequency oscillations coordinate long-range&nbsp;</span><span>communications (von Stein et al., 2000)
and gamma &nbsp;oscillations (40-150) coordinate local&nbsp;</span><span>communication (Buzsaki and Draguhn, 2004;
von Stein et al., 2000).&nbsp;</span><span>Cross-frequency coupling,
in particular phase-amplitude coupling, has been attributed an important role
for communication between brain &nbsp;areas (Canolty &nbsp;and Knight, 2010;
Canolty et al., 2006; Jensen and Colgin, 2007). Phase-amplitude coupling
provides a mechanism for&nbsp;</span><span>brain network information,
which reconciles previous findings and theories &nbsp;on long-range
communications between neural populations.</span></p>

<p>The communication of
low-frequency oscillations' phase needs to be time locked with no phase delay,
since cortical and subcortical hubs facilitate synchronization of distant
oscillatory activity &nbsp;with zero lag (Haider er al., 2006). The hubs act as
dynamic relays of long- distance cortico-cortical information. Excitability
&nbsp;cycles of local neural populations &nbsp;need to be synchronized to form
a network. High frequency bursts (i.e. gamma) are preferentially occurring
about the trough &nbsp;of the low frequency phase cycles of local field
potentials &nbsp;(Canolty et al., 2006). If low-frequency phases are
asynchronous (e.g. occurring at different &nbsp;frequencies and/or &nbsp;with
&nbsp;a phase delay), the "gate is closed", &nbsp;and
consequentially, coherent high-frequency oscillations &nbsp;and/or
&nbsp;synchronous&nbsp; cell firing are less likely to occur, leading to
suboptimal communication /coactivations between two brain regions (Florin &amp;
Baillet, 2015).</p>

<h3><a name="_Toc28940483"><b>Default Mode Network</b></a></h3>

<p>The most well-known of the
resting state networks&nbsp; is the default mode network, which is an area of
the brain that&nbsp; is active when the brain is in wakeful rest. Generally
speaking,the DMN is online when we are not doing anything in particular, but
are instead simply "being." When we see hypo phase lag, as we do
here, there is a possibility&nbsp; that the DMN is off balance, and that the
process of resting in a present state is off balance.</p>

<p>Observations of the default
mode network (DMN) during sleep show, just as during the DMN activity in mind
wandering, that portions of the pre-frontal cortex are active during dreaming,
as are the medial temporal lobe structures and the posterior &nbsp;cingulate
(all of these points are nodes that make up the network of the DMN).
Conversely, other studies show that,&nbsp;<span>in REM sleep,
executive-processing regions of the pre-frontal cortex are mostly deactivated,&nbsp;</span><span>beyond levels seen during waking mind
wandering, which suggests that &nbsp;dreaming may be an "intensified"
version of waking mind wandering (Fox, Nijeboer, Solomonova, Domhoff, &amp;
Christoff., 2015). Rizzolatti, Semi, &amp; Fabbri-Destro (2013) contend that
the activation ofthe DMN might &nbsp;correspond to the psychoanalytic
&nbsp;unconscious (p. 5).</span></p><p><span>Here is an interesting video on the Default Mode Network</span></p><p><span><a href="https://www.youtube.com/watch?v=QdPhkP9D2-A">DMN video</a><br></span></p><p><span><br></span></p>

<h2><a name="_Toc28940484"><b>Fasiculli</b></a></h2>

<p>Fasiculus means "little
bundle" in Greek. These are cortical-cortical, intrahemispheric connections. They are nerve fibers
in the central nervous system. Most&nbsp; projection pathways run dorso-ventral
(descending) or vento- dorsal (ascending). Most association tracts run longitudinally
along and antero-posterior axis from the frontal lobes to the projection areas and vice versa and
connect cortical areas within the fasiculi. Arcurate fasiculli connect the frontal cortex to the temporal lobe.</p><p>Damaged fasiculli can reflect dementia, as well as learning disabilities (which can also be the result of wiring differences from normal demographic).&nbsp;<span style="font-size: 1rem;">&nbsp;</span></p><p>Here is a video on the Fiber Pathways of the Cerebrum</p><p><a href="https://www.youtube.com/watch?v=LVasm5bqn-Y">Fiber Pathways of the Cerebrum</a></p><p></p><h3>Short
Fasiculi: Also known as U-Fibers, shaped like a bow, which interconnect
cortical regions.</h3>

</div>

<p style="text-align: center;"><img src="@@PLUGINFILE@@/short%20fasiculi.png" alt="Short Fasiculi" width="500" height="311" class="img-responsive atto_image_button_middle" style="font-size: 1rem;"></p><br clear="all"></h5><p><br></p><p></p><p><span style="font-size: 1.715rem;">Superior Longitudinal Fasiculus: Connects the frontal, temporal,
parietal and occipital lobes</span><br></p><p style="text-align: center;"><img src="@@PLUGINFILE@@/Superior%20Longitudinal%20Fasiculus.png" alt="Superior Longitudinal Fasiculi" width="501" height="342" class="img-responsive atto_image_button_middle" style="font-size: 1.715rem;"></p><p></p><p><br></p><p><br></p><p></p><p>Arcuate Fasiculus: Subset of the Superior Longitudinal Fasiculus,
connects Broca’s to Wernicke’s Areas</p><p style="text-align: center;"><img src="@@PLUGINFILE@@/Arcuate%20Fasiculus.png" alt="Arcuate Fasiculus" width="499" height="339" class="img-responsive atto_image_button_middle" style="font-size: 1.715rem;"></p><p></p><p><br></p><p><br></p><p></p><p>Inferior Longitudinal Fasiculus: Connects Occipital and Temporal
Lobes</p><p style="text-align: center; "><img src="@@PLUGINFILE@@/Inferior%20Longitudinal%20Fasiculus.png" alt="Inferior Longitudinal Fasiculus" width="500" height="334" class="img-responsive atto_image_button_middle"><br></p><p><br></p><p><br></p><p></p><p>Uncinate Fasiculus: Connects Anterior Temporal and Inferior
frontal Lobes</p><p style="text-align: center; "><img src="@@PLUGINFILE@@/uncinate%20Fasiculus.png" alt="Uncinate Fasiculus" width="500" height="321" class="img-responsive atto_image_button_middle"><br></p><p><br></p><p></p><p><span style="font-size: 1.715rem;">Cingulum (C-shaped) fasiculus: Connects the hemispheres and runs
parallel with the cingulate and the parahippocampal gyrus</span><br></p><p style="text-align: center; "><span style="font-size: 1.715rem;"><img src="@@PLUGINFILE@@/fasicului.png" alt="fasicului" width="600" height="368" class="atto_image_button_middle"><br></span></p><br><p></p><p><br></p><p>Perpendicular Fasiculus: Runs up and down, intralobular in the
occipital lobe</p><p style="text-align: center;"><img src="@@PLUGINFILE@@/Perpendicular.png" alt="Perpendicular" width="500" height="351" class="img-responsive atto_image_button_middle" style="font-size: 1.715rem;"></p><p></p><p><br></p><p><br></p><p><span style="font-size: 1.715rem;">Corpus Callosum: Bundle of fibers that connects the hemipsheres of
the brain</span><br></p><p style="text-align: center;"><span style="font-size: 1.715rem;">&nbsp;</span><img src="@@PLUGINFILE@@/Corpus%20Callosum.png" alt="Corpus Callosum" width="435" height="335" class="img-responsive atto_image_button_middle" style="font-size: 1.715rem; text-align: center;"></p><p style="text-align: center;"><br></p><p></p><p><span style="font-size: 1.715rem;">Anterior Commisure: connects the anterior temporal lobes and the
olfactory bulbs</span><br></p><p style="text-align: center;"><img src="@@PLUGINFILE@@/Anterior%20Commisure.png" alt="Anterior commisure" width="501" height="347" class="img-responsive atto_image_button_middle" style="font-size: 1.715rem;"></p><p></p><p><br></p><p><br></p><p><span style="font-size: 1.715rem;">Corona Radiata: Connects the cortex to the subcortical structures,
such as the thalamus, the brainstem, etc.</span><br></p><p style="text-align: center;"><img src="@@PLUGINFILE@@/Corona%20Radiata.png" alt="Corona Radiata" width="500" height="401" class="atto_image_button_middle" style="font-size: 1.715rem;"></p><p></p><p><br></p><p><br></p><p></p><h3><a name="_Toc28940485">Internal Capsule:</a> </h3>

<h5><p><br>The&nbsp;<a href="https://www.sciencedirect.com/topics/medicine-and-dentistry/internal-capsule" title="Learn more about Internal Capsule from ScienceDirect's AI-generated Topic Pages">internal capsule</a>&nbsp;is a thick sheet of white matter consisting of&nbsp;<b>projection fibres</b>&nbsp;passing to and from the cerebral cortex. It makes a sharp ‘knee-bend’ or&nbsp;<b>genu</b>&nbsp;around the apex of the lentiform nucleus (Latin: genu, knee). This gives it a V-shape when viewed in axial (horizontal) section (Fig. 3.22). There is therefore an&nbsp;<b>anterior limb</b>&nbsp;(between the lentiform nucleus and the head of the caudate nucleus) and a&nbsp;<b>posterior limb</b>&nbsp;(between the lentiform nucleus and the thalamus).</p><br></h5><p style="text-align: center;"><img src="@@PLUGINFILE@@/internal%20capsule.png" alt="fasiculi" width="500" height="426" class="img-responsive atto_image_button_middle" style="font-size: 1.715rem;"></p><p></p><p><br></p><p><br></p><p><a name="_Toc28940486">Fornix</a></p><h5><a name="_Toc28940486">The&nbsp;<b>fornix</b>&nbsp;(meaning
"arch" in Latin) is a C-shaped bundle of nerve fibers in the brain
that acts as the major output tract of the hippocampus. The&nbsp;<b>fornix</b>&nbsp;also carries
some afferent fibres to the hippocampus from structures in the diencephalon and
basal forebrain. The&nbsp;<b>fornix</b>&nbsp;is part of
the limbic system.</a></h5><p style="text-align: center; "><img src="@@PLUGINFILE@@/Fornix.png" alt="Fornix" width="501" height="323" class="img-responsive atto_image_button_middle"><br></p><br><p></p><p></p><p></p></div></h3><p></p>