For today's episode, we will cover autism and
communication disorders. These are a few, four,
five, or six disorders right before the autism
section of the DSM -5 -TR. These are heavily
involved with speech and language abilities.
We will cover the brain regions, connectivity,
brainwave patterns, how they are measured, longitudinal
studies, and a rare region of interest for the
podcast, interventions. I don't love it, but
some genetics as well. We will mostly cover this
as part of expanding on the autism and speech
and language episode from the spring and last
week's Decoding the Brain, how reading works
in autism and dyslexia. We are kind of piecing
this together because this is all in play here
as well. Mostly we are talking about criteria
A, the abnormalities in social communication
and interaction of the autistic phenotype criteria
A. These are things like language abilities,
nonverbal communication, starting and stopping
conversation. understanding sarcasm, and even
maintaining conversational flow. All pretty much
challenges for the autistic phenotype. For social
or pragmatic communication disorder, this is
SCD. This is kind of pragmatic problems. 50 to
70 percent of individuals with autism show pragmatic
deficits that resembles social pragmatic communication
disorder. However, these cannot coexist. You
should never have a co -diagnosis of autism and
social communication disorder, sometimes called
pragmatic disorder. Here's a wide range. 4 to
22 percent experience childhood onset fluency
disorder. Now previously, this was just called
stuttering. In the DSM -5, they think they're
being kind now, I guess. I don't know. Child
onset fluency disorder with stuttering highlighted.
20 % to 30 % have speech sound disorder, and
up to 50 % meet criteria for developmental language
disorder. So those are the four. Social communication
disorder, or pragmatic. child onset fluency disorder
or stuttering, speech sound disorder, and developmental
language disorder. These overlaps stem from disruptions
in shared neural circuits, particularly those
involved in language processing and motor control
and social cognition modulated by some genetic
factors. And here are the two that we're going
to kind of spend most of the time on. FOXP2.
And one you might recognize if you listen to
the podcast, as it's been mentioned several different
times and even with Dr. Hannah Stevens. CNT -NAP2.
These specific comorbidities are crucial for
developing targeted interventions that address
both the autistic phenotype and these other communication
style disorders. So here are some shared neural
features, some brain regions involved, and pretty
much all of these. And they're very popular.
If you listen to the podcast, these are very
popular. The medial prefrontal cortex, which
is one of my favorites. Temporal parietal junction.
We've talked about that in several episodes,
both of those regions actually. The superior
temporal sulcus. Remember that from the decoding
the brain episode on reading. These three are
critical for social cognition and a so -called
theory of mind, which is kind of incomplete.
The ability to understand others' perspectives
and intentions are what we basically are talking
about. In the autistic phenotype, these regions
consistently show hypo activation. during tasks
requiring social understanding, such as interpreting
facial expressions or conversational context
leading to difficulties in social communication.
Some examples for you. When individuals with
autism process social cues, MRI studies reveal
reduced activity in the right temporal parietal
junction. which is essential for perspective
taking. The so -called mirror neuron system.
Now mirror neurons are kind of hit or miss, but
I think for this topic it's kind of important
to mention. These are located in the inferior
frontal gyrus. Remember last week's episode on
decoding the brain. This includes Broca. So it's
huge for language processing. and also the inferior
parietal lobe. This is responsible for imitating
actions and understanding others' intentions.
So hard stop. I just really want to mention this.
The benefit of the autistic phenotype is to be
our own person, not be influenced or caught up
or care even about what other people are doing.
That is not that bad of a thing. Our so -called
internal state, remember the definition or translation
of autism itself. It's very entertaining and
intense with these imaginations and visual thinking.
Whereas the outside world is one very chaotic.
Remember the sensory processing episodes in those
so -called heightened states. hyper, brain waves,
staying in gamma. The outside world is complicated.
And most of the time, it's not as interesting,
just quite frank. In the autistic phenotype,
these so -called mirror neurons exhibits reduced
activation during tasks like observing gestures,
contributing to deficits in social interaction
and communication. The cerebellum is also involved.
Remember Dr. Reza Shadmir, particularly in the
cerebellum, the vermis. This plays a role in
motor coordination and speech porosity, porosity
maybe, which is melodic lines of speech, such
as the frequency, the intensity and duration
of the spoken word. Pitch, volume, pace, and
rhythm. Think monotone is not that. The autistic
phenotype, there's plenty of impressive data
here. And remember our guest, Dr. Shadmere, sharing
information here. Such a great episode. He's
such a great human being. Shows reduced Purgenji
cell density. This is very, very common and leads
to atypical speech patterns such as monotone
or irregular porosity. These tongue movements,
too. These are reduced. Some shared functional
and structural connectivity. The autism phenotype
is characterized by disrupted connectivity patterns
that affect communication and social processing.
Functional connectivity assessed through resting
state. FMRI reveals under -connectivity in long
-range networks. such as those linking frontal
to temporal regions. Remember these are extremely
distal. We could probably spend every episode
talking about distal connections. Even remember
Dr. Richard Fry talking about Leukovorin. Leukovorin
rescues these distal connections. It's one of
the things that is helping with the autistic
phenotype especially the non -verbals. This is
a very interesting product and I'm glad it's
taking place and getting some highlights here
now with the administration saying this should
be a treatment option. Luke O 'Voren see the
episode with Dr. Richard Fry from the spring.
Those poor distal connections that are under
connected. They have a hard time keeping up with
sensory processing and kind of orchestrating
different movements and understanding of the
social world. Local circuits such as those within
the occipital or temporal regions often show
over -connectivity. Remember, we've talked about
this quite in detail with the sensory processing
episode and the decoding the brain episode. We
won't have to go into this, but that diffusion
tensor imaging is wild. The data here are so
wild. Remember the arcuate fasciculus. Here's
a new one, the superior longitudinal fasciculus,
SLF, and this supports social and executive functions.
So this is huge here. And also lower fractional
encetropy, again, remember it's measuring water,
indicates compromised fiber integrity that correlates
with language and social deficits. So there's
a new fasciculi. We have many different fasciculi.
The arcuate fasciculi or arcuate fasciculus is
for those speech and language connections. This
new superior longitudinal fasciculus this is
so -called connecting executive functioning to
language so it's also including language mainly
in the frontal parietal and temporal lobes. Now
if you're a lumper You will combine the arcuate
fasciculi into this superior longitudinal fasciculus.
Now some people say the arcuate is just a part
of this SLF. That's a lumper. They lump regions
together. If you are a splitter, you will split
the arcuate fasciculus and the superior longitudinal
fasciculus apart into two distinct fasciculi.
So brainwave patterns. Brainwaves measured through
EEG and MEG provides insight into the temporal
dynamics of neural activity in the autistic phenotype.
Temporal, not meaning the temporal lobe, but
time, the time component here. Reduce gamma band
30 Hertz to 80 Hertz and synchrony as a hallmark
of autistic phenotype so a reduced gamma band
and this reflects impaired local processing and
sensory integration particularly in frontal and
temporal regions. This reduction is evident during
tasks requiring attention to social stimuli such
as processing faces or voices. Once again the
study on six weeks old humans from UCLA, showing
that different connection from the salient network,
the salient network with these younger autistic
subjects in this study. Now they later track
them to indicate, yes, autism, no, not autism.
The autistic ones had different connections of
the salient network. Insula to the sensory motor
compared to the typicals. Insula to the frontal
cortex. This is all in play here. This is all
connected. In addition, a typical alpha band,
so remember the 812 Hertz, suppression, alpha
band suppression, which typically occurs during
attentional tasks, suggests deficits in modulating
attention. to relevant stimuli. This contributes
to social and communication challenges. However,
increased theta band 4 to 8 Hz, increased theta
band power in frontal regions indicates compensatory
effort as the brain attempts to overcome processing
deficits during complex tasks like language comprehension.
So it's trying to rescue itself in these frontal
areas, but it's having a hard time keeping up.
A measurement technique. A range of neural imaging
and electrophysiological tools are used to study
autism's neural profile. Task -based fMRI indicates
regional hypoactivation. For instance here in
the medial prefrontal cortex or that temporal
parietal junction during social and language
task. While resting state fMRI quantifies connectivity
disruptions in networks like the default mode
network. The resting state fMRI is what the UCLA
study used on six -week code. EEG measures event
-related potentials. You might recognize that
from the Sensory Processing Part 2 episode. This
is such as N400, which is reduced in the autistic
phenotype during semantic or pragmatic processing,
indicating difficulties with context integration.
ItMeG's provides high temporal resolution to
detect abnormal gamma and beta coherence reflecting
abnormal neural synchrony. DTIs quantifies white
matter integrity through the FA diffusion tensor
image. Remember diffusion is nerd speak for movement.
It's measuring water and the arcuate fasciculus
is abnormal here. It's very under connected.
Okay, some genetic contributions. The FOXP2 and
CNT -NAP2. I don't love it. It's not my role
to love it. Just convey it. I don't love the
genetic stuff though. It seems like a dead end
with the autism research. It's very suspicious.
It's very even perhaps nefarious. FOXP2 and CNT
- NAP2 genes are pivotal though in shaping the
neural circuits underlying the autistic phenotype
and its comorbid speech and language disorders.
So this is why these are kind of a region of
interest for us. This influences language, motor,
and social processing. FOXP2 is a transcription
factor that regulates genes critical for neural
development particularly. in regions like the
inferior frontal gyrus and a favorite of mine
the basal ganglia and the cerebellum which are
essential for language production and motor coordination.
By modulating synaptic plasticity and dendritic
growth FoxP2 ensures the formation of robust
neural connections make it necessary for articulating
speech and complex language processing. So pretty
important there. Sounds like a region of interest
for us. Mutations in the FoxP2 disrupt articulation
in the speech sound disorder and synaptic processing
and the delayed language disorder and speech
planning and stuttering. In the autistic phenotype,
FOXP2 variants contribute to language delays
and pragmatic deficits by impairing the inferior
frontal gyrus function, which is of course a
crucial area for both the language production
and social communication. Some longitudinal studies
have shown that FOXP2 expression levels correlate
with language development trajectories in the
autistic phenotype, with lower expression associated
with persistent delays in verbal communication.
That's shown in a 2013 study from molecular autism.
So here's fascinating. This is a very fascinating
part here. The FOXP2 regulates downstream genes
like the CNT -NAP2. So it's kind of a sequela
here. If upstream is abnormal, downstream is
going to be abnormal. This is a very big message
constantly repeated across the podcast in many
different episodes. Upstream is always the place
to go. The CNT -NAP2 encodes a Norexin family
protein. This is involved in cell adhesion and
synaptic transmission. With high expression in
frontal and temporal cortices, the basal ganglia
and the cerebellum. All regions of critical interest
for language and social processing. This gene
regulates potassium channel clustering and myelination.
No surprise. Processes that ensure efficiency.
neural communication and connectivity. So the
autistic phenotype and social communication disorder,
the pragmatic disorder. Remember these don't
coexist. So some overview here though between
the two. Social communication disorders characterized
by difficulties in the social use of language,
such as maintaining conversational relevance,
interpreting, non -verbal cues like eye contact
or gestures or understanding non -literal language
such as metaphors and things. Now you can see
why these aren't really comorbid problems. If
you have the things that it has said and you
have the repetitive restricted behaviors, the
criteria B, well you have autism. So there's
a chance that you can differentiate between these
two and just have the social communication disorder
and not have autism but if you have the autism
and you have these conditions well you have autism
and it might very well be who is diagnosing you
who is assessing you through the autism is it
somebody with clinical relevance and training
or not and it's very much a problem here in 2025
so some longitudinal studies here The longitudinal
research provides critical insights into the
developmental trajectory of these two situations
here, the autistic phenotype and social communication
disorder. A five -year fMRI study by Lombardo
et al. in 2015 from Nature Communications, very
good journal. They followed children with autism
and found persistent hypoactivation. in the medial
prefrontal cortex and the temporal parietal junction
during tasks requiring pragmatic understanding
such as interpreting irony. Yeah, good luck with
that. This hypo activation correlated with social
communication disorder like deficits and CNT
NAP to risk Ls predicting worse social communication
outcomes over the time. The study also showed
slower maturation of the default mode network.
Now, if you remember the temporal parietal junction,
and if you remember the autism in default mode
network episode, that's probably your connection
there. And the study also showed reduced fractional
anzeotrophy and the superior longitudinal fasciculi.
And this persisted into adolescence. But... Early
social skills interventions such as structured
social training improve default mode connectivity
in some children suggesting neuroplasticity and
the potential for targeted interventions to mitigate
deficits. So some personalized interventions
more specifically will help improve this connectivity
between the medial prefrontal cortex and the
temporal parietal junction. for social skills
development. These programs teach explicit social
rules such as how to initiate and maintain conversations,
which if you want improvement in this area, there
are options here. If you want improvement in
this area, repetitive transcranial magnetic stimulation
targeting the medial prefrontal cortex shows
promise in improving social communication by
modulating neural activity in social brain regions.
With studies reporting, improved default mode
network coherence in both autistic phenotype
and social communication disorders. Experimental
CNT -NAP2 -based therapies such as, here you
go, CRISPR gene editing in animal models, aimed
to restore synaptic function in social circuits,
offering a potential future treatment. This is
done by Daniel Gershwin. Daniel Gershwin just
received one of the 13 autism new initiative
funding by the new NIH. Okay. This was done in
2011 in Cell Press, a top journal. cell press.
These CRISPR gene studies in animal models and
even humans now, I think, is a you pick, you
choose. So autism and the childhood onset fluency
disorder. In other words, autism and stuttering.
This is my childhood. Childhood onset fluency
disorder. These are disruptions in speech fluency,
such as repetitions, prolongations, or blocks.
Often I kind of refer to my speech as blockage.
I have blockage sometimes. In the podcast, I
can just redo it. In real life, I have to just
kind of stick with it and hopefully it lands.
Stuttering here affects 4 to 22 percent of the
children with autistic phenotype. And this prevalence
is significantly higher than the 1 % observed
in general population. So what I just said, if
you have autism, it increases your chances and
it will kind of hit 4 to 22 % of the children
instead of 1 % of the children. It's a big thing.
This high comorbid rate reflects shared deficits
in motor and language networks, particularly
those involved in speech planning and timing,
making it very critical to understand the neural
overlap for effective intervention. So the basal
ganglia here is heavily involved. and this includes
the putamen and the caudate. Remember the four,
five, maybe even six episodes from last winter
of basal ganglia? The putamen and caudate are
the input areas and there's a high kind of connection
with the medial prefrontal cortex and the sensory
motor cortex that's kind of above and in the
middle of your head at the top middle. That's
the sensory motor area. So the basal ganglia
is involved with the motor timing and coordination.
And this is in large part the substantia nigra
pars compacta in the midbrain. This is dopamine
one or excitation and dopamine two or inhibition.
The one dopamine is receptors one and five. And
those are excitation, D2 dopamine, or receptors
two, three, and four. And these are inhibition.
This is all related to orchestrating timing of
motor movements. Remember the basal ganglia is
a go, no -go area. In other words, go and stop.
And if you think about stuttering, stuttering
is go, stop, go, stop. Go stop. Just trying to
find a smooth connection here. And it's not happening.
FMRI studies show heightened motor planning efforts.
Really want to highlight the efforts part. It's
trying. It's building up. It's ratcheting. But
the go no go area say, okay, no, okay, no, okay,
no. It's kind of disrupted there. Longitudinal
studies here, a 10 -year longitudinal DTI, diffusion
tensor imaging study by Chang et al. in 2019,
human brain mapping, followed children with autism
and stuttering. They found persistent FA reductions
in the arcuate fasciculus, no surprise, and the
cortical spinal tract. That's new. also though
loaded with water, that's water, which correlated
with stuttering severity. Some personalized interventions
here are targeting the basal ganglia in the motor
circuits to improve fluency. Repetition or repetitive
transcranial magnetic stimulation, or RTMS, target
the pertainment. This modulates dopamine signaling.
reduced stuttering severity with preliminary
success in autism and stuttering. Now remember
the Dr. Hannah Stevens episode and she talked
about, she has a paper which led me to her about
the high density of dendrites in the dorsal striatum
in the autistic phenotype. There's no pruning.
It's just very dense here. Autism really... highlights
and increases the risk of stuttering problems.
I think over time practice and so forth just
having the chance for our connections and brains
to kind of clean up and clear out these deficits
help. So over time hopefully you have some improvements
in stuttering. That intense blockage you can
feel it you can feel it in your neck even in
the back of the head. You can just feel that
blockage. Okay, autism and speech sound disorder.
This is a thing, speech sound disorder. This
involves difficulties with producing speech sounds
accurately, leading to an articulation or phonological
error. This involves Broca's area or the left
inferior frontal gyrus. in the superior temporal
gyrus remember last time with the decoding the
brain and reading a lot of these brain regions
are shared from that episode longitudinal studies
a seven -year longitudinal fmri study by red
clay et al 2018 developmental cognitive neuroscience
followed children with autism and speech sound
disorder Finding persistent hypoactivation in
the inferior frontal gyrus and the superior temporal
gyrus during articulation task. This is correlating
with speech sound errors. Once again, reduced
FA in the articulate fasciculus was also observed.
And these variants in the FOXP2 and CNT -NAP
variants predicted poorer outcomes with speech
therapy. However, early speech therapy initiated
before the age of 6 improved FA in the arcuate
fasciculus and articulation accuracy in some
children, highlighting the potential for early
intervention to enhance neural connectivity.
speech outcomes. Most autistics are hopefully
getting some sort of speech therapy. I remember
in the 1980s getting some and this is even rare
in the 1980s. The small group reading interventions.
Remember a previous episode I was putting small
groups in the 1980s elementary school and the
groups are like maybe four or five with Ms. Blazey
was the teacher's aide. I was the slowest of
the slow. A so -called task base fMRI reveals
reduced inferior frontal gyrus and superior temporal
gyrus activation during articulating task. While
resting state fMRI confirms auditory motor under
connectivity. EEG measures the P1N1P2 complex,
which is reduced in response to speech sounds.
This indicates impaired auditory processing.
We'll have a future episode on autism and auditory
processing. MEGs detect decreased gamma band
power in the superior temporal gyrus during speech
perception. task, and DTI quantifies lower FA
in the arcuate fasciculus. This was showed way
back in 2003 in annuals of New York Academy of
Sciences by Ledlow and Laux. There's a specific
articulation focus therapy called prompts for
restructuring oral, muscular, Photonic Targets
or PROMPT for short. This is tailored to autistic
phenotype sensory sensitivities and improves
the inferior frontal gyrus superior temporal
gyrus connectivity. And this is shown through
post -intervention fMRIs. This is highlighted
in Morgan et al. in 2018 of Journal of Speech
Language and Hearing Research. so prompt. These
therapies use tactile cues to guide articulation
movements and enhancing speech accuracy. RTMS
targeting the left inferior frontal gyrus enhances
phonological processing by stimulating neural
activity in language areas. With preliminary
successes, in the autistic phenotype and speech
sound disorders. EEG -based neurofeedback targets
gamma band power and the superior temporal gyrus
improves speech sound perception by training
the brain to enhance auditory processing. That
kind of sounds complicated, but it is an option.
So... the autistic phenotype and speech sound
disorders kind of highlight articulation errors
okay and lastly autism and developmental language
disorder dld dld is characterized by persistent
difficulties in language comprehension or production
affecting vocabulary grammar or discourse, and
this affects up to 50 % of children with autism.
This high comorbidity rate reflects significant
overlap in language networks, making it a critical
area for understanding communication challenges
in the autistic phenotype. Some neural networks
include dysfunction in the Broca's area and Wernicke's
area. This is critical for syntax and language
comprehension. The dorsolateral prefrontal cortex
is also affected here, impairing executive aspects
of language, such as planning complex sentences.
Cerebellar abnormalities in both disorders disrupt
porosity and language timing. Contributing to
atypical speech patterns, the autistic phenotypes
broader sensory and social deficits involving
regions like the medial prefrontal cortex and
occipital cortex accelerate developmental language
disorders, language specific impairments. This
creates a more complex communication profile
whenever they coexist. Longitudinal studies show
a 12 -year longitudinal DTI study. in the Journal
of Neurodevelopmental Disorders. This followed
children with both autism and developmental language
disorder, finding persistent F .A. reductions
in the archicoid fasciculus, correlating with
severe language delays. CNT -NAP2 variants predicted
poorer outcomes, with effects persisting into
adolescence. Early language therapy initiated
before the age of five improved FA in the arcuate
vesiculus and language outcomes in some children.
It's easy for me to say and you don't have to
hear that early intervention especially with
speech language is very beneficial. Earlier the
better. Task -based fMRI reveals reduced inferior
frontal gyrus and superior temporal gyrus activation
during sentence processing task while resting
state fMRI confirms language network under connectivity
EEG measures delayed in 400 so remember roughly
400 milliseconds responses during semantic task
indicating comprehension deficits this is well
aligning with the data and coverage of Decoding
the Brain, Reading an Autism and Dyslexia episode.
This fits the timing. MEG deficits detect reduced
gamma band power in the inferior frontal gyrus
and the superior temporal gyrus during language
task. DTI quantifies lower FA in the arcuate
fasciculus with even more severe reductions in
the autistic phenotype plus developmental delayed
disorder. So some personalized interventions
for these two. Syntax -focused therapies such
as narrative -based interventions are tailored
to the autistic phenotype's sensory and social
deficits, improving the IFG inferior frontal
gyrus and the superior temporal gyrus connectivity.
as shown by post -intervention fMRI and 2016
autism. These therapies focused on building grammatical
skills through storytelling, which engages both
language and social circuits. RTMS targeting
the left Broca area enhances syntactic processing
by stimulating neural activity in language areas
with preliminary success in the autistic phenotype
and developmental learning disorder comorbid
condition. EEG's based neural feedback targeting
gamma band power in language areas improves comprehension
by training the brain to enhance processing efficiency.
This goes in line with that delayed processing
in the downstream connections. Earlier, it's
heightened. But downstream, that arrival point
from point A to point B, there are five steps.
Those last steps are going to be under connected
and delayed. However, some things are really
significant here. Earlier, the intervention,
the better. And kind of pinpointing Which problems
are consistent with that Autistic Phenotype,
with that individual? What kind of additional
speech language communication problems is the
Autistic Phenotype having? Remember, earlier
intervention the better. If you are listening
to the podcast, listening to the episode, please
feel free to leave a review or rating. In podcasting,
Reviews ratings and downloads are huge and I
very much appreciate your feedback. You can contact
me on X at RPS 47586 We can have discussions
about autism. I always appreciate your discussions
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can email me info dot from the spectrum Thank
you for listening to From the Spectrum Podcast.