FINAL Flashcards
What are the two domains of compromised development that provides the basis of the DSM diagnosis for autsim spectrum disorder
- Social and communication deficits
- Repetitive sensory-motor behaviours and fixated interests
Symptoms emerge in early childhood
What is the prevalence of autism spectrum disorder?
1 in 88
3-4 times as many boys as girls (could be from missed diagnoses based on outward symptoms)
Define social cognition
Learning that occurs through a social context
How do social stimuli affect children?
- Social stimuli are generally more salient for children (caregivers are salient for children)
- Saliency drives attention, attention drives learning at an early age.
Define theory of mind
The ability to attribute mental states to others
- This is a key milestone in development that develops at around 5 years old
Define joint attention
The capacity to coordinate one’s visual attention with the attention of another person
What are fixated interests in ASD?
- Preoccupation with one or more stereotyped and restricted pattern of interest that is abnormal in intesity or focus
- Can lead to Savant Talents
- Prefer routines, become distressed with change
How are genetics related to ASD? (5)
- ASD has a strong genetic contribution
- High heredity and family clustering
- Hundreds of genes identified
- Mix of risk variants and de novo mutations, with mutations more frequent with older parents
- ASD is highly comorbid with other disorders
What is the SCN2A gene?
A gene that encodes the voltage-gated sodium channel Na(v)1.2, which plays an important role in the initiation and conduction of action potentials
What is the growth dysregulation hypothesis of ASD?
Normally well-controlled processes of brain growth and organization go awry, leading to the symptoms of ASD
- growth w/o guidance
- frontal/temporal regions (amygdala)
- 2-4 year old with ASD larger MRI based brain volume
What is the over-pruning hypothesis of ASD?
Too many neurons are pruned in the motor and/or sensory regions
- 8-16 year old with ASD smaller MRI based volume
How are mirror neurons affected in ASD?
- Activity in the anterior component of the MNS was found to be reliably greater in typically developing children
- There is a negative correlation between scores on social subscales and MNS activity
What is the empathizing-systemizing theory in ASD?
- Systemizing is the drive to analyze or construct systems (orderly/patterns)
- There seems to be an inverse correlation between having: below-average empathizing, above-average systemizing
- Males tend to be more systemizers than females
What are some current pharmacological interventions of ASD?
Oxytocin has been used to reduce social impairment in ASD. Oxytocin reduced the tendency for participants with ASD to fixate on the most systemized stimuli.
- Oxytocin is elevated following childbirth and facilitates bonding and empathy
- Mixed results: Some studies show benefits while others do not (which could be related to dosing, timing, heterogeneity of ASD)
Who is the first person to claim that the left hemisphere was asymmetrically dominant for speech?
Marc Dax
How did Broca discover the left hemisphere’s dominance in language?
Paul Broca reported the results of postmortem exams of two aphasic patients that they had diffuse left hemisphere damage, centering in an area of the inferior left prefrontal lobe, just in front of the primary motor face area.
- “LeBrougne” was one of his patients that was only able to say “tan”.
What are the three core symptoms that defines Broca’s aphasia?
- Agrammatism: severe issues using grammar
- Anomia: inability to produce the right words
- Articulation problems
What did Carl Werincke report on?
A new type of language disorder: Wernicke’s aphasia (inability to comprehend language, but can speak fluently)
What was Liepmann’s work with the left hemisphere?
Liepmann showed that apraxia was almost always associated with left hemisphere damage.
What is apraxia?
Difficulty performing movements with either side of the body when asked to do so, but not when performing them spontaneously
What is the Wada Test (aka Sodium Amytal test)?
- Sodium amytal is injected into one carotid artery; this anesthetiezes the ipisilateral hemisphere and allows the abilitites of the contralateral hemisphere to be assessed.
- Administered to patients prior to neurosurgery to determine side of speech lateralization.
What is the dichotic listening task?
- Two different syllables played to different ears.
- The ear that hears one sound the most means that the contralateral hemisphere is dominant for language
What has fMRI data shown for lateralization?
- During word generation task, (where participants are shown a probe letter and have to think of as many words starting with that letter as possible within 30s) increased fMRI activation found in the dominant hemisphere
- During passive listening there is increased activation in the dominant hemisphere
- There is still some activation in the non-dominant hemisphere though!
What did the study by Hausmann find in regards to lateralization?
When participants spoke, a majority opened the right half their mouth slighty more than the left