Brain Based Pathology of Autism Spectrum Disorders Asynchronous Webinar Survey of Autism Graduate Certificate in the Education of Students with Autism: Hybrid Model Chris Swanson Johns Hopkins University

Everyday Autism You Tube: You Tube:

The Parts of the Brain Kailasanath & Fu, HOPES Brain Tutorial – Stanford University, Kailasanath & Fu, HOPES Brain Tutorial – Stanford University,

Brain Structures Implicated in Autism

Brain Development Abnormally large growth spurt at 6 months. Abnormally large growth spurt at 6 months. Average weight by adolescence Average weight by adolescence Larger head circumference Larger head circumference Under connectivity/formation of neocortical neural systems Under connectivity/formation of neocortical neural systems Lack of typical symmetry Lack of typical symmetry

Brain Development Over development of white matter Over development of white matter Truncation of dendritic tree Truncation of dendritic tree Decreased neuronal connections in cerebellum Decreased neuronal connections in cerebellum Increased cell density in hippocampus & amygdala among other regions Increased cell density in hippocampus & amygdala among other regions Impacts the limbic system – learning, memory, behavior & emotion Impacts the limbic system – learning, memory, behavior & emotion

Right Brain vs. Left Brain

Research Gains since the 1980s Gains since the 1980s Focused on High-Functioning ASD Focused on High-Functioning ASD Greatly improved by fMRI and PET Greatly improved by fMRI and PET Evoked Potentials (EPs) – scalp electrodes measuring response to stimuli Evoked Potentials (EPs) – scalp electrodes measuring response to stimuli Exogenous Potentials – Reflex reaction to a visual stimuli Exogenous Potentials – Reflex reaction to a visual stimuli Endogenous Potentials – Mental tasks Endogenous Potentials – Mental tasks EP research not focused on social, language, and reasoning deficits EP research not focused on social, language, and reasoning deficits MRI and CT measure topography MRI and CT measure topography

Language Cerebrum (forebrain): Cerebrum (forebrain): Frontal LobeFrontal Lobe Occipital LobeOccipital Lobe Parietal LobeParietal Lobe Temporal LobeTemporal Lobe Right HemisphereRight Hemisphere Left HemisphereLeft Hemisphere Cerebral CortexCerebral Cortex  Corpus Callosum

Significant Findings Less lateralization (M ü ller et al., 1999; Boddaert at al, 2003; Just et al., 2004) Less lateralization (M ü ller et al., 1999; Boddaert at al, 2003; Just et al., 2004) Reversed asymmetry (Herbert et al., 2002; Just et al, 2004) Reversed asymmetry (Herbert et al., 2002; Just et al, 2004) Suggest left temporal impairments Suggest left temporal impairments Significantly longer communication between spheres Significantly longer communication between spheres

Temporal Lobe Speech Memory Hearing

Wernicke and Broca’s Area Part of Brodmann’s Area Part of Brodmann’s Area

Broca’s Area Production of speech Production of speech Sends information for oral-motor activities Sends information for oral-motor activities Typical impairments seen in stutterers Typical impairments seen in stutterers

Wernicke’s Area Receptive Language Center Receptive Language Center Language is recognized and understood Language is recognized and understood

Geschwind’s Territory

Hippocampus Associative memory and chaining Associative memory and chaining Spatial navigation Spatial navigation Behavior Inhibition Behavior Inhibition Inconsistent findings, but altered size Inconsistent findings, but altered size

Frontal Lobe Executive Functioning Executive Functioning Behavior InhibitionBehavior Inhibition Linked causal relationshipsLinked causal relationships Similarities and differencesSimilarities and differences Long-term memoryLong-term memory Organization and planningOrganization and planning Information retrievalInformation retrieval Emotional regulation/motivationEmotional regulation/motivation Higher-level abstract reasoningHigher-level abstract reasoning

Parietal Lobe Integrates sensory information Integrates sensory information Knowledge of numbers and relations Knowledge of numbers and relations Manipulation of objects Manipulation of objects Contributes to visuospatial processing Contributes to visuospatial processing

Occipital Lobe Processes visual information and sends to the visual cortex Processes visual information and sends to the visual cortex Dysgraphia seen in occipital impairments Dysgraphia seen in occipital impairments

Cingulate Cortex Ridge in the medial part of the brain Ridge in the medial part of the brain Connects to the thalamus, neocortex, and the cerebral cortex Connects to the thalamus, neocortex, and the cerebral cortex Works with the limbic system to control emotion, learning, and memory Works with the limbic system to control emotion, learning, and memory Unconscious priming (executive function) Unconscious priming (executive function)

Social Functioning Deficits in social perception: Reading facial expressions Social cognition/Theory of Mind Social Motivatoin

Fusiform Gyrus Small ridge on the underside of the temporal lobe Small ridge on the underside of the temporal lobe Designed to discriminate faces from other objects Designed to discriminate faces from other objects Fusiform Face Area (FFA) – recognition of faces Fusiform Face Area (FFA) – recognition of faces Superior Temporal Sulcus (STS) – recognition of human speech and other non-verbal social cues from other sounds Superior Temporal Sulcus (STS) – recognition of human speech and other non-verbal social cues from other sounds

Fusiform Gyrus Waiter et al (2004) found enlargement in ASD Waiter et al (2004) found enlargement in ASD Specific enlargements seen in the FFA region Specific enlargements seen in the FFA region Amygdala Amygdala Pre-frontal cortex Pre-frontal cortex Temporal lobe Temporal lobe Frontal lobe Frontal lobe

Behavior Outward Aggression Outward Aggression Self-Injury Self-Injury Repetitive Repetitive Stereotypic Stereotypic Self-Stimulatory Self-Stimulatory

Cerebellum Sensory perception and motor control Sensory perception and motor control Increased size/ white matter Increased size/ white matter Lack of vermis originally theorized Lack of vermis originally theorized

Amygdala Social behavior, emotion, cognition Social behavior, emotion, cognition Inconsistent findings Inconsistent findings Range in sizes Range in sizes Asperger’s shows larger left side amygdala than infantile autism Asperger’s shows larger left side amygdala than infantile autism

Amygdala & Emotions YouTube: YouTube:

Basal Ganglia Associated with motor and learning (group of structures) Associated with motor and learning (group of structures) Speculated cause of repetitive behaviors Speculated cause of repetitive behaviors Larger the caudate, the more repetition Larger the caudate, the more repetition

Thalamus Kind of connector – arousal, alertness, sleep, consciousness, information processing Kind of connector – arousal, alertness, sleep, consciousness, information processing Underdeveloped connections Underdeveloped connections

Corpus Callosum White matter that connects the hemispheres White matter that connects the hemispheres Some studies report reduction in size Some studies report reduction in size Don’t know much Don’t know much

Brainstem Controls body functions Controls body functions Contrasting findings Contrasting findings

How this Impacts Learning Needs: Needs: AbstractionAbstraction Conceptual reasoningConceptual reasoning Memory and languageMemory and language Spatial reasoningSpatial reasoning Sensoriperceptual reasoningSensoriperceptual reasoning Motor abilities (Rumsey & Hamburger, 1988/1990)Motor abilities (Rumsey & Hamburger, 1988/1990)

HFA/Asperger’s Enhanced Abilities: Enhanced Abilities: AttentionAttention Sensory perceptionSensory perception Elementary motor planningElementary motor planning Simply memorySimply memory Formal languageFormal language Rule learningRule learning Visuospatial processingVisuospatial processing

Dr. Joe Piven, UNC Chapel Hill M.I.N.D. Institute Lecture Series, UC Davis, February 7, 2007