1 Psychology 304: Brain and Behaviour Lecture 24

2 Neurodevelopmental Disorders and Sensory Processing 2. How are sensory systems organized? 1. What neurodevelopmental disorders have been identified? (continued)

3 By the end of today’s class, you should be able to: 3. describe the hierarchical organization of sensory systems. 2. distinguish between sensation and perception. 1. describe the causes and symptoms of disorders associated with neurodevelopmental abnormalities.

4 6. review proposed explanations for synesthesia. 5. define the term “synesthesia.” 4. describe the “polymodal” functions of neurons of association areas.

5 What neurodevelopmental disorders have been identified? (continued) 6. Williams syndrome  Occurs when a region of genes on chromosome 7 fails to replicate and, therefore, is missing. Caused by errors in cell division.

6  Among the genes that are missing on chromosome 7 is a gene that controls the production of elastin, a protein that contributes to elasticity in internal organs and tissues.  Associated with abnormal brain development: characteristic patterns of atypical cortical volume.

7 William Syndrome: Cortical Volume

8  Accompanied by mental retardation, impaired spatial cognition, hypersociability, abnormalities in internal organs, and altered facial and body features.  Although individuals with Williams syndrome display language deficits, their language skills are remarkable given their relatively low IQ. Often, great musical abilities are observed.

9 William Syndrome: Physical Characteristics

10 William Syndrome: Physical Characteristics

11 How are sensory systems organized? Sensory systems are organized hierarchically: (a) Each level of a sensory system receives the majority of its input from the level below it. (b) Levels that are relatively high in the hierarchy have more specific functions and perform more complex functions than levels that are relatively low in the hierarchy.

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13 Neurodevelopmental Disorders and Sensory Processing 2. How are sensory systems organized? 1. What neurodevelopmental disorders have been identified? (continued)