Brain About 100 billion multipolar neurons 3 major portions: –Cerebrum Largest part Contains nerve centers associated with sensory and motor functions Provides higher mental functions, including memory and reasoning –Cerebellum - includes centers that coordinate voluntary movements –Brain stem – Connects parts of the nervous system (???) Regulates some visceral (???) activities

Hemisphere Dominance Right-Left Brain Test The dominant hemisphere controls the ability to use and understand language. Which hemisphere do you think is dominant in most of the population? Broca’s area (???) in the dominant hemisphere controls the muscles used in speaking.

Hemisphere Functions Dominant Hemisphere Non-dominant Hemisphere Language-related activities: reading, writing, speaking Nonverbal functions: 1. Motor tasks requiring orientation of body in space Complex intellectual functions requiring verbal, analytical, and computational skills 2. Recognition and understanding of musical patterns 3. Nonverbal visual experiences

Corpus Callosum (???) and Hemisphere Dominance What is it? Nerve fibers connecting the 2 cerebral hemispheres Functions: –Allows the dominant hemisphere to control the motor cortex of the non- dominant hemisphere. –Transfers info received by the non- dominant hemisphere to the dominant hemisphere for use in decision-making.