The Brain: Our Control Center

1. The Brain:Our Control Center Unit II

2. The Three Brains • Hindbrain – Found at the rear base of the brain & involved in the basic processes of life. • Responsible for automatic and survival functions • Three Parts • Medulla • Pons • Cerebellum

3. The Three Brains • Midbrain – Located just above the hindbrain and relays sensory information (vision & hearing) upward. • Contains the Reticular Activating System • Forebrain – Located at the front of the brain and controls complex emotions, thoughts, and movements. • Most highly developed portion of the brain • 4 Parts • Thalamus, Hypothalamus, Cerebrum, & Limbic System

4. Three Brains

5. Hindbrain • Medulla – controls breathing, heart rate, swallowing, digestion – vital life functions • Pons – Involved in regulating body movement, attention, sleep, alertness, and facial expressions. • Cerebellum – Involved in balance and coordination. • Effected by alcohol (DUI test)

8. Midbrain • Reticular Activating System (RAS) – Stretches from the hindbrain through the midbrain into the lower part of the forebrain. • The “ignition” system of the brain • Coordinates basic sensory information involving attention, sleep, & arousal (heart rate/blood pressure) • Damage to the RAS can result in a permanent coma. • “Adapts” to sounds (ex. Sounds in the city) • Alcohol reduces activity

9. Midbrain

10. Forebrain • Thalamus – Relay station for sensory stimulation • Sorts & sends messages from the sense organs to the cerebral cortex for interpretation. • Hypothalamus – regulates vital functions – body temperature (homeostasis), storage of nutrients, motivation, and emotion • Hunger, thirst, sexual behavior, caring for offspring and aggression are regulated. • Controls the release of hormones from the pituitary gland.

11. Forebrain • Cerebrum – 70% of the brain’s weight • Receives sensory information • Transmits voluntary (conscious) motor information • Cerebral Cortex – the thinking center of the brain • Wrinkled surface of the brain • Involved in memory, language, emotions, complex motor functions, perception, etc. • Corpus Callosum – Connects the two brain hemispheres of the cerebral cortex

12. Forebrain • Limbic System – Located in the core of the forebrain on the inner edge of the cerebrum • Involved in learning & memory, emotion, hunger, sex & aggression • Two Structures: • Amygdala • Memory during emotional events • Fear & Aggression • Hippocampus • Memory Formation

14. Brain Lobes • Occipital Lobe (Back Of The Brain) • Main center for visual processing • Enables experiencing shapes, color, and motion. • Damage can cause blindness • Parietal Lobes (Top & Rear) • Involved in touch sensation (integrates sensory systems) • Touch, Temperature, & Pressure • Damage can destroy sense of touch

15. Brain Lobes • Temporal Lobe (Side, Behind Ears) • Hearing/Auditory Area • Wernicke’s Area • Involves the understanding of written & spoken language • Damage results in difficulty understanding written/spoken language • Can speak quickly & easily but speech often makes no sense • Broca’s Area • Involves the production of speech • Damage involves difficulty speaking • Damage to areas causes “aphasia” • Trouble understanding/Producing Language

17. Brain Lobes • Frontal Lobe (behind forehead) • Executive Center – Higher Mental Processes • Planning, Social Skills, Emotional Control, Problem Solving & Abstract Thinking • Motor Skills - Involved in the coordination of movement

19. Cerebral Hemispheres • Corpus Callosum – Collection of nerve bundles that carries messages between the two hemispheres • Each hemisphere controls the opposite side of the body. • Ex. Left hemisphere controls right side of the body

20. Cerebral Hemispheres • Lateralization – Specialization of a hemisphere in a particular function • Left Hemisphere – Generally handles verbal processing, language, speech, reading & writing • Right Hemisphere – Generally handles nonverbal processing, spatial relations, music, and visuals • People often thought of as “right or left-brained” • Misconception • Primary sensory & motor areas are symmetrical.

22. “Left-Brained” Or “Right-Brained”

23. Split Brain Patients • Patients who suffer from severe epileptic seizures have their corpus callosum severed • Epileptic Seizures – Bursts of abnormal neuron firings that generally occur in one hemisphere and then spread to the other • Subtle effects on brain functions • Ex. Able to describe verbally an object in their left hand but not in their right hand.

25. Accidents • Phineas Gage • 3.5 foot rod shot through his skull • Survived but extreme personality change • Shows that certain parts of the brain control certain aspects of our personality

26. Studying The Brain • Computerized axial tomography (CAT Scan) • X-rays beam around the head (3D view) • Pinpoints injuries and brain deterioration

27. Studying The Brain • Position Emission Topography (PET Scan) • Can see which areas of the brain are activated when performing tasks • A radioactive solution is injected into the body • Shows activityvs snapshot

28. Studying The Brain • Magnetic Resonance Imaging (MRI) • Can see structures in detail, hard to see areas • Magnetic fields and radio waves • More powerful than CAT scan, “slice images”

29. Studying The Brain • Electroencephalograph (EEG) • Measures electrical activity of brain using small electrodes pasted to you scalp • The rhythmical patterns produced are “brain waves”

30. Brain Lobes • Frontal Lobe (behind forehead) • Executive Center – Higher Mental Processes • Planning, Social Skills, Emotional Control, Problem Solving & Abstract Thinking • Motor Skills - Involved in the coordination of movement