![Paul Broca [1800s]
• Suggested localization](https://image.slidesharecdn.com/lecture8brainstructure-141015141033-conversion-gate01/85/Lecture-8-brain-structure-23-320.jpg)
Lecture 8 brain structure
- 1. Brain Structure and Function
- 2. “If the human brain were so simple that we could understand it, we would be so simple that we couldn’t” -Emerson Pugh, The Biological Origin of Human Values (1977)
- 3. Phineas Gage • September 13th, 1848 • Phineas 25 years old • Rutland & Burlington Railroad, Cavendish, VT • Paving the way for new RR tracks • “Tamping Iron” – 1.25in x 3ft
- 5. • Accident Phineas Gage – Quick Recovery • Months later: “No longer Gage” – Before: capable, efficient, best foreman, well-balanced mind – After: extravagant, anti-social, liar, grossly profane • Stint with P.T Barnum • Died 12 years later • Video Clip
- 6. Evolution of the Brain Reptilian Paleomammalian Neomammalian
- 7. The Brain • Brainstem –responsible for automatic survival functions • Medulla –controls heartbeat and breathing
- 8. hippocampus BRAINSTEM Heart rate and breathing CEREBELLUM Coordination and balance Parts of the Brain amygdala pituitary THALAMUS Relays messages
- 9. The Cerebellum –helps coordinate voluntary movement and balance
- 10. The Limbic System • Hypothalamus, pituitary, amygdala, and hippocampus all deal with basic drives, emotions, and memory • Hypothalamus Hunger, thirst, body temperature, pleasure; regulates pituitary gland (hormones) • Pituitary “Master Gland” – Stimulates other glands to produce hormones • Amygdala Aggression (fight) and fear (flight) • Hippocampus Memory processing
- 11. The Limbic System Hypothalamus neural structure lying below (hypo) the thalamus; directs several maintenance activities Eating, drinking body temperature helps govern the endocrine system via the pituitary gland linked to emotion
- 12. The Limbic System Pituitary Gland A pea-sized gland attached to the hypothalamus by a thin stalk. Has two bulb-like lobes Secretes hormones that are used to control other glands GH – stimulates cells to grow & produce proteins FSH – stimluates ovaries to produce eggs/testes to produce sperm Prolactin – stimulates mammary glands to produce milk
- 13. The Limbic System • Amygdala two almond-shaped neural clusters that are components of the limbic system and are linked to emotion and fear
- 14. The Brain • Thalamus – the brain’s sensory switchboard, located on top of the brainstem – it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
- 15. The Cerebral Cortex • Cerebral Cortex –the body’s ultimate control and information processing center
- 16. The lobes of the cerebral hemispheres
- 17. The lobes of the cerebral hemispheres Planning, decision making speech Sensory Auditory Vision
- 18. The Cerebral Cortex • Frontal Lobes – involved in speaking and muscle movements and in making plans and judgments – the “executive” • Parietal Lobes – include the sensory cortex
- 19. The Cerebral Cortex • Occipital Lobes – include the visual areas, which receive visual information from the opposite visual field • Temporal Lobes – include the auditory areas, each of which receives auditory information primarily from the opposite ear
- 20. The Cerebral Cortex • Frontal (Forehead to top) Motor Cortex • Parietal (Top to rear) Sensory Cortex • Occipital (Back) Visual Cortex • Temporal (Above ears) Auditory Cortex
- 21. The Cerebral Cortex Aphasia impairment of language, usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding) –see clips Broca’s Area an area of the left frontal lobe that directs the muscle movements involved in speech Wernicke’s Area an area of the left temporal lobe involved in language comprehension and expression
- 22. Language Areas • Broca Expression • Wernicke Comprehension and reception • Aphasias LEFT HEMISPHERE
- 23. Paul Broca [1800s] • Suggested localization
- 24. Techniques to examine functions of the brain 1. Remove part of the brain & see what effect it has on behavior 2. Examine humans who have suffered brain damage
- 25. 3. Stimulate the brain 4. Record brain activity
- 28. Our Divided Brains • Corpus collosum – large bundle of neural fibers (myelinated axons, or white matter) connecting the two hemispheres
- 29. Hemispheric Specialization LEFT Symbolic thinking (Language) Detail Literal meaning RIGHT Spatial perception Overall picture Context, metaphor
- 30. Contra-lateral division of labor • Right hemisphere controls left side of body and visual field • Left hemisphere controls right side of body and visual field
- 31. Split Brain Patients • Epileptic patients had corpus callosum cut to reduce seizures in the brain • Lives largely unaffected, seizures reduced • Affected abilities related to naming objects in the left visual field
- 32. Brain Plasticity
- 33. Brain Plasticity • The ability of the brain to reorganize neural pathways based on new experiences • Persistent functional changes in the brain represent new knowledge • Age dependent component • Brain injuries
- 34. Environmental influences on neuroplasticity Impoverished environment Enriched environment
- 36. Sensation • The process by which the central nervous system receives input from the environment via sensory neurons • Bottom up processing – Piece together information to build a more complex system or a “bigger picture”
- 37. Perception • The process by which the brain interprets and organizes sensory information • Top-down processing – Overview details more specific details – “breaking it down”
- 38. The psychophysics of sensation • Absolute threshold the minimum stimulation needed to detect a stimulus with 50% accuracy • Subliminal stimulation below the absolute threshold for conscious awareness –May affect behavior without conscious awareness • Sensory adaptation/habituation diminished sensitivity to an unchanging stimulus
- 39. The five major senses • Vision – electromagnetic – Occipital lobe • Hearing – mechanical – Temporal lobe • Touch – mechanical – Sensory cortex • Taste – chemical – Gustatory insular cortex • Smell – chemical – Olfactory bulb – Orbitofrontal cortex – Vomeronasal organ?
- 40. The sixth sense And the seventh…and eighth…and ninth… • Vestibular balance and motion – Inner ear • Proprioceptive relative position of body parts – Parietal lobe • Temperature heat – Thermoreceptors throughout the body, sensory cortex • Nociception pain – Nociceptors throughout the body, sensory cortex
- 41. Thresholds of the five major senses
- 42. The Retina The retina at the back of the eye is actually part of the brain! Rods – brightness Cones – color