Neuroscience and the Brain

1. Neuroscienceand the Brain

2. Cerebral Cortex and Hemispheres • Cerebral cortex: outermost layer of the brain • Spread out all the wrinkles-cerebral cortex is the size of a bath towel! • Fissure marks the separation between hemispheres • Corpus callosum connects the hemispheres

3. Lobes • Frontal lobe • Motor strip • Sensory strip • Parietal lobe • Occipital lobe • Temporal lobe

4. Frontal Lobe • Complex! Prefrontal lobe: allows us to “mentally travel in time,” to remember past events and “see” ourselves in past situations Frontal lobe: allows us to come up with strategies or plans of action and makes sense of our environments Likely also responsible for social control and following social rules—case of Phineas Gage

5. Motor and Sensory Strips • Motor strip: controls all movement; contained in frontal lobe • If you activate parts of the motor strip during neural surgery, different parts of the body will react and move • Sensory strip: controls all feeling; contained in parietal lobe • If you activate parts of the sensory strip in surgery, the patient would feel itches, tingles, and even pain in parts of the body (most neurosurgery patients are awake during surgery!)

6. Occipital Lobe • Responsible for VISION • Even when your eyes are closed, all images in your thoughts and dreams activate your occipital lobe

7. Temporal Lobe • Responsible for HEARING and SPEECH • Some centers for speech are located here, though they overlap • Most speech areas are only in left hemisphere

8. Hemispheres and Handedness • One hemisphere has dominance—you can tell by what hand you write with!

9. Famous Lefties

10. Hemispheres • Left: verbal or speech material, language, logic, writing • Right: objects in space, art, music, some mathematical reasoning, emotional material

11. Lower Level Brain Structures • Brainstem: “basement” of the brain, begins where spinal cord swells and meets the brain, forming the Medulla • Pons: assists in controlling autonomic functions, sleep, arousal • Reticular formation: finger-shaped network of neurons that extends from spinal cord to the thalamus • Reads and directs nerve impulses between brain and body • Controls alertness

12. Lower Level Brain Structures • Thalamus: all senses except smell are routed through thalamus; also receives the brain’s replies and then directs them to the cerebellum and medulla • Cerebellum: “little brain” • Coordinates voluntary movement

13. Limbic System • Hippocampus: essential to memory processing • Amygdala: aggression and fear • Hypothalamus: regulates hunger and thirst, body temperature, sexual behavior • Smell is routed through limbic system, hence its connection to memory

14. Nervous System • Somatic: controls movements of skeletal muscles • Autonomic: controls glands of muscles of internal organs, including heartbeat, digestion, and glands • Sympathetic: prepares us for defensive action • Parasympathetic: counters the sympathetic nervous system; keeps us in a steady internal state

15. Endocrine System • Linked to neurons through neurotransmitters