400 likes | 722 Views
The Brain. How is the Brain studied?. CASE STUDIES. Study patients w/ brain damage ( case studies ). LESION METHOD. damaging an animal’s brain and observing. EEG. Electroencephalogram uses Electrodes measures brain waves Needle electrodes (this wires inserted into brain)
E N D
CASE STUDIES • Study patients w/ brain damage (case studies)
LESION METHOD • damaging an animal’s brain and observing
EEG • Electroencephalogram • uses Electrodes • measures brain waves • Needle electrodes (this wires inserted into brain) • Microelectrodes (can fit into one single cell)
MRI • magnetic resonance imaging • uses magnetic fields to produce vibrations in the center of atoms • these are then picked up by special receivers. • A computer then analyzes the signals.
Joseph Gall – • Phrenology • parts of brain serving different functions • ideas totally wrong • But concept is valid
Localization of function • particular functions for certain parts of the brain
BRAIN STEM • Located at base of the skull • Two main structures include:
Brain Stem (in yellow & green) Reticular activating system (RAS)
BRAIN STEM • Pons—sleeping, waking, & dreaming (& other things) • Medulla—breathing & heart rate & other things not consciously controlled {medulla is severed in hangings}
BRAIN STEM • Reticular Activating System(RAS)—screens info, demands that things get done, connects with higher areas, (could not be alert w/o RAS)
CEREBELLUM • On top of brain stem • Controls balance or coordination (may have other functions too)
cerebellum (in yellow) Reticular activating system (RAS)
LIMBIC SYSTEM • Group of brain areas which are involved in emotional reactions & behavior
Limbic System Reticular activating system (RAS)
THALAMUS • Deep in the interior • traffic officer of the brain • relays motor impulses from higher centers to spinal cord
THALAMUS • relays sensory messages to higher centers • smell is only sense that by passes thalamus
HYPOTHALAMUS • & PITUITARY GLAND • located under the thalamus • regulates drives in the human body (thirst, hunger, sex, body temperature, sweating, etc)
HYPOTHALAMUS • pituitary gland hangs from hypothalamus • master gland • secretes hormones (which send messages)
Amygdala • evaluates sensory information • helps mediate depression & anxiety (PET scans show high activity here in depressed people)
Hippocampus • looks like a seahorse • compares sensory info with what the brain has learned to expect about the world (when something is familiar it does not get activated, but the unknown stimulates it—example, one cant’ get excited everytime a car goes by)
Hippocampus • Gateway to memory (helps brain store info) • Example H.M. had it removed and could no longer remember new info (old stuff he could)
CEREBRUM • Looks like cauliflower • higher order activity takes place here • contains two cerebral hemispheres • connected by the corpus callosum
Cerebral Cortex • protects the cerebrum • thin layers of dense cells75% of all brain cells are in cortex • crimpled look provides enough room for all cells (without having giant heads)
Occipital lobes Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe • lower back of brain • receive visual info
Parietal lobes Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe • top of the brains cortex, receive info on pressure, pain, touch, & temperature • messages from hands & face are especially sensitive thus more signals are used for them
Temporal lobes Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe • sides of the brains cortex (above ears), involved in hearing, memory, perception, emotion, (language comprehension usually in left lobe)
Frontal lobes Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe • front of brain’s cortex, short term memory, higher order thinking, initiative, creativity, social judgment, * (speech production usually in left lobe)
Frontal lobes Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe • motor cortex is here • Broca’s Area (speech production)
INTERESTING FACTS ABOUT LOBES • Bilingualism in early childhood is stored in same area (Broca’s Area), • but if 2nd language learned later in life it is not stored here.
INTERESTING FACTS ABOUT LOBES • If stimulated, the lobes would produce the same effects as when they receive the info from the body. • (example, if parietal lobe stimulated you might feel tingling or mild sensation)
INTERESTING FACTS ABOUT LOBES • But many areas are “silent” and do not do anything when stimulated
INTERESTING FACTS ABOUT LOBES • The PREFRONTAL CORTEX appears to be what separates humans from other species. • area barely exists in mice • 3.5% in cats • 7% in dogs • 17% in chimps • but almost 30% in humans.
INTERESTING FACTS ABOUT LOBES • Phineas Gage • (spike in head through frontal lobes) • retains cognitive functioning but personality changed forever.