NeuroscienceNeuroscienceand the Brainand the Brain

Cerebral Cortex and Cerebral Cortex and HemispheresHemispheres

Cerebral cortexCerebral cortex: : outermost layer of the outermost layer of the brainbrain

Spread out all the Spread out all the wrinkles-cerebral cortex wrinkles-cerebral cortex is the size of a bath is the size of a bath towel!towel!

Fissure Fissure marks the marks the separation between separation between hemisphereshemispheres

Corpus callosum Corpus callosum connects the connects the hemisphereshemispheres

LobesLobes

Frontal lobeFrontal lobe Motor stripMotor strip Sensory stripSensory strip Parietal lobeParietal lobe Occipital lobeOccipital lobe Temporal lobeTemporal lobe

Frontal LobeFrontal Lobe Complex!Complex!Prefrontal lobe: Prefrontal lobe: allows us to “mentally allows us to “mentally

travel in time,” to remember past events travel in time,” to remember past events and “see” ourselves in past situationsand “see” ourselves in past situations

Frontal lobeFrontal lobe: allows us to come up with : allows us to come up with strategies or plans of action and makes strategies or plans of action and makes sense of our environmentssense of our environments

Likely also responsible for social control Likely also responsible for social control and following social rules—case of and following social rules—case of Phineas GagePhineas Gage

Motor and Sensory StripsMotor and Sensory Strips Motor strip: Motor strip: controls all movement; contained controls all movement; contained

in frontal lobein frontal lobe If you activate parts of the motor strip during If you activate parts of the motor strip during

neural surgery, different parts of the body will neural surgery, different parts of the body will react and movereact and move

Sensory strip: Sensory strip: controls all feeling; contained in controls all feeling; contained in parietal lobeparietal lobe

If you activate parts of the sensory strip in If you activate parts of the sensory strip in surgery, the patient would feel itches, tingles, surgery, the patient would feel itches, tingles, and even pain in parts of the body (most and even pain in parts of the body (most neurosurgery patients are awake during neurosurgery patients are awake during surgery!)surgery!)

Occipital LobeOccipital Lobe

Responsible for Responsible for VISIONVISION

Even when your Even when your eyes are closed, all eyes are closed, all images in your images in your thoughts and dreams thoughts and dreams activate your activate your occipital lobeoccipital lobe

Temporal LobeTemporal Lobe

Responsible for Responsible for HEARING and HEARING and SPEECHSPEECH

Some centers for Some centers for speech are located speech are located here, though they here, though they overlapoverlap

Most speech areas Most speech areas are only in left are only in left hemisphere hemisphere

Hemispheres and Hemispheres and HandednessHandedness

One hemisphere has dominance—you One hemisphere has dominance—you can tell by what hand you write with!can tell by what hand you write with!

Famous LeftiesFamous Lefties

HemispheresHemispheres

Left: verbal or speech material, language, Left: verbal or speech material, language, logic, writinglogic, writing

Right: objects in space, art, music, some Right: objects in space, art, music, some mathematical reasoning, emotional materialmathematical reasoning, emotional material

Lower Level Brain Lower Level Brain StructuresStructures

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

Lower Level Brain Lower Level Brain StructuresStructures

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

Limbic SystemLimbic 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

Nervous SystemNervous System

Somatic: Somatic: controls movements of skeletal muscles

Autonomic: Autonomic: controls glands of muscles of internal organs, including heartbeat, digestion, and glands

Sympathetic: Sympathetic: prepares us for defensive action Parasympathetic: Parasympathetic: counters the sympathetic

nervous system; keeps us in a steady internal state

Endocrine SystemEndocrine System

Linked to neurons through Linked to neurons through neurotransmittersneurotransmitters