Psychology 2.6

The "old" brain (or the reptilian brain)

• "Reptilian" ("old" brain)= parts of brain connected with survival/basic functions

Breathing, moving, thirst/hunger, rest, emotions, memories....

• All "older" brain functions occur automatically (no conscious effort)

**Our brains process most sensory information outside of our conscious awareness.

Where is the brainstem?

Begins on top of spinal cord (after entering skull)

"Crossover point": nerves from each side of brain connect with the opposite side of body

What does the brainstem do?

Controls the flow of messages between brain/rest of the body (regulates central NS); also controls basic body functions such as breathing, swallowing, heart rate, blood pressure, consciousness, feelings of fatigue/alertness

What are the three parts of the brainstem?

midbrain, pons, medulla oblongata

Where is the medulla located?

the base of the brainstem

What does the medulla do?

controls heartbeat and breathing

What is the Pons/where is it located?

part of brainstem that links medulla oblongata and thalamus

Connects upper and lower parts of the brain

What does the Pons do?

(serves as a message/relay station between cortex and cerebellum)

Relays signals pertaining to sleep and arousal levels

Where is the midbrain?

above the pons

What is the midbrain/what does it do?

Involved in visual and auditory information processing and coordination, as well as motor coordination

An assistant, not central processing area

Where/what is reticular formation?

Nerve network that travels through the brainstem and thalamus

What does reticular formation do?

Filters incoming stimuli and relays important info into other brain areas

Helps enable/control arousal, states of consciousness (alertness/sleep)

Where/what is the cerebellum?

Extends from rear of brainstem, called the "little brain"

What does the cerebellum do?

Processes sensory input, coordinates movement and balance, enables non-verbal learning/memory, helps us judge passing of time, modulates emotions, discriminate sounds/textures

Cerebellum injuries/damage= trouble walking, keeping balance, etc.- jerky, exaggerated movements

Alcohol/drug use affects cerebellum (similar loss of motor control)

What is the limbic system (mammal brain)?

Connects "old" brain parts with "new/neo-mammalian" brain (the cerebral hemispheres, cortexes; more sophisticated, in-depth activity)

Associated with emotion, behavior, motivation

What does the limbic system consist of?

Thalamus

Amygdala

Hippocampus

Hypothalamus

Where is the Thalamus?

located on top of the brainstem

What does the Thalamus do?

Brain's sensory control center (directs incoming sensory information to sensory-receiving areas in the cortex, transmits replies to cerebellum and medulla)

Like a travel "hub"= traffic passes through on their way somewhere else (similar function to the pons; acts as a relay station)

Where is the amygdala located?

medial temporal lobe (in front of the hippocampus)

What does the amygdala do?

• Neural clusters linked primarily to aggression and fear

• Electrical stimulation of amygdala= can produce aggression or massive fear (cats scared of mice)

Where is the hippocampus located?

temporal lobe (seahorse shape)

What does the hippocampus do?

*Processes conscious memories

"Seahorse" shape

• also involved in spacial perception (where an object is)

Where is the hypothalamus located?

located below the thalamus

What does the hypothalamus do?

governs many bodily "maintenance" activities (eating/drinking, body temperature, fight-or-flight response)

Also governs endocrine systems via pituitary gland (linked to emotion/reward)

What are the two sides of the thalamus?

lateral and ventromedial

What does the LH (lateral) part of the thalamus do?

regulates hunger. If damaged= no appetite (less hunger)

What does the VMH (ventromedial) part of the thalamus do?

regulates satiety/fullness. If damaged= people never feel full (very much hunger)

What 4 f's does the thalamus regulate?

Fighting, fleeing, feeding, and mating

Cerebrum

(our two hemispheres) contribute 85% of brain's weight (enable perceptions, speaking, thinking- more sophisticated, complex activities)

Cerebral cortex

• covers the 2 hemispheres of our brain

• (thin surface layer of interconnected neural cells- acts as our body's control and information-processing center)

• Cerebral cortex= 20+ billion neurons and over 300 trillion synaptic connections

left and right hemispheres

• interior is filled mainly with axons connecting the cortex to other regions of the brain.

Grey matter

• outermost layer of the cerebral cortex (the visible parts)

• Comprised of neuron cell bodies (somata) and unmyelinated axons

White matter

• inner layers of the cerebrum

• Comprised of myelinated axons of neurons

Glial cells

• Cells in nervous system that support, nourish and protect neurons (like worker bees)

• Neurons are like queen bees (cannot feed/sheathe themselves)

Oligodendroglia

glial cells in the CNS that myelinate axons

Schwann cells

produce myelin in PNS

Astrocytes

(found in CNS: star-shaped, provide nutrients to neurons, envelop/protect blood vessels in brain, absorb dead neural cells)

Frontal lobe

located in front, behind forehead (involved with thinking/judgement, speech, muscle movements, problem-solving skills)

Temporal lobe

located beside ears (involved with hearing)

Occipital lobe

located in back of head (involved with vision)

Parietal lobe

top/back of head (involved with touch/sensory processing)

Somatosensory cortex

• located in front of parietal lobes; registers/processes body touch, sensation of movements

Receives incoming sensory info (inbox)

• More sensitive body regions= greater area in somatosensory cortex devoted to them

Motor cortex

• area at rear of frontal lobes; controls movement

Sends messages out to body ("outbox"/movement/motor activity)

Fritsch/Hitzig

• mild electrical stimulation to an animal's motor cortex made parts of its body move; also discovered that stimulating parts of either right or left hemisphere caused movements on the opposite side of body

• Body parts that require precise control and have higher sensitivity (fingers, mouth) occupy more motor cortical "space" than others (back, calf, etc.)

Association areas

Remaining cerebral cortical areas are dedicated to "higher-level" cognitive functions (thinking, speaking, learning, memory

AA's

primarily involved in processing/integrating info from the senses (to provide you with your perceptual experience- how you interpret sensory input)

AA's in prefrontal cortex

• AA's enable judgment, planning, processing of new memories, emotional control

• Damage can cause altered personality characteristics and lowered inhibitions (Phineas Gage)

AA's in parietal lobe

AA's enable math/spatial reasoning, spatial awareness (of one's own body)

AA's in temporal lobe

AA enables facial recognition

If damaged by stroke/head injury= loss of "memory" of faces (facial blindness)

Can still describe characteristics, facial features, gender, age, etc. but not ID a specific person

Broca's area

• located in the left frontal lobe (disrupts speaking ability- Broca's aphasia- can still comprehend normally)

Broca= babbling (B/B)- words often improperly formed, slow speech

Wernicke's area

• left temporal lobe (disrupts comprehension AND expression- Wernicke's aphasia; unable to comprehend anything AND "word salad" gibberish responses (clear speech, just nonsensical)

Left hemisphere

• more involved in logical, verbal, linear tasks

• controls right side of body

Right hemisphere

• more involved in intuitive, spatial, creative tasks

• controls left side of the body

Dual processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks

Significant damage to which of the following parts of the brain will most likely cause a person to fall into a deep coma from which the person will be unable to awaken?

reticular formation

ectrically stimulating a rat's amygdala would most likely produce which of the following?

agression

The person most strongly associated with identifying deficits in the motor speech area and in the ability to produce speech is

Paul broca

During a psychology experiment, a researcher uses a probe to lesion the ventromedial nucleus of a rat's hypothalamus. After the procedure the rat most likely will

eat more/gain weight

If an individual has lost the ability to feel pain in the left arm, there is most likely damage to what area of the brain?

right parietal lobe

People who have experienced severe damage to the frontal lobe of the brain seldom regain their ability to

make and carry out plans

For most people, which of the following is an activity based in the right hemisphere of the brain?

spatial reasoning

Which of the following parts of the brain is most active in decision-making?

cerebral cortex

Brain lateralization refers to the

inclination for certain cognitive processes to be specialized to one hemisphere of the brain or the othe

The right occipital lobe receives visual information from the

right half of both retinas