Ch.3 Flashcards
Phrenology
Wildly popular theory in the 1800s. Assessed bumps on the head and attributed various personality and intellectual characteristics to those who sought their “expertise.” Phrenology —> bumpology assumed that enlargements of the skull corresponded to brain enlargement and that the brain enlargements were linked directly to different psychological capabilities. Franz Josh Gall based his hypothesis about supposed associations between brain areas and personality traits almost entirely on anecdotal observations, but it’s one virtue, was that it was falsifiable.
Deep brain stimulation (DBS)
Neurosurgical procedure that implants battery powered electrodes within the brain to provide electrical stimulation directly to specific areas. Wilbur Penfield discovered that depending on where he stimulated brain is produced highly specific responses, such as movements or vivid recall of memory. Worked to the existing idea that the brain stimulation could influence brain functions.
Which part of our brains do we use for what? A caution about localization of brain function
Localization a function when they identify brain areas that are particularly active during a specific psychological task. Be careful not to over emphasize localization of function though. We can’t always dissect higher brain functions in to narrower compounds. Because most brain regions work in concert. Just as multiple brain regions contribute to each psychological function, individual brain areas contribute to multiple psychological functions.
Ex: Broca’s Area, plays a role in speech production, also becomes active when we noticed that a musical note is off key. There’s enhanced activity in areas of the brain associated with strong emotions when listening to inspiring music, even though these regions are traditionally known as “musical areas.”
Neurons and its components
Neurons- nerve cells specialized for communication with each other. What makes a neuron a neuron is it electrified membrane- outer covering of cells that enables it to exchange electrical and chemical signals with other neurons.
Cell body- also called Soma it manufactures new cell components. Consists of small and large molecules. contains nucleus where proteins are made, serious damage to this part is fatal. Also provides continual renewal of cell components.
Dendrites- branchlike extensions for receiving information from other neurons.
Axons and axon terminals- specialized for sending messages to other neurons. Narrowness creates an area that’s usually activated by incoming signals. Tiny spheres called synaptic vesicles travel the length of the axon to the axon terminal. Once synaptic vesicle reaches end of the axon terminal, it waits for an electrical signal to travel down the length of the axon causing it to release neurotransmitters, the chemical messengers is that neurons used to talk with.
Synapses
Information is exchanged between cells at the synapse, between two neurons, or between a neuron and another cell, like a muscle or skin cell. Synaptic cleft, a gap Into which neurotransmitters are released from axon terminal. This gap is surrounded by small patches of membranes on each site. One on sending axon of the first neuron, and other on the receiving dendrite of a second neuron. As neurotransmitters are released from the axon of all into snaps, they are picked up quickly by receptors On dendrites of nearby neurons.
Glial cells
Astrocytes- most abundant of glial cells. Communicate closely with neurons, increasing their accuracy of transmission, to help control blood flow in the brain and play a vital role in development of embryo. Astrocytes, in concert with other glial cells, are intimately involved in thought, memory, and immune system. Can find astrocytes in abundant supply in blood brain barrier- a protective shield of blood vessels the insulate the brain from infection by bacteria, poisons, etc. Without the brain barrier, we’d be much more vulnerable to infection in the brain. Barrier is especially important because neurons, unlike other cells, aren’t easily replaceable or interchangeable. 
Oligodendrocyte- Promotes new connections among nerve cells and releases chemicals to aid in healing. In addition to this cell produces a rapper around axons in the brain and spinal cord called myelin sheath. Myelin sheath insulates axons and speeds up transmission of electrical signals down the length of the axon. Gaps along the way are called nodes. Between nodes electrical signal doesn’t stop. Neural signal jumps from node to node = speeding up it’s passage down the axon. Also clear away debris, acting as brains cellular garbage disposal. 
Potential difference
Resting potential
Threshold of excitation
Action potential’s
Absolute refractory period
-Electrical charge inside versus outside neuron.
-Baseline state, more negative inside and outside.
-When electrical charge inside neuron reaches a high enough level relative to outside, and electrical impulse called an action potential is triggered.
-Positively charged particles flow rapidly into axon and then flow out just as rapidly, causing a dramatic and sudden spike in positively charge followed by a dramatic and sudden decrease in charge, with inside charge ending up at a slightly more negative level than the original resting value. When action potential reaches axon terminal, it triggers the release of neurotransmitters into the synapse.
-Is a brief interval during which another action potential can’t occur.
Neurotransmission communication
After neurotransmitters released into the synapse, they bind with receptor sites along the dendrites. Neurotransmitters can be halted by reuptake back into axon terminal. Think of the release and reuptake as letting some will liquid trip out of the bottom of a straw (release) and then sucking it back up (reuptake). Different neurotransmitters send different messages. Some excite the nervous system increasing, its activity, whereas others inhibit the nervous system, decreasing it’s activity. Some play a role in movement, others in pain perception and others in thinking and Emotions. Specific meds target production or inhibit of the certain neurotransmitters. Trucks to interact with neurotransmitters system or called psycho active, meaning they affect mood, thinking, arousal, or observable behaviour.
Agonist- increase or mimic affect of neurotransmitter‘s. Reduce emotional response to painful stimuli, others block reuptake of neurotransmitters. Other neurotransmitters to remain in synapse longer than usual, these enhance the neurotransmitter‘s effect.
Antagonist- Block or decrease effect of a neurotransmitter.
Glutamate & GABA
Most common neurotransmitter in central nervous system. Glutamate rapidly excites neurons, increasing odds that they’ll talk with other neurons. Release of glutamate is associated with enhanced learning and memory. When abnormally elevated though it may contribute to schizophrenia and other mental disorders because in high doses it can be toxic, damaging neural receptors by overstimulating them. GABA inhibit neurons, thereby dampening neural activity. Tend to suppress overactive brain areas linked to worry and unwanted thoughts. Please critical roles in learning, memory, and sleeping.
Acetylcholine
Plays a role in arousal, selective attention, memory, and sleep. Neurons that connect directly to muscle cells also release this, allowing them to trigger movement.
This is how most insecticide to work; they limit breakdown of acetylcholine. (Allowing more Acetylcholine to stick around in the synapse).
Monoamines
Norepinephrine, dopamine, and Serotonin or monoamines neurotransmitters. (Because only contain one amino acid). Dopamine plays a critical role in motivation and in reward experiences that occur when we seek out or anticipate goals, whether they be sex, a fine meal, etc. Norepinephrine and Serotonin activate or deactivate various parts of the brain, influencing consciousness, arousal, movement, or readiness to respond to stimuli.
Neuropeptides
Are short strings of amino acids in the nervous system. Acts somewhat like neurotransmitters, but they tend to be more narrowly specialized in their jobs. Endorphins play specialized roles in pain reduction. Our brains contain a host of other neuropeptides: some regulate hunger and satiety (fullness) and others like neuropeptide Y, can alter learning and memory.
Neural plasticity
Nature- our genetic make up influences what kind of changes are possible and when they all occur during life. Nurture- consisting of learning, life events, injuries, and illnesses, affects our genetically influenced course.
Plasticity describes the nervous system’s ability to change overtime. Such as response to damage. Be skeptical about being “hardwired”, there are precious few human behaviours that are truly a hardwired. We are genetically predisposed towards these abilities, but they aren’t fixed, let alone predetermined. Nervous system continually changing sometimes by leaps and bounds. Unfortunately the nervous system often doesn’t change enough following injury or stroke, leading to permanent paralysis and disability.
Neural plasticity over development & learning
Brain is most flexible during early development. In order to be adaptable babies need to be born without too many sat patterns in the brain. That way, they can adapt to their circumstances across physical and culturally diversity Firemans.Network of neurons changes over the course of development in for primary ways:
1) Growth of dendrites and axons.
2) Synaptogenesis, formation of new synapses.
3) Pruning, consisting of death of certain neurons and retraction of axons to remove connections that aren’t useful. During pruning 70% of all neurons die off. This process is helpful because it’s streamlines neural organization, Thereby enhancing communication among brain structures.
4) Myelination, Insulation of axons with myelin sheath.
Brains change as we learn. These changes can result from formation of new synapse, generating increasing connections and communication among neurons. Also results from strengthening of existing synaptic connections, so that neurotransmitters released into synapses produce stronger, more prolonged response. This phenomenon is called potentiation.
Neurogenesis
Creation of new neurons in adult brain. Issue remains scientifically controversial. Neurogenesis me also play a useful role in learning, there’s some evidence of adult neurogenesis in humans involved in long-term learning.
Stem cells-haven’t committed themselves to a specific function, so they have the potential to become a wide variety of specialized cells.
Central nervous system
Divide central nervous system into six distinct sections or systems. Brain and spinal cord are protected by meninges, three thin layers of membranes, further production is afforded by cerebral ventricles, fluid filled pockets extend throat the brain and spinal cord. A clear liquid, called cerebrospinal fluid, runs through these ventricles and baths our brain and spinal cord, providing nutrients and cushioning us against injury.
Cerebral cortex
Consists of:
Frontal lobe: performs executive functions that coordinate other brain areas, motor planning, language and decision making.
Parietal lobe: processes touch information, integrate senses.
Temporal lobe: processes auditory information, language, and long-term memory.
Occipital lobe: process is visual information.
Cerebral cortex is the outer most layer of the cerebrum or forebrain and consists of two cerebral hemispheres and the corpus callosum connects the two hemispheres and permits them to talk with each other. Gray matter on the outside, white matter inside the brain.
Basal ganglia
Controlled movement, motor planning and skill and habit learning.
Structures in forebrain that help to control movement. After sensory information reaches primary and association areas, it’s transmitted to the basal ganglia. Which calculates a course of action and send blueprints of movement to the motor cortex. Also helps control our emotions, language, and memory. Guides our actions when we have a specific goal in mind and enable us to learn new skills and develop habits for behaviours that we value and find enjoyable and rewarding.
