Psychology study guide chapter 2 Phrenology Developed by Franz Gall in the early 1800 s Study of bumps on the skull and the relationship to mental abilities and character traits Yielded one big idea: different areas of the brain so different things Location and function Structure of neuron Action potential Neural impulse that travels down like a wave Waves move down the axon through it is only mode made up of ion exchanges moving in and out Action potential (send) when at threshold Threshold is reached when excitatory (fire!) signals out weigh don t fire Cant fire harder or softer; either it fires or is doesn t More pain means that more neurons are firing Synapse is goes from one neuron to another (between cells) Through the terminal branches to a new cell Synapse Junction between axon tip of sending neuron and dendrite cell body of receiving neuron Synapse also known as synaptic junction or synaptic gap Neurotransmitters
Chemicals used to send a signal across the synaptic gap Reuptake Recycling neurotransmitters Neurotransmitters stimulates the neurons on the recycling neuron the chemicals are taken back up into the sending neuron to be used again Roles of neurotransmitters Chemicals Serotonin Dopamine ACH Norepinephrine Gaba Glutamate Effect Mood, hunger, sleep, arousal/depression, also anti-depression (depending on amount) Movement, learning, attention, emotion; over supply can cause schizophrenia undersupply can cause ADHD and paresis Muscle burn, learning, memory, producing neurons can cause Alzheimer s and disease progress Control arousal an undersupply can depress and ADHD problems Major inhibitory neurotransmitter and undersupply can cause seizures, tremors and insomnia Major excitatory involved in memory and oversupply can cause migraines and seizures (why people avoid MSG) Serotonin pathways Networks of neurons that communicates with neurons and help regulate mood
Dopamine pathways Networks of neurons that communicate with dopamine are involved in focusing attention and controlling movement Neurotransmitter note Like a lock and key-it has to fit all of the way there cannot be any parts of the key missing Agonist: molecule fits in the receptor site and activates it acting like the neurotransmitter Antagonist: molecule fills the lock so that the neurotransmitter cannot get in and activate receptor site Nervous system Central nervous system (CNS) The brain and spinal chord Peripheral nervous system (PNS) Everything else Neurons Sensory neurons: messages in from the body s tissue and sensory receptors to CNS for processing Motor neurons: instructions out from CNS out to the body s tissues Interneurons: (in the brain and the spinal chord) process information between sensory input and motor output Nerves Not the same as neurons Cables containing many axons Part of PNS and connects muscles glands and sense organs to the CNS Nervous system Central Periphery Automatic Self regulated action internal organ glands Sympathetic Arousing Parasympathetic Calming Somatic Controls voluntary movements skeletal muscles Parasympathetic: NS calms (rest and digest) NS arouses Fight on flight Brain is a web of neural networks Spinal chord is full of interneurons that sometimes have a mind of their own Neural networks These complex webs of interconnected neurons form with experience Remember; neurons that fire together wire together Interneurons in your spine
Your spines interneurons trigger your hand to pull away from a fire before you can say ow Example of reflex reaction Endocrine system Hypothalamus: brain region controlling pituitary gland Thyroid gland: activates metabolism etc. Adrenal glands: inner part helps trigger fight-or-flight response Testis: male sex hormone Ovary: female sex hormone Parathyroid: help regulate level of calcium in blood Pituitary gland: secrets many different hormones some which affect other glands Pancreas: regulate level of sugar in blood Endocrine system: refers to a set of glands that produce chemical messages called hormones Sends molecules as messages Like the nervous system but it sends it through the blood stream, not synapses Molecules are called hormones, produces in various glands around the body Message to brain and other tissues Adrenal glands Produce hormones such as adrenaline, epinephrine, noradrenaline, norepinephrine and cortisol Synaptic fight-or-flight nervous system responds to stress by sending a message to the adrenal glands to release happiness Effect: increase heart rate blood pressure and sugar, these produce energy fro fight-on-flight Pituitary gland Master gland of endocrine system Controlled through NS by near by brain area the hippocampus Produces hormones that regulate other glands such as the thyroid Also produces growth hormone especially during sleep and oxytocin, the bonding hormone Brain Strategies find out what is different between mind if brain is not working Injury, how does it impact the mind Brain damage Lesions: surgical destruction of brain tissue On animals Some insight especially bout less complex brain structures No longer necessary now chemically or magnetically able to deactivate or deactivate the brain to get the same information Split brain patients Split = surgery which the connection between the brain hemispheres is cut in order to end seizures of the brain studies of split brain patients has yielded insights Stimulate brain
Parts of brain and neurons can be stimulated chemically electrically and magnetically Result in behaviors such as giggling head turning or stimulates vivid recall Researchers can see which neurons of neuron networks fire in conjunction with certain mental experiments and even specific concepts EEG a recording of electrical waves sweeping across the brain surface Useful In Studying seizures and sleep PET scan -Allows us to see what part of the brain is active by tracing where a radioactive form of glucose goes while brain performs given task MRI -makes images from signals produced by the spin of atoms Schizophrenics have done this FMRI reveals brain activity and function rather than structures fmri compress successive MRI images taken a split second apart and shows changes In The level of oxygen in blood flow in the brain Brain functions Brain stem and cerebellum: Coordinate body Limbic system arranges emotions and connects thought to body Cortex (outer covering) integrated info Brains less complex structures Brain stem made of pons and medulla Medulla controls breathing and heart beat Pons helps coordinate automatic and unconscious movements (swallow, blink) Someone with total brain damage above the medulla can breathe independently someone with brain damage in the medulla cannot Thalamus Inner chamber is the sensory switch board and router all sensory messages except smell are routed through the thalamus on the way to the cortex higher outer brain also sends messages from the cortex to medulla and cerebellum Reticular formation the network in the brain stem that enables alertness (arousal) from coma to wide awake (cat experiments) filters sensory information Cerebellum the little brain it helps coordinate voluntary movement such as playing a sport has many other functions including enabling nonverbal learning and memory
The limbic(border) system Limbic system coordinates emotions, fear, aggression, basic drives, hunger, sex, formation of episodic memories Hippocampus (seahorse) processes and conscious episodic memory Works with the amygdala to form emotionally charged memories Amygdala (almond) has two Lima bean shaped clusters that help process fear and aggression Hypothalamus Body temperature food and water intake like homeostasis involved in sex drive Hypothalamus below directs endocrine system via messages to pituitary gland Cerebral cortex Outer gray bark structure that is wrinkles in order to create more surface area for 20+ billion neurons Inner white stuff is axons linking part of the brain 180+filial cells which feed and protect neurons and assist in neural communication Brain has right and left hemisphere Frontal lobes Involved in speaking and muscle movements and in making planes and judgments Parietal lobes Include sensory cortex Occipital lobes Include visual areas receive visual information from opposite visual field Temporal lobes Include auditory processing areas sensory functions in cortex Sensory strip deals with info from tough stimuli Occipital lobe deals with visual info Temporal lobe deals with auditory info more complex animals have more cortical space devoted to integrating and associating info Frontal lobes active in executive functions such as judgment planning and inhibit action of impulses active in use of working memory and processing new memories Frontal line associating areas many functions in area behind sensory strip managing input from multiple senses performing spatial and mathematical reasoning monitoring sensation of movement temporal lobe association areas some abilities managed here
recognizing specific faces managing sensory input related to sound helping with understanding of spoken words Whole brain functions involves complex activities which require communication among association areas across the brain such as memory language attention meditation consciousness Specialization and integration visual cortex receives written words as visual stimulation angular gyrus transforms visual representation into auditory ones Wernicke s area interprets auditory code Boca s area controls speech muscles via motor cortex Motor cortex is how word is pronounced Plasticity (brain flexibility) if the brain is damaged in the general association areas in the cortex brain does not repair damaged neurons nut can restore some functions it can form new connections reassign excitatory networks and insert new neurons (some growth from stem cells) Our 2 hemispheres lateralization: going to one side 2 hemisphere serve some different functions How do we know about the functions? brain damage studies revealed many functions of the left hemisphere brain scans and split brain studies show more about the functions of the two hemispheres and how they coordinate with each other Split brain studies to end whole brain seizures some people have had surgery to cut the corpus callous (band I neural axons connecting two hemispheres) Researchers have studied the impact of this surgery on patients functioning Each hemisphere controls the opposite side of the body and is aware of visual field on the opposite side Without corpus callosum the halves of the brain cannot communicate and the two halves of the visual field do not work together Only the left half of the brain. Has enough verbal ability to express thoughts out loud Split visual field each hemisphere does not perceive what each eye sees, instead it perceives half of the view of what is I. Front of you that Divided brain people are able to follow two instructions and draw two shapes at the same time Drawback, people can be frustrated that the left and right sides do different things