Presentation on theme: "Neuroscience and Behavior"— Presentation transcript:
1 Neuroscience and Behavior Myers PsychologyChapter 2Why are psychologists concerned with human biology? Everything psychological is simultaneously biological. We think, feel and act with our bodies. We are gaining understanding of sleep, dreams, depression, schizophrenia, hunger, etc.
2 Kinds of NeuronsSensory Neurons carry incoming information from the sense receptors to the CNS.Motor Neurons carry outgoing information from the CNS to muscles and glands.Interneuron connects the two neurons.
4 NeurotransmittersAcetylcholine (ACh): arousal, attention, memory, and motivationDopamine: motor disorders, such as Parkinson's diseaseSerotonin: emotions, arousal, and sleepNorepinephrine: wakefulness and arousal, as well as learning, memory, and emotional moodEndorphins: Reduce pain by inhibiting the neurons that transmit pain messages to the brainACh is found at every junction between a motor neuron and skeletal muscle- it causes muscles to contract.Endorphins (natural opiates) are released in response to pain and vigorous exercises- runners high and indifference to pain in some seriously injured people
5 Remember, the dendrite fibers receive information from sensory receptors or other neurons and the axon fibers pass that information along to other neurons- the Myelin sheath insulates the axons and helps speed up their impulses.
6 Pressure, heat, light or chemical messages can trigger an impulse (excitatory signal – inhibitory signal exceeds the threshold) The action potential is the impulse- the electrical charge that travels down the axon.Nerve cells communicate by using chemical messangers called neurotransmitters as they travel across the synapse.
7 ReuptakeNeurotransmitters in the synapse are reabsorbed into the sending neurons “applies the breaks” on neurotransmitter action.
8 Agonist or AntagonistREMEMBER agonist is an agent mimics the neurotransmitter antagonists are against blocks the neurotransmitterBotulism- This toxin prevents the release of AchHeroine or MorphieThorazine- Prevents dopamine from binding to receptor sitesCurare- Blocks ACH (so, what happens?)Botulism can cause paralysis or death.Thorazine is used to treat schizophreniaCurare- Poison darts Stuns or kills prey Blocks the Ach receptorsCaffeine increases the release of excitatoryneurotransmitters by blocking the transmitter (adenosine) that inhibits excitatory neurotransmitters, Prevents dopamine from being reabsorbed Leads to excess amounts of accumulated dopamine and Results in heightened arousal of the entire nervous system
9 Neuron Terms Resting potential: sitting and waiting…. Polarization: inside of neuron is negatively charged relative to the outsideNeural impulse (action potential): firing of a nerve cellThreshold: level an impulse must exceed to cause firingAll-or-None Law –no “in-between”Direction of impulse- only oneAbsolute- RESTING POTENTIAL- period when a neuron cannot fire again regardless of the strength of incoming message (typically 1 ms)
10 The Nervous System Telegraph Line video Click on the Youtube link to see School House Rock’s Telegraph Line.Telegraph Linevideo
11 Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS)The CNS= Simply the brain and spinal cordThe pNS= links the CNS to the rest of the body
12 Basic TasksSensory Input: Monitoring of external and internal environments.Integration: brain processes info- memory.Motor output: If necessary, signal effected organs to respond
13 Somatic vs. Autonomic Voluntary Skeletal muscle Axon terminals release acetylcholineAlways excitatoryControlled by the cerebrumInvoluntaryAxon terminals release acetylcholine or norepinephrineCan be excitatory or inhibitoryControlled by the homeostatic centers in the brain – pons, hypothalamus, medulla oblongata
14 Autonomic Nervous System 2 divisions:Sympathetic“Fight or flight”“E” divisionExercise, excitement, emergency, and embarrassmentParasympathetic“Rest and digest”“D” divisionDigestion, defecation, and diuresisSympathetic arouses your system-Parasympathetic calms your system
15 Nervous vs. Endocrine System Similarities:monitor stimuli and react to maintain homeostasis.Differences:The NS is a rapid, fast-acting system usually short lastingThe ES acts slower (via blood-borne chemical signals called Hormones) lasts longer.
16 HormonesHormones chemicals synthesized by the endocrine glands and secreted in the bloodstream.Growth, reproduction, metabolism and moodKeeps everything in balance when responding to stress, exertion, and internal thoughts.
17 Pituitary Gland AKA- Master Gland The anterior lobe = hormones that regulate other glands AND growth hormoneThe posterior lobe regulates water and salt balance AND secretes Thyrotropin for thyroid actionPineal Gland= Melatonin- sleep and wake cycles related to light and dark
18 Thyroid and Parathyroid Glands Thyroid – Thyroxin & Calcitonin increase metabolic rate and heart beatParathyroid – parathyroid hormone= increases calcium in the blood
19 Adrenal Glands Part of the Nervous System- function like hormones! Adrenal gland- stress hormone: cortisolMedulla (interior lobe) adrenaline AKA epinephrine and noradrenalin AKA norepinephrine(Remember- this is an international test, so you shouldn’t see adrenaline!)
20 Gonads Sex glands are located in different places in men and women. Regulate bodily development and maintain reproductive organs in adults.
22 Did you know? The human brain only weighs 3lbs. It consumes up to 20% of your body energyThe brain makes up less than 2.5%of your total body weightThe main sources of energy foryour brain comes fromglucose and oxygen.
23 Techniques to Study the Brain Lesion experimentally destroys brain tissue to study behaviors after such destruction.LobotomyECTHubel (1990)Clinical observations – Generally postmortum Studies of alterations in brain morphology (changes through time) due to neurological and psychiatric disease.Link is to a 7 minute video clip showing aggressive behaviors in animals and a human case of changing behaviors through a brain lesion.
24 Electroencephalogram (EEG) EEG- An amplified recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp.PET (positron emission tomography) Scan is a visual display of brain activity that detects a radioactive form of glucose (dye) while the brain performs a given task.MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce computer- generated images that distinguish among different types of brain tissue..FMRI (functional MRI)- looks at the mind in action
25 The Three Layers of the Brain Brain Stem and Cerebellum: Drives vitalfunctions - heart rate, breathing, digestion and motor coordination. (AKA reptilian brain, old brain)Limbic System: Involved in emotion and memory.Cerebrum: Enables reasoning, planning,creating and problem solving.
26 Brain StemThalamus: “Relay Station” of the brain.-for senses- except smell- switchboard for the brain.Midbrain: Regulatesbasic movement patterns -eating, drinking- Relay station for audio and visual stimulationPons: Regulates brainactivity during sleep anddreaming.- connects upper and lower brainMedulla: Controlsbreathing and heart rate.RETICULAR FORMATION: neurons that extend from the spinal cord to the Thalamus:
27 The CerebellumTwo “egg-shaped” pieces attached to the rear of the brain stem.Coordinates many functions:Movement and balanceHelps process sensory informationNonverbal learning, and memoryNew Research (Bower and Parsons) indicates that it also helps us judge time, modulate emotions, and discriminate sounds and textures.
28 Primarily linked to memory, emotions, and drives. The Limbic SystemPrimarily linked to memory, emotions, and drives.Hippocampus: Involved in establishing and processing long-term memories.Amygdala: in memory and emotion, (aggression & fear)Hypothalamus: Monitors blood to determine condition of body, pleasure rewards **** Stimulating the lateral hypothalamus causes a desire to eat, while stimulating the ventromedial hypothalamus causes a desire to stop eatingThe hormones of the hypothalamus influence the pituitary gland- thus a major link between the nervous and endocrine systems
29 The CerebrumCerebral Cortex: Thin gray-matter covering ofthe cerebrum. Carries on the major portion of our “higher” thinking and perceiving.It is the body’s ultimate control and information processing center.
30 Functions of the Cortex The Motor Cortex is the area at the rear of the frontal lobes that control voluntary movements. The Sensory Cortex (parietal cortex) receives information from skin surface and sense organs.OBJECTIVE 16| Summarize some of the findings on the functions of the motor cortex and the sensory cortex, and discuss the importance of the association areas.
31 Association AreasMore intelligent animals have increased “uncommitted” or association areas of the cortex.
32 The Frontal Lobe * is the largest part of the cortex *allows you to move parts of your body at will*it also allows you to think about the pastand plan for the future*it allows you to focus your attention,reflect, make decisions, solve problems,and engage in conversation
33 motion sensitive cells The Occipital LobesThis is where yourvision is processed*are located at the back of the brainThrough research scientistshave discovered that thereare:motion sensitive cellscolor sensitive cellsstrait line cells
34 The Temporal Lobe This part of the brain is concerned with perception andrecognition of auditorystimuli (hearing) andmemory (hippocampus).Language can be effected bytemporal lobe damage. Lefttemporal damages disturbrecognition of words.Right temporal damagecan cause a loss orinability to talk.
35 Language and the BrainAphasia—partial or complete inability to articulate ideas or understand language because of brain injury or damageBroca’s area—plays role in speech productionWernike’s area—plays role in understanding and meaningful speech
36 Brain has 2 Hemispheres Left & Right sides are separate Corpus Callosum : major pathway between hemispheresWhen “cut” sensory and motor output are still crossedHemispheres can’t share dataSome functions are ‘lateralized’ *not 100%)language on leftmath, music on rightLeftHemisphereCorpus CallosumRightkey words: left hemisphere; right hemisphere
37 Split brain operation—procedure used to reduces recurrent seizures of severe epilepsy Corpus callosum—thick band of axons that connects the two cerebral hemispheresA Hammer is Flashed in the LEFT visual field of a split brain patient.When asked, “What did you see?”What will they say?
38 2 Types of Plasticity (Ability for the brain tissue to repair itself or adopt functions) Structural Plasticity – Actual changing of the neuron or actually growing new neurons (Neurogenesis) only occurs in the hippocampusFunctional Plasticity – When an area of the brain takes up a new function to replace a damaged area of the brain.