Notes covering lectures 4-7
Notes covering lectures 4-7 PSYCH 100
Popular in Introductory Psychology
verified elite notetaker
Popular in Psychlogy
One Day of Notes
verified elite notetaker
This 11 page Class Notes was uploaded by Christopher Raite on Friday February 5, 2016. The Class Notes belongs to PSYCH 100 at Pennsylvania State University taught by Joshua Wede in Winter 2016. Since its upload, it has received 33 views. For similar materials see Introductory Psychology in Psychlogy at Pennsylvania State University.
Reviews for Notes covering lectures 4-7
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 02/05/16
Lecture 4 – Neurons and Neurotransmitters Neuroscience and Behavior • Everything psychological is simultaneously biological • Everything we do/think happens because of patterns of activity in our brain Neurons • The body information system is built from billons of interconnected cells • Estimates of 100 billion (w/ 100 trillion connections between the them) Parts of a Neuron • Dendrite – Branching extensions at the cell body receives messages from other neurons • Cell Body (Soma) - Life support center of the neuron. • Axon - Cords of single extension of a neuron, covered with the myelin sheath to insulate and speed up messages to other neurons • Terminal Branches of axon - Branched ending of axons. Transmitting messages to other neurons. Action Potential • A brief electrical charge that travels down an axon • Generated by the movement of positively charged atoms in and out of channels in the axon’s membrane. • Input at dendrites • Strong enough input crosses a threshold and the cell fires – Action Potential: Ions run in and out of a cell body • Properties of action potentials o All-or-none response When activity exceeds the threshold neuron will fire and go below the threshold o Intensity All the same intensity Synapse Junction between the axon tip and the dendrite Tiny gap is called the synaptic gap or cleft Molecular Structure • Molecules have a particular 3-d shape • Different molecules have different shapes Neurotransmitters and Receptors • Similar to a lock and key o Accepts some neurotransmitters o Rejects others • When it accepts a neurotransmitter, it starts a chain reaction of events o physical, chemical, electrical o locally changes the cell membrane excitation (depolarization) inhibition (hyperpolarization) • Excitatory neurotransmitter – More likely for receiving cell to fire o agonists mimic/enhance neurotransmitter effect on receptor sites • Inhibitory neurotransmitter – More likely for receiving cell to stop firing o antagonists block/reduce cell’s response to other neurotransmitters How Neurotransmitters Influence Us • Serotonin- Regulates mood and sex drive • Prozac- One of the most widely prescribed drugs in the world o Some forms of depression seem to be related to limits in the use of serotonin o SSRI Prozac keeps serotonin bound to a receptor for longer than usual, increasing the effect (Inhibitory neurotransmitter) • Dopamine pathways are involved with diseases like schizophrenia, Tourette’s syndrome and Parkinson’s disease Nervous System • Nervous System: Consists of all the nerve cells. It is the body’s speedy, electrochemical communication system. • Central Nervous System (CNS): The brain and the spinal cord • Peripheral Nervous System (PNS): Everything else in body NOT including brain and spinal cord Kinds of neurons • Sensory Neurons - Carry incoming information from the sense receptors to the CNS. • Motor Neurons – Carry outgoing information from CNS to muscles/glands, neurons we use to move • Interneurons - Most neurons we have in our body and all the neurons in the brain are interneurons Central Nervous System • The spinal cord and reflexes • Simple reflexes: Hard wire reactions that are stored in the spinal cord Neural Networks • Interconnected neurons form networks in the brain. • These networks are complex and modify with growth and experience. • Provide basis for all cognition Lecture 5 – The Brain What's the deal with left and right brains? How can I measure what the brain does? •Neuropsychology •EEG (electroencephalogram) •PET (positron emission tomography) •fMRI (functional magnetic resonance imaging) Neuropsychology -People get damage to certain areas of the brain - Lose certain abilities Electroencephalogram (EEG) -An amplified recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp. -Watch the electrical current change through time - Great temporal resolution - Poor spatial resolution Positron Emission Tomography (PET) -Ingest radioactive glucose -Scanner detects where glucose goes while brain performs a given task Magnetic Resonance Imaging (MRI) -MRI Scans: Like an x-ray machine, but can look at soft tissue - Can see the structure of the brain - Excellent spatial resolution -Functional MRI -measures concentrations of oxygen -Can I read your mind? •Researchers have started to study whether fMRI measurements can indicate what you are thinking or experiencing – Reliably predicts whether you are looking at a house or a face –Can tell whether you are adding or subtracting two numbers (Haynes et al., 2006) -Can I detect a lie? Brain Structures - Brainstem - the oldest part of the brain, beginning where the spinal cord enters the skull. - Responsible for automatic survival functions -Thalamus - the brain’s sensory switchboard, located on top of the brainstem. - Direct messages to the sensory area of the cortex -Cerebellum - the “little brain” attached to the rear of the brainstem. - It helps coordinate voluntary movements and balance -Limbic system - A doughnut-shaped system of neural structures at the border of the brainstem and cerebrum - Associated with emotions such as aggression and drive for sex and food Structure of the Cortex - Each brain hemisphere is divided into four lobes seperated by promient fussures Our Divided Brain - Our brain is divided into two hemispheres Contralateral Processing -Processing in the brain is done on the opposite side of the body - Control of the left arm is from the right side of the brain -Information from the left field of view (not left eye) is processed in the right side of the brain Corpus Callosum - Hemispheres connected by a mass of nerval fibers -In severe cases of epilepsy, the corpus callosum may be cut, in order to prevent seizures from spreading throughout the brain -Behavior changes very little Split Brain Patients -Shown different words to left or right visual field -Subjects given two tasks –Verbal report –Spatial task (pick object, draw object, etc.) Results -If “key” flashes on left side –Subject cannot name it –Subject can pick up key with left hand -If “ring” flashes on right side –Subject can name it –Can pick it up with right hand Hemispheric Specialization -Lateralization -Left hemisphere – Specializes in language -Right hemisphere – Specializes in art and music perception -This seems to indicate that each hemisphere processes different information -Results led to further study and common belief –Left side: language, analytical, classification –Right side: art, music, recognition of faces and shapes Functions of the Cortex -Motor Cortex – Area at rear of frontal lobe controlling our voluntary movements -Sensory Cortex (parietal cortex) receives information from skin surface and sense organs. -Visual and Auditory Function -Particular areas of the brain associated with vision and audition - Vision – occipital lobe -Audition – temporal lobe -Association areas-More intelligent animals have increased “uncommitted” or association areas of the cortex. -Language - Aphasia is an impairment of language, usually caused by left hemisphere damage either to Broca’s area (impaired speaking) or to Wernicke’s area (impaired understanding). Brain's Plasticity -Brain is sculpted by our genes but also by our experiences. -Plasticity – Refers to the brains ability to modify itself after some sort of illness or injury Lecture 6 – Sensation and Perception Sensation & Perception • How do we construct our representations of the external world? • Sensation • Detection of physical energy (stimulus) from the environment and conversion into neural signals • Perception • How we select, organize, and interpret our sensations Information processing • Cognition requires two types of processing • Bottom-up Processing • Begins with sensory information • Works up to the brain’s integration of sensory information • Top-down processing • Begins with knowledge and expectation • Interpret sensory, physical data Physical World Psychological World Psychophysics Light Brightness A study of the relationship between physical characteristics of stimuli and our Sound Volume psychological experience of them. Pressure Weight Sugar Sweet Absolute Threshold – Minimum amount of stimulation needed to detect a stimulus 50% of the time Difference Threshold –Minimum difference between two stimuli required for detection 50% of the time o Weber’s Law - Two stimuli must differ by a constant percentage (rather than a constant amount), to be perceived as different. Sensory Adaptation Diminished sensitivity as a consequence of constant stimulation. Attention The world contains more information than we can fully interpret or process all at once The ability to deal with some stimuli and not others is Selective Attention Part of attention seems to be due to mental effort on your part Part of attention seems a natural side effect of mental effort Part of attention seems effortless Attention is a powerful force o When you are busy doing something else, you can fail to observe even very significant things o That’s why is not a good idea to talk on a cell phone while driving a car Another way to interpret these results is that attention is necessary to detect stimulus changes o Explains how people can “look” but not “see” walking into doors driving into trains why magicians use flashes of light! We can’t possibly process all of the information from our environment Selective attention allows us to process information that is important to us o Focus on limited parts of the environment Can lead to unintentional blindness/change blindness o Failing to detect visible object when attention is directed elsewhere Lecture 7 – Vision Why do we see afterimages? Transduction In sensation, transformation of stimulus energy into neural impulses. Phototransduction – conversion of energy into neural impulses The Stimulus Input: Light Energy Light Characteristics Wavelength (hue/color) Intensity (brightness) Saturation (purity) Wavelength (Hue) Wavelength the distance from the peak of one wave to the peak of the next. Different wavelengths of light result in different colors Intensity (Brightness/Lightness) Intensity – Amount of energy in a wave Related to perceived brightness Parts of the eye Cornea Transparent tissue where light enters the eye. Iris Muscle that expands and contracts to change the size of opening Pupil Adjustable opening that lets light into the eye Lens Focuses the light rays on the retina. Retina Contains sensory receptors that process visual information and send it to the brain. The Eye The Lens Accommodation The eyes lens change shape to help focus objects in the retina Nearsightedness Image focused in front Farsightedness Imaged focused behind retina Retina The light sensation in the inner surface of the eye Contains reception of cones Plus layers of other neurons (bipolar, ganglion cells) that process visual information. Fovea, Optic Nerve & Blind Spot Fovea Optic nerve Carries neural impulses from the eye to the brain. Blind Spot Point where optic nerve leaves the eye Test your Blind Spot Close your left eye, and with the right eye fixate on the black dot. Move the page towards and away from your eye. At some point the dot on the right will disappear due to blind spot. + Photoreceptors Visual Information Processing Optic nerves connect to the thalamus in the middle of the brain, and the thalamus to the visual cortex. Nerve cells in the visual cortex respond to specific features, like edges, angle, and movement. Shape Detection Specific combinations of temporal lobe activity occur as people look at shoes, faces, chairs and houses Theories of Color Vision Trichromatic Theory Retina contains three receptors maximally sensitive to red, blue and green wavelengths. Color Blindness Most people are trichromatic If red cones filled with green photopigment (or vice versa): dichromats more common in males (approx. 10%) Opponent Process Theory We process four primary colors opposed in pairs of red-green, blue-yellow, and black-white (Hering). Competition between colors Can not see both at the same time
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'