Textbook Notes (368,434)
Canada (161,878)
Psychology (1,112)
PSYC 221 (51)
Chapter 2

PSYC 221 Chapter 2: PSYC221 Chapter 2 Textbook Notes
Premium

7 Pages
35 Views
Unlock Document

Department
Psychology
Course
PSYC 221
Professor
Monica Castelhano
Semester
Winter

Description
PSYCHOLOGY 221: COGNITIVE PSYCHOLOGY WEEK 1 Chapter 2: Cognitive Neuroscience - What physiological changes happen in your mind when you hear your alarm clock and turn it off in the morning? o Happens in steps: hearing the sound when sound wave shit his ear, stimulate receptors, change sound energy to electrical, reach auditory area of the brain etc o Before this, must know that pressing snooze button will silence alarm temporarily o Complex series of events - Cognitive neuroscience is the study of the physiological basis of cognition - Understand basic principles of nervous system functioning by first considering neurons that are the building blocks and transmission lines of the nervous system o How they are organized to form the brain and signal information about the environment and our actions in the environment Neurons: The Building Blocks of the Nervous System The Microstructure of the Brain: Neurons - Nature of electrical signals in the brain and pathways that they travel began to be discovered in 19 century - By adding special stains to brain tissue, this increases the contrast between different types of tissue o Saw a network called nerve tract that was believed to be continuous which would provide a complex pathway for conducting signals - At the time, microscopes could not show details and without this, the nerve net appeared to be continuous - In 1870s, Camillo Golgi developed a stain completed by immersing slide of brain tissue in silver nitrate, colouring less than 1% of cells completely o Allowed to see structure of a single neuron - Ramon y Cajal wanted to understand the nature of nerve net o Used Golgi stain, staining only a few cells in brain tissue o Decided to study newborn animal brain tissue because lower density of cells ▪ Combination of these saw that they were individual cells ▪ This was the centerpiece of neuron doctrine, the idea that individual cells transmit signals in the NS and these cells are not continuous with other cells - Cell Body: contains mechanisms to keep the cell alive - Dendrites: branch out from the cell body to receive signals from other neurons - Axon/Nerve Fiber: transmit signals to other neurons - Neuron has a receiving and transmitting end and role, according to Cajal was to transmit signals o Won a Nobel Prize in 1906 for his ideas - 1 - PSYCHOLOGY 221: COGNITIVE PSYCHOLOGY - Also concluded: (1) there are also neurons in the brain that pick up info from the environment, like ones in our eyes or on our skin – called receptors – that have same structure but have specialized receptor to pick up info - (2) gap between end of neuron axon and dendrites of another is called a synapse - (3) Neurons are not indiscriminately connected to others, but form connections only with specific neurons to make a neural circuit The Signals that Travel in Neurons - In the 20s, Edgar Adrian recorded electrical signals from single sensory neurons due to development of electronic amplifiers o Made electrical signals generated by a neuron visible - Used microelectrodes (small hollow glass filled with conductive salt solution that pick up electrical signals) on single neurons - The recording electrode is connected to a recording device and the reference electrode is located outside of the tissue o Always measuring difference in charge o Ex. Difference starts as -70mV and when a nerve impulse or action potential is transmitted down the axon, the oscilloscope records these changes - Adrian also found that an AP travels all the way down an axon at same magnitude - Others showed that a chemical neurotransmitter is released at the end of the axon across the synapse to send a signal - Adrian studied the relationship between nerve firing and sense by increasing pressure on skin and recording changes o Height and shape of AP stayed the same, but rate of firing (# of Aps down an axon per second) increased o CONCLUSION: intensity of a stimulus can be represented by rate of nerve firing; rate of neural firing -> related to intensity of stimulation -> related to magnitude of experience - Quality of experience is associated with each sense (ex. Sound for hearing, smell for olfaction, light for vision) o Quality within a sense (ex. Different shapes, colours, movements) o All action potentials are basically the same o Neurons serving different cognitive functions transmit signals to different areas of the brain – called localization of function - 2 - PSYCHOLOGY 221: COGNITIVE PSYCHOLOGY Localization of Function - Specific functions are served by specific areas of the brain - Cognitive functions served by n the cerebral cortex – 3mm thick tissue that covers the brain Localization for Perception - Primary receiving areas for senses is one of the basic demonstrations of localization o Ex. When sound stimulates receptors in the ear, signals reach the temporal lobe - Occipital lobe: vision - Parietal lobe: skin – touch, temperature and pain - Frontal lobe: received signal from all senses; coordination of info from 2 or more senses - Taste and smell = underside of temporal and part of temporal (smell) - Initially identified by noting effects of brain damage - Prosopagnosia is an inability to recognize faces due to damage to lower right side of brain in temporal lobe o Sometimes can’t even recognize their own reflection o Restricted only to faces; can recognize objects, places etc - Localization of function also demonstrated by recording from neurons in different areas of animal brains - Brain imaging allows researchers to see when and where the brain is active when humans carry out cognitive tasks o Position Emission Tomography (PET): centered around concept that blood flow increases to active areas of the brain ▪ Radioactive tracer injected into a person’s bloodstream and then scanned to measure the signal from the tracer at each location in brain ▪ Subtraction technique: - 3 - PSYCHOLOGY 221: COGNITIVE PSYCHOLOGY ▪ Have control state, stimulation state when the person does the task, and the activity due to manipulation is determined by subtracting the control from stimulation activity o Functional Magnetic Resonance Imaging (fMRI): also based on blood flow ▪ Hemoglobin contains a ferrous (iron) molecule and has magnetic properties so when a mag field is presented, hemoglobin lines up ▪ Hemoglobin in areas of high brain activity lose some oxygen, making them more magnetic and so, react more strongly ▪ Subtraction method also used - Fusiform face area (FFA): area that responds to faces; corresponds to prosopagnosia; in temporal cortex - Parahippocampal place area (PPA): activated by images showing indoor and outdoor scenes; important for spatial layout – activity increased for empty and full roo
More Less

Related notes for PSYC 221

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit