Class Notes (835,426)
Canada (509,186)
York University (35,236)
Psychology (4,108)
PSYC 2510 (86)
Lecture

Chapter 3 The Biological Bases of Behavior.pdf

6 Pages
57 Views
Unlock Document

Department
Psychology
Course
PSYC 2510
Professor
Agnieszka Kopinska
Semester
Fall

Description
Chapter 3: The Biological Bases of Behavior Monday, October 03, 201112:07 PM Nervous Tissue - Myelin Sheath-- Insulating material that speeds up the transmission of signals - Glial Cells-- Provide structural support for neurons ○ Account for over 50% of brain's volume ○ Nourish neurons, help remove waste in neurons, and contribute to myelin formation ○ New research suggests they play a much more important role than once thought Neural Impulses - Neural impulses are the electrochemical messages relayed from one neuron to another - Involve the concentration of positively (Na+ and K+) and other negatively charged (Cl-) ions on oither side of the cell membrane - Resting potential-- when the neuron is inactive, negatively charged - Action potential-- neuron briefly shifts to a less negative or even positive charge ○ All-or-none law - The refractory period follows an action potential - Synapse-- junction where information is passed between neurons - Neurotransmitters ○ Stored in the terminal button ○ Often released by an action potential ○ Binds to specific receptors on postsynaptic neuron membrane - Postsynaptic Potential (PSP)-- the voltage change at the receptor site of a postsynaptic neuron upon receiving a neural impulse - Does not follow the all-or-none law: ○ Excitatory PSP ○ Inhibitory PSP - Neurotransmitters' fate: ○ Diffusion ○ Enzyme deactivation ○ Glial cells ○ Reuptake into the presynaptic neuron Neural Networks - Many neurons must be firing and communicating to effect an action - Across development, neural networks get organized and more refined ○ Pruning-- "Use it or lose it" Neurotransmitters - Chemical messengers - Play important role in physiological and psychological functioning - Lock and key system with receptors ○ Agonist-- chemical that mimics a neurotransmitter and binds to its receptors ○ Antagonist-- chemical that counteracts the effect of a neurotransmitter by blocking its access to receptor - Acetylcholine ○ Acts between motor neurons and voluntary muscles to allow movement (e.g., walking) ○ Contributes to attention, alertness, memory, and REM sleep Too much: convulsions, muscle paralysis, death Unit 1 Page 1 ○ Too much: convulsions, muscle paralysis, death ○ Too little: Alzheimer's (memory deficits) ○ Nicotine is an agonist - Monoamines ○ Regulate many aspects of daily life ○ Linked to many psychological disorders ○ E.g., dopamine, serotonin, norepinephrine - Dopamine ○ Regulates voluntary movements (e.g., walking) ○ Involved in learning, attention, emotion, and thought ○ Too much: links to schizophrenia ○ Too little: Parkinson's disease - Serotonin ○ Involved in regulation of mood, sleep, impulsivity, aggression, and appetite ○ Deficits may result in suicide and increased aggressive behavior - Norepinephrine ○ Involved with sleep, eating, and mood ○ Too little of both is linked to depression ○ SSRIs-- antidepressant medication - Amino acids ○ GABA-- produced inhibitory postsynaptic potentials of anxiety ○ Glutamate-- produces excitatory postsynaptic potentials  Learning  Memory - Endorphins ○ Natural pain killers, similar to opiates (e.g., opium, morphine, heroin) ○ Contribute to response to stress  Provide relief from pain  Produce feelings of pleasure - There are many other kinds of neurotransmitters in our nervous system The Nervous System - The peripheral nervous system (PNS) ○ The nerves other than those found in the central nervous system (CNS) ○ Nerves-- bundles of axons that run through the body ○ Subdivided into the somatic and autonomic nervous systems  Somatic nervous system □ Carries sensory and motor information to and from the CNS □ Allows for voluntary movements □ Afferent nerves-- carry info to the CNS □ Efferent nerves-- carry info from the CNS  Autonomic nervous system □ Regulates involuntary bodily processes (e.g., breathing, digestion, heart rate) □ Sympathetic system-- regulates the flight-or-flight response □ Parasympathetic system-- conserves physical resources - The central nervous system (CNS) ○ Consists of the brain and the spinal cord ○ Meninges protect the CNS ○ Cerebrospinal fluid (CSF) also protects the CNS from injury and nourishes the brain  Functions of the CSF: Unit 1 Page 2  Functions of the CSF: □ Buoyancy and circulation □ Protection from injury □ Chemical instability-- rinses metabolic waste from CNS to maintain pH □ Reduced intracranial pressure ○ Spinal cord  Bundles of axons transmit neural impulses from brain to peripheral nerves and vice-versa  Plays important role in communication between motor neurons and the brain ○ The brain  Weighs approximately 1.5kg  Is made up of billions of neurons  Is the executive coordinator of the nervous system Brain Research Approaches - Historically, the brain could only be examined through autopsies - Technological advances allowed for the study of the live brain ○ Mapping of brain function as opposed to only structure - Electrical Recordings ○ Broad patterns of brain electrical activity are recorded using an electroencephalograph (EEG) ○ Electric potentials in the brain cells are added up and amplified ○ Output is brain waves  Non-invasive  Ideal for use with children  Good measure of brain-behavior relationships  Helpful to measure changes in patterns of activity across development - Lesioning ○ The controlled, intentional destruction of a part of the brain ○ Done with animals in humane conditions (e.g., anesthetics) ○ Purpose is to study the relationship between brain and behavior more directly ○ Performed with a stereotaxic instrument - Electrical Stimulation of the Brain (ESB) ○ Stimulating a part of the brain using a weak electrical signal (not as strong as in lesioning) ○ Used mainly with animals ○ Can be used with humans in the context of brain surgery ○ Has been used in research on learning, seizures, and pain reduction, among others - Transcranial Magnetic Stimulation (TMS) ○ Temporarily alters brain activity in a specific brain area ○ Creates virtual lesions in small, specific, surface areas of the brain ○ Used to evaluate damage from strokes, MS, and spinal cord injuries ○ Non-invasive ○ Cannot be used to stimulate deep structures of the brain - Brain Imaging Techn
More Less

Related notes for PSYC 2510

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