Class Notes (811,321)
Canada (494,649)
Psychology (3,457)
PSY396H1 (20)
Ljubojevic (19)

PSY396 June 5.docx

10 Pages
Unlock Document

University of Toronto St. George

PSY396 June 5, 2013 Addiction - Set of behaviours that revolve around one object more commonly a drug or specific behaviours - Unusual behaviours follow basic princapals of addiction Characterisitics of addition - Addiction of disorder 6 characterisitics - Salieance - Mood mod - Tolerance - Withdrawl – upon removal - Conflict – diagreemnt withing person or person and spciety - Relapse – defining addict after remoival of object of addiction bheaviour may carry over to relapses Video game - Wow young people tied down to computer videogames - Videogame addiction not recognized by dsm Gambling - Problem gambling defined difficulty time or money spent on gambling - Gambling small doses not problem but more time money and efforts person starts going into realm of problem gambling - Or pathological – loss in live – money and is recognized by dsm Symptoms of it - Exhibit – 5 from list of 10 diagnosed with disorder Biological contributing factors - Why wont to know about addiction - Interesting fidnign addiction difficult gambling – park disease start gambling - Affect nigrostriatal – detroiate and lead to hose of symptoms of motor control and movement - One drug used is ldopa – precursor to dopamine - Parkinsion patient – received ldop and boosting levels in brain become succeptile to gambling addicition - Hint dopamine in addiction - Not with dop nigrostriatal but in mesolimibic and less in mesocortical Dopamine reqard system - Main feature is function of dop neurtrans and mesolimbic projections - From vta to nucleus accumbens - Pathway is final common pathway for reward - Meaning – receive large modulatroory inputs from other prts of brain it is central player in determing motivation and emotion - Academic activity and ingestion of food and sex behavior activate the pathway – and activation signals reward value of behaviours Sketch - Vta - To nuc accubmes - Spiny – downstream nothing enjoyable occurring - Vta and nuc revieve input from many areas - Amygdala project to both and other areas and raphe nuclei provide sert imput - Arcuate nucle - Ppt – hold cholinergic cell bodies chole to vta - Axis is simple - But modulatory influences leave chance for quite few conflicts Dopamine reawd system - How reward is ecperienced - Influences - Bottom up – reasctuve reard system – reward and cues related to rewrding beh - Top down – to nuc acumbens and modulate experience of reward and involved difernt pfront areas and all contribute to modulatory input on to reward – reg of emotions planning of reward and impulsivity Reactive system - Vta nuc and amygldfa - Vta to nuc and amygdlaad - And amygfal to nuc and vta - Both influence each other and overall outputs influence nuc – further downstream something rearding is happening or about to - Activity is more basal – more impulsive less cognitive and related to an event that is tempting to a persn Top down - Top down influences more cog influences or conscious inf on ecperienc of reward - Amongst themselves and output influence nuc acumbens - Thought of as consciously avoid reward the will power Tow - Often in tug of war - Angel and devil on shoulder where activity of bottom up suppreses top down - Act of more cog in frontal cortex supreesion of bottom up of basic influences Dop reward system - Red increase and blue decrease Dop - Who wins tug of war determine what nuc acumbens do and signal to brain something reawarding is happening and effect change in affective state and emotional caputer of salient stimuli and behavior modicituon - How goal comes to be - Change in affective state – or experience of please is mediated through pathway in center - Meso lim – presence of reward - Experience of pleasure – mod by other brain area likely the insula - Attention capture – mesolib some stimuli interesting in some way but shift in attention is performed by other brain areas - Modify sensory processing area to commit as many neurons on most salient stimuli - Mod of behavour is mediated at lobe pallidum and cortex - Next slide for last sent Patw - Obtaining reward in addicts obtain ignn drug Dop reward system - Motivate us to look for things necessary for survival - Drugs hijack Drug addicition Common used drugs Major classes of abused drugs - More dangerous due to side effects and used or abused - Drugs stimulants amp and meth - More commonly in recent years perscripttion medications Additional pharm characteisitics - Drug use – sporadic or infrequent use of a drug experimentation of drug - Abuse – more frequent use of the drug beaviour modification and lead to negative consequence s - Addiction – pattern of behavior ass with drug abuse - Dependence – change in brain structure or function result of prolonged use - Dependence only functioning normaly in drug or changes in brain - Toleranc e- higher doses to reach desired effect – same smaller and smaller effects - Relapse – recureene of original condition Drugs and dopamine - Most drigs of abuse target mesolimbic so dop from vta released more freq or larger quantities to nuc acumbens - Boost releted to reawadign effects - Coke – blocks presynaptic dop tranporter following release prevents reuptake of dope Next - Act of dop projections and lead to dependence or neuradaptive changes - Drugs not indeuce changes but change in brain as reaction to drug - Reduction in number of dop receptors in nuc accumebs - Accumbens cells reduce number of dop receptors - Bring closer to some sort of baseline - Pet scans of human brain – healthy control - Chem. – rectivitied bings to dop d2 receptors and becomes radioactive only bind to dop receptors - How many receptors there to bind strength of signal - Healthy more receptors then addicited - Other comp mechanism - Strength of glucose metabolism in pre forntal or ofc – consequence of prolonged drug use brain changes itself to adapt to long term dependence fo drug Withdrawl - Brain acts some normal way when drug is there - Neuradaptioan works against adduct with drug not there - Mesolim – reduced d2 on nuc accumbesn lead to adverse effects us not experiencing pleasure , eat - Strong withdrawl symptoms – quit opitates A contimuum of risk - 3 higher - How strongly drug develops depende ce - And dangerous physiological side effects of drug - Heroin both dangerous and strong dependce Addiction and amygdala - Feature of drug diff to quit - With drug bottom up activated where dop in nuc accumbens is promoted and infleucne of amydala increases - Amygdala – sums contextual info and allows us to learn what dif cues in env mean - Enhanced dop transmisoon amygdala learn better – amyg learn all cues ass with drug - Learning in amydala and ass of cues become reaarding experience - Amygala and vta – cue centered experience of reward and to weaking of top down Interim summary Nicotine - Drug abused around the world - Circle of events or series that occur in smokers - Smoking changes release of dop in rbain - Lead to craving and back to smoking a cig - Why first is peer pressure and curiosity - Other thing – nicotine enhance cog through few mech Changes - Nicotine exerts infl
More Less

Related notes for PSY396H1

Log In


Don't have an account?

Join OneClass

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

Sign up

Join to view


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.