WK3_Biological_revised (1).pdf

1/25/24 Chap 2: Biological Psychology Marie-Joëlle Estrada 1 How the brain...

1/25/24 Chap 2: Biological Psychology Marie-Joëlle Estrada 1 How the brain relates to behavior: A case study Phineas Gage: 25-year-old railroad supervisor 1848: spark ignited gunpowder, propelling a rod into his head 2 © Marie-Joëlle Estrada, 2023 1  1/25/24 How the brain relates to behavior: A case study § Frontal lobes were badly damaged – He became irritable, demanding, and unable to plan § Frontal lobes are involved in thinking, planning, and inhibiting impulses § Human brain and nervous system are an integrated system consisting of different specialized parts 3 Biological Psychology § Biological Psychology – The study of the brain, the nervous system, genetics, and how they relate to behavior and mental processes – How these unobservable physiological process influences behavior 4 © Marie-Joëlle Estrada, 2023 2  1/25/24 Outline § 1) The Nervous system § 2) Neurons § 3) The Brain § 4) Drugs & their effects 5 1) Nervous System § Nervous System: electrochemical communication network that connects the brain and spinal cord to all organs, muscles, and glands – Central Nervous System: brain and spinal cord – Peripheral Nervous System: nerves that radiate from the spinal cord (CNS) to the rest of the body Somatic Nervous System: transmits signals from sensory organs to CNS and from CNS to skeletal muscles Autonomic Nervous system: connects CNS to smooth involuntary muscles, organs and to glands 6 © Marie-Joëlle Estrada, 2023 3  1/25/24 VOLUNTARY AUTOMATIC ENERGIZING CALMING 7 9 © Marie-Joëlle Estrada, 2023 4  1/25/24 11 The Neuron Receive message Transmit message Action potential 12 © Marie-Joëlle Estrada, 2023 5  1/25/24 Types of Neurons § Types of neurons: 1. Sensory: from tissues and sensory organs to brain and spinal cord 2. Motor: carry outgoing info from CNS to muscles and glands 3. Interneurons: internally communicate between sensory inputs and motor outputs 13 Reflex § Interneuron: – Allows the sensory neuron to communicate directly with a motor neuron in reaction to painful stimuli 16 © Marie-Joëlle Estrada, 2023 6  1/25/24 Action Potential § Neuron: – fires an action potential when it receives signals from sense receptors or when it is stimulated by chemical messages – “all or none” law: either fires or doesn’t – strength of the stimulus doesn’t affect the action potential’s speed 17 18 © Marie-Joëlle Estrada, 2023 7  1/25/24 Action potential § Action potential- the take home: – Resting potential is negative inside neuron – Action potential Opens Na+ (Sodium) gates = Na+ passes inside the neuron Subsequently causes K+(potassium) gates to open = K+ passes outside the neuron Process continues down the neuron Initial resting potential inside neuron restored using a proton pump 19 20 © Marie-Joëlle Estrada, 2023 8  1/25/24 Types of Neurotransmitters § Acetylcholine (ACH): – One of the most common NT -at every junction between a motor neuron and skeletal muscle – When released, muscle contracts – When blocked, muscles can’t contract Botox: ACH antagonist – Undersupply: Alzheimer’s disease 21 Types of Neurotransmitters § Dopamine: – Can both excite or inhibit depending on the receptors on other neurons – Influences mood, control of voluntary experiences & processing of rewarding experiences – Too much: linked to schizophrenia – Too little: Parkinson’s (tremors) § Serotonin – Mood regulation, also controls eating, sleeping, arousal & pain – Targeted by many anti-depressants (SSRIs) 22 © Marie-Joëlle Estrada, 2023 9  1/25/24 23 Types of neurotransmitters § GABA (gamma-amino butyric acid) – Inhibitory neurotransmitter of the nervous system : prevents neurons from generating an action potential – When GABA binds to receptors it causes an influx of negatively charged chloride ions into the cell. – Facilitates sleep & reduces arousal of the nervous system. E.g. Xanax: a GABA agonist 24 © Marie-Joëlle Estrada, 2023 10  1/25/24 3) Brain Regions & Structures 26 Hindbrain & Midbrain § Hindbrain (brainstem, aka medulla/pons & cerebellum) = responsible for basic functions that sustain the body. § Midbrain = structures that control basic Hindbraind sensory responses and those that are involved in the control of voluntary movement 27 © Marie-Joëlle Estrada, 2023 11  1/25/24 a) The hindbrain § i) Brainstem (Medulla & Pons) – Nerve cells in the medulla connect with the body to perform basic functions such as regulating breathing, heart rate, sneezing, salivating, vomiting (actions w/out conscious control) § ii) Cerebellum (“little brain”) – lobe-like structure at the base of the brain involved in the details of movement, maintaining balance, and learning new motor skills – Other brain areas *plan* movement but cerebellum specializes in their coordination & timing 28 b) The Midbrain § The midbrain – Resides just above the hindbrain and primarily functions as a relay station between sensory and motor areas E.g. tectum: coordinates the sensation of motion with actions – Includes neurons that contain very dense concentrations of dopamine receptors and activity that send messages to higher brain centers that control movement Parkinson’s disease = loss of dopamine production 29 © Marie-Joëlle Estrada, 2023 12  1/25/24 c) Forebrain § The forebrain – Most visibly obvious region of the brain – Consists of multiple interconnections & structures critical to complex processes as emotion, memory, thinking & reasoning – Substructures include Basal ganglia Limbic system 30 c) Forebrain: The basal ganglia § The basal ganglia – functions in facilitating planned voluntary movement and the processing of rewards E.g. playing an instrument, Tourette’s – Substructure: The nucleus accumbens Implicated in experiencing pleasure & reward Activity in n.a. accompanies all sorts of pleasure, including sexual excitement, satisfying a food craving, and drug abuse 31 © Marie-Joëlle Estrada, 2023 13  1/25/24 c) Forebrain: The limbic system § The limbic system – Integrated network involved in emotion & memory – At the border (limbus) between the brain’s older parts and the cerebral hemispheres – Made up of several substructures Amygdala Hippocampus Hypothalamus Thalamus 32 c) Forebrain: The limbic system § Amygdala – Facilitates memory formation for emotional events, mediates fear responses, and plays a role in recognizing and interpreting facial expressions – Connects with structures in the nervous system that are adaptive for fear responses E.g. freezing responses § Hippocampus – Greek for seahorse – Critical for learning & memory, particularly the formation of new memories 33 © Marie-Joëlle Estrada, 2023 14  1/25/24 c) Forebrain: The limbic system § Thalamus – Involved in relaying sensory information to different areas of the brain – Most incoming sensory information is routed through the Thalamus and then proceeds to more specialized regions of the brain (e.g. cerebral cortex) § Hypothalamus – Serves as a thermostat maintaining appropriate body temperatures, and regulating drives (e.g. sex, hunger) in conjunction with the endocrine system E.g Orgasms 34 Hormones & the Endocrine System § Hypothalamus: – Regulates basic biological needs & motivational systems by stimulating the pituitary gland via releasing factors – The pituitary gland: master gland of the endocrine system that produces hormones & sends commands about hormone production to the other glands of the endocrine system. § Hormones: – Chemical messengers secreted in the blood and travel through the body – Helps contribute to homeostasis 35 © Marie-Joëlle Estrada, 2023 15  1/25/24 The endocrine system 36 Types of hormones § Cortisol & epinephrine: – Pituitary glands signal adrenal glands to release these hormones in response to stress – Responsible for fight or flight § Endorphins: – Produced by the pituitary gland and hypothamus – Functions to reduce pain and induce feelings of pleasure E.g. strenuous exercise, sexual activity – Morphine is an endorphin agonist 37 © Marie-Joëlle Estrada, 2023 16  1/25/24 Types of hormones § Testosterone: – Serves multiple functions e.g. physical & sexual development, increases during threat & sexual activity – Correlated with aggression 38 d) Cerebral Cortex 39 © Marie-Joëlle Estrada, 2023 17  1/25/24 Gray & White brain matter 40 d) The Cerebral Cortex 41 © Marie-Joëlle Estrada, 2023 18  1/25/24 d) The Cerebral Cortex Frontal Lobe Important in numerous higher cognitive functions, such as planning, regulating impulses & emotion, language production & voluntary movement - Primary motor cortex - Broca’s area 42 Motor Cortex 43 © Marie-Joëlle Estrada, 2023 19  1/25/24 44 c) The Cerebral Cortex Parietal Lobe Involved in our experience of touch as well as bodily awareness. Also involved in performing mathematical & visuo-spatial tasks. - Somato-sensory area 45 © Marie-Joëlle Estrada, 2023 20  1/25/24 Somatosensory Cortex 46 Comparison of motor & sensory cortex space 47 © Marie-Joëlle Estrada, 2023 21  1/25/24 48 49 © Marie-Joëlle Estrada, 2023 22  1/25/24 Right Temporal-Parietal junction RTPJ 50 d) The Cerebral Cortex Temporal Lobe Located at the sides of the brain near the ear and is involved in hearing, language and higher- order aspects of vision such as object recognition - Wernicke’s area 51 © Marie-Joëlle Estrada, 2023 23  1/25/24 Broca’s & Werneke’s areas § BROCA’S AREA – Frontal lobe, L hemisphere – Speech generation – Damage =results in difficulty speaking & making frequent grammatical errors. § WERENEKE’S AREA – Temporal lobe, L hemisphere – Comprehend language, meaning associated with words – Damage = fluid, nonsensical speech devoid of meaning 52 53 © Marie-Joëlle Estrada, 2023 24  1/25/24 54 Common questions about damage to Broca’s/Werneke’s areas 1) Do people with damage to Wernicke's area know that their language is nonsensical? Do they use a consistent "wrong" word for the same item? How does this affect their writing? § Many subtypes of Werneke’s aphasia with different results. Those affected can: – have a word structure error that still has some logical sense (e.g. "sickser" - for doctor), – use completely made-up words (neologisms), – have anomia (can't find/use nouns) – have comprehension problems; don’t understand the language others use. *from https://gawron.sdsu.edu/intro/course_core/lectures/aphasia_cases_slides.html 55 © Marie-Joëlle Estrada, 2023 25  1/25/24 Common questions about damage to Broca’s/Werneke’s areas – Those affected are incapable of reading (can understand words but can't make sense of texts) & writing & are unaware of their problem. – The fact that they can’t use nouns suggests that they don't have a regular nonsense word that they use in substitution of the "real" word. *from https://gawron.sdsu.edu/intro/course_core/lectures/aphasia_cases_slides.html 56 Common questions about damage to Broca’s/Werneke’s areas 2) How does damage to Broca's area affect people's ability to write? – Apparently damage to Broca's area can also affect people's ability to produce language, although some research suggests that this may also include some comprehension issues. – These people also seem to struggle with function words (e.g. the, of, by, a) and have both reading and writing deficits. – Unlike people with damage to Wernicke's area, they are aware that something is wrong. *from https://gawron.sdsu.edu/intro/course_core/lectures/aphasia_cases_slides.html 57 © Marie-Joëlle Estrada, 2023 26  1/25/24 Common questions about damage to Broca’s/Werneke’s areas 3) Does alcohol affect either Broca or Wernicke's areas? – YES; it can affect Broca’s area. See this link below for more information: – Two additional areas of the brain are involved in speech production and affected by alcohol. The supplementary motor area is associated with creating sentences, and Broca’s area controls language processing. These areas can be affected very differently due to individual differences, including gender, weight, age, and alcohol tolerance. – People with higher language processing ability may experience less slurring because these areas of their brain process it more effectively. *from https://www.alcohol.org/effects/slurred-speech/ 58 Common questions about damage to Broca’s/Werneke’s areas 4) Do deaf signers with brain damage have sign- language deficits? And if so, did the deficits resemble either Wernicke’s or Broca’s aphasia? – YES. Some patients’ disorganized signing and apparent lack of comprehension of others’ signs were very similar to the symptoms of hearing patients with Wernicke’s aphasia. – Other patients had extreme difficulty producing signs similar to Broca’s aphasia. They struggled to shape and orient their hands for every sign attempted *from http://lcn.salk.edu/Brochure/SciAM%20ASL.pdf 59 © Marie-Joëlle Estrada, 2023 27  1/25/24 Common questions about damage to Broca’s/Werneke’s areas – This defect wasn’t a motor control problem: when patients asked to copy line drawings of objects such as an elephant or a flower they could. and their comprehension of sign language was excellent.. – The brain damage that caused these sign aphasias was visible lesions in their left hemispheres similar to patients with the same issue. *from http://lcn.salk.edu/Brochure/SciAM%20ASL.pdf 60 d) The Cerebral Cortex Occipital Lobe -Visual cortex which processes all visual information 61 © Marie-Joëlle Estrada, 2023 28  1/25/24 Visual cortext & corpus callosum § Cereberal Cortex: – Divided into two hemospheres: L & R § Corpus callosum: – 4-inch long, ¼ inch thick bundle of nerve fibers that connects the 2 brain hemispheres and carries messages between them – Cutting this sometimes prevents epileptic seizures – Each hemisphere has different functions 62 63 © Marie-Joëlle Estrada, 2023 29  1/25/24 Hemisphere Lateralization § Left hemisphere (Analysis): – Specialized in the analysis of information – the extraction of elements that make up the whole of the experience – Specialized in serial events like language (reading, writing, speaking) & math – Responsible for SPEECH GENERATION= Broca’s area § Right hemisphere (Synthesis): – Specializes at putting together isolated incidents to create a whole – Enables us to read maps, draw 3D sketches, & construct complex objects – UNDERSTANDS language, but doesn’t play a role in speaking 64 Split brain patient Speech Speech generation – comprehension Broca’s area 65 © Marie-Joëlle Estrada, 2023 30  1/25/24 66 4) Drugs & their effects § There are several categories of substances: – A) Depressants (alcohol) – B) Stimulants – C) Hallucinogens – D) Cannabis – E) Love as a drug 67 © Marie-Joëlle Estrada, 2023 31  1/25/24 A) Depressants - Alcohol § Effects of alcohol: – helps GABA shut down neurons and “relax” the drinker = “depress” the CNS Explains the impairments in balance & coordination – Acts at dopamine and opiate receptors to produce euphoria & relieve anxiety § If alcohol *increases* an inhibitory NT (Gaba) why do people become less inhibited as they drink? – Alcohol appears to impairs the frontal lobe’s ability to inhibit behaviors and impulses 68 B) Stimulants § Stimulants – are substances that increase the activity of the central nervous system (CNS) – Cause increase in blood pressure, heart rate, and alertness – Cause rapid behavior and thinking § The three most common stimulants are: – i) Cocaine – ii) Amphetamines – iii) Caffeine 69 © Marie-Joëlle Estrada, 2023 32  1/25/24 70 i) Cocaine § Cocaine – Stimulant – 28 million people in the U.S. have tried cocaine, 2% currently using § Cocaine produces a euphoric rush of well-being. It stimulates the CNS and decreases appetite – works by increasing dopamine at key receptors & by preventing its re-absorption – Also appears to increase norepinephrine and serotonin – The greatest danger of use is the risk of overdose – Excessive doses depress the respiratory system & stop breathing – Cocaine use can also cause heart failure 71 © Marie-Joëlle Estrada, 2023 33  1/25/24 The effects of cocaine 72 73 © Marie-Joëlle Estrada, 2023 34  1/25/24 ii) Amphetamines § Amphetamines are stimulant drugs that are manufactured in the laboratory: – Increase energy and alertness and lower appetite when taken in small doses – Produce a rush, intoxication, and psychosis in high doses – Cause an emotional letdown as they leave the body – stimulate the CNS by increasing dopamine, norepinephrine, and serotonin – E.g. Methamphetamines (Meth) 74 75 © Marie-Joëlle Estrada, 2023 35  1/25/24 Meth and brain chemistry § Repeated use of meth – Changes brain chemistry making it impossible to experience any pleasure at all – Possible for tissue to regrow over time, but repair might never be completed § Study by Volkow for NIDA: meth abstinance – Meth addicts who have abstained for 14 months regrow most of the damaged dopamine receptors – More than a year later still show sever impairment in memory, judgment & coordination (e.g. Parkinsons) 77 78 © Marie-Joëlle Estrada, 2023 36  1/25/24 80 Side effect of meth: Severe tooth grinding 81 © Marie-Joëlle Estrada, 2023 37  1/25/24 iii) Caffeine § Caffeine is the world’s most widely used stimulant § Increase release of dopamine, serotonin & norepinephrine – Increases arousal & motor activity & reduces fatigue – Increases heart rate but constricts blood vessels in the brain, decreasing its blood supply 82 Caffeine § Caffeine Intoxication: – 2/3 cups of coffee (250 mg of caffeine) can produce restlessness, nervousness, anxiety, stomach disturbances, twitching, increased heart rate § Cut back on caffeine = withdrawal symptoms – Symptoms include headaches, depression, anxiety, and fatigue 83 © Marie-Joëlle Estrada, 2023 38  1/25/24 Caffeine in mg in popular drinks Taken from: https://examine.com/articles/caffeine- consumption/ 84 85 © Marie-Joëlle Estrada, 2023 39  1/25/24 Caffeine’s effects on spiders 87 C) Hallucinogens § Hallucinogen – A substance that causes powerful changes primarily in the sensory perception, including strengthening perceptions and producing illusions and hallucinations – Includes LSD, mescaline, psilocybin, MDMA (ecstasy) 88 © Marie-Joëlle Estrada, 2023 40  1/25/24 i) LSD § LSD – Lysergic acid diethylamide – Binds to some of the neurons that normally receive serotonin & change the activity at that site. – Hallucinations, strengthened visual perceptions, synethesia, “bad trips” – Long terms effects: potential for psychosis or mood disorders, flashbacks 89 ii) Ecstasy § Ecstasy – MDMA (3,4 methylenedioxymethamphetmine) – Synthetically produced drug that is technically a stimulant (similar to amphetamines) but also produces hallucinogenic effects (also considered hallucinogenic drug) – Ecstasy causes serotonin (and to a lesser extent, dopamine) to be released all at once in the brain – so first dramatically increase levels, then dramatically deplete levels. 90 © Marie-Joëlle Estrada, 2023 41  1/25/24 Ecstasy § Dangers of ecstasy: – Immediate psychological problems (e.g. confusion, depression, sleep difficulties, anxiety, paranoia) that can continue for weeks – Physical symptoms: muscle tension, nausea, blurred vision, teeth grinding for hours at a time, – Increased heart rate & blood pressure – Reduced sweat production Overheating: heat stroke/hyperthermia Water poisoning: hyponatremia – Reduced serotonin production 91 Long term effects of Ecstasy 92 © Marie-Joëlle Estrada, 2023 42  1/25/24 D) Cannabis § Cannabis – Produced from varieties of hemp plant – Most powerful is hashish, lease powerful is marijuana – Produces a mixture of hallucinogenic, depressant and stimulant effects – Contains several hundred chemicals, but the two primary ones: Tetrahydrocannabinol (THC): stimulant Cannabinol (CBD): anxiolytic 93 94 © Marie-Joëlle Estrada, 2023 43  1/25/24 Marijuana’s effects on the Brain The active compounds in marijuana are similar to a class of molecules in our bodies called endocannabinoids. The endocannabinoid system influences our immune system, protects nerve cells from premature death, and influences mood, memory, appetite, sleep, sensation, and movement 97 Can Cannabis be therapeutic? § YES. Cannabis can be therapeutic – lowers certain types of pain; has antianxiety, anti- inflammatory, and antispastic effects; and enhances appetite. § Cannabinol blocks anxiety provoked by THC; – cannabis with high CBD content is associated with fewer psychotic experiences & also attenuates the memory-impairing effects produced by THC Taken from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498425/ 98 © Marie-Joëlle Estrada, 2023 44  1/25/24 The endocannabinoid system 99 Why does marijuana have such different effects? § CB1 receptors are found mainly in your brain, especially in areas that control body movement, memory and vomiting. – explains why marijuana use affects balance, coordination, impairs short-term memory & learning, & why it can be useful in treating nausea, pain and loss of appetite. – These receptors causes psychoactivity. § CB2 receptors are found in small numbers elsewhere i.e. in tissue of the immune system (spleen &lymph nodes). – The function of these receptors is not well understood; they may serve as brakes on immune system function, which may help explain why marijuana suppresses your immune system. Taken from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498425/ 100 © Marie-Joëlle Estrada, 2023 45  1/25/24 Cannabis Intoxication § Low doses: – Joy, relaxation, quiet or talkative, may become anxious, suspicious or irritated. – Sharpened perception of sights/smells – Time seems to slow down, distances & sizes greater than they are – Physical changes: reddening of eyes, fast heartbeat, increase in appetite, dryness in mouth & dizziness § High doses: – Odd visual experiences, hallucinations, worry, confusion or impulsive behaviors § Note: the indicence of psychotic disorders (e.g. schizophrenia) is increased in frequent cannibis users 101 Dangers of cannabis § Physical dependence § Increases in strength of drug § Panic attacks § Cognitive consequences § Tar levels and lung disease 102 © Marie-Joëlle Estrada, 2023 46  1/25/24 E) Romantic Love as a drug/addiction? 103 Addiction in the brain § Romantic love shows addiction characteristics, – e.g. intense focus/attention on the beloved, mood swings, cravings, obsession, compulsions, distortion of reality, emotional dependence, personality changes, risk-taking, loss of self- control, tolerance § “Constructive” addiction when love is returned but destructive when it isn’t 105 © Marie-Joëlle Estrada, 2023 47  1/25/24 Fisher, Brown, Aron, Strong & Mashek, 2010 § Participants: – 10 women, 5 men who had recently been rejected in love – Each asked to provide a picture of the rejecter and a familiar but neutral other person of the same gender § Method: – Pps’ brain activity measured in an MRI – Pps shown rejector for 30 s, distracter task for 40 s, then neutral person for 30 s, distracter task for 20 s – Rejector/neutral start counterbalanced across pps 106 Fisher, Brown, Aron, Strong & Mashek, 2010 § Results – Pps had activity in cortical/subcortical areas associated with craving and addiction when viewing the rejecter vs neutral image – Nucleus Accumbens: Activated during cocaine administration Craving for cocaine associated with significant increase of dopamine in nucleus accumbens – Orbito/prefrontal cortex Activity in these areas has also been associated with the evaluation of gains/losses and risks (gambling) 107 © Marie-Joëlle Estrada, 2023 48  1/25/24 Reward systems Right prefrontal cortex Nucleus Accumbens Ventral tegmental area 108 Research on “Withdrawal” § Fisher (2006) – Hypothesizes that there are two stages to rejection – Initial stage: Protest Protest stage associated with elevated levels of dopamine and norephinephrine that would be adaptive for any abandoned animal Frustration- attraction – Secondary stage: Resignation/despair Reduced activity in the subcortical dopmanic pathways 109 © Marie-Joëlle Estrada, 2023 49