PSY101 Chapter 3: Brain and Nervous System PDF

BASAL GANGLIA Basal Ganglia Forebrain structure that helps control movement o o voluntary motor movements& habit learning behavior switching. o Association areas  basal ganglia  motor cortex (calculate the course of action) o o o Action selection; the decision of which of several possible...

BASAL GANGLIA Basal Ganglia Forebrain structure that helps control movement o o voluntary motor movements& habit learning behavior switching. o Association areas  basal ganglia  motor cortex (calculate the course of action) o o o Action selection; the decision of which of several possible behaviors to execute at any given time. Allows us to perform movements to obtain rewards and reinforcement. (motivation & goal-directed beh.) Parkinson’s disease - lack of control over movement. Hunghinton’s disease – irregular & involuntary movements of the muscles and progressive loss of cognitive ability. o Tourette’s syndrome https://www.youtube.com/watch?v=_ZfpJbjgCcI BASAL GANGLIA BASAL GANGLIA LIMBIC SYSTEM o Limbic System: a set of highly interconnected brain regions dedicated to emotion o o process info. about our internal states (e.g., blood pressure, heart rate, respiration, emotions) smell, motivation & memory. o thalamus, hypothalamus, amygdala & hippocampus. ▪ Thalamus: Relays information from the sense organs to primary sensory cortex (as sensory relay station). sensory info.  thalamus  related primary sensory cortex. LIMBIC SYSTEM LIMBIC SYSTEM ▪ Hypothalamus: Located on the floor of the brain, regulates & controls internal bodily states & pituitary gland. o Different areas of hypothalamus  emotion & motivation. o Hunger, weight, thirst, sexual motivation, childbirth, blood pressure, digestive juices, emotional beh.s, balancing body fluids & body temperature. ▪ Amygdala: fear, excitement & arousal & emotional memories. ▪ Fear conditioning; learn to predict when stg. scary is about to happen. Damage  problems related to detecting fears LIMBIC SYSTEM LIMBIC SYSTEM ▪ Hippocampus: forming & storing autobiographic memories & spatial memories e.g. Taxi drivers ▪ Amnesia : problems with forming new memories but leaves the old memories intact ▪ short-term memory  long-term memory. ▪ Dementia ▪ Alzheimer’s Disease: damaging of the brain, resulting in impaired memory, thinking & behaviour https://www.youtube.com/watch?v=Vwigmktix2Y BRAIN STEM ▪ Brain Stem: Connects the cerebral cortex & spinal cord. • Basic bodily functions. • relay station btw. the cortex & rest of nervous system. • Evolved 500 million years ago (most ancient part) [Midbrain + (hindbrain - the cerebellum)] (Midbrain + pons + medulla) 60 BRAIN STEM 61 BRAIN STEM o Alertness, sleep cycles, consciousness, reflexes & basic survival functions (e.g., breathing, heartbeat & blood pressure) o "reptilian brain“ o Diseases  pupil abnormalities, changes in sensation, muscle weakness swallowing, breathing co-ordination problems o Damage  vegetative stage, coma, death BRAIN STEM o ▪ Hindbrain & Midbrain Midbrain: comm. info. btw. hindbrain  the forebrain (info. from eyes & the ears (reflexes triggered by sound). • Reticular formation/ Reticular Activating System (RAS): stereotypical patterns of behavior (e.g.walking), sleeping, attention & muscle reflexes. •Sleep  neurons in the RAS  Awake  neurons in the RAS  • Turn off RAS  dog will fall asleep. • Damage to midbrain  coma. BRAIN STEM 64 HINDBRAIN o Hindbrain: cerebellum +pons + medulla o Cerebellum (Little Brain): sense of balance & coordination of movement & learn motor skills. Plays a role in physical activity & prevents us from falling down. o o o o o o o Pons: located above the medulla & forms a kind of bridge btw. the medulla & the cerebellum. relays messages btw. the cerebellum & the cerebrum. It plays a role in sleep; triggers dreams Medulla: connects the brain to the spinal cord. breathing, heartbeat, & other vital functions. Regulates the cardiovascular & respiratory systems, reflexes such as vomiting, swallowing, coughing & sneezing HINDBRAIN 66 HINDBRAIN https://www.youtube.com/watch?v=owFnH01SD-s 67 SPINAL CORD o o o o Extends from the brain stem & runs down the middle of our backs. nerves  signals btw. the brain & the body. Center of reflexes (e.g. knee jerk; withdrawal, ) Sensory nerves : body  brain, (internal organs & external stimuli) o Motor nerves: brain  body. (internal organs, glands & muscles) o Vertebrae : protects the spinal cord SPINAL CORD SPINAL CORD PERIPHERAL NERVOUS SYSTEM o o o Somatic nervous system: conveys info. btw. the CNS & the body Controls & coordinates voluntary movement. Autonomic nervous system: controls the involuntary actions of internal organs & glands; • • o Sympathetic: is engaged during a crisis or after actions requiring fight or flight Parasympathetic: controls rest & digestion When one is activated, the other is inactive PERIPHERAL NERVOUS SYSTEM ENDOCRINE SYSTEM  Consists of glands that release hormones, molecules that influence particular organs  Also helps regulate emotions PITUITARY GLAND Controls the other glands in the body.  Controlled by Hypothalamus.  Releases hormones that influence growth, blood pressure, & other functions  Oxytocin: responsible for number of reproductive functions & plays role in maternal & romantic love ADRENAL GLANDS o adrenaline & cortisol (emotional arousal) o Adrenaline: boosts energy production in muscle cells, thrusting them into action. Sympathetic nervous system  adrenal glands  adrenaline. o (opening bronchioles, contradiction of heart muscles, breakdown of glycogen into glycose, largening of pupils) o o o o (also pleasurable & exciting activities) Cortisol: released in response to physical or psychological stresses. blood pressure & cardiovascular function, & use of proteins, carbohydrates, fats Anxiety disorders  cortisol. SEXUAL REPRODUCTIVE GLANDS o o Glands; Testes  males & ovaries  females. Ovaries- estrogen (female sex hormone); (breasts, regulation of menstrual cycles , wider hips, pubic hair &armpit hair. etc..) Men  libido, erectile function, & spermatogenesis o Testes- testosterone (male sex hormone) (testes, prostat, increased muscle & bone mass, the growth of body hair) Women  reproductive tissue, bone mass o Both sexes  testosterone & estrogen o Testosterone  agression, sex-drive BRAIN MAPPING METHODS o o o o There have been many attempts to map the mind onto the brain; which part of the brain???  which function??? Phrenology; Franz Joseph Gall (1800’s) Phrenologists  enlargements of the skull (bumps ) & various personality traits, abilities Wrong! • Patients with damage to specific brain areas did not experience the kinds of psychological deficits predicted by phrenologists. • The shape of the skull does not closely match the underlying brain. BRAIN MAPPING METHODS o o o o o o o o Brain Damage: patients with brain damage. Scientists  create lesions in experimental animals Electroencephalograph (EEG): electrical activity generated by the brain. Electrodes placed on skull Can tell which regions of the brain are active during specific tasks or whether a person is awake or asleep. can detect very rapid changes in the electrical activity of the brain & used to study the brains of patients with schizophrenia, epilepsy & other psychological disorders. It is not sufficient for determining exactly where the brain activity is occuring. BRAIN MAPPING METHODS BRAIN MAPPING METHODS o o o Neuroimaging techniques allow us to see brain structure, function, or both. Computed tomography (CT): uses multiple X-rays to construct threedimensional images. Used for diagnosing tumors, fractures, bony structures, and infections in the organs. BRAIN MAPPING METHODS o Magnetic Resonance Imaging (MRI):Uses a magnetic field energy & radiowaves to make pictures of organs and structures inside the body. o Positron emission tomography (PET) measures consumption of glucose-like molecules to give a picture of neural activity Functional MRI (fMRI) uses magnetic fields to visualize brain activity These both measure structure and function o PET SCANS SHOW MORE REGIONS DISPLAYING LOW ACTIVITY (BLUE AND BLACK AREAS) IN AN ALZHEIMER’S DISEASE BRAIN (RIGHT) THAN A CONTROL BRAIN (LEFT), WHEREAS THE CONTROL BRAIN DISPLAYS MORE AREAS SHOWING HIGH ACTIVITY (RED AND YELLOW).