PSY101 Chapter 3: Brain Structures and Functions PDF

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

BASAL GANGLIA Basal Ganglia Forebrain structure that helps control movement o o o o o o voluntary motor movements& habit learning behavior switching. Association areas  basal ganglia  motor cortex (calculate the course of action) 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 process info. about our internal states (e.g., blood pressure, heart rate, respiration, emotions) smell, motivation & memory. o thalamus, hypothalamus, amygdala & hippocampus. o ▪ 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 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 o o adrenaline & cortisol (emotional arousal) Adrenaline: boosts energy production in muscle cells, thrusting them into action. Sympathetic nervous system  adrenal glands  adrenaline. (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 o o Magnetic Resonance Imaging (MRI):Uses a magnetic field energy & radiowaves to make pictures of organs and structures inside the body. 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 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).