TA_ReviewExam2_JM.pptx

Review for Exam 2 Exam format Format: in-person during scheduled class time Duration: 75 minutes (Monday- 10/7 from 5:30-6:45PM) Questions: Multiple choice questions: 33 True-false questions: 20 Short answers: 9 (50 points) Labeling: 4 (36 points) Extra credit M...

Review for Exam 2 Exam format Format: in-person during scheduled class time Duration: 75 minutes (Monday- 10/7 from 5:30-6:45PM) Questions: Multiple choice questions: 33 True-false questions: 20 Short answers: 9 (50 points) Labeling: 4 (36 points) Extra credit Main topics Historical Methods of Cognitive Psychology New Methods of Cognitive Neuroscience Development of the Nervous System Methods of Experimental Psychology What are the two basic units of measurement? Accuracy Reaction/ Response Time Be familiar with one of the main characteristics of human performance Speed-accuracy trade-off: as speed improves, accuracy suffers (and vice versa) Single vs. Double Dissociation Single dissociation: 1 patient group, 1 control group, 2 tasks Difference between groups only occurs in Task A Issues with this? Both tasks assumed to be equally sensitive to group differences Single dissociation may result from general effects of trauma, not specific effect of the lesion Double dissociation: 2 patient groups, 1 control group, 2 tasks patient groups differ on task affected, control group unaffected Declarative vs Nondeclarative memory Be able to describe the difference between the two Declarative (explicit) memory: Involves the conscious recollection of events and information. Refers to memories that can be consciously recalled E.g., recalling your address, date of birth, etc. Nondeclarative (implicit) memory: Does not involve conscious thought Procedural memory: allows us to carry out commonly learned tasks without conscious thought E.g., tying a shoe, riding a bike, etc. Priming: exposure to a stimulus influences our response to a later experience E.g., answering “Dallas” when asked to name a city that begins with “D”. Patient HM HM, suffering from severe epileptic seizures, underwent what procedure to end them? Bilateral resection of medial temporal lobe most (not all) of his hippocampi and amygdalae Know which parts of HM’s brain function were normal…. Working memory and procedural memory And which parts were not normal….. Long term memory Posner Task Task procedures: Examine two letters and determine whether they are from the same category (capitalization and vowel/consonant are both varied) Results and their implications Multiple representations (i.e., physical, phonetic, and category) are activated by a single stimulus Sternberg Task Task procedures: Memorize a string of letters over a brief time interval and determine if a letter shown afterwards was included in the original set that was presented Hypothesized stages? Encode, compare, decide and respond Results and their implications Response times increases with increasing memory set size Memory retrieval is a serial comparison process Each comparison takes a fixed amount of time Mental operations can be quantified in terms of the amount of time they take Word Superiority Effect The word superiority effect is a phenomenon that is observed during which task? Sternberg Task Target letters can be identified faster inside a word than if they are inside random letter combinations or by themselves in a string of X’s. Stroop Task Task procedures: Name the color if ink in which a letter string or word is presented Results and their implications (the “Stroop Effect”)? Response time increases for subjects to name a color word when it is printed in a color that does not match the word (e.g., RED, GREEN, BLUE, etc.) Multiple representations compete for control of response processes “Privileged access” of some representations over others 1st representation: the actual physical color of each stimulus 2nd representation: the color concept associated with each word The “Lesion Method” Laid empirical foundation for modern cognitive neuroscience What is the idea behind this method? The role of a missing brain region may be inferred from what the patient is unable to do following its removal. Single Unit Recording Electrodes are attached to the skull of the specimen Single cell penetrated by micropipette Requires fine control Requires tolerance within 1 micron Three basic types Extracellular: strongest signal is obtained from closest cell, filters are used to wipe out weaker signal, and requires repetition to determine if signal is typical Intracellular: actual penetration of cell by pipette. Requires fine control Microiontophoresis: simultaneous recording while depositing chemicals on the neuron. Difficult to know what to manipulate. Uses the multi-barreled micropipette Electroencephalography (EEG) EEG does NOT measure the electrical activity of individual neurons in the brain  it measures the summed results of brain activity across the scalp High temporal resolution, low spatial resolution Requires trial averaging to gather reliable EEG data Signal varies with states of consciousness Position Emission Tomography (PET) Useful in evaluating diseases of the brain  can capture diverse processes Can acquire activity of neurotransmitters Type of tracer used = different gamma rays are given off and detected Have a basic familiarity with the methodology behind PET: Positron releases 2 gamma rays that have same energy but go in opposite directions. PET scanner detects these gamma rays as they leave the body. Computer receives information about the location of gamma rays and produces picture. Functional Magnetic Resonance Imaging (fMRI) Review the methodology of fMRI Radiofrequency pulses alter the spin of hydrogen protons Energy released back by hydrogen protons is recorded  different between different types of tissue Know the difference between structural and functional MRI Structural MRI: produces anatomical images Functional MRI: produces maps of blood oxygen level changes  method of blood- flow measurement that we use to infer neural activity Can see “active” brain regions during cognitive performance How it works: Active neurons need more oxygen More oxygen is provided by increase in blood in location of neural activity (hemodynamics) fMRI detects changes in relative levels of oxygen in different areas of brain. Hemodynamic response = vital Naturally Occurring Lesions Tumors A mass of abnormally growing tissue Named after the region the tumor grows in Ex: astrocytoma = astrocytes; meninges = meningioma Degenerative Disorders Infection Head trauma Ex: contra coup (e.g., closed head injury)  usually results in frontal and parietal damage Epilepsy Degenerative Disorders Parkinson’s Disease Death of dopamine-producing cells in the substantia nigra Symptoms of Parkinson’s most commonly present as problems with motor control Huntington’s Disease Degeneration of which two structures due to a reduction in which neurotransmitter? Caudate and Putamen; GABA Alzheimer’s Disease Progressive deterioration from posterior cortex to anterior cortex Which symptoms tend to present first? Memory loss Pick’s Disease Rarer than Alzheimer’s disease, and progresses in the opposite direction (anterior to posterior) Characterized by presence of cortical “pick’s bodies” Which symptoms tend to present first? Personality disorders Phineas Gage A tamping iron severely damaged the left frontal lobe of his brain Revealed important role for prefrontal cortex in personality, executive function, and impulse control Be familiar with his personality before and after Before: diligent, polite, etc. After: irreverent, impatient, aggressive, profane, etc. Quote from his peers describing him after the accident: “Gage was no longer Gage”  Development of the nervous system Gross development: Multicellular blastula: first structure to form after penetration of egg by sperm Contains precursor cells: undifferentiated cells  will go on to become glial cells, neurons, and ependymal cells 3 methods of division for precursor cells Divides into brain cells Brain cells and PC cells (neural precursor cell) PC cells Development of the nervous system Developmental sequence of multicellular blastula: Gastrulation: invagination and cell migration in blastula to form ectoderm Neurulation: Ectodermal cells form neural plate  neural plate invaginates as neural folds push up  neural folds form the neural groove 3 layers of the neural plate: Ectoderm: forms nervous system and outer skin Endoderm: forms gut and digestive organs Mesoderm: forms skeletal system and voluntary muscle Development of the nervous system Neurogenesis = creation of neurons Process continues after embryonic development Brain is changing throughout the lifespan (e.g., synaptic formation and pruning, myelination) Prefrontal regions are not fully developed until adulthood (around 25) Human embryo Primitive brain consists of 3 cavities that will form ventricles Ependymal cells are those that do not migrate and stay behind to form ventricular walls Gross features of brain are then formed through a series of bends (flexures) Cortex forms from the inside out Method for developmental timecourse: 3H-thymidine labeling (radioactive substance injected into embryo)- labels DNA in cells undergoing division Rakic’s Evidence for Hypotheses Hypothesis: type of neuron a cell will become is determined by their genesis point (i.e., timepoint at which it was created) Evidence that supports this hypothesis: Correlational- determination of cell type correlated with time of creation during gestation Experimental- cells transplanted from one animal to another migrate to region of cortex determined by their creation time Transplantation does not affect connectivity Consequences of radial migration Cells migrate along radial glia Cells born next to each other remain near each other in adult brain Cells born remote to each other remain remote to each other in adult brain Creates a topographic relation between cells formed adjacent to one another in the ventricular zone Result = columnar/laminar organization of cortex Cortical column is a principal unit of cortical organization Radial cells turn into astrocytes after completion of cellular migratory processes Radial unit hypothesis- Pasko Rakic Reeler Mice experiment Genetic manipulation reorients radial glia Neuronal organization disrupted Laminar organization reversed Mice demonstrate Reduced cerebellar volume Ataxic gait Dystonia Tremors Rakic’s “protomap” hypothesis Genetic factors predetermine organization Brain organization is determined in the ventricular zone Neurons in ventricular zone “attract” function-specific afferent fibres according to protomap organization Rakic’s hypothesis: radiations and protomaps Final role of cells determined by a complex interplay of genetic and environmental factors Interplay studied by microsurgical experimental techniques Jean Piaget His theory: knowledge in humans developed in 4 cognitive structure or developmental stages Sensorimotor Pre-operational Concrete operations Formal operations Cognitive structures = patterns of physical or mental actions that underlie specific acts of intelligence What three processes function to develop these structures? Adaptation: infants attempt to adapt to world Assimilation: interpretation of events in terms of existing cognitive structures Accommodation: changing of cognitive structures to make sense of the environment Piaget’s Theory of Developmental Stages Sensorimotor From birth to about stage age 2 Unconnected intelligence, sensation, and thought Goals of stage are sensory and sensory-motor integration Poor concepts of objects and no object permanence (ability to know that an object still exists in the world despite being out of view  hallmark sign of infant development) Pre-operational From about age 2 to about age 7 Develop conservation of quantity, imagination, and imitation Concrete Operations From about age 7 to about age 11 Rise of ability to solve logical problems, classify, and categorize Concrete concepts and an understanding of reversibility develop Formal Operations From about age 12 and on Abstract thought, problem-solving, “scientific thought” Concerns of social issues and identity Neo-Piagetians Know the aspects of Piaget’s theory they challenged Developmental stages may not be as rigidly fixed as initially thought Neo-Piagetians believed that cognitive abilities actually presented much earlier than Piaget theorized Found their empirical results did not correspond well with Piaget’s theories Know the different neo-piagetians discussed in class, their work, and implications for Piaget’s theory… Rene Baillergeon Studied: Object permanence Methodology: Object shown to child, then hid behind screen, which is then dropped Sometimes object was there, sometimes object was not Findings and their importance: Infants from 3-and-half months express surprise if object appeared to disappear Onset of object permanence may be earlier than Piaget said Judy DeLoache Studied: symbol use Methodology: Showed child a prize (e.g., big snoopy) in a scale model of a room Child then searches the actual room to find prize Findings and their importance: Age 2 and half shows difficulty (they randomly searched), BUT ….. Children 3 years old have no trouble at all Onset of symbol use may earlier than Piaget theorized Gretchen Van de Walle Studied: ordinality Methodology: Children shown two trays and asked to pick the one with more objects (the “winning” tray) First set, one with one object and one with two objects Next set, one with three objects and one with four objects Findings and their importance: 2-year-olds reliably picked the “winner” Onset of quantitative skills may be earlier than Piaget theorized