Lecture1 psych125 bunge
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The document provides information for a psychology course on the developing brain, including introducing the professor and GSI, noting important dates like exams, and discussing various brain imaging techniques that are commonly used in developmental cognitive neuroscience research, such as EEG, MRI, DTI, fMRI, and optical imaging.
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Lecture1 psych125 bunge
- 1. Welcome! Please note: seats are reserved for enrolled students The Developing Brain PSYCH 125 BUNGE Fall 2012
- 3. About your professor • Background • Lab website: http://bungelab.berkeley.edu
- 4. About your GSI, Jared Saletin • Graduate student in Matthew Walker’s Sleep & Neuroimaging Lab: http://walkerlab.berkeley.edu • Background in psychology & neuroscience, including developmental cognitive neuroscience • Launching a sleep study in adolescents & will give a guest lecture on this • E-mail: jsaletin@berkeley.edu
- 5. Introductions Ask the student sitting next to you: • What’s your name? • Where did you grow up? • What was an early interest or experience that helped to shape who you are & what you do today?
- 6. Poll What’s your major? A) Psychology B) Cognitive Science C) Molecular and Cell Biology D) Integrative Biology E) Other
- 7. Course content • Organized around key questions • Learning objective: become sufficiently literate in the science of brain development to have an informed opinion on each of these questions • 1 exam on each of 3 sections of the course: • Part I: Foundations • Part II: Emerging brain functions • Part III: From science to society
- 8. Lecture slides • PDF will be posted online – in most cases, the night before the lecture • PDF will include all the content slides. It won’t include the polls or movies – for these extras, come to class!
- 9. Wiki Project • Goal: an open-access course reader about the developing brain! (It may serve as the prototype of a future textbook…) • One book section per topic covered in class, with several essays/section. • Sign up for one of the topics in your class Section. • Each student will produce a high-quality essay on this topic, receiving & giving detailed feedback from/to other students working on the same topic • Most students will give a 10-minute presentation about their topic in Section. • For each topic, we will need 1 volunteer (a “closer”) to write a high-quality introduction & conclusion to the section & then collate and format the essays on the last day of class (Wiki Party!). Closers will not need to give oral presentations.
- 10. Exams • Each exam covers 1/3 of the material • i.e., the final exam won’t explicitly test earlier material • But, the exams will get more sophisticated • fewer multiple-choice, more short-answer questions • less emphasis on memorization, more on understanding
- 11. Grades • No ‘grading on a curve’ • If you learn the material, you will do well in the course • Standard grade conversion for UCB:
- 12. Extra credit • Research Participation Program (RPP) • Additional 2% per RPP credit (up to 3) • The extra 6% could take you from a B+ to an A • For instructions, see doc in bSpace: “ResearchParticipationCredit.doc” • Don’t wait until the end of the semester to sign up…
- 13. Key dates to put in your calendar • Sept 26th: Exam #1 • Oct 29th: Exam #2 • Nov 30th: Paper due • Dec 10th: Exam #3
- 14. Special requests • Please read the syllabus carefully • We strive to be fair to everyone in the class – please help us out by… • Not asking for exceptions to guidelines in the syllabus. • Not fishing for extra points, a.k.a. “grade grubbing” • Don’t be shy about asking me to repeat or clarify during lecture • Bring your i>clickers so that we can have some fun!
- 15. Questions?
- 16. Why do/should we study the developing brain? • To satisfy our curiosity: How do we become our unique, fascinating, complex selves? • The coolness factor. Many unanswered questions & rapid pace of discovery with cutting-edge technology. • To provide critical information about brain development to the broad range of people who work with or make decisions about children: parents, educators, clinicians, judges, parole officers, policy-makers, etc.
- 17. How do we study the developing brain?
- 18. Brain imaging techniques • For brief overview, see Bunge & Kahn encyclopedia entry on bSpace • Here, we will focus on the ones that are most commonly used in children: • Scalp recordings (EEG, ERPs) • Structural MRI • Diffusion Tensor Imaging • Functional MRI • Optical imaging
- 19. Scalp electrode recordings • Electroencephalography (EEG) and event-related potentials (ERPs)
- 20. Scalp electrode recordings • Pick up electric signals on scalp surface that stem from large populations of neurons • Measure voltage fluctuations over time: electroencephalography (EEG) • To derive a signal related to a particular event, need to average over many trials aligned on a particular event: called Event-Related Potentials (ERPs) • excellent temporal resolution: can detect changes on the order of ms • poor spatial resolution: localizing the source of signal is hard
- 22. Magnetic resonance imaging (MRI) • Brain Imaging Center (BIC) in Li Ka Shing • Recommendation: volunteer for a study
- 23. MRI vs. fMRI MRI (or ‘structural MRI’) Functional MRI (fMRI) is is used to study used to study brain anatomy. brain function. Slide from Jodi Culham
- 24. Structural MRI We use structural MRI to measure changes in brain anatomy with age, and to localize brain activation hich of these scans (T1 or T2) shows gray matter as gray and white as whit What is gray matter? What is white matter?
- 25. (synapses) White matter: myelinated axons in long-range fiber tracts
- 26. Diffusion tensor imaging (DTI) Klingberg et al., 2000 Method for imaging fiber tracts: direction + integrit
- 27. Water diffuses everywhere... ...but doesn’t like crossing boundaries
- 28. When structure is imposed, diffusion becomes directional
- 29. Water diffusion along a fiber tract We use DTI to measure how fiber tracts change over development
- 30. Functional MRI What does fMRI measure?
- 31. Blood flow to the brain W. W. Norton
- 32. The First “Functional Brain Imaging Experiment” E = mc2 ??? Angelo Mosso Italian physiologist (1846-1910) “[In Mosso’s experiments] the subject to be observed lay on a delicately balanced table which could tip downward either at the head or at the foot if the weight of either end were increased. The moment emotional or intellectual activity began in the subject, down went the balance at the head-end, in consequence of the redistribution of blood in his system.” -- William James, Principles of Psychology (1890) Slide from Jodi Culham
- 33. fMRI: Blood Oxygen Level Dependent (BOLD) signal • An indirect measure of neural activity • Based on fact that oxygenated and deoxygenated blood have different magnetic properties Increased BOLD signal Increased neural • Surplus of freshly Increased activity oxygenated blood blood • flow Deoxy/oxyhemoglobin ratio changes
- 34. Hemoglobin
- 35. Conventional fMRI: Identify regions exhibiting heightened blood flow during task
- 36. Developmental neuroscientist: Nadine Gaab
- 37. Optical Imaging • Like fMRI, it involves the detection of oxygenated vs. deoxygenated blood • Place laser diodes on the head, along with detectors • Light picked up at detector can tell us about oxygenation level of blood • Fairly limited as far as neuroimaging techniques go, but Bortfeld, Wruck, & Boas, 2007 low-cost & easy to use in infants
- 38. Neurological disorders with childhood onset Attention Deficit Hyperactivity Disorder Autism spectrum disorders Brain tumors Cerebral Palsy Depression Down Syndrome Dyscalculia Dyslexia Epilepsy Obsessive-Compulsive Disorder Pediatric Acquired Brain Injury Schizophrenia Stroke (perinatal or sickle cell disease) Tourette Syndrome Williams Syndrome “Pervasive Developmental Disorder Not Otherwise Specified”
- 39. Next lecture • A brief overview of brain anatomy • Central nervous system, peripheral nervous system • Gross anatomy, 4 major lobes, major gyri, subcortical nuclei • Histology, cell layers, fiber tracts • Neurons, synapses, dendrites, axons • Primary sensory areas, motor areas, association areas • Medial, lateral, anterior, posterior, dorsal, ventral • Coronal, sagittal, axial slices
- 40. Children have a remarkable capacity for learning
Editor's Notes
- Test out the i>clicker
- Background: Spent summers in the countryside, exploring with my dog, and got very interested in Biology. Studied biology in college, and got into a neuroscience lab, so started taking lots of neuroscience classes. There weren’t many at the undergrad level, so I took 1-2 grad seminars as well. Spent lots of time in lab & around grad students. Not focused on getting a top GPA. Got to know a few professors quite well. Applied for grad school in Neuroscience, where I got to try out 4 labs before settling down into one. Ended up studying ‘cognitive neuroscience’, or the neural basis of human cognition. Then did a postdoc, and got my first faculty position & started my own lab. And then I moved to Berkeley 5 years ago. I have a joint appointment in Psych and Neuro, even though I never took Psychology classes, but read a lot in that field. Life is very busy, but I have lots of freedom to study what I want to, & it’s extremely rewarding.
- OK, let’s hear from a few of you --- raise your hand if I can call on you --
- The i-clicker system for instructors hasn’t arrived yet, so we’re going to do a low-tech poll. Raise your hand if you’re in Psych --- XXX --- XXXX If you answered ‘other’, what’s your major?
- Questions we want to tackle
- EEG is the oldest functional brain imaging technique. It dates back to the discovery in 1929 (by Berger) that brain electrical activity could be recorded from electrodes placed on the scalp. This technique is still widely used today because of its ability to provide real-time measurements of brain activity. EEG records the net flow of electrical current across the cellular membrane during neuronal depolarization associated with postsynaptic potentials. Global EEG is used to measure neural activity during different brain states, such as sleeping and waking. A more powerful tool for cognitive neuroscience than global EEG measurements consists of event-related potentials, which refer to EEG activity averaged over a series of instances (or trials) triggered by the same event (e.g., the presentation of a visual stimulus).
- ‘ inverse problem,’ which is the challenge of identifying the source of the underlying signal. This source can be a great distance from the point on the scalp at which it is measured, and it is affected by factors such as head shape and dipole location and orientation. Thus, it is necessary to build source localization algorithms to determine the likely source of a signal
- Large magnet. Typically 3 Tesla these days. Safe for use in humans, if the right precautions are taken. Used from infancy through old age. Now even being prenatally
- MRI provides excellent detailed structural information and enables the naked eye to distinguish gray matter from white matter. This method can be used to track the normal and abnormal development of neural pathways in childhood.
- Talk about how myelin wraps around the axons of neurons and insulates the electrical signal which passes down them. Point out how tightly wrapped the myelin is around the axon.
- A surprising amount of the brain is dedicated to white matter ---- to the fibers that connect different parts of the brain. Diffusion tensor imaging, has been developed to specifically visualize white matter fiber tracts in the brain. This method captures the diffusion of water molecules.
- We use DTI to measure how fiber tracts change over development.
- In the late 1800s, scientists understood that blood nourishes the brain. Angelo Mosso tried to show that thinking hard made more blood flow to the brain… And then Roy and Sherrington showed in 1890 in lab animals that brain stimulation led to a local increase in blood flow to active populations of neurons.
- The same logic holds for our modern-day tool, fMRI… it identifies the brain regions that are working hardest during mental activity, e.g. while
- Hemoglobin contains iron molecules at its core. When hemoglobin is carrying oxygen, it covers up the iron core, which changes the magnetic properties of the blood. So, we can measure how much freshly oxygenated blood is coming to the site
- There are more sophisticated fMRI analyses now, so this approach of measuring level of activation relative to a baseline condition can be called ‘conventional fMRI’
- In addition to studying the typically developing brain, researchers study a number of different kinds of disorders and pathologies that begin in childhood. This is just a partial list… and when doctors don’ t know what the problem is, they use the term PDDNOS ------
- If you ’ve taken Cognitive Neuroscience or Human Neuropsychology, or if these terms are already familiar, you don’t need this lecture – just review the slides & the assigned readings from Biological Psychology text (on bSpace)