HDS 110 Brain and Behavioral Development PDF

HDS 110 Brain and Behavioral Development “Methods and Myths” January 13th, 2025  Methods Lesion studies Animal Studies Neuropsychology EEG/ERP Imaging Studies Understand the kind of measures that are used to study the developing brain Think...

HDS 110 Brain and Behavioral Development “Methods and Myths” January 13th, 2025  Methods Lesion studies Animal Studies Neuropsychology EEG/ERP Imaging Studies Understand the kind of measures that are used to study the developing brain Think about advantages and disadvantages of each Think about what brain measures can tell us about behavior and how it develops  Lesion Damage to a particular part of the brain can result in specific behavioral effects Examples Amygdala (emotion) Hippocampus (memory) Frontal lobes (executive function, language) Visual cortex (blindsight) Parietal cortex (attention)  Animal Studies You can look directly at brain with animals Whatever you want to look at Do specific lesions Highly controlled What are some concerns about animal studies?  Neuropsychology Behavioral method derived from lesion and animal studies These behaviors are associated with parts of the brain from lesion, animal, or imaging Provides an indirect measure of brain correlates of behavior Advantages and disadvantages? Case Study: Phineas Gage Gage’s friends found him “no longer Gage,” Harlow wrote. The balance between his “intellectual faculties and animal propensities” seemed gone. He could not stick to plans, uttered “the grossest profanity” and showed “little deference for his fellows.” Electroencephalography (EEG) Measures “brain waves”, i.e., electrical activity produced by the brain Gross measure of integrity of the brain as a system Can be used as a very low level indicator (is this person alive) Can be used to measure very broadly activity that is related to different states e.g. Sleep, Changes in social situation, Focusing on a task vs. resting How does it work? Brains produce electricity Neurons do their business basically by acting like wires Electrodes placed on scalp record brain electrical activity Measures include the amount of activity in particular frequency bands  Event-related Potentials (ERP) Definition: Brain electrical activity that comes from simultaneous firing of synapses, and is related to a specific event. How do you measure them? Electrodes placed on the scalp record brain activity Activity is recorded in response to a specific discrete event. Averaging over enough trials gets rid of the “noise” of the background EEG. Brain Imaging CT/CAT Scan PET Scan MRI fMRI  CT/CAT Scan and MRI CT: Computerized axial tomography Uses X-rays MRI: Magnetic Resonance Imaging Uses magnetic field & radio waves CT and MRI vs X-ray CT & MRI better to evaluate soft tissues such as the brain, liver, and abdominal organs, as well as to visualize subtle abnormalities that may not be apparent on regular X-ray tests CT vs MRI CT less expensive, faster MRI is best when the images need to be very detailed, looking for cancer, causes of dementia or neurological diseases, or looking at places where bone might interfere (spinal cord and nerves, tendons and ligaments)  PET/CT Positron emission tomography (PET) Uses small amounts of radioactive materials called radiotracers, a special camera and a computer to help evaluate your organ and tissue functions at the cellular level Combination of PET and CT scans provide images that pinpoint the anatomic location of abnormal metabolic activity within the body Lifetime limit of PET scans  MRI/fMRI (functional) Magnetic Resonance Imaging fMRI: Uses magnetism to estimate blood flow Once oxygen in blood is depleted (because neurons that have been activated need oxygen), blood is affected by magnets fMRI involves starting and stopping magnetism and measuring spin given off by magnetized blood Indirect measure of blood flow Relies on subtraction between conditions  Diffusion Tensor Imaging (DTI) Uses MRI technology to measure water movement along myelinated axons Gives a picture of how brain areas are connected to each other  Left vs Right brain MYTH https://www.ted.com/talks/elizabeth_waters_the_left_brain_vs_right_brain_myth/transcript?language=en#t-205161  Phrenology MISCONCEPTION Phrenology is the determination of a person’s mental capacity according to the shape of the skull Stronger/larger areas = bulges in the scalp Gall proposed the size of a brain region is directly connected to its functional strength The idea behind phrenology stems from the notion that mental functions are localized to discrete areas of the brain (not completely wrong)  Phrenology MISCONCEPTION Phrenology is the determination of a person’s mental capacity according to the shape of the skull Stronger/larger areas = bulges in the scalp Gall proposed the size of a brain region is directly connected to its functional strength The idea behind phrenology stems from the notion that mental functions are localized to discrete areas of the brain (not completely wrong)  Phrenology MISCONCEPTION Phrenology is the determination of a person’s mental capacity according to the shape of the skull Stronger/larger areas = bulges in the scalp Gall proposed the size of a brain region is directly connected to its functional strength The idea behind phrenology stems from the notion that mental functions are localized to discrete areas of the brain (not completely wrong) We only use 10% of our brain MYTH We only use 10% of our brain MYTH  How much of your brain do you use? https://www.ted.com/talks/richard_e_cytowic_what_percentage_of_your_brain_do_you_use/transcript?language=en  Development is complete at 25 MYTH Individual development varies Development continues past age 25 Next Class Reading Stiles pg. 72-81, 108- 118 Eliot pg. 80-89 Reading Summary 5-6 sentence summary of Stiles pg. 72-81, 108-118 (one summary that includes both sections) 1 quiz question and answer