A. The brain has more parts than any other physical entity we know about. B. Physicists have largely ignored biology. C. Nervous systems are influenced by multiple factors we can't (yet) measure effectively. D. Physicists only study "toy" problems.
A. The brain has more parts than any other physical entity we know about. B. Physicists have largely ignored biology. C. Nervous systems are influenced by multiple factors we can't (yet) measure effectively. D. Physicists only study "toy" problems.
A. Boundaries B. Components C. Interactions among components D. Inputs and outputs E. Readily predictable behavior
A. Boundaries B. Components C. Interactions among components D. Inputs and outputs E. Readily predictable behavior
What can observation tell us about brain and behavior? Vital role of tools/methods/techniques in discovery "If I have seen further, it is by standing on the shoulders of giants." – Isaac Newton, 1676
Mental functions controlled by organs in the head, the brain Mental functions can be influenced by substances we consume Head injury can impair behavior and thinking Something flows from brain to body via nerves
A. Limited technology. B. Limited cultural support for systematic observation, description. = SCIENCE C. Lack of ability to use knowledge even if it were acquired.
Descartes' 'reflexes' Reflexes “reflect” events in the world Not the same as voluntary functions Descartes' reflexes Descartes' 'dualism' Reflexes and animal “minds” are physical Human mind is not “Dual” influences on behavior Physical + spiritual Soul controls body via pineal gland Causes muscles to “inflate” Pineal Gland Pineal gland Do you agree with Descartes? A. Yes, human minds are fundamentally different from animal minds. The human mind is influenced by both physical and extraphysical processes. B. No, human minds are similar to animal minds. The human mind arises solely from physical processes. How would you test Descartes idea about the role of the pineal gland? The lessons from history Neuroscience shaped by new methods, tools Neuroscience shaped by great debates Mind == brain debate Are functions local or distributed? Nature of neural communication Forms at multiple levels of analysis contribute to function Levels of analysis Spatial resolution Spatial and Temporal Resolution Sejnowski 2014 Spatial Resolution in Detail Within an individual molecular genetic receptor chemical neurotransmitter/hormonal cellular neuronal firing Spatial Resolution in Detail Internal to individuals network lateral inhibition area V1 varies by ~2x region Wiring/connectivity differences system Spatial Resolution in Detail External to individuals Social Friends, family, teachers, others Non-social Neighborhood, school, state/region, country Physical environment Temporal Resolution in Detail Within one lifetime Microseconds detection position from acoustic stimulation Milliseconds action potential Seconds changes in EEG power short-term memory Temporal Resolution in Detail Within one lifetime Minutes synaptic plasticity Hours memory consolidation Hormone (melatonin, cortisol) levels Days Temporal Resolution in Detail Within one lifetime Weeks Months Years education & training disease processes cultural change Temporal Resolution in Detail Across lifetimes Centuries cultural changes Millenia Natural & sexual selection Why does this matter? Different methods, different levels of analysis Challenge of linking phenomena across levels How does the micro affect macro or vice versa? Challenge of interpretation Neuroscience methods Methods to the madness Tools in the neuroscientist’s toolkit What they tell us, and what they don’t Evaluating methods What is the question? What are we measuring? Structure Activity Strengths & Weaknesses Cost Invasiveness Spatial/temporal resolution Spatial and Temporal Resolution [@sejnowski2014putting] Types of methods Structural Mapping the circuitry Anatomy & connectivity Functional (next time) What does it do? Physiology/Activity Mapping structures Cell/axon stains Golgi stain – whole cells Camillo Golgi Nissl stain – cell bodies only Franz Nissl Cellular distribution, concentration, microanatomy Golgi stain Nissl stain Retrograde vs. anterograde histochemical tracers Neuron information flow polarized–flows in one direction Retrograde (from axon terminal to cell body); anterograde (from cell body to axon terminal) What connects where Retrograde vs. anterograde tracers Brainbow [@lichtman_technicolour_2008] Brainbow [@lichtman_technicolour_2008] Clarity Evaluating cellular tracing techniques Invasive (in humans post-mortem only) High spatial resolution, but poor temporal resolution Why? Mapping structures Computed axial tomography (CAT), computed tomography CT X-ray based Tomography Tomography http://static.howstuffworks.com/gif/cat-scan-pineapple.jpg CT scan of stroke Magnetic Resonance Imaging (MRI) Magnetic resonance Some common isotopes (e.g., H) & complex molecules have a magnetic dipole Axes align with strong magnetic field When alignment perturbed by radio frequency (RF) pulse, speed of realignment varies by tissue Realignment emits RF signals MRI http://s.hswstatic.com/gif/mri-steps.jpg How MRI works Structural MRI Reveals tissue density/type differences Gray matter (neurons & dendrites & axons & glia) vs. white matter (mostly axons) MR Spectroscopy Region sizes/volumes Structural MRI of the brain Diffusion tensor imaging (DTI) Diffusion tensor imaging (DTI) Type of structural MRI Reveals integrity/density of axon fibers Measure of connectivity Voxel-based morphometry (VBM) Voxels (volume-based elements) Morphometry, measure ("metry") form/morphology. How does brain size or thickness vary by age, disease status, etc.? http://www.frontiersin.org/files/Articles/18691/fnhum-06-00184-HTML/image_m/fnhum-06-00184-g003.jpg Main points Spatial vs. temporal resolution Structural methods (parts, sizes, connectivity) Next time… Functional neuroscience methods Neuroanatomy
Reflexes and animal “minds” are physical Human mind is not “Dual” influences on behavior Physical + spiritual Soul controls body via pineal gland Causes muscles to “inflate”
Pineal gland Do you agree with Descartes? A. Yes, human minds are fundamentally different from animal minds. The human mind is influenced by both physical and extraphysical processes. B. No, human minds are similar to animal minds. The human mind arises solely from physical processes. How would you test Descartes idea about the role of the pineal gland? The lessons from history Neuroscience shaped by new methods, tools Neuroscience shaped by great debates Mind == brain debate Are functions local or distributed? Nature of neural communication Forms at multiple levels of analysis contribute to function Levels of analysis Spatial resolution Spatial and Temporal Resolution Sejnowski 2014 Spatial Resolution in Detail Within an individual molecular genetic receptor chemical neurotransmitter/hormonal cellular neuronal firing Spatial Resolution in Detail Internal to individuals network lateral inhibition area V1 varies by ~2x region Wiring/connectivity differences system Spatial Resolution in Detail External to individuals Social Friends, family, teachers, others Non-social Neighborhood, school, state/region, country Physical environment Temporal Resolution in Detail Within one lifetime Microseconds detection position from acoustic stimulation Milliseconds action potential Seconds changes in EEG power short-term memory Temporal Resolution in Detail Within one lifetime Minutes synaptic plasticity Hours memory consolidation Hormone (melatonin, cortisol) levels Days Temporal Resolution in Detail Within one lifetime Weeks Months Years education & training disease processes cultural change Temporal Resolution in Detail Across lifetimes Centuries cultural changes Millenia Natural & sexual selection Why does this matter? Different methods, different levels of analysis Challenge of linking phenomena across levels How does the micro affect macro or vice versa? Challenge of interpretation Neuroscience methods Methods to the madness Tools in the neuroscientist’s toolkit What they tell us, and what they don’t Evaluating methods What is the question? What are we measuring? Structure Activity Strengths & Weaknesses Cost Invasiveness Spatial/temporal resolution Spatial and Temporal Resolution [@sejnowski2014putting] Types of methods Structural Mapping the circuitry Anatomy & connectivity Functional (next time) What does it do? Physiology/Activity Mapping structures Cell/axon stains Golgi stain – whole cells Camillo Golgi Nissl stain – cell bodies only Franz Nissl Cellular distribution, concentration, microanatomy Golgi stain Nissl stain Retrograde vs. anterograde histochemical tracers Neuron information flow polarized–flows in one direction Retrograde (from axon terminal to cell body); anterograde (from cell body to axon terminal) What connects where Retrograde vs. anterograde tracers Brainbow [@lichtman_technicolour_2008] Brainbow [@lichtman_technicolour_2008] Clarity Evaluating cellular tracing techniques Invasive (in humans post-mortem only) High spatial resolution, but poor temporal resolution Why? Mapping structures Computed axial tomography (CAT), computed tomography CT X-ray based Tomography Tomography http://static.howstuffworks.com/gif/cat-scan-pineapple.jpg CT scan of stroke Magnetic Resonance Imaging (MRI) Magnetic resonance Some common isotopes (e.g., H) & complex molecules have a magnetic dipole Axes align with strong magnetic field When alignment perturbed by radio frequency (RF) pulse, speed of realignment varies by tissue Realignment emits RF signals MRI http://s.hswstatic.com/gif/mri-steps.jpg How MRI works Structural MRI Reveals tissue density/type differences Gray matter (neurons & dendrites & axons & glia) vs. white matter (mostly axons) MR Spectroscopy Region sizes/volumes Structural MRI of the brain Diffusion tensor imaging (DTI) Diffusion tensor imaging (DTI) Type of structural MRI Reveals integrity/density of axon fibers Measure of connectivity Voxel-based morphometry (VBM) Voxels (volume-based elements) Morphometry, measure ("metry") form/morphology. How does brain size or thickness vary by age, disease status, etc.? http://www.frontiersin.org/files/Articles/18691/fnhum-06-00184-HTML/image_m/fnhum-06-00184-g003.jpg Main points Spatial vs. temporal resolution Structural methods (parts, sizes, connectivity) Next time… Functional neuroscience methods Neuroanatomy
A. Yes, human minds are fundamentally different from animal minds. The human mind is influenced by both physical and extraphysical processes. B. No, human minds are similar to animal minds. The human mind arises solely from physical processes.
Neuroscience shaped by new methods, tools Neuroscience shaped by great debates Mind == brain debate Are functions local or distributed? Nature of neural communication Forms at multiple levels of analysis contribute to function
Within an individual molecular genetic receptor chemical neurotransmitter/hormonal cellular neuronal firing
Internal to individuals network lateral inhibition area V1 varies by ~2x region Wiring/connectivity differences system
External to individuals Social Friends, family, teachers, others Non-social Neighborhood, school, state/region, country Physical environment
Within one lifetime Microseconds detection position from acoustic stimulation Milliseconds action potential Seconds changes in EEG power short-term memory
Within one lifetime Minutes synaptic plasticity Hours memory consolidation Hormone (melatonin, cortisol) levels Days
Different methods, different levels of analysis Challenge of linking phenomena across levels How does the micro affect macro or vice versa? Challenge of interpretation
What is the question? What are we measuring? Structure Activity Strengths & Weaknesses Cost Invasiveness Spatial/temporal resolution
Structural Mapping the circuitry Anatomy & connectivity Functional (next time) What does it do? Physiology/Activity
Cell/axon stains Golgi stain – whole cells Camillo Golgi Nissl stain – cell bodies only Franz Nissl Cellular distribution, concentration, microanatomy
Neuron information flow polarized–flows in one direction Retrograde (from axon terminal to cell body); anterograde (from cell body to axon terminal) What connects where
Magnetic resonance Some common isotopes (e.g., H) & complex molecules have a magnetic dipole Axes align with strong magnetic field When alignment perturbed by radio frequency (RF) pulse, speed of realignment varies by tissue Realignment emits RF signals
Reveals tissue density/type differences Gray matter (neurons & dendrites & axons & glia) vs. white matter (mostly axons) MR Spectroscopy Region sizes/volumes
Voxels (volume-based elements) Morphometry, measure ("metry") form/morphology. How does brain size or thickness vary by age, disease status, etc.?