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What makes us SAPIENS
What quality has made you reach here?
Widen the perspective ---What made us survive in the competition against other Humans ?
•“ The difference in mind between man and the higher animals, great as it is , is cerainly of a degree and not of a kind.”
Charles Darwin
Functional neuroanatomy
• Overview of brain anatomy & systems– Localization/networks– Scale in the nervous system– Sensorimotor systems
• How our brains interact with the external world (loops)– States ‘of mind’ (and body)
• Specific functional systems– Memory & emotion
• How our brains use previous experience to modify behavior
• Vision & attention; language
Site of Thinking: Heart, Ventricles, Brain
Approaches to the study of brain function
•Animals & humans: anatomy, physiology, & behavior•Tract tracing•Single unit recordings•Behavioral studies; pharmacology
•Patients with focal brain lesions•Behavioral studies & post-mortem anatomy•Structural imaging: In vivo structure/function correlations
•Neuroimaging/brain mapping•Functional neuroimaging
Phrenology and Localization of Function
Localization of function in the nervous system
Phrenology (Gall, early 1800s)1.The brain is the organ of the mind.2. The mind is composed of multiple distinct, innate faculties.3. Because they are distinct, each faculty must have a separate seat or "organ" in the brain.
Neurons as Units or a Neural Net
Jan PurkinjePurkinje cell – first viewed in 1837
Cajal and Golgi – 1906 Nobel Prize in Physiology
Santiago Ramon y Cajal Camillo
Golgi
Sherrington and the “Synapse”
1932 Nobel Prize in Physiology
The Brain is Composed of Discrete Cells: Neurons and Glia
The Brain is Composed of Discrete Cells: Neurons and Glia
columns
T able 4 1 Spatial Scales of Cortical T issue Structure and Function
• Structure Diameter NeuronsDescription• Minicolumn 0.03 102 Spatial extent of inhibitory
connections• CC column 0.3 104 Input scale for corticocortical fibers• Macrocolumn 3.0 106 Intracortical spread of pyramidal
cell• Region 50 109 Brodmann area• Lobe 170 1010 Areas bordered by major cortical folds• Hemisphere 400 1011 Half-brai
Electricity in Brain
Johannes Muller
• . The nervous system is an intermediary between the object and your consciousness.
• Each of the five kinds of nerves (visual, auditory, olfactory, gustatory, skin-sensory) imposes its own quality to the mind) Your optical nerve as the "seeing" energy, your auditory nerve, the "hearing" energy.
• Doctrine of specific nerve energies• It is not until Helmhotz that the speed of the nervous
impulse is measured.
Helmholtz
• Student of Johannes Müller.• Measure of the speed of the nervous impulse. And …..
(reaction time).• Tri-chromatic theory of vision (together with Young)• Makes the difference between sensation ( sensory level)
and perception (having to do with the interpretation of sensation.
• Research on audition: harmony, discord, resonance.• Concept of unconscious inference. (ex: in depth
perception)
Neurons have specialized processes that support electrochemical transmission
Neurons communicate with each other primarily through synapses
Integration of information• PSPs are small. An individual EPSP will not produce
enough depolarization to trigger an action potential.• IPSPs will counteract the effect of EPSPs at the same
neuron.• Summation means the effect of many coincident IPSPs
and EPSPs at one neuron.• If there is sufficient depolarization at the axon hillock, an
action potential will be triggered.
axon hillock
Neuronal firing: the action potential
• The action potential is a rapid depolarization of the membrane.
• It starts at the axon hillock and passes quickly along the axon.
• The membrane is quickly repolarized to allow subsequent firing.
Glia support and maintain neurons
• Protect by surrounding and buffering• Speed transmission by forming myelin sheaths
Functional neuroanatomy
How do thought, emotion and behavior arise from this?
Brain anatomy
Brain anatomy
Brain anatomy
Brain anatomy
Brain anatomy
Brain anatomy
Phineas Gage--1848Phineas Gage--1848
Penfield
Localization of function in the nervous system: Paul Broca & language
1860s
Conduction apahasia
Lashley’s Search for the Engram in the 1920s
Rats are trained to run through a maze without entering blind alleys.
After training, cortical lesions are made. Three different lesion locations are shown in red, blue, and yellow
Errors are associated with the size rather than the locus of the lesion.
Donald Hebb and the Cell Assembly 1949
Localization of function in the nervous system: Maps and networks
1909 2005
Motor function
Motor system
Motor system
Motor system
Motor system
Motor system
Motor system:Topography
Motor system
Motor system
Somatosensory function
Somatosensory function
Somatosensory function
Auditory function
Auditory function
Vision
Visual systemVisual system
Visual systemVisual system
Visual systemVisual system
Visual systemVisual system
Visual systemVisual system
Visual systemVisual system
Localization of function in the nervous system: Functional networks
5 major brain systems subserving cognition and behavior
Left perisylvian language networkParieto-frontal network for spatial attentionOccipitotemporal network for object/face recognitionMedial temporal/limbic network for learning & memoryPrefrontal network for attention & comportment
From Mesulam MM, Brain, 1998
What Makes us Human?• SIZE
• context
• Continuity or a break
• Connectivity
Scale in studying the nervous system
