Memories and your Brain Psychology 3717

Introduction Look, your memories MUST be in your brain Look, your memories MUST be in your brain Somewhere….. Somewhere….. Questions arise though like umm where are they stored? Questions arise though like umm where are they stored? How are they stored? How are they stored? Is it just new connections or something else? Is it just new connections or something else?

Don’t be afraid, it is just a bit of rote memorization Unless you know Greek and Latin… Unless you know Greek and Latin… Brain is organized in, at best, a semi random pattern Brain is organized in, at best, a semi random pattern Some of the names are confusing Some of the names are confusing Substantia negra Substantia negra Zona inserta Zona inserta Some make a teeny bit of sense Some make a teeny bit of sense Hippocampus Hippocampus amygdila amygdila

A few key terms Anterior Anterior Caudal Caudal Dorsal Dorsal Frontal Frontal Inferior Inferior Lateral Lateral Medial Medial Posterior Posterior Rostral Rostral Sagittal Sagittal Superior Superior Ventral Ventral dorsal dorsal

Time for a diagram!

Some important Subcortical structures Hippocampus Hippocampus Amygdila Amygdila Thalamus Thalamus Hypothalamus Hypothalamus Nucleus accumbens Nucleus accumbens Medula Medula

The cells There are two basic types of cells in the brain, neurons and glial cells There are two basic types of cells in the brain, neurons and glial cells Neurons do the transmitting Neurons do the transmitting Glia do the support functions Glia do the support functions There are many types of neurons and glial cells, but we don’t have to be too concerned about those There are many types of neurons and glial cells, but we don’t have to be too concerned about those

Fall in to the gap Between neurons there are teensy gaps Between neurons there are teensy gaps The synapse The synapse Neurotransmitters go across the gap to cause the next neuron to fire Neurotransmitters go across the gap to cause the next neuron to fire Why not direct connections? Why not direct connections? Allows for modulatory properties of drugs and other chemicals Allows for modulatory properties of drugs and other chemicals

Learning and memory may happen here Seems sensible that learning and memory could happen here Seems sensible that learning and memory could happen here New synapses? New synapses? Enriched rats Enriched rats Long Term Potentiation Long Term Potentiation Maybe Maybe Looked really promising Looked really promising

On a more oh macro level, how can you measure brian activity There are many imaging techniques There are many imaging techniques Before even EEG we had techniques like those Penfield used Before even EEG we had techniques like those Penfield used Neurosurgeons were usually a tad busy and had pesky operations to take care of… Neurosurgeons were usually a tad busy and had pesky operations to take care of…

EEG Oldest form of brain imaging Oldest form of brain imaging

CAT Scan Computerized axial tomography Computerized axial tomography

PET scan Positron emission tomography Positron emission tomography

MRI Magnetic Resonance Imaging Magnetic Resonance Imaging

So, how do you combine this stuff Easy (if expensive) Easy (if expensive) Put a subject in an MRI or PET scanner Put a subject in an MRI or PET scanner scan scan Have her read a passage Have her read a passage Do a distracter task Do a distracter task scan scan Remember Remember scan scan

Some selected results Aplysia and habituation Aplysia and habituation Feature detectors Feature detectors Face detectors Face detectors Place cells Place cells HM HM KC KC

conclusions Look we KNOW memories are up there somewhere Look we KNOW memories are up there somewhere However, we are a LONG way from figuring out where However, we are a LONG way from figuring out where We are also a long way from figuring out how We are also a long way from figuring out how Even once we do, someone has to design the behavioural end of cognitive neuroscience Even once we do, someone has to design the behavioural end of cognitive neuroscience