PSY 446 Lecture Notes - Lecture 15: Magnetic Resonance Imaging, Otto Loewi, Karl Lashley
5 May 2018
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Memory and the brain
● Most early studies
● The major reason behind this apparent “neglect” is due to the lack of technological
resources to handle the complexity of the human brian
● Neurons are the building blocks of the nervous system
● The “prototypical” neuron has three main components
● Dendrites: structure that integrates signals from the dendrite
● Cell body: structure
● The transmision of the brain in the nervous system
● A key experiment for demonstrating the role of chemical agents conducted by Otto
Loewi
● Whem stimulating the nerve, Loewi produced a well-known inhibition of the heart
inhibition
● Despite their importance, neurons are far outnumbered by glia cells that provide
funtional and structural support to neuron
● Transmission less efficeint with no mylen
● The structure of the brain can be characterixed by the structural methods such as
magnetic resonance imaging (MRI) which uses changes in magnetic fields to distinguish
between different tissues
● Functional imaging such as fMRI allow us to observe change in the activity of the brain
at the time of the
● EEG uses electrodes across the scalp to measure the electrical acitivity
● Single cell recordings provide us with direct information on the firing rate of a specific
neuron
● Some of the most famous experiment brain lesion studies of learning and memory were
conducted by Karl Lashley
● Lashely was interested in finding the location of the engrams- the physical changes in
the brain that form the basis of memories.
● Lashely removed the brains of rats and they couldnt remeber the maze and where the
food in the maze was.
● Lashely proposed that memories are not stored in one area of the brian
● Intead the brain operates as a whole to store memories
● Although an improvement over phrenology, it still overlooked the specific roles of the
brain
● HM’S case is extremely important due to its selective influence
○ 1. Cognitive and motor functions were unaffected- can do daily chores and
knows how to perform activites
○ 2. His childhood memories were intact
○ 3. Some learning abilities were preserved
■ For example, he was able to show improvements in motor tasks involving
drawings
■ Improvements were also observed in visual identification tasks
● In a study by Squire (1987) amneciacs performance was found to be impaired in recall
tasks but not stem completion
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Document Summary
The major reason behind this apparent neglect is due to the lack of technological resources to handle the complexity of the human brian. Neurons are the building blocks of the nervous system. The prototypical neuron has three main components. Dendrites: structure that integrates signals from the dendrite. The transmision of the brain in the nervous system. A key experiment for demonstrating the role of chemical agents conducted by otto. Whem stimulating the nerve, loewi produced a well-known inhibition of the heart inhibition. Despite their importance, neurons are far outnumbered by glia cells that provide funtional and structural support to neuron. The structure of the brain can be characterixed by the structural methods such as magnetic resonance imaging (mri) which uses changes in magnetic fields to distinguish between different tissues. Functional imaging such as fmri allow us to observe change in the activity of the brain at the time of the.
