Mountcastle et al Flashcards
Conclusions
● Some neurons adapt, some directly encode
● Neurons encode not only direct input, but position/state
● Receptive fields change in size across the body
● Columnar organization
Table 1
Never observed cross activation between groups!
A table showing distribution of all units observed between the various modality sub-groups. Note especially high proportion of “undriveable” neurons that discharged initially positive spikes. Evidence that this loss of driveability is due to damage is given in preceding paper. Term NBD indicates neurons activated by stimulation of skin, for which more complete identifications were not made.
Figure 1
Mountcastle hypothesised that there’s a functional organisation of cortical area. Purpose is to explore how inducing peripheral stimuli will lead to diff responses in the cells of the different areas of the cortex, can see how it’s organised in layers.
Figure 3
Showing the change in the discharge rate from the neuron in response to the flexing of the elbow. The peaks are when the elbow is not flexed and when flexed at 0. Must more rapid joinT rotation in A, slower joint rotation in B - see that the neuron has different rates of discharge depending on how flexed the joint is.
Figure 4
As opposed to extension of elbow, the wrist was held in steady flexed position away from neutral. Shows the despite no movement of the wrist there was firing of the neuron. Representing position, angle of the wrist, not just movement.
Figure 5
Two cells firing reciprocally. Two alternating flexing and extending. First unit is flexion, second extension. Each becomes completely silent when the other neuron is excited.
Figure 6
Firing rate of neurons in cortex during flexing and extension of shoulder joint. Can see the same alternation pattern but occurs more rapidly. Showing nerves that are close together in the cortex are activated reciprocally by reciprocal joint movements.
Figure 7
