Transcript Review - Objectives

Review – Objectives
Transitioning 4-5
• Spikes can be detected from many neurons near the
electrode tip. What are some ways to determine which
spikes belong to which neurons?
• Describe how a tetrode helps isolate spikes
• What kind of probes are better for current source density
of LFPs and what kind are better for single unit isolation
(of spiking activity)?
Review – Objectives
Transitioning 4-5
• What does a Fourier analysis do to a time-varying signal,
like LFPs or ECoG? (Why would a neuroscientist use it?)
• Describe an assumption that is made about the signal
you process with Fourier analysis. (p.105 and footnote)
•
Name the two parameters that are orthogonal (i.e.
independent) in a Fourier analysis. (Related to previous
question)
• Describe a solution that allows both of the independent
parameters to be characterized (p. 106)
Review – Objectives
Cycle 5
• Give the term for the magnitude of a given frequency
band – one output of a Fourier transform.
• An increase in magnitude of the Fourier transform can
arise from two separate changes in the signal. Name
them. (this relates to the independence question)
• Brain oscillations occur at specific frequency bands
during specific behavioural states. Collectively, what
relationship do the observed bands have? Shown in
figure 5.1
•
List several reasons the brain might have so many
oscillations (p. 114)
Review – Objectives
Cycle 5
• An EEG signal shows a power-law
relationship between what two
parameters?
• Define (or draw) white pink and brown
noise and describe ways in which they
differ.
• Select the type of noise associated with
cortical activity, and give and example of
when that activity deviates from ‘pink’.
Cycle 6:
Oscillations and Synchrony
• What is an oscillator?
– Name two types of oscillators
– Components of oscillations
• Define differences between
types of oscillators:
• Oscillators can be considered at
the neuron or neural population
level. Give a description at each
level.
Cycle 6:
Oscillations and Synchrony
How could resonance at varying frequencies be
accomplished? p. 144
What is the low-information problem and what is a
neuron’s default state, giving examples.
Define Synchrony, including the concept of a ‘time
constant’.
How does synchrony differ across classes of
oscillators?
Cycle 6:
Oscillations and Synchrony
• Define stochastic resonance, providing two
‘scenarios’ of how it could operate in the brain.
• Describe features of cell assemblies, and why
their action may be useful in encoding patterns.
• Describe how synchrony is efficient
Cycle 7: thalamocortical circuit
• Describe the ion channel dynamics
responsible for thalamocortical
oscillations. Know the specific role of It, Ih,
Na, and Ca++ currents in producing the
delta rhythms in thalamocortical cells.