What is a neuron bank? In the Dropout paper they refer to neuron banks on page 15:

... the
  activity a^i
  (x,y) of a neuron in bank i at position (x, y) in the topographic organization ...

What is a neuron bank?
Context:

 A: bank = array or set. The term comes from the signal processing terminology.
A hint from the paper you mention:

In this way, a bank of neurons
  in a CNN applies a convolution operation to its input. A single layer in a CNN typically has
  multiple banks of neurons, each performing a convolution with a different filter. These banks of
  neurons become distinct input channels into the next layer.

The parameter of each neuron  bank in a convolutional layer is called a  filter bank or just filter (a.k.a. kernel a.k.a. feature detector).
For example, using this illustration from Stanford's deep learning tutorial: 

The filter bank is the yellow sliding window, and its value is:
\begin{bmatrix}
    1      & 0 & 1  \\
    0      & 1 & 0  \\
    1      & 0 & 1  
\end{bmatrix}
The green array is the input to one neuron bank, and the pink array is the output of one neuron bank.
I don't think the term  neuron bank is commonly used nowadays.
(That's a lot of confusing terms for a simple mathematical operation… )
