Equation 3 · Part 1 · What a Neural Recording Actually Records
Symbol y
What this part means
linear.
Its job in the formula
y is part of the quantity the equation computes from the expression on the right.
Full expression→Symbol y→Article meaning
Where the article explains it
Writing it this way exposes what is being assumed rather than measured: that h is known, that it is the same across regions, subjects and states, and that the mapping from n to y is linear.
The passage around this formula
Nearly all standard analysis assumes that neural activity and the measured signal are related by a linear time-invariant system, so that the measured time course is a convolution of an underlying activity time course with a canonical response function plus noise: . Writing it this way exposes what is being assumed rather than measured: that h is known, that it is the same across regions, subjects and states, and that the mapping from n to y is linear. Each of those is an approximation with documented exceptions.
Learn the underlying idea
A function assigns an output to each allowed input. The expression f(x) means “apply f to x”.
Open the illustrated functions: inputs become outputs guide →
See this notation across published equations →
Sources cited in the article section
- [10] Neurophysiological investigation of the basis of the fMRI signal ↗
- [11] What we can do and what we cannot do with fMRI ↗
These citations provide research context; check each source for the exact claim it supports.