## Problem 106 — rank:27

**Title:** Credit assignment in the brain

**Added binding assumptions (LaTeX):**

```latex
Use the update $w\leftarrow w-\eta\widehat g$; the displayed positive alignment is a descent condition only under this sign convention. Define the expectation over trial data and update noise conditional on the current weights. Smooth expected loss and a step-size restriction are needed to convert alignment and second-moment bounds into an actual expected loss decrease.
```

**Direct edits:** 0. **Fresh external checks:** None; supplied sources retained as provenance.