# Tutor profile: Cameron S.

## Questions

### Subject: Writing

Should the Oxford comma be used in APA style? How about MLA and AP?

Both APA and MLA support the use of the Oxford comma. However, if writing a journalism piece following AP style the Oxford comma should not be used.

### Subject: Statistics

What is the relationship between z-score and standard deviation?

The standard deviation is a representation of the total variance in a data set. The Z-score normalizes the standard deviation to describe a particular point on the normal curve; A Z-score of 1 is one standard deviation from the mean, a Z-score of 2 is two standard deviations from the mean, etc.

### Subject: Cognitive Science

Provide an example of how stress can impact an individual's cognitive development.

Chronic stress leads to an increase in cortisol produced by the adrenal glands. The excess cortisol over-stimulates the hippocampus, which down-regulates the number of available hippocampal cortical receptors. This down-regulation reduces the efficiency of memory and inhibits both passive and active learning.