Note that preceding each plot also identifies extreme data points in the dataset which may have an influence upon the regression line (line drawn through the data). The extreme values are represented in bold within the plot itself.
For example,in all of the preceding plots, you can see that observation 26 is considered an outlier with respect to the other covariates.
Print this observation to the console along with some of its neighbors. You can see how this could be considered an outlier just by inspection, since two variables (Duration and Treatment) immediately pop out as being different from the surrounding observations:
This is the output which is sent to the console:
Treatment Gender ...