Pattern 1 extension incorporates notes from improvising pattern 1 with some extra notes on the fretboard. This extended pattern is also commonly used for improvisation. Note the arrows indicating ascending or descending slides.
Use the ascending slide on the way up the pattern and use the descending slide on the way down the pattern, as illustrated in the following example.
Practice playing pattern 1 extension in different positions on the fretboard and use it to improvise. Even though the previous example starts on the 3rd fret, the pattern one starting note (for determining what position to improvise against a progression) is still the note on the 5th fret of the 6th string, so the pattern is still centered around the 5th position.