Here is an excerpt from an interview with Anthony Jackson who sites Jack as an influence.
Perhaps more of a surprise to some will be Jackson’s influence from Jack Casady.
“Casady, whom I'd first heard on Jefferson Airplane's Surrealistic Pillow album in late 1966, had a big, rich, metallic sound with a full bottom and a curious, guitaristic way of playing that I was immediately drawn to. When I saw him perform live, I was struck by his dignity and serious mien.”
says Jackson in a 1990 interview in Bass Player magazine. (Note that this quote hints Jackson's fascination with the playing of the bass in relation to the guitar - see below.) Casady played with a pick, which Jackson has also always had at least an ability for.
“It was Casady's sound that kept me exploring the expressive possibilities of using the pick. To this day, when I use one and a flanger, Casady's influence emerges and can be clearly detected by an aficionado.”