One could surmise the mediocrity of Diminished Capacity from reading the synopsis alone: Cooper (Matthew Broderick), a small-town-boy-made-good in the big city but lately suffering from the lasting effects of a serious concussion, heads back home to visit his fading Uncle Rollie (Alan Alda). As Cooper's mother explains of the latter's condition in a letter, "Dr. Hoyt calls it 'diminished capacity'; that's the legal term for a man who thinks that fish are typing poetry out on the end of his pier." Got that last bit? To clarify: Rollie connects fishing lines to each letter on his typewriter, the nibbling of which results in a jumble of words (Rollie edits).
That this precious and strangely empty conceit plays a structuring role in the narrative (inspiring the opening and closing images) is symptomatic of the movie's oblivious blandness; that a central character's dementia is used as an excuse for added quirk is just bad taste. As directed by actor Terry Kinney (of the Steppenwolf Theatre) and written by Sherwood Kiraly (based on his novel), Diminished Capacity suffers from a generalized aimlessness which might seem fitting given the subject matter except that it never takes purposeful shape.