In this very intelligently written piece in the New Yorker, Maria Konnikova discusses writer’s block and it’s psychological correlates. She notes that Graham Greene, while in psychotherapy, started a dream journal, something he would come back to to help him with his (infrequent) bouts of writer’s block. She describes research by Barrios and Singer on writer’s block that suggests that, while different people respond differently to having writer’s block, what they all share is reduction in their production of mental imagery, of daydreaming and even of dreaming. Although Konnikova doesn’t say this, the implication is that superego conflicts are primary in most creative blocks.
Her conclusion: “the main message of research into writer’s block: It’s useful to escape from external and internal judgment—by writing, for instance, in a dream diary, which you know will never be read—even if it’s only for a brief period. Such escapes allow writers to find comfort in the face of uncertainty; they give writers’ minds the freedom to imagine, even if the things they imagine seem ludicrous, unimportant, and unrelated to any writing project.”