It is seldom appreciated that what one is aware of usually “just happens,” all for free and without any effort or intent one one’s part. Upon waking, for example, one opens one’s eyes and immediately experiences visual objects, sounds, smells, and perhaps even high-level thoughts, such as an “ear worm” playing incessantly in one’s head. (An ear worm is the involuntary mental imagery of a song, as when someone says "I can't get that tune out of my head.") The dream world, too, is generated in this manner. After waking, one may also experience, out of the blue, a thought such as “time to water the plants.” Where do these thoughts come from?
Helmholtz, who influenced the thinking of Freud (who in turn influenced Jung's work on the collective unconscious), proposed that conscious contents arise from the workings of sophisticated, ‘unconscious inferences.’ These inferences are not under one’s control.
Freud considered such thoughts as intruding (the term "Einfall" in German) into consciousness (see "Freud's Unconscious Was Not a Subliminal One"), the result of "psychic determinism" (see recent, relevant study here), which functioned according to certain mental laws. (It has been proposed by many theorists that the thinker prefers when these laws are followed, and when conscious contents do not arise in a random manner; see treatment here.)
These inferences can arise even during complicated processes such as automatic word reading, in which a visual stimulus (e.g., the word HOUSE) automatically activates a conscious, sound-based phonological representation (e.g., /haus/) in one’s mind. (Research is also beginning to reveal that attentional processes can also arise in this passive, involuntary manner. From this standpoint, attentional mechanisms are construed as an effect of enhanced processing rather than as a cause of enhanced processing, see counterintuitive theory here.)
Some might argue that such thoughts can occur from processes such as perception or the retrieval of information from memory, which often happens automatically, but not from high-level processes involving, say, "executive control" and symbol manipulation, such as when rotating a visual object in the mind’s eye (e.g., can you imagine this letter T rotated 180 degrees?). Symbol manipulation is held to be a very high-level form of executive control, involving the frontal cortex. Can such a process, too, occur involuntarily?
Consistent with the notions put forth my Helmholtz, new research reveals that even high-level processes involving symbol manipulation and, presumably, the frontal cortex can arise involuntarily from processes resembling those of unconscious inferences. In one experiment conducted at my lab, the involuntary symbol manipulation resembled that which is carried out in the childhood name of Pig Latin (e.g., "CAR" is transformed into "AR-CAY"). Click here for more information about this experiment. This research supports the new theoretical framework Passive Frame Theory, which proposes, among many things, that the vast majority of conscious contents (e.g., an ear worm or sight of the sun) arise involuntarily.