Have you ever seen advertisements for “sleep-learning” tapes or recordings that promise to teach you something (such as a new language) while you doze comfortably in your bed? This idea of sleep-learning (also called “hypnopaedia”) has been around for nearly a century, but so far it has not been proven to have any measurable effect. While it’s true that you can often solve a problem, or come up with the answer to a question that’s troubling you, by “sleeping on it” – giving your unconscious mind time to put together facts and arrive at solutions – there has not been any conclusive evidence that hypnopaedia is effective in teaching concrete, precise elements of knowledge. In one sense your mind will “hear” the lesson being played out loud while you sleep, but the parts of your brain that connect that information and fix it in your memory are not active, and you won’t remember what you “heard” when you wake up.

On the other hand, a lot of the information we collect is done unconsciously – not in the sense that we are unconscious or sleeping at the time, but that we are constantly (while awake) and automatically gathering information about the sounds, sights, and activities around us, and processing those data in our brains. Part of that process is hearing words that are being used by other people, or seeing those words in print somewhere. For example, you might be on the bus, headed to work, and not really thinking about anything in particular, when the two people seated behind you begin a conversation about their co-worker and refer to his idiosyncratic habit of always lining up his pens at the right edge of his desk – never the left! You’ll overhear this conversation, and if you don’t know the meaning of the word “idiosyncratic” then you’ll unconsciously make note of it as something different and unusual. If you get distracted once you’re off the bus, you may not immediately look up the word to satisfy your curiosity, but the next time you see or hear the word, it will trigger a recollection in your brain about this overheard conversation, and you’ll be more likely to research the word, learn it, and be able to use it in the future.

Active, directed study is the quickest way to improve your vocabulary, but your unconscious mind will also be learning words throughout the day. You can help this process by being more alert and aware of the words you hear and see, jotting down notes in your vocabulary journal to remind yourself to look them up later.

By the way, “idiosyncratic” is an adjective often used to describe an individual’s unique and personal quirk or habit, often one that’s slightly odd or eccentric.