You knew you were going to read this

Psychology Today notes that there is soon to be published evidence of people having a small, but apparently consistent, ability to be influenced by the future. The experiments sound quite interesting:

For example, we all know that rehearsing a set of words makes them easier to recall in the future, but what if the rehearsal occurs after the recall? In one of the studies, college students were given a list of words and after reading the list, were given a surprise recall test to see how many words they remembered. Next, a computer randomly selected some of the words on the list as practice words and the participants were asked to retype them several times. The results of the study showed that the students were better at recalling the words on the surprise recall test that they were later given, at random, to practice. According to Bem, practicing the words after the test somehow allowed the participants to "reach back in time to facilitate recall."

In another study, Bem examined whether the well-known priming effect could also be reversed. In a typical priming study, people are shown a photo and they have to quickly indicate if the photo represents a negative or positive image. If the photo is of a cuddly kitten, you press the "positive" button and if the photo is of maggots on rotting meat, you press the "negative" button. A wealth of research has examined how subliminal priming can speed up your ability to categorize these photos. Subliminal priming occurs when a word is flashed on the computer screen so quickly that your conscious brain doesn't recognize what you saw, but your nonconscious brain does. So you just see a flash, and if I asked you to tell me what you saw, you wouldn't be able to. But deep down, your nonconscious brain saw the word and processed it. In priming studies, we consistently find that people who are primed with a word consistent with the valence of the photo will categorize it quicker. So if I quickly flash the word "happy" before the kitten picture, you will click the "positive" button even quicker, but if I instead flash the word "ugly" before it, you will take longer to respond. This is because priming you with the word "happy" gets your mind ready to see happy things.

In Bem's retroactive priming study, he simply reversed the time sequence on this effect by flashing the primed word after the person categorized the photo. So I show you the kitten picture, you pick whether it is positive or negative, and then I randomly choose to prime you with a good or bad word. The results showed that people were quicker at categorizing photos when it was followed by a consistent prime. So not only will you categorize the kitten quicker when it is preceded by a good word, you will also categorize it quicker when it is followed by a good word. It was as if, while participants were categorizing the photo, their brain knew what word was coming next and this facilitated their decision.

There are other types of experiments as well. I see now that the actual paper is available, but at the moment I don't have time to read it.

The effect was apparently small but statistically significant and consistent, and also showed that some people showed stronger future influence than others.

Well, this is all pretty fascinating, isn't it? It would be great if this type of experiment can be repeated and holds up over time in different labs. Until now, I think it's fair to say that Ganzfeld experiments have been held up as the most convincing proof of a psi effect, as they have been repeated in many different labs and generally been considered to show small but positive results. (A good detailed history of this type of experiment, and the controversy over whether they really are showing a psi effect or not, is given in this Wikipedia article.)

However, as the examples that Dean Radin has been providing at his website lately show, there is always an element of interpretation involved in scoring the "hits". (In fact, in this example Radin gives of someone trying to guess the correct photo, what I find surprising is that all 4 photos seem to have elements the woman is "receiving", even though the "sender" only sees the target.) But clearly, it would be great to get away from experiments that involve interpretation of what constitutes a "hit" in proving a psi effect.

Of course, we are yet to hear the skeptic take on the new Bem studies, and I guess we do have to wait to see if other psychologist can replicate them, but they sound rather promising.