Don't even think about it: Why thought control is so difficult

Don’t even think about it: Why thought control is so difficult
When asked not to think of something, like a red apple, thought-substitution has been shown to be effective. Credit: Shutterstock

Whatever you do, don't think about a red apple.

Chances are, when you read the sentence above, that's exactly what you did do. But not to worry, that's quite a normal reaction for our chattering human brains.

It turns out that even those people who are good at suppressing certain thoughts still harbour traces of the thought in their unconsciousness, according to the latest research to come out of UNSW's School of Psychology.

Researchers at UNSW's Future Minds Lab conducted experiments with participants who were instructed to either imagine or avoid imagining red or green vegetable or fruit objects for seven seconds.

Ten participants were randomly shown one of six written cues: "red apple," "red chili," "red tomato", "green broccoli," "green cucumber," or "green lime".

After being instructed to avoid thinking about the written cue objects, participants were then asked to indicate if the thought popped into their heads by pushing a button. Following this, they were shown a red-green image in (where an image is shown to each eye separately) and then asked to indicate which colour was dominant.

The researchers found that there was an above average chance that a participant picked the colour associated with the original written cue words.

Specifically, when participants attempted to not think about a red apple, chili or tomato, they were significantly more likely to report red in the subsequent rivalry illusion presentation. This suggests, say the researchers, that thought suppression was ineffective at preventing the sensory trace of visual thoughts from forming.

UNSW Future Minds Lab director Professor Joel Pearson says this was a surprising result, particularly for the participants who had not pushed the button, indicating they had succeeded – or thought they had succeeded – in thought suppression.

"Even though they had not thought about the objects, we could still measure the sensory trace of a thought," Professor Pearson says.

"In other words, despite not being aware of the thought there was still a representation of it there, most probably in the visual cortex, that was systematically biasing the binocular rivalry illusion.

"Through various control experiments we show this is the most likely explanation of the data."

Interestingly, Professor Pearson says that in another task where participants were told to use a distraction strategy to avoid thinking about the object – for example, thinking about a white cloud – the bias effect went away.

"This shows that thought-substitution is a better strategy than direct thought control, while other data shows that mindfulness might aid in general thought control at a sensory level," he says.

The research could also inform new ways of thinking about strategies to deal with the cognitions involved with addiction.

"This is an exciting discovery as it tells us for the first time that even when we feel like a thought is not there, because we have successfully suppressed it from our minds – it is actually still there," Professor Pearson says.

"Which suggests using brute force to not think about something – that cigarette or that drink – simply won't work because the is actually there in our brains.

"This discovery changes the way we think about thoughts of desire and suggests unconscious thoughts can emerge and drive our decisions and behaviour."

Moving ahead, Professor Pearson says he and his fellow researchers are now looking at the neural representations of these unconscious suppressed thoughts using function brain imaging (fMRI) to show exactly where they are in the brain.

Explore further

Our brains reveal our choices before we're even aware of them, study finds

More information: Eugene L. Kwok et al. Measuring Thought-Control Failure: Sensory Mechanisms and Individual Differences, Psychological Science (2019). DOI: 10.1177/0956797619837204
Journal information: Psychological Science

Citation: Don't even think about it: Why thought control is so difficult (2019, April 30) retrieved 17 September 2019 from
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Apr 30, 2019
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Apr 30, 2019
Buddhist type 'enlightenment' training is all about getting past this sort of thing. to understand the mind from the outside, all while being inside of it.

They don't come to you as it is a thing where you have to go to it. otherwise the mind is going to reject it. Sometimes quite violently. it is handled on a one to one basis as the methods are intense enough to break the mind and allow its self to empty itself of it's more poorly made and poorly handled constructs.

to the deepest parts of the mind, that's a whole life whole world eternal and never ending threat, especially to the ego construct. It's no casual thing or pill you can take on weekends or give lip service to. It takes all of you to subdue, to understand, to encompass and expand -- all of you.

Note that modern society and it's manipulations are all about remaining the animal and not being the more complete human.

Keep them stupid and malleable.

Apr 30, 2019
This is a bit can you not think of something under instruction without knowing what it is you are supposed to not think about, and this requires the thing to be avoided to remain in short term memory.

It is like a sign post that says "sign posts are prohibited in this area". You need to erect a sign post to warn about not posting sign posts. Or a sign that says 'don't read this'. You only know not to read it after you've read it.

Perhaps they were trying to prove the non-existence of dualism, there is no magical entity separate from the brain that could remember to not think of something and instruct the brain to comply...

An alternative method of testing is to ask the participants what they were supposed to have not thought about. If they give the right answer then they have retained the sanctioned thought in short term memory, which liberally overlaps with current thinking anyway.

Apr 30, 2019
To not think on A, the strategy is to focus the mind on B and always on B. After time, the mind obeys and moves to B effortlessly, like a puppy. The reason is that the mind needs to be at some state, it can not be "stateless".

It has been known for centuries in the meditation circles. It has been called recently "focus-attention-meditation".

Apr 30, 2019
It's the same reason why if you hear a few bars of a familiar song and it cuts off suddenly your brain keeps right on playing the rest of the song in your head. Even if you try to stop it. There are mental processes out of conscious control. You can sooner tell your lungs to stop sucking air than tell your brain to stop thinking about that random Queen song. When you sleep you think nothing is happening outside your control? You basically put your body on auto pilot and there's no reason it has to shut off while you're awake too.

May 01, 2019
participants were then asked to indicate if the thought popped into their heads by pushing a button

That's setting the subjects to fail, because in order to check that you're not thinking about it, you have to think about it.

May 01, 2019
@ RobertKarlStonjek; Or something like 'Unauthorized Personnel Only' sign on a door

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