Filters – what do you see, hear and feel?

NLP is about making changes in the way your mind works, in the way you use your mind, and in the way you process information. If you want to improve the way your mind works, a good starting point is to examine how this amazing machine enables you to make sense of the world – which is where the concept of filters comes in.

What do you really see, hear and feel as you go about your life? How does your mind filter the massive amount of information available to it in order to create your model of the world? And can you improve your filtering system?

We are continually receiving information from our environment through our five senses. This huge potential input of information has been estimated to amount to around 2,000,000 bits of data per second. Only a fraction of this is ‘important’, so we have many filters in place to limit the amount of data that reaches our conscious mind. If these filters were not in place, we would simply go insane.

Consider for a moment the feel of your shoe on your foot. This would not have been in your conscious awareness until we mentioned it. It has also not been committed to memory, as you have no recollection of how it felt five minutes ago. The information about how your foot feels has been filtered out, along with almost every other bit of data available from your five senses. It has been estimated that only around 100-200 bits of data per second actually reach our conscious mind from the flow of sensory data. That is only 0.01 per cent, which is a very narrow torch beam onto your field of sensory experience.

This of course raises the question as to what gets filtered out and what gets left in. In other words, could it be that some of your filters are too restricting? Once you have figured that out, the next question is whether you can change your filter settings if you don’t like how they are working. Read on...


We use many filters, all interacting with each other at different levels. In fact, the data handling is quite a computational feat, far beyond anything the fastest computer in the world today could do.

The filters are composed of our

  • Beliefs
  • Memories
  • Values
  • Attitudes
  • Current state
  • Culture
  • Language
  • Personality preferences
  • Interests
  • Assumptions
  • Other factors (for example, we are barely on the threshold of discovering the effect to which our DNA may affect our likes, dislikes and so on).

These filters operate in three ways:

  • They delete information
  • They distort information
  • They generalise as a way of simplifying and categorising information.

A lot of people have a problem with receiving feedback. Quite often, over-critical teachers at school caused them to put up a set of filters to avoid being hurt by unfair criticism. These filters stay on into adult life, still fully operational.

As a result, they are so preoccupied with their perception of being criticised, that they delete the information that will help them to learn how to improve; they distort the tone of voice and intent behind the feedback, and they make unhelpful generalisations (‘I’m a failure; no one ever has anything good to say about me’, and so on).

Compare this with someone who has an open-minded, learning attitude, and is grateful to be given feedback and the opportunity to improve.

Our minds are inevitably deleting, distorting and generalising all the time, but sometimes we need to examine the filters we use.


Much of the data we receive through our senses is simply deleted, especially if it’s not changing from moment to moment. The deletions include most of the environmental data, such as the temperature, ambient sounds and smells, the feel of your clothes and the furniture and so on. If any of these undergoes a rapid change (if someone let’s an icy blast in through the door, for example), the filters immediately let it through, and we become conscious of it.

Notice, though, that if we are absorbed in a task, we can delete even big changes in data, such as somebody saying something to us.

We also delete data that does not conform to our expectations.


Read the following sentence:

I love
Paris in the
the spring

Most people do not notice that the word ‘the’ is repeated. They delete the extra one as it does not ‘conform’.

This process of deleting what does not conform to what we expect or believe is very strong. The old saying ‘I will believe it when I see it’ would be better phrased as ‘I will see it when I believe it’. It is said that when Captain Cook arrived in Hawaii, the locals did not see the huge sailing ships in the bay, just Cook and his men in their longboats rowing to shore. They did not believe such large ships could exist; therefore they did not see them.

This is also what is going on when you are looking for your keys and cannot see them on the table because you ‘know’ that they could not be there. You would ‘never’ put them there and thus they must be somewhere else. It is only when someone else picks them up do you see them.

By definition, we are unaware of what we delete, though we may become aware that we must have deleted something – for example, when someone shakes your shoulder and says ‘Didn’t you hear me?’


Psychological experiments demonstrate that people exhibit a taste for consistency. People are inclined to interpret new evidence in ways that confirm their pre-existing beliefs. This leads to a distortion of the sensory input so it ‘makes sense’ to the observer.


An anthropologist took some deep jungle pygmies to the edge of the savannah. They had only ever lived in a world where all the things they could see were close. They asked the anthropologist what the strange insect was that they could see, and thought he was joking when they were told it was a buffalo. They ‘knew’ what a buffalo was, and it could never look that small.

You have also no doubt heard of the differing testimonials given by witnesses to a traffic accident. They can be so different that one would think the people were describing entirely different events. All the witnesses are recounting what has been stored in their memory after the sensory input data has been through their filters.

Fear is often the result of distortion. Remember the creak on the stairs that in your mind turns into a burglar, even though it is just the house settling in the cooler night air.

Or have you ever had the experience of taking a comment from someone you dislike or suspect of bias against you ‘in the wrong way’? When people are not getting on well at work (or elsewhere), distortion often comes into play. A neutral remark is made, yet in the hearer’s mind it is fitted into their belief about the other person’s hostility and the words are ‘heard’ as if spoken in a negative tone of voice. Sometimes it can come as a surprise when a third party says something like ‘Oh, I don’t think it was meant that way at all...’

Whatever we receive via our senses has to be fitted into our model of the world in order for us to make sense of it. Sometimes it is a force fit, and this leads to distortion.

Think of it this way. All is well when we see things as they are, not as we wish or fear them to be. This is when our mental map matches reality. Some would call this being sane. If our mental map is distorted, if it does not match reality, our filters will distort what we experience so that it agrees with our distorted mental map. This is how people stay sane even when their mental map is out of kilter with what is actually happening around them.


Over time we notice that some things stay the same, and that there is some consistency in our experience. We categorise these regularities so that we can simplify the model of the world we build within our mind. We tend to think of classes of things and then treat all things that fit that class the same way. Of course, this can all too easily lead to mistakes, when we put something or someone into the wrong pigeonhole. At its worst, this can lead to racial stereotyping and other diversity problems.


A study was set up with student volunteers who were asked to report to a desk in order to register for an experiment for which they would get paid. The experiment did not exist – the real action took place at the desk.

They were given a form to fill in by a man in a blue shirt. As they were filling in the form, the man ducked down behind the desk on the pretext of getting another form, and swapped places out of sight with a second man who was of similar build but wore an orange shirt and otherwise looked quite different.

Some 75 per cent of the form fillers did not notice the switch. Of those that did, many were very unsure of just what they noticed.

Internal movie

Once the inbound sensory information has been through our filters, we re-present it on our ‘internal screen’. It’s a bit like a movie going on in our head, but complete with all the senses, not just sight and sound.

We then also have our own internal dialogue going as a commentary on the movie. You know... that voice in your head that seems ever present.

Since so much information is filtered out, we need to put information back into the data flow so that what is re-presented as a movie seems complete and is meaningful. This added data comes from memory.

If this seems a bit far-fetched, consider that we have a blind spot in each eye where the retinal nerve attaches to the eye. No visual data is available for this part of our visual field, and yet we ‘see’ a complete picture. We are obviously filling in the gaps, and this process of filling in is much more important and pervasive than most people realise.

Something else we do with our internal screen is play old movies, or what we would call memories, and mix them up with what we are ‘perceiving’ through our senses. We also do quite a bit of editing and creative movie making when we are daydreaming, or thinking about the future.

We often act as though this internal movie is identical to what is happening ‘out there’, but of course it is not. Our filters have seen to that. If you think about it, we cannot really ever know what is happening ‘out there’ because the only way we can access information about ‘out there’ is via our filters. This means that we have to make allowances for the fact that what is on our internal movie will be different to what is playing on somebody else’s, even though we are observing the same event.


Ask a friend to describe something you are both looking at – for example, a sunset – complete with all the feelings and memories it evokes. In other words, ask them to verbalise what is playing on their internal screen, and then notice how different it is to what is playing on yours.

Depending on what we are playing on our internal screen, we will experience emotional changes within ourselves. If it is a happy movie, we will feel happy; if a sad movie, we will feel sad, and so on. So our movies affect our state. The reverse is also true in that if we are happy, we are likely to choose happy movies to play.


Your state has a tremendous affect on you. It is a major central driver within the system outlined in the diagram above. Everything you do or say or think is profoundly influenced by your state.

See Managing your state for more about what your state is.


Your state affects everything you do, and the way that you do it – your behaviour. This includes ‘external’ things, such as driving a car or using your computer or talking with somebody else. It also includes ‘internal’ things, such as the posture you adopt, the way your face changes expression and the way you move; it even affects the speed at which your heart beats.

Think about how you would stand and move if you were feeling pretty low. Now think about how you would stand and move if you were feeling fantastic. Interestingly, there is a feedback loop here, as your posture and physiology also influence your state.


Take several deep breaths and stand tall, with your head up and a big grin on your face. Now try to feel sad.

It simply is not possible. The physiology and posture of feeling great does not allow you to feel down.

How you do something has a direct affect on the results you will get from that activity, and how you do something is controlled by your state.


Imagine you are in sales and a big order has just come in by fax. You have easily made your bonus this month and you feel just great!

How would you handle some cold calling you need to do?

Now imagine that a second fax arrives, cancelling the order.

How would you handle the same cold calls?

Of course, this also has a feedback effect, since you observe your results through your perceptual filters. Depending on your results and how your filters are set, you will create your internal movies and hence affect your state and thus your behaviour.

Changing the filters

The filters actually change dynamically as we change our state.

If you are feeling down and you tread in a puddle and get water in your shoe, it feels like just one more thing that went wrong today. If you are feeling great and the same water gets in your shoe, you will probably shrug it off with a laugh. Your filters change as a result of your state.

The filters also change as we go through life and our beliefs and values get updated, and we have more experiences and so have more memories in our database.

You can, to some extent, be purposeful about these changes by seeking particular experiences and by seeking specific things to learn. But the easiest way to change the filters, and by far the quickest, is by Managing your state.