What’s going on in your head?: The science behind our inner voice

As a neuroscientist, one aspect of brain-science that has always intrigued me is the idea that we may never know exactly how another person experiences the world and whether their experiences differ from our own. I know what the red ball (pictured right) looks like to me but how do I know that you’re seeing same thing? In fact, I’ve often wondered what it would be like to see the world through the eyes of someone whose perceptions differ from mine, for example someone with colour or face blindness.

Sadly though, I’ve always assKarl_Pilkington_2008-02umed that my own experiences are disappointingly mundane and ‘average’. That was until ‘life guru’ Karl Pilkington taught me otherwise…

A few months ago, during a particularly long experiment, I was passing time listening to old exerts from the Ricky Gervais show when I came across the following dialogue:

Reading from Karl’s diary: “While I sat listening to The Kinks on my iPod, I wondered if everybody thinks in their accent. I know I do.”

Stephen: What’s this? What are you talking about?

Ricky: How do you know you think in your accent? Tell me a typical thought

Karl: I thought “that’s weird innit?” not “that’s weird isn’t it?” and I thought “I actually think in my accent”

Ricky: No, but, when I think I don’t think the sentence as like I’m saying it, it’s just a thought, the thought appears, it’s conceptual and it’s already there. It’s not like I go, “Rick?” “What?” “Just err… looking at that fella over there were you?” “Yeah, I was yeah. Erm, I was think he looked a bit weird” “Oh, so was I”, I don’t think out whole sentences…

Stephen: Is that how your mind works?

Karl: In a way, yeah

Ricky: Brilliant, it’s great, he has to think out whole sentences!

Stephen: That explains a lot!

This sparked my curiosity since, as far back as I can remember I’ve always thought in complete sentences, often to the extent that I have conversations with myself inside my own head – I just assumed that this was a pretty normal thing to do!

So, I decided to do a bit of my own research into this ‘inner monologue’. This research began life (as many eminent and respected studies often do) on Facebook, where I asked a number of friends:

“What is it like to climb inside someone else’s head? – I’m researching for a post on the inner monologue and, although I think in words like I’m narrating my own life, apparently there are people who don’t…what’s it like inside your head? and if you don’t think in complete sentences, how do you think?”

From this question I got some pretty interesting answers – In brief, most people who responded had some kind of inner voice but few regularly thought in complete sentences or engage this voice in conversation. Some interesting answers included:

“I think in pictures like I’m watching a silent film. In order to submit things to memory I have to have visuals as i struggle to remember audio descriptions. So most of my memory is made up of pictures and that’s how my thought processes work!”

“I sometimes imagine a highly adapted version of something I’ve read or watched – featuring me – and tailored to my real life situation of the time. Less actual words, more images, but like I’m an outsider observing myself observe my situation.”

“I think I only think in words when I’m either a) questioning something (“why’s that there?”) or b) making a decision to do something (“cup of tea!”). I often say such things aloud too when I’m alone.”

“I was wondering about my very minimal inner monologue after talking to my husband about it earlier this week. I find it incredible how most people seem to constantly be thinking in words/sentences. It sounds exhausting to me. I think in actions, visualizations, feelings, impulses and only really have a proper inner monologue when reading or writing. I never know internally what I’m about to say out loud (unless I force myself to do so, or if I’m nervous about talking in specific situations). Often my mind seems blank with no thoughts. I find meditation very easy.”

“I have narrated my life for as long as I remember. Sometimes, when something is particularly challenging, I sort of Parkinson interview myself, as if the problem is now in the past, and I’m discussing how I overcame it….I’ve done that since I was a teenager!”

So, it seems like people experience a huge spectrum of inner ruminations –  from short sharp assertions “cup of tea!” to long complex “Parkinson style” inner interviews.

But what do scientists actually know about this inner voice? Well, unfortunately it seems that this is one topic that’s been neglected by modern science. However, inspired by the theories of L. S. Vygotsky, modern research has now again picked up the baton and started to delve into the inner workings of the verbal mind.

Where does the inner voice come from?:

16931172632_0f1676a803_mVygotsky believed that inner speech starts to develop in early childhood, evolving from a phenomenon known as ‘private speech’. Many young children talk to themselves while playing – I remember I used to talk to myself, I’d also sometimes have conversations with inanimate objects (perhaps a downside of being an only child?). Vygotsky called this dialogue private speech and suggested that it comes from social dialogues with parents which, in later childhood, becomes internalised as inner speech.

This would imply that inner speech relies on the same biological mechanisms as those used when we speak out loud. Interestingly, we know that inner verbalisation is accompanied by tiny muscular movements in the larynx – it’s as though audible speech is almost produced but is then silenced at the last minute. If anyone’s like me, they may have experienced the phenomenon of externalised inner speech: when I’m deep in internal thought I’ve been known to accidentally say things out loud which should have stayed in my head.

Neuroscientists have also found that an area within the left inferior frontal gyrus, known as Broca’s area, is active when we speak out loud and also during inner speech. Intriguingly, if this region is disrupted using magnetic brain stimulation both outer and inner speech can be altered.

And, to answer Karl’s question….It has been suggested that, assuming inner speech derives from childhood verbalisations, the voice you hear in your head should sound like your own voice – as Karl would say “everybody thinks in their accent”.

Screen Shot 2015-10-10 at 17.01.37Interestingly, studies of limericks suggest that this is indeed the case! Ruth Filik and Emma Barber from the University of Nottingham asked participants to read two limericks silently in their heads, these being:

1) There was a young runner from Bath, Who stumbled and fell on the path; She didn’t get picked, As the coach was quite strict, So he gave the position to Kath.

2) There was an old lady from Bath, Who waved to her son down the path; He opened the gates, And bumped into his mates, Who were Gerry, and Simon, and Garth.

All participants were native to the UK, some having northern accents and others southern. In the UK there is a strong regional divide in the pronunciation of the words bath and path, with southerners rhyming bath/path with Garth while northerners rhyme bath/path with Kath (this being the correct way to pronounce things). By tracking participants eye movements the researchers were able to tell when they were reading a rhyming or a non-rhyming sentence. From this they found that both groups appeared to read silently in their own regional accent (although this is not always the case).

So, what does inner speech actually do?

4929178358_dac74312b0_zVygotsky thought that inner speech may help people to perform difficult tasks. Thinking a task through in words may make it easier to accomplish – there are definitely a lot of words going through my mind when I’m building Ikea furniture. Actually, a number of studies have found that people tend to perform worse on tasks which require planning (like playing chess) if their inner voice is suppressed while performing the task.

Recent studies have also found that inner speech often has a motivational quality. In fact, one of my friends offered this example of her inner voice: “I tend to ask myself questions and then think through the different answers. Also I cheer-lead myself along- ‘Right, ok, you can do this!’”.

The self reflective tendency of the inner monologue may also allow us to reflect more on who we are as individuals. Indeed, Canadian psychologist Alan Morin suggests that people who use inner speech more often also show better self understanding: “Inner speech allows us to verbally analyse our emotions, motives, thoughts and behavioural patterns,” he says. “It puts to the forefront of consciousness what would otherwise remain mostly subconscious.” This idea is further supported by a study of neuroanatomist Jill Bolte Taylor who reported a lack for self awareness after a stroke which damaged her language system.

But, I doubt my friends who reported the lack of an inner voice suffer from any associated lack of self awareness. Therefore, I’m sure that there are still a number of individual differences which remain unaccounted for in these studies.

The dark side:

2967650878_1f436efd1c_zJust as your inner voice can be your own personal cheerleader giving you a boost when you’re feeling low, it can also be your worst enemy. Alongside my Facebook friends, I also posed my question to a group of individuals who, like myself, have been or are currently struggling with depression and/or anxiety. I was intrigued to find that, of all 30 responses, only a couple of people reported not having an internal monologue and most said that their inner voice was conversational (like my own). Not just this but most also said that their inner voice was ‘nasty’ and ‘cruel’ repeating phrases such as “you are useless” or “you aren’t good enough”.

There are a number of studies which support this observation, specifically suggesting that depressed older people rely more heavily on negative internalised speech than social communications when constructing their view of reality (giving them a negative outlook on life). Indeed, the backbone of cognitive behavioural therapy (a commonly used tool in the treatment of mental illness) relies on teaching individuals to re-frame or alter negative thought processes like those mentioned above – “I can’t do it” may become “it’s a challenge but I’m capable given enough time”

Researchers are still not sure how the inner monologue, negative thought processes and social isolation interact in the case of depression. It may be that withdrawal from social interaction leads to a greater dependence on internal processes or perhaps disordered negative thoughts breed the need to withdraw from society. Whatever the case, a better understanding of the mechanisms behind our inner critics may help understand and treat those suffering from depressive illnesses.

Researchers from Durham University found that around 60% of people report that their inner speech has the to-and-fro quality of a conversation. So, despite Ricky and Stephen’s surprise, it seems that Karl perhaps isn’t that abnormal after all. With inner speech being such a wide-spread phenomenon and knowing its possible links with mental health, perhaps it’s time scientists paid a bit more attention to the little voice in our heads?

Post by: Sarah Fox

15 thoughts on “What’s going on in your head?: The science behind our inner voice

  1. The ‘red ball’ part has always interested me. You could have two different people look at a ‘red’ ball, yet they could ‘see’ something completely different. Yet they both will call it ‘red’ because they’ve been taught that *that color* is ‘red’. Sort of weird if you think about it.

  2. Not only do I internally speak in sentences and have face blindness until I’m comfortable with you, but my face has expressions of what I’m thinking about. My children frequently ask me what I’m thinking about. I respond that its nothing if I want it to be kept private. I am not aware that my face is moving. I also believe that I have another complete life in my head and sometimes it is sad and afraid but sometimes it is more fun than imaginable. I love my brain

  3. I remember realizing, when I was 5 years old, that I had a choice to think “in pictures” ( I guess like a silent movie of what I experienced in the past and what I intended to do in the present), or else in words ( saying to myself my perceptions, opinions, or intentions). For a while I consciously switched back and forth between the two ways of thinking; then, my perception at the time was that I switched entirely to thinking in words and lost the ability to think in pictures. Now it seems to me that there is a lot of automatic, wordless processing of my experience; a lot of self-talk like running subtitles; and also the deliberate use of repetitive internal speeches to various imaginary audiences to help me analyze situations, problem-solve, and rehearse what I will say in response to social situations.

    I also wonder, if sensory perception is a brain event, does the color happen in the brain, so people blind from birth use the vision part of the brain for other senses, and maybe hear in color?

  4. Yes Winie. Not only can some people see sounds but there is a case of a blind person who uses that part of his brain to build an internal image of his surroundings using eccho location.

    As for the inner voice, I believe it’s the voice of our subconscious. As children, before we learn words and meanings, we think in pictures. Our minds are a lot more observant than most people realize and we learn by watching the adults we come into contact with. At that age we don’t really know right from wrong or even reality from imaginary. Therefore it is crucial not to expose small children to violent movies.

    As we get older, we learn about morals and social behaviour, but this gets imprinted in our conscious minds. What we learnt before that remains in our subconscious until such time as we lose control of our conscious mind and the subconscious takes over. This is when we do things we can’t explain and sometimes don’t even have any recollection of doing.

    Subconscious actions are controlled fully by emotions while conscious actions are rational. Most of us learn to control these subconscious impulses when we become adults. But not everyone. The truth is that most of us don’t even know what lies in our subconscious mind. We get glimses of it but usually block those thoughts. They cause feelings of guilt and shame. Some thoughts even frighten us. It all depends on your experiences growing up. Those who have no demons hiding in their subconscious won’t know what I’m talking about and those who do won’t admit it.

    Well that’s how I see it.

  5. For years I never really, truly understood why characters on T.V. shows and movies had internal narration. I merely thought it was a way for the characters to communicate their thoughts to the audience, but after talking to a few friends and family members I realized it was actually a reflection of what really happens. I have never heard a ‘voice’ in my head. I never questioned it because I thought it was normal until my friends were talking about how they hear themselves think in their own voice or accent. Personally, I thought it must be annoying af to hear yourself think like that, I don’t think I could stand it. But it also made me question why I don’t hear that voice. When I try and research that question all I get is either a diagnosis of a mental disorder or some research stating that people without internal dialogue are illiterate and or not capable of deep self-awareness- yeah, thanks Google.
    I think the internal dialogue they are actually referring to is the ability to internalize thought- not think about the words.
    I’m still really curious about it. I never talk to myself because I think in concepts and ideas are ‘just there’ like that guy said. In fact when I described my thought process to my friends that was pretty much my exact explanation ‘It’s just there, I don’t know’.
    Sometimes it makes me feel abnormal because apparently there is a joke that “everyone talks to themselves but no one wants to admit it”. I never felt the need to talk to myself…

    I really wish I could talk to someone else who thinks like this! or at least kind of understands lol I feel like I’m grasping straws here.

    • That is so interesting to me. You don’t have an internal dialogue as you’re typing or reading even? I’m trying to imagine what goes through your head when being asked a question that causes you to stop and think about the answer.

  6. I’ve actually only find out (after 20 years of existence) that people actually think and can easily imagine what they say and easily assimilate what is told to them and usually automatically describe what’s going on around them.
    I don’t have any kind of inner speech, I “think” about nothing all the time… and because of that, It’s hard for me to understand the stories in the movies, the stories in the series episodes, the stories in books, what people say…
    I’ve always been kinda slow but I didn’t know why… and I’ve always asked how can people express themselves so fast and accuratly in a matter of seconds… then I went on a research and now I’ve completely awareness on what’s wrong with me…
    I just know that… and now it’s has become quite difficult to handle this situation now that I know that I just… just don’t think and don’t feel things as others do.

    • I’m fascinated by how someone who can’t hear thoughts in their head can nevertheless express coherent speech out loud, but even more surprisingly, can perform the slower task of reproducing that speech in the form of writing. My experience is of the need to keep mentally rehearsing the thought words in order to keep track of the sense-making on the page.

  7. I recently discovered this and aphantasia, I find it fascinating that people are leading such different internal mental lives. I’ve been wondering though whether the problem is quite what it seems and perhaps these two things are related. Could it be that people can’t “hear” their inner voice when its not talking, rather than it being absent? Surely you could test this. Something like this.
    * You say a noun out loud
    * then you draw a picture of it.
    * then you say it out loud

    We then see if they match…which surely they will. Now you repeat but next time you whisper the first time; then you just mouth it. Perhaps you listen to white noise so you can’t hear yourself talk. Do the images still match?

    What makes me think about this is that people seem to report thinking in pictures vs thinking in words. Perhaps some people come to use different sides of the brain for housing their identity. Hence they can be somewhat or completely unaware what’s going on in the other side of the brain unless it acts – in this case talks out loud.

    I’d imagine most people are bilateral, they can have an internal monologue and they can visualize images (think in pictures?). Some people favour one side more than the other, some favour one side to the exclusion of the other. Depending on which side is favoured you might get aphantasia or no internal monologue.

  8. I process what am going to say in my head before I say it I believe this come from me playing chess at an early age whit my dad people often get annoy to my slow response to question I also Realize people have conversation & often do not get what each other are talking about so before I answer I will translate back what I got from a comment to the Person before giving answer or comment

  9. I’m constantly talking to myself internally in my mind. Only when I’m very focused on something outside of myself like sports or a movie does it stop. I actively do it. It isn’t something that just happens, but it is something very hard for me to stop doing. I’m consciously aware of it all the time. Sometimes I address myself by name and ask myself questions and go back and forth with a conversation. Contemplation, analyzing and conclusions all take the form of dialogue. All my reading takes the form of audible words in my mind. I just assumed that everyone did this and looked it up just today because I realized that Helen Keller wouldn’t have been able to do it with audible words. I’m wondering how people explain things to themselves without putting it into words. How do you figure out what you are going to write without first putting it into words? How do these people take their thoughts and put them into words to write? How do they contemplate options when making a decision? I find this fascinating because it means there is a whole different way of thinking that I wasn’t aware of. I wonder what these people do for careers and if there are any similarities in the types of careers they choose. I would think that certain careers would be very difficult for people that don’t think in words, i.e. print journalism or any field that involves a lot of writing.

  10. A problem with this experiment could be that even though people are experiencing the same experience but understand and translate it in a different manner

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