This article was originally posted on The Brain in Action Blog and translated by Rumia Bose. Minor changes were made.
I seem to have misplaced my iPhone. It’s not in my pocket or on the charger.
In my thoughts, I trace my route through the house and the rooms where I have been today: the bedroom, living room and kitchen. But I cannot see myself laying it down in any of these spaces with my mind’s eye.
I recall having a USB port in my new car, where I sometimes plug my phone in to charge. I hurry to my car, and indeed, there it lies.
This search occurs largely inside my head, looking with my mind’s eye. It goes much the same way with my memories. They are often played out like a sort of film in my head, as described in Remembering an event that changes your memory.
How does it work if you see with your mind’s eye? Are there visual signals? They do not, at any rate, enter through the eyes.
Seeing With Your Eyes
When you see, signals are sent through your eyes to the primary visual cortex, right at the back of your brain (Fig. 1). From here, they are transmitted progressively further forward to other parts of your brain, where they are processed and integrated with other data (Fig 2). For instance, in the temporal lobe, they are combined with information from your memory to recognize objects and faces.
In the parietal cortex, they are combined with other sensory inputs to determine where the item you see is located in space and in relation to other objects. Also, here, your brain determines if what you see is important. If it isn’t, then you automatically direct your attention to something else, and further processing of the original object of focus stops.
If what you see is important, you must decide what to do. For this, all the information is combined in the frontal cortex. Signals can be sent out from here to the premotor and motor cortex to take action.
Seeing With The Mind’s Eye
The entire process goes reverse when you see with your mind’s eye. It starts with what I must do if I misplace my iPhone; my frontal cortex “says” to search. I walk through the house, not physically but in thought. My temporal lobe comes into play for the identification of my phone.
Should I look for it in my study?
With the help of my parietal cortex, I know that I won’t find it there because I haven’t been there in the past two days. This information came from my autobiographical memory.
Seeing with your mind’s eye begins in the frontal cortex, and from there on, you use areas of your brain that lie progressively further behind. The rearmost area – the primary visual cortex – was not used when I looked for my iPhone. That is only required when you need to see something highly detailed with your mind’s eye, such as all the specifics – the edges, the controls – of the phone.
Seeing with your mind’s eye is usually relatively vague and hazy. Try to retrieve something you can visualize in your memory, such as a room in your previous house you were very familiar with. And now, concentrate on one object and try to bring all the details into sharp focus.
This attempt usually only meets with moderate success.
People Without a Mind’s Eye
But some people are unable to do this! They cannot see with their mind’s eye.
When you ask them what they see when remembering things, they answer: “Nothing.”
They do know that room in their previous house and have recollections of it, but without images.
I cannot imagine how that can be because I need those images. If my wife asks, “Do you remember that restaurant beside the museum in Assen?”
I search for images in my memory. And if I cannot find these, then no memories resurface. But if she then says, “….with the staircase through the middle…” then the images come back, and I see where we sat and perhaps even what we ate.
A Test: How Good is My Mind’s Eye?
You can test how well you can see with your mind’s eye with the Vividness of Visual Imagery Questionnaire (VVIQ). For each scenario you try to form a mental picture of the people, objects, or setting. The scoring lies between 1 – no image and 5 – perfectly realistic, as vivid as seeing. Average scores lie between 2 and 2.5 for each scenario. My average score for each scenario is 1.7, meaning my mind’s eye is quite strong.
Oliver Sacks Lacked A Mind’s Eye
In 2015 an article in the popular press set off a wave of realization for hundreds of people that they did not have the faculty of a mind’s eye. Before this, most of them thought that this was normal.
Watkins, a physicist who also lacks a mind’s eye, describes his experiences and quotes Oliver Sacks, a neurologist. He, too, did not have a mind’s eye, but Sacks once used amphetamines, which helped him conjure up visual images. Amphetamine may provide the experience of a mind’s eye if you lack one of your own. Sacks writes:
“Something perhaps analogous happened to me in 1965 […] I was taking massive doses of amphetamines. For a period of two weeks, I found myself in possession of a number of extraordinary skills I normally lacked […]. I could not only recognize everyone I knew by smell, but could hold very accurate and stable visual images in my mind and trace them on paper, as with a camera lucida. My powers of musical memory and transcription were greatly increased, and I could replay complex melodies on my piano after a single hearing. My enjoyment of these newfound powers and the world of greatly heightened sensation that went with them was mitigated, however, by ﬁnding that my abstract thinking was extremely compromised.”Oliver Sacks, Musicophilia
I can’t do without my mind’s eye for my neuroscientific endeavours. As I describe brain areas above, I see them in my mind. Abstract thought and a powerful mind’s eye apparently do not make good bedfellows, as Oliver Sacks also experienced.
Watkins describes yet another characteristic: a severe limitation of autobiographical memory, known as SDAM (Severely Deficient Autobiographical Memory). While he does have early memories, they are much vaguer and less detailed than people with a mind’s eye.
And he finds it difficult to imagine his future.
People With a Super Mind’s Eye
The reverse is also possible: people who experience almost everything in vivid images and moving pictures. They often are not very good at abstract thinking. And as you might have guessed, these people are often creative and artistically inclined. There must be differences in brain dynamics between people without and with a highly developed mind’s eye. But this has not yet been found.
For me, the moral of this story is that one should be careful not to assume that everyone sees their past or future in the same way as I do. What’s more, this difference in degree may apply to almost every aspect of thinking.