If you randomly talk with people and ask them absurd non-personal questions about their thoughts, you’d quickly realize that the most common human experiences are completely incomprehensible and alien to many of them.
Imagine seeing a face but not seeing the details. Imagine there is no visual in the mind when you think. Imagine music doesn’t feel like music. Prosopagnosia, Musical anhedonia & amusia, and Aphantasia are unusual human experiences that involve a deficit in processing some of the most common aspects of everyday experiences.
All I’ll do in this article is introduce these lack of experiences, partly because I lack 2 of them. Some of you who know me personally know which ones!
Prosopagnosia, aka face blindness
pronunciation: Pro-sop-agno-sia
Prosopagnosia is a reduced ability to recognize faces and process the details of a face[1]. They can remember faces shortly after seeing them, but the amount of facial details encoded is quite low[2], so the memory of a face itself is low resolution and ambiguous. The biggest problem with this is that even slightly similar faces look exactly alike or lead to massive face confusion, even though others can clearly notice the differences. Most of these cases are caused by some form of trauma, like a brain injury or lesion, in the fusiform gyrus, a brain region dedicated to face perception. But there are also many congenital cases where people have always seen faces in low definition their entire lives, and without any obvious brain damage. Unsurprisingly, considering that the brain has dedicated “face cells” to recognize faces[3], and many different structures to recognize other types of non-facial information like shapes and locations, those with prosopagnosia have no problem recognizing other stimuli like voices, words, and other complex sensations.
Many people with prosopagnosia, in its various intensities, learn to recognize faces by focusing on highly definable features like the shape of hair, the shape of a nose and mouth, etc. For them, recognizing faces is an active mental effort as opposed to others who simply recognize faces without any analysis.
Various estimates suggest that about 0.2 to 2% people are likely to have life-long prosopagnosia[4] (not caused by brain injury), and 33% of autistic people may have prosopagnosia according to 1 study[5], which also creates adjustment problems like social anxiety and socializing mistakes.[6]
Imagine having a full-blown conversation with someone, thinking they are someone else, and completely misreading social cues and expectations.
Side note: Children with autism[7] may seem like they have face blindness, but they typically don’t. Instead, it is a lack of attention toward faces that neurotypicals often give instinctively. So, it appears that they are blind to facial features, but they just pay less attention to faces.
Amusia, aka music blindness
pronunciation: A – mew – sia
Some people do not comprehend music – a condition called amusia[8]. For them, music is a meaningless arrangement of sounds. A slightly more common condition is musical anhedonia[9]. Those who have it comprehend music as a meaningful arrangement of sounds with rhythm, pitch, and varied timbre at a cognitive level, but they do not derive pleasure from it – they lack the emotional appreciation of music. For them, there is less interaction between 2 brain regions: the auditory cortex (sound perception) and the nucleus accumbens (reward center). They are still able to process[10] and emotionally respond to other emotional sounds (vocalizations like crying) and can appreciate other forms of complex stimuli like visual art. Just music has a blunted pleasure response in an otherwise physically, emotionally, and cognitively healthy body.
One estimate[11] suggests 5.5% of all people have low music-reward sensitivity or musical anhedonia. It’s safe to assume that amusia and musical anhedonia are mostly genetic (but causes not yet identified), with a very few cases caused by brain injury[12]. However, depressed individuals who experience anhedonia – a lack of pleasure – in many things like food, physical touch, money, exercise, and movies, can temporarily experience musical anhedonia during the course of the depressive episode.
Across studies, there is no dislike toward music in amusia, just indifference. And, there are varying levels of reward value coming from music of any kind, which creates a spectrum, with some people still deriving some reward from music. However, there is a small number of people who actually do dislike music. And coincidentally, one of psychology’s most famous names – Sigmund Freud, was one of them[13].
A very odd discovery is that people with musical anhedonia still have the urge to groove to music[14]. This discovery supports the idea that grooving is a pleasurable activity in itself, and even though it often occurs in response to music (as in caused by listening to music), it is not caused by the pleasure of music. Either a cognitive or primitive bodily channel (but not an emotional channel) is a separate link between music and the groove instinct[15], which almost bypasses pleasure. According to that theory, the pleasure of grooving IS the reward sensation of music, in a way that grooving creates a pleasure that compensates for the lack of pleasure by listening.
Side note: You might know people who can listen to just about any music and have a great time dancing and grooving to it, and yet never seem to enjoy songs for the sake of enjoying them. They may have some level of musical anhedonia with a preserved groove instinct!
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Aphantasia, the inability to mentally visualize
pronunciation: A – fan – tay – sia
Many completely healthy people with no health-related abnormalities in the brain are unable to create mental images[16] when asked to imagine an object or recall a memory. Their imagination does not take the form of a mental image, regardless of whether their eyes are shut or open. However, they do have the capacity to imagine and fantasize because their spatial cognition is a little boosted, so their imagination is more process-like and is more abstract and often in different forms. The lack of a visual component changes how they imagine, and other sensory aspects like movement, sounds, smells, and linguistic aspects like words and concepts dominate imagination. In some aphantasics, there is no imagination via any sense either. They are unable to visualize sound, smell, touch, or taste. Although for most people, this may seem more relatable.
About 3-4% of people have aphantasia, and contrarily, about 1% people have the opposite – hyperphantasia[17], which is the ability to vividly imagine in high visual resolution. A lot more people have some milder form of both, and it can be assumed that most people will be on the spectrum between aphantasia and hyperphantasia. But extreme aphantasia – complete lack of mental visualization whatsoever – is expected in about 0.8% people.[18] Those with aphantasia do have dreams, although often not very vivid.[19] Aphantasia is also weakly associated with[20] neurodivergence, prosopagnosia (face blindness), and weak autobiographical memory (remembering personal experiences).
Here’s a neat representation. 1 is hyperphantasia. 5 is absolute aphantasia. Both are 1% experiences.
Side note: Regardless of how you mentally visualize – as an image or an abstract process, did you know you could “visualize” your way to improve your physical skills?
As a closing statement, I would say that these perceptual oddities, which may fall under the broad experience of “neurodivergence”, shape people’s lives in ways most people can’t even imagine. The irony of my statement is not intended.
There are other similar types of experiences, too.
- Anendophasia – no internal dialog or inner speech
- Alexithymia – emotion blindness, reduced ability to recognize and express their own emotions
- Color Agnosia / Achromatopsia – lowered ability to perceive colors
You wouldn’t realize others have these hidden un-experiences unless you see some odd behavior or ask them ultra intrusive questions.
Sources
[2]: https://www.sciencedirect.com/science/article/abs/pii/S0010945214003335
[3]: https://www.sciencedirect.com/science/article/abs/pii/S0959438819301424
[4]: https://www.sciencedirect.com/science/article/abs/pii/S0010945223000138
[5]: https://onlinelibrary.wiley.com/doi/full/10.1002/aur.3030
[6]: https://www.sciencedirect.com/science/article/abs/pii/S0022399908001578
[7]: https://srcd.onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-8624.2009.01342.x
[8]: https://www.medicinenet.com/script/main/art.asp?articlekey=19458
[9]: https://www.pnas.org/content/113/46/E7337.short
[10]: https://www.sciencedirect.com/science/article/abs/pii/S0079612318300177
[11]: http://brainvitge.org/papers/Mas_MP_2013.pdf
[12]: https://www.sciencedirect.com/science/article/abs/pii/S0028393217300362
[13]: https://pmc.ncbi.nlm.nih.gov/articles/PMC1629124/
[14]: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0312030&trk=public_post_comment-text
[15]: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0301478
[16]: https://www.sciencedirect.com/science/article/abs/pii/S0010945217303581
[17]: https://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(24)00034-2
[18]: https://www.sciencedirect.com/science/article/abs/pii/S1053810021001690
[19]: https://link.springer.com/article/10.1038/s41598-020-65705-7?fromPaywallRec=true
[20]: https://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(24)00034-2
Hey! Thank you for reading; hope you enjoyed the article. I run Cognition Today to capture some of the most fascinating mechanisms that guide our lives. My content here is referenced and featured in NY Times, Forbes, CNET, and Entrepreneur, and many other books & research papers.
I’m am a psychology SME consultant in EdTech with a focus on AI cognition and Behavioral Engineering. I’m affiliated to myelin, an EdTech company in India as well.
I’ve studied at NIMHANS Bangalore (positive psychology), Savitribai Phule Pune University (clinical psychology), Fergusson College (BA psych), and affiliated with IIM Ahmedabad (marketing psychology). I’m currently studying Korean at Seoul National University.
I’m based in Pune, India but living in Seoul, S. Korea. Love Sci-fi, horror media; Love rock, metal, synthwave, and K-pop music; can’t whistle; can play 2 guitars at a time.
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