Visual memories and sensory experiences

It seems people who lose vision use information that transfers between the senses to retrieve visual memories. And that their visual memories decay when they have reached a certain level of experience in the other senses. (See our blog for the scientific approach, the crossmodal correspondences between the senses, and Decay and maintenance of sensory memories). But what happens when people who are born blind gain vision and then lose it again?


I have invited P.B. to share his experiences of visual memories and sensory information when going from blind to partially sighted and back to being blind again. P.B. was born blind with some light perception in one eye. After surgery and other medical treatments, he had gained about 7% vision in the other eye at three and a half years old. P.B. does not remember this shift from being blind to being partially sighted. Then, in his early twenties, P.B. had an accident that rendered him totally blind in both eyes. P.B. thinks of himself as a sighted person who happens not to see. He visualises when making plans. And his dreams are always visual. P.B. approved this text before we posted it on our blog.


P.B. has several visual memories from when he was little. From the house he grew up in, for example, he remembers the light from a chandelier hanging over the coffee table in the living room, the patterned wallpaper in his room, and the countries on the world map hanging on the wall. And he remembers the colours on the outside walls, the doors, and the window frames.


Today, when he has no new visual input, P.B. creates visual images based on his memories and knowledge. For example, that of a White Swiss Shepherd Dog working as a guide dog from his memories of both the white colour and the German Shepherd Dog. As well as his knowledge of guide dogs.


His visual memories are typically triggered by somebody describing how something looks, like a bright red sunset – not by information from the other senses.


P.B.’s visual memories “flash up almost like the flavour when eating or drinking”.


He has to decide not to focus on visual memories and images when talking to people: the memories are now 20 years old and people have changed. And his created visual images of what new people look like may be very wrong.


P.B. has to actively suppress his urge to retrieve visual memories or create visual images of people based on their voices.


He describes not having visual memories and images of spatial relations and distances. P.B. rather remembers them through his body. He walks around in the city centre with no vision, a podcast or some music in his ears, and shoes with a thick curved sole (which makes it difficult to feel the surfaces on pavements, streets, steps, floors, etc.). He does not count steps or any of that and pauses the podcast or music in his ears only when he feels he might get lost.


For P.B., sensory experiences include a variety of simultaneous sensations as well as visual memories and created images – they are multisensory. The forest, for example, is the sound of wind and trees, the texture of surfaces under his feet, scents, and the memories of colours. He zooms in on whatever attracts his attention: indeed, not on one piece of sensory information after the other in a certain order. For example, zooming in on a sudden shift from soft to hard texture under his feet.


An interesting sensory experience, according to P.B., is that of new flavours, the texture of the food, and the sound of crunch when chewing, He describes a cloudberry cream dessert as “not very sweet, but also not sour, light orange colour, and creamy texture”. But a redcurrant jelly only as “something wobbling on the plate”. He does not describe the flavour, scent, and/or feel in his mouth – merely how the jelly looks on the plate.


Was he not able to suppress his visual memories of jelly – did they take over?


When P.B. is sensory tired, he relaxes his senses by listening to “concentration music, like opera or prog rock where I can immerse myself and get absorbed by a different universe”.


It seems P.B. can maintain his visual memories and ability to create visual images through people’s descriptions of what something looks like. But, at the same time, these memories and images are distracting him from focusing on sensory information that is more relevant to him today with no vision, for example, people’s voices and the feel of wobbling jelly in his mouth, So is this, in fact, a negative spiral – that maintaining visual memories prevents experiences in the other senses, which in turn helps nurture the visual memories?


See our blog for Activities; especially 49-51.

Emotional perceptions associated with sound environments

People pay more attention to sounds when vision is absent than when it is present. Typically identifying individual sounds of people and objects; activities and scenes; locations and distances. They listen more to sounds for pleasure. For example, to trees whistling, cracking, and hissing in the winter; echoes in narrow places; constantly varying soft sounds; birds singing and the sea. (See our blog for Sensory mismatch, Decay and maintenance of sensory memories, and Using the senses when vision and hearing are impaired). And they describe more emotional perceptions too.


I have invited Professor Christina Eviutami Mediastika, School of Creative Industry, Universitas Ciputra to write this blog post on the emotional perceptions people who are visually impaired and fully sighted describe in soundscapes and soundwalks. Christina E. Mediastika has conducted and published a series of studies on emotional perceptions in parks, on pavements, and inside shopping centres in Surabaya and Yogyakarta, Indonesia. And one study in cinemas.


According to United Nations Development Programme data from 2017, Indonesia has the second largest population of people who are visually impaired (after India), with 1.5% of its population having a visual impairment. The pavements are narrow, damaged, contoured or uneven, and obstructed; the parks are most often located next to major streets, even within roundabouts. And the streets are noisy, polluted, hazardous, and unpleasant. The shopping malls are busy housing a wide variety of offices, and clinics as well as retail.


In our studies, people with visual impairments were encouraged to explore these public facilities and data about their emotional perceptions of each surrounding sound environment was collected. Our studies were based on the ISO 2014 and 2018 Acoustics – Soundscape.


People who are visually impaired describe more emotional perceptions of soundscapes than the fully sighted, especially when outdoors. For example, those with a visual impairment used 56 words and the fully sighted 32 words in urban parks; with “eventfulness” and “pleasantness”, respectively, as the most important emotional perceptions. This finding indicates that engagement with the sonic environment is higher for people who are visually impaired than for those who are fully sighted.

 


More specifically, for people who are visually impaired the most important aspect is how much data the outdoor sound environment provides, which impacts both their ability to navigate and their feeling of being safe (related to “eventfulness”). In contrast, for the fully sighted the most critical aspect is whether the sonic environment makes them feel comfortable (related to “pleasantness”).


Furthermore, people who are visually impaired associate more words to each perceived emotion than the fully sighted. On pavements, for example, “pleasantness” is the most important emotional perception for the fully sighted and “pleasantness-direction-safety” for those with a visual impairment. The fully sighted associate five words to “pleasantness” – comfort, fun, safe, easy, and clear route. And those with a visual impairment three more to “pleasantness-direction-safety” – clear direction, know the location, and soothing: they find pleasantness when they believe in their direction and feel safe.


Regarding indoor sound environments. Both groups perceive “pleasantness” as their dominant emotion inside shopping malls, using words like happy, comfortable, luxurious, and modern.


Moreover, when people who are visually impaired watch movies with a fully sighted narrator guide, their three most significant emotional perceptions are pleasure, storyline, and sound dynamic. Pleasure is associated with comfort, clear sound, and interest in the story. Storyline dimension is the extent to which the storyline was understood. Sound dynamic is connected to intensity and quality of the soundtrack.


There is a misconception that people who are visually impaired have more sensitive hearing than sighted individuals. Both groups have equally sensitive hearing. However, people who are visually impaired rely on sound for many aspects of their daily lives because they are forced to do so, which trains their hearing to be used to its fullest potential. This includes being aware of their surroundings, understanding the direction, recognising safety or danger, and experiencing enjoyment using their surrounding sounds.


See our blog for Activities; especially 46-48.


Some suggestions for further listening, reading, and watching:

Emotional responses to music

From Perception to Pleasure

How the sound in your home affects your mood

Soundspace: A Manifesto

The Psychology of Sound and Emotions

Urban noise: Why cities need to turn down the volume