Spatial sequence synesthesia

Often abbreviated to SSS

Other, less-used, names for it are Sequence-spatial, Sequence-space and Visuo-spatial synesthesia

Image created by The_Flower_Garden in this post on Reddit/Synesthesia. 2022

Spatial sequence synesthesia consists of visualising certain sequences in physical space. There are different types, and a particular synesthete may have just one type or several at the same time. The types are:


1. Calendar synesthesia (time-space synesthesia)


2. Number form synesthesia


3. Letter form (or alphabet form) synesthesia


4. Spatial visualisation of other sequences (school subjects, books of the Bible and signs of the zodiac are a few examples).


The first type (calendar synesthesia) is more common than the others, while type no. 4 appears to be the least common. In any case, even though no exact figures are currently agreed on, spatial sequencing has a high prevalence within the synesthete population and is even often found among non-synesthetes or people who have no other types of synesthesiaIn the early study What is the relationship between synaesthesia and visuo-spatial number forms? (2005), Noam Sagiv and other major researchers found that 71% of a group of 114 colour synesthetes and 29% of 311 non-synesthete controls had some manifestations of one or more of the first three types, suggesting that spatial sequencing is quite a common phenomenon among both synesthetes and (otherwise) non-synesthetes alike, opening the door to questioning whether it should perhaps be considered an overlapping phenomenon also experienced by non-synesthetes, or whether the synesthetic population is actually much larger than the 4% estimated up to now. For more information on this aspect, see the last section of this page, with a link to another scientific study.

"Spatial sequencers" perceive the months, dates, numbers, letters or other elements in a sequence in the physical space around them or in front of them. Apart from spatial position, these elements may also have their own colour, texture and shape. Projectors (a minority) see their sequences literally outside their own body space, while associators see them in the mind’s eye but not physically. Although the exact spatial arrangement is different for each person, it is consistent and tends to remain the same throughout their lifetime. The visual configuration of the sequences can be relatively simple, highly complex or anything in between: the elements might be on a horizontal, vertical or diagonal plane, in a ring or spiralling out of sight, progressing from left to right or vice versa and sometimes with many sudden or gradual changes of direction. Typically, the subject’s viewpoint can vary and the perspective can shift when necessary, so the synesthete feels that they are standing in front of the current month of the year, for example, with the rest of the months positioned accordingly and some of them even behind them and out of sight.


(the title links go to a description of each type, with examples)

Image: Chavdar Jordanovin the Gallery of the website Sensequence

Image: Francis Galton, 1881

Image: Herey, in her blog Rhymes with Fairy

Image: Finn F, in his blog Synaptic Synnie and on DeviantArt

More about spatial sequencing in synesthetes and non-synesthetes

Many non-synesthetes experience something very similar to this, so should we consider that SSS isn’t actually synesthesia? Or perhaps that there are many more synesthetes in the population than we had previously thought? 

It has been observed that spatial sequencing can be present in people who would not normally be considered synesthetes. It may even occur in much higher percentages of the general population than the 4% accepted today as being the total percentage of synesthetes: different studies have estimated that around 15%-29% of the general population might experience it to some degree. Research is still needed to accurately determine whether these types occur more strongly or differently in people we would normally consider synesthetes than in other individuals. Perhaps the occurrence of a similar phenomenon to SSS in non-synesthetes is merely a result of the SNARC effect (this stands for “spatial numerical association of response codes” and means that we all have a tendency to adapt our spatial reasoning to commonly accepted cultural conventions such as writing from left to right in the Western cultures and from right to left in some other alphabets, ordering the numbers from left to right or arranging the months from right to left or perhaps from top to bottom).

If you are interested in finding out more about this phenomenon, you could read this scientific study: The objectification of overlearned sequences: A new view of spatial sequence synesthesia (D. Eagleman, Baylor College of Medicine, Houston, Texas, USA, 2009).

In this study, a large-scale characterisation of spatial sequence synesthesia was performed, comparing synesthetes and non-synesthetes. Here is an excerpt from some of its findings and information:

There has been an ongoing discussion about whether spatial sequences should qualify as a form of synesthesia. At first glance, the objectification of sequences does not seem to fit the definition of synesthesia as a sensory coupling; however, the fact that the inducers are the same as the more wellstudied color synesthesia seems to implicate it as a related phenomenon. In this case, the overlearned sequences trigger an experience of objecthood, in the same way that experiences of shape, texture, color, and illumination can also be triggered by sequences (Eagleman and Goodale, 2009). Therefore it seems appropriate to classify the automatic objectification of sequences as a form of synesthesia. (...)

One possibility is that the difference results from individual differences in the vividness of the visual imagery, which is known to vary widely in the population. Another, non-exclusive possibility for why a subset of the population has vividly conscious access to sequential spatial mappings is an inherited genetic component, as is thought to occur in colored sequence synesthesia.

 An open question is whether the implicit spatial mapping illustrated in non-synesthetes by phenomena such as the SNARC effect represents the same phenomenon. To address this possibility, we examined month-forms from 571 selfreported synesthetes, and found several pieces of evidence that can be interpreted to weigh in favor of a shared basis between the SNARC effect and SSS.”

This page last updated: 8 April 2024


  1. Hi - I just found out a Substacker - Jay Rollins - has this type of syn.


  2. Wow... I feel dumb.. I got hit by a car when I was five and got brain trauma. Ever since then I've been able to see space, time is a little fuzzy as it's intertwined with space. But this explains everything from my eidetic memory, sound and pheromone residue etc etc.. but every night at about 8pm est earth is swamped by a strange green glow. Never finding any information on what it is.. or why some but not all street lamp posts have black and purple beams radiating upward and never changes with the angling of the perceived space. But the green fog is like ambient energy more like a light cloud..and seeing that it's not hallucinations... They have to be caused by something
    . But it's never a sound, number, symbols spoken words or tastes..