Letter
The Cognitive Foundations of Writing’s Evolution
By: Avishye Moskowitz
Introduction
Since its invention, writing has proved necessary for success and growth in countless cultures around the world. Among other qualities, writing also allows for ideas and valuable information to transcend time and space and can help us to find insights into the mysteries of the past. But how did human beings come to develop such a medium for expression and innovation? What pre-existing cognitive abilities enable us to see, comprehend and find meaning in marks on a paper? This paper will attempt to answer these questions and address how cerebral constraints contributed to the evolution of writing and its cross-cultural regularities. Due to the limits of our cognitive abilities, writing has taken on many different forms while still maintaining certain universal characteristics such as how they are written, contrast from background, character shape, and their developmental processes. To better understand this phenomenon, one must first understand which of the areas and functions of the brain are involved in encoding and processing writing. Additionally, through careful examination of the evolution of script, one will see how this evolution was honed to better accommodate our cognitive abilities. It is subsequently important to explore how cerebral constraints have also guided the usage of contrast in the form of ink, texture, or indentations to aid in object-recognition. Finally, through an analysis of the use and history of the Vai script it can be demonstrated how over time language has been compressed to maximize efficiency in accordance with the brain’s ability to process visual stimuli.
How the Brain Processes and Encodes Writing
There are two ways in which to approach the conversation regarding cerebral constraints’ effects on writing. The first viewpoint focuses on the concept of reading and how developmentally the cerebral constraints associated with it guide the process through which the human brain comprehends and interprets writing. The second viewpoint is concerned with how, over time, cerebral constraints affect how the script itself develops. These approaches signify the importance of examining both the creation and interpretation of a script to better appreciate and understand the full extent of cerebral constraints on writing. The latter idea will be expanded upon later in greater detail.
There are several regions of the brain associated with reading, comprehension, and writing. Reading, in particular, relies on a left-lateralized network of brain regions that include the pre-lexical processing regions of the ventral stream. Through anatomical MRI researchers have found that reading is affected by early cerebral constraints, which are the products of specific regions of the brain, including the sulcal morphology of the left lateral occipitotemporal sulcus (OTS) [1]. The OTS has been observed to be more consistently activated in response to visual presentations of words, rather than for other categories of stimuli [1]. Additionally, the mid-portion of the left occipito-temporal sulci facilitates the coding for more abstract visual forms of letters and words. Due to its functionality pertaining to lexical processing, this area of the brain has been coined the term “visual word form area” (VWFA) [2].
In order to understand cerebral constraints on cognitive abilities, it is important to analyze the VWFA, since its functioning is determined in-utero and remains stable with age [1]. This quality allows researchers to study its function both in-utero and as a person develops and is exposed to outside linguistic and scriptural influences. Furthermore, there are several factors which contribute to the neurodevelopmental processes during the in-utero stage that shape the folded cerebral cortex, including differential tangential expansion and structural connectivity through axonal tension forces [1]. These cerebral processes result in connectivity constraints which lead to a compact layout, which in turn optimizes the transmission of neuronal signals of brain regions and their functioning [1]. This process of development gives testament to how cerebral constraints from an evolutionary perspective are designed to maximize efficiency.
The VWFA has several specialized functions and abilities that are tailored for identifying shapes and contrast. It is the only brain region sensitive to bigram frequency; that is, it has internalized the statistics of letter pairings in the participant’s language. Therefore, one can look at a grouping of lines and junctions and learn to gain meaning from it. Additionally, the VWFA is confirmed as a major neural correlate of literacy acquisition and can increase its response after only a few reading sessions [3]. This could be attributed to the fact that the VWFA shows a word-specific pattern of orthographic priming, suggesting that it may contain neural populations sensitive to morphemes or short words in the reader’s language. The VWFA has the unique ability to distinguish between words and their mirror images; an indispensable feature given the presence of mirror letters (such as b and d in Latin- based alphabets) but remains mirror-invariant for pictures and faces. Interestingly, a similar specialization can be observed for mandarin characters in mandarin readers [3]. This specialization allows the VWFA to function in a more diverse capacity in different natural scenes cross-culturally as well. Fascinatingly, the VWFA doesn’t just respond to written words but also activates the surrounding cortices when exposed to objects and faces. A recent study demonstrated that in the blind, the VWFA can function relative to a tactile control task. This region, therefore, possesses a general capacity for identifying shapes, whether visual or tactile, and mapping this information onto language regions, ultimately helping one better understand the extent of this region’s abilities [3].
How the VWFA Evolved to Process Writing
Having understood which brain regions are involved in reading scripts, another question must be answered. How did the function of the VWFA evolve to accommodate the advent of writing? A study on “the unique role of the visual word form area in reading,” found substantial evidence to connect the cerebral processes involved with facial and object recognition with the development of writing [3]. Since the invention of writing is relatively new, it isn’t possible that the brain could have developed specific functioning just to be able to read and write, which is why researchers believe the neuronal recycling process must be involved and act as a conduit for reading and writing [3]. The neuronal recycling process is the process whereby pre-existing cortical systems are harnessed in order to perform a function different from the brain’s intended function. Here it would apply to the idea that the mid-portion of the left occipito-temporal sulci utilizes functioning for face and object recognition to interpret and gain meaning from writing on a page and be able to replicate it [3]. The neuronal recycling process also emphasizes that plastic neuronal changes occur in the contexts of strong cerebral constraints imposed by the prior evolution of the cortex. This explains that the reallotting of the brain’s resources to evolve to learn how to read and write all stems from cerebral constraints from when Homo sapiens evolved from Homo erectus. Additionally, all the signs selected through this process seem to be used cross-culturally since they all required minimal cortical change to learn [3].
When a new system of writing is invented, it develops through trial and error onto character shapes of “proto-letters” that human brains are already equipped to comprehend. Many of the shapes used in different early scripts have non-accidental properties which are highly invariant across viewpoints and give valuable information about object shapes and spatial relations [3]. A notable example is the shape of the letter T, which signals an occlusion of one shape by another. This is important since the visual system relies heavily on such line junctions to recognize objects, as this facilitates more effective differentiation from other shapes [3]. This detail is also pertinent since it demonstrates that the visual system relies on this observation of object-related contrast, which in turn sheds light on the neuronal processing of writing. Cross-cultural analysis has exemplified that many of these sets of line junctions are universally shared with a frequency pattern that matches the frequency profile of natural scenes [4]. This analysis is a key observation since it further demonstrates the earlier mentioned fact that much of the shape structure used for writing was derived from surrounding natural scenes. It was also found that the mid-portion of the left occipito-temporal sulci had a strictly visual and prelexical response, yet was invariant for location and the case of the stimulus words [2,3] This finding indicated the extent of the diverse functionality that the VWFA exhibits and informs us that this region also has abstract capabilities in addition to its perception of concrete objects, contrast, and faces.
Evolution of Writing to Optimize Encoding
Now that the cognitive components involved in reading scripts have been understood, it can now be addressed how script’s characters developed to be best observed and encoded. When first approaching how scripts have developed over time, one must begin by conceding that whether through trial and error or extraordinary intuition, the first scribes appeared to have been aware that the shapes they chose should be the easiest to read [4]. This idea supports the claim that a direct connection can be drawn between cerebral constraints and writing, when one regards that there are two potential selection pressures shaping visual signs, corresponding to reading and writing. The first selective pressure exists in that the visual signs must-have shapes that we are able to recognize with our pre-existing visual systems. Secondly, the signs must be able to be produced (very often) by hand [5]. Notably, shape complexity and natural scenes have shown that visual stimulus complexity is determined by its ecological probability: the more complex a structure, the less likely it is to appear in nature and vice versa [5]. These insights into selective pressures and shape complexity can help illuminate key factors of writing that contribute to its uniformity and accessibility across the cultural and temporal spectrum.
A study titled, “The Structures of Letters and Symbols throughout Human History Are Selected to Match Those Found in Objects in Natural Scenes,” by cognitive scientist Mark Changizi was conducted on the ecological hypothesis which posits that the shapes of visual signs have been selected to resemble the conglomerations of contours found in natural scenes, thereby tapping into our pre-existing object recognition mechanism [5]. This hypothesis goes further to say that the reason writing has evolved in this way is because that is what the human brain has evolved to be good at visually processing [5]. Additionally, the hypothesis helps to establish why the writing system has evolved as a direct function of our cerebral capacities to interpret and interact with the world around us.
Prior to further analysis of this study, it is important to note that when this study refers to shape it specifically means “configuration type”. The authors first cataloged 115 non-logographic writing systems of human history, varying in characters from 10 to 200, and found that the average number of strokes per character is approximately 3, regardless of writing system size [5]. This indicated a common trend that the brain’s ability to identify shapes is optimized at a complexity of three strokes per character. In addition to the maximum number of strokes which can be found in scripts cross-culturally, another characteristic is how the shapes maintain a generic identity [5].
This supports the observation that the typological notion of a shape maintains its integrity, even when the shape undergoes significant geometrical variation [5]. Recognizing object junctions, which are topologically defined conglomerations of contours, is crucial to understanding the process of shape development in early script formulation. As described in the study, the letter T can differ slightly in the ways it is written each time, but its typology remains the same [5]. This concept is also demonstrated when considering the many types of fonts one can produce a T in. Each time the T might look slightly different, but one can still deduce that it is in fact a T. Furthermore, topologically defined shapes provide a useful definition for shape for both visual signs and conglomerations of contours found in natural scenes, allowing us to compare these two realms [5]. This is an important point as it is what ties shapes of visual signs to conglomerations of natural scenes. Additionally, typologically defined shapes are found to be more invariant throughout different ecological environments which helps strengthen their recognition across all parts of the world [5]. To support this claim further, the study also found that the configuration distribution for natural scenes does not vary very much as a function of the kind of natural scene. This could indicate that the formulation of shape follows the mold of what could be observed naturally in many different places on earth and contributes to the system’s universal accessibility , so whether civilization was located in the desert, valleys, or mountains wouldn’t drastically affect the configuration distribution of that shape [5]. Therefore, it is possible that the formulation of shape follows the mold of what could be observed naturally in many different places on earth and contributes to the system’s universal accessibility.
Another important question can be asked regarding the nature of the evolution of writing the mold of cerebral constraints: are the shapes that we use for non-logographic script selected for motor or for vision? In response to this question, Changizi seems to suggest that the shapes were primarily selected for vision. Using the example of trademark symbols for businesses, he asserts that since they are difficult to replicate using motor and yet are easy to read via vision, writing must be selected for vision [5].Their research states that visual sign topological shapes have been selected whether via cultural evolution or by trial and error so that more common configuration types among visual signs are the more common configuration types among natural scenes [5]. Thereby again supporting the claim that writing employs what humans have evolved to be good at visual processing, and further proving that cerebral constraints have guided how we write and read these alphabetic scripts.
How Contrast Evolved to Help the Brain Identify Writing
Following discussion of the regions and functions that aid in script recognition and acquisition, this paper will now discuss how contrast in shade either between ink and paper or indentations helps to further facilitate the identification and recognition of shapes. Additionally, it can be demonstrated that this contrast has been selected by cerebral constraints for optimal processing. In regards to how letter structures are selected to match their natural scenes, Changizi asserts that it would be hard to detect visual signs present in natural scenes because of the lack of color contrast which exists in the surrounding environment. However, over time human generated visual signs have been selected to be read and distinguished with contrast to their environment such as bare sand, plain soil, paper, papyrus, and not just from the natural scenes [5]. One could easily assume that this development as well, results from cerebral constraints which also contributes to better optical processing.
Research has also shown that most ganglion cells in the retina are insensitive to large surfaces of homogenous color. In fact, they usually discharge in response to contours of objects or junctions of two surfaces where the contrast in color or tone is detectible [4]. One notable study, examined cortical activation while performing fixed visual tasks, using three different primary visual cues: motion, texture, or luminance contrast [6]. The result of this study demonstrated a convergence of these visual cues in the occipital lobe complex and provided strong evidence to suggest it has an important role in object processing [6]. As can be understood from Changizi’s study, humans have based many of their shapes in developing scripts based on objects which could be observed in the surrounding environment [5]. Also, having in mind how the contrast between objects and their backgrounds activates and is processed in the mid occipito-temporal sulci, further insight can be made into how object contrast is an important factor in processing writing and indicates the cerebral process involved.
Vai Script Shows Linear Progression Towards Compression
Finally, it is interesting to examine how writing develops in a predictable fashion, which is best demonstrated through the Vai script, confirming that cerebral constraints are the motivating factor to drive this predictable evolution. The Vai script was a script that was developed in isolation by the non-literate of Liberia around ca. 1833. Over the 171 years since its genesis, the script has been compressed in a way similar to the evolution of early writing systems, and this was tracked by scholars throughout the 19th, 20th, and 21st centuries [7]. The script was created by at least eight men, who had probably been exposed to the Arabic and Roman scripts, but were not literate in either of them and didn’t use any of the rules of these previous scripts when creating their syllabary [7]. For much of its history, the institutionalized teaching of this script didn’t exist, so if someone wanted to learn it, they had to seek out a literate of the script on a voluntary basis [7]. However, there were three different attempts to standardize the Vai script, of which the second attempt was most noteworthy. In 1962, the University of Liberia gathered 11 consultants to form an official Standardization Committee [7]. The committee settled on having one sign per syllable and eliminated all variant graphemes from the script. These changes furthered the compression process in a way that allows the script to be accessed and better encoded by users and plays to the cognitive abilities of its users.
How does the compression of the Vai script help to prove the effects of cerebral constraints on writing? How are the characteristics of this Liberian script indicative of the larger scale evolution of writing over time? There is a generally accepted argument presented by 19th-century paleographic theorists which postulates that graphic forms go through a process of simplification or “compression” which occurs in the course of recollection and reproduction by individual writers and their transmission from one writer to the next [7]. Over time, through this process, systems of signs become compressed so that the same amount of information conveyed previously is still received, yet the way it is written is in a more concise fashion. Because older scripts are almost impossible to understand and trace how they evolved and did or did not become compressed, researchers and scholars look at emergent scripts to point to trends in their development [7]. An emergent script is defined as a functional writing system developed by nonliterates from the minimal stimulus. These emergent scripts are invaluable because they can serve as naturalistic transmission experiments in script change, which allow scholars to reimagine with better accuracy how a script evolves from generation to generation. By studying the Vai script, one can gain a better insight into the learning process of a new script as well. With that in mind, one can deduce that since apprentices of the Vai script learn by doing, there might be some characters that they might not need in communication and might never learn those characters. This hints at the process of how else a script becomes compressed. In viewing how people over the past two centuries have learned and passed on the Vai script, researchers were able to assert that the compression effects that occur are in terms of transmission dynamics. This is in the sense that when one user passes knowledge onto the next user, that information passes through a memory and learning bottleneck (cerebral constraint) [7]. The most learnable characters are encoded, while the features which are harder to recall or reproduce tend to get left behind [7]. Furthermore, it is noticeable that many early writing forms, which originally exhibited extensive iconicity, lost their iconicity in the later derivatives of the script. Yet, in some instances like the Egyptian hieroglyphics, the iconicity was maintained over the entire history or script [7]. This general trend of simplification over time is driven by the brain’s cerebral constraints to only retain what is absolutely necessary for adequate transmission of information and ideas.
One study proposes that the tendency for scripts to compress over time is a direct result of the least effort principle (inspired by Zipf 1949), which states that spoken languages tend to minimize the effort speakers must invest in saying words, by shortening frequently pronounced words which usually also happen to be the least informative least. This process leads to a higher production and processing rate for the speech being spoken. The study also proposes a version of the least effort principle which states that writers are motivated to reduce their cognitive and motor exertion when tracing a letter, up to the point where further simplification would make the letter indistinguishable from other letters. This principle is useful in proving that the progression of writing is one of simplicity or concision, further proving that cerebral constraints dictate the formation of writing and the way we use it. The study also posits that simplification should stop around the point where it makes letters too difficult to distinguish between one another. Further, the principle predicts this because the decrease in legibility will lead to a future increase in future effort to interpret this hard-to-read script. This prediction seemingly informs the conclusion that this baseline of legibility is demanded by the brain’s need for some level of consistency in the script’s representation and complexity.
Another important observation in the Vai script’s development highlights the deviation from logograph into a less complex shape structure to enable easier encoding. The study asserts that logograms that are used in the Vai script and contain iconic relationships to their meanings were simpler to invent and recall and therefore demanded greater attention to form which in turn results in higher visual complexity. It adds that a related pressure leading to this initial complexity is that, for the inventor, ease of imagination and recall matters more than ease of production. In other words, inventors believed that creating a distinctive script is more important than one that is easier to replicate because the distinctive traits might be better encoded to memory than one with less memorable characteristics. However, this assertion proved antithetical, since over time these visual complexities due to their logographic nature proved inefficient and Vai writers discarded their logographic scaffolding and allowed for phoneticism to take over. This ultimately offers script learners a streamlined ability to access and understand the script. Also, this study hypothesized that graphemes that were initially more complex were more likely to increase in simplicity, more so than phonemes that are initially more simplistic [7]. Finally, variance in complexity among characters should decrease with successive versions of the script. Overall, it was concluded that images have become graphically optimized in terms of information storage, retrieval, and reproduction by human agents [7]. This process occurs as a result of our brains’ attempt to encode information more efficiently.
Conclusion
This paper demonstrates how different aspects of writing are formed and pruned by our brain’s cerebral constraints. It described the regions of the brain involved in the reading comprehension of scripts. In addition, it detailed the unique functions of these regions and how the brain draws on functions, which originally were intended for facial and object recognition and how the brain formed new pathways to keep up with the innovation of writing. Additionally, this paper delved into the ecological hypothesis and how our cerebral constraints have guided the formation of character shapes to best compliment the brain’s pre-existing cognitive abilities. Furthermore, this paper discussed how contrast, whether manifested in paper and ink or textured background and indentation has been selected as the best medium for shape recognition and retainment. Finally, these discussions were demonstrated in the portrayal of the Vai script in which, due to its recent development, has become a microcosm of writing which has informed researchers and scholars as to how the evolution of writing likely progressed. Most importantly, the Vai script contributed the invaluable insight of script compression which supported the claim of this paper that the cerebral constraints of the human brain since the dawn of writing has shaped the very nature of writing and how it has developed cross-culturally in a remarkably similar fashion.
References
1. Borst, G., et al. “Early Cerebral Constraints on Reading Skills in School-Age Children: An MRI Study.” 2016
International Mind, Brain, and Education Society and Wiley Periodicals, Inc., vol. 10, no. 1, 18 Feb. 2016, pp. 47–55. March 2016.
2. Hertz-Pannier, L., et al. “Advanced structural and functional MRI in childhood epilepsies.” Handbook of Clinical
Neurology, 2013, pp. 777–784, https://doi.org/10.1016/b978-0-444-52891-9.00080-4.
3. Dehaene, Stanislas, and Laurent Cohen. “The Unique Role of the Visual Word Form Area in Reading.” Trends in
Cognitive Sciences, Elsevier Current Trends, 16 May 2011, https://www.sciencedirect.com/science/article/abs/pii/S1364661311000738.
4. Dehaene, Stanislas. “Chapter 4: Inventing Reading.” Reading in the Brain: The Science and Evolution of a
Cultural Invention, Viking, New York, 2009.
5. Changizi, Mark A, et al. “E-Articles: The Structures of Letters and Symbols throughout Human History Are
Selected to Match Those Found in Objects in Natural Scenes’ .” The American Naturalist, vol. 167, no. 5, May. 2006, pp. E117–E139., https://doi.org/10.2307/3844686.
6. Grill-Spector, Kalanit, et al. “Cue-Invariant Activation in Object-Related Areas of the Human Occipital
Lobe.” Neuron, Cell Press, 11 Apr. 2001, https://www.sciencedirect.com/science/article/pii/S0896627300805267.
7. Kelley, Piers, et al. The Predictable Evolution of the Letter Shape. Dec. 2021.