Broca, Birds, and Books


Humans share 98.5% of our genome with animals. While my dog can howl a fair rendition of “Fly Me to the Moon”, I can talk and she can’t. Genetic switches control and regulate how our genes are expressed, and some scientists see this as the key to evolution. That may be so, but culture, language, and the repurposing of older brain functions for new challenges is essential to the survival of our species as well.

Broca

Articulate words are a harsh clamor and dissonance. When man arrives at his highest perfection, he will again be dumb!…for I suppose he was dumb at the Creation, and must go round an entire circle in order to return to that blessed state…                                                                                           Nathaniel Hawthorne

In order to communicate, early man had to first pay attention. Joint attention, is essential for checking the reactions of our communicative partner against our own. Joint attention readies us for action (Brunik & Gardenfors, 2003; Locke, 2007) and allows us to mimic the actions of others (Fogassi & Ferrari, 2004). Each partner has an awareness that the attention and action are shared.

The idea that gestural communication preceded oral communication is well accepted (Ardila, 2004; Kan et al., 2008; Fogassi & Ferrari, 2004; Locke, 2007; Okanoya, 2004; Masatuka & Noburo, 2007). Just thinking about moving the hands or retrieving knowledge of tools via pictures activates the motor cortex and Broca’s area (Kan, et al 2006; Lock, 2007). Recently, scientists have identified neurons that likely gave rise to the mimicking behaviors that are considered foundational for human communication. These “mirror neurons” are brain cells that are activated, triggering the motor cortex, when an animal (or person) performs a directed action that it observes performed by another (Locke, 2007; Kan et. al., 2006; Fogassi & Ferrari, 2004). Mirror neurons have been identified for both hand and mouth movements.

Language ought to be the joint creation of poets and manual workers…                                                                                                                          George Orwell

Primates are able to imitate, cooperate, and use primitive tools. Surprisingly, they have a Broca-like area of the brain that includes left-hemisphere specialization and close proximity of manual and oral-motor control centers (Locke, 2007; Matsutuka & Noburo, 2007; Fogassi & Ferrari, 2004). If we assume that joint attention was adaptive and imitation was a substrate of that behavior, we can begin to form a picture of left-hemisphere areas, previously wired for motor movement, becoming increasingly specialized for another form of communication.

Birds

Once early man could imitate and form a theory of mind regarding another’s actions, he cooperated. As people formed groups, competition was replaced by working together to reach common goals. Cooperation is adaptive. According to Brenik & Gardenfors (2003), pressure for future-directed cooperation was a driver for the evolution of language. The ability to share information about the location of resources as well as potential hazards along the way would be highly adaptive (Kazukor &Bartlett, 2004; Brenik & Gardenfors, 2003).

Language in art remains a highly ambiguous transaction, a quicksand, a trampoline, a frozen pool which might give way under you…                           Harold Pinter

How did we develop the language structures necessary to move from simple naming to complex grammar? Song birds are able to construct unique and varied vocal patterns (Gertner, 2007;Leutwyler, 2001). They also demonstrate adaptive reciprocity through “song-splitting”, whereby mated pairs sing sequences together (Masatuka & Noburo, 2007; Okanoya, 2004). A specific gene is responsible for the normal development of song in birds, rapid movement sequences in mice, and the rapid oral-motor movements necessary for speech in humans (Ridley, 2009). Language is marked by syntax, which maps the structure. Prosody overlays intent and meaning through phrasing, inflection, intonation and tone.

Music, a universal cultural artifact, also contains a grammar and its own sort of prosody. Is music a substrate for language grammar? Sacks (2007) calls this hypothesis “audacious”, yet he frequently writes about aphasics who have regained language syntax through music, as well as victims of various brain-related pathologies who retain their musical abilities or memories. Indeed, music stimulates the limbic system, at the seat of our emotions and one of the ancient structures of our brain (Leutwyler, 2001; Holmes, 2008). Could this be an evolutionary accident?

It is not only fine feathers that make fine birds…                                                                                                                                                                             Aesop

Everett, (2005) studied a monolingual tribe in the Amazon that uses a very limited phonology. As a result, their use of prosodic elements is highly complex. In order to teach these structures, mothers sing rhythmic patterns constantly to their children. There are clues from the ontogeny as well—human newborns can track changes in pitch and tone, they can discriminate melody, and they orient to music immediately (Holmes, 2008).

Kazukar & Bartlett (2004) noted that ancient aboriginal “songlines” were used as “sung maps”. These songs marked the temporal-spatial aspects of the landscape, much like syntax and prosody mark the spatial and temporal aspects of language. Using computer modeling, Kazukar & Bartlett were able to track the development of syntax in a pseudolanguage over four generations through a shared resources cooperation model. Perhaps cooperation did drive language.

High thoughts must have high language…                                                                                                                                                                           Aristophanes

 Books

Writing began with the standardization of pictograms (Ardila, 2004) and moved toward symbolic representation. Symbolic representation connected the visual areas of the brain to regions in the occipital, temporal, and parietal lobes (Wolf, 2007). As logographic systems emerged, the frontal lobes became involved for analysis, planning, and focused attention (Ardila, 2004; Wolf, 2007). These systems required extensive visual-spatial memory due to the thousands of symbols and combinations of pictograms and grapheme-phoneme correspondences (Wolfe, 2007).  Alphabetic systems were much more efficient, allowing for automaticity and fluent production. Wolfe (2007) notes that this more efficient system allowed the automaticity necessary for reallocation of brain structures previously employed for decoding and encoding of pictograms to the generative process that reading is today. Sacks (1990) also feels that hemispheric specificity migrated to the left as skills became more automatized. Beginning readers access the parieto-temporal system to slowly analyze, segment, and map phonemes to graphemes. Novice readers also access Broca’s area, at the front of the brain, to slowly analyze words. Expert readers, however, access the occipito-temporal region, which responds in less than 150 milliseconds to the whole word as a pattern (Shaywitz, 2003). Once again, our brains repurposed older structures for vision and language to learn the newer skill of reading. In order to homogenize these changes within the species, print had to become accessible to the masses. This new skill of reading gradually became available to the masses with the invention of the printing press in the 1400’s. In 1950, over 40% of the world’s population was illiterate (Ardila, 2004).

The printing press is either the greatest blessing or the greatest curse of modern times, sometimes one forgets which it is…..                                  Sir James Barrie

Today, digital media is undoubtedly driving the culture, print access, and flow of information available. Information overload and constant divided attention is the order of the day. Culture drives cognition, so what will be the result? Areas of convergence between digital media and cognitive development include the development of attention and the ability to shift attention (Freidman 2007; National Research Council, 2000; Weigel and Heikkenen, 2007), the ability to filter and organize information (Freidman, 2007; Weigel and Heikkenen, 2007), and the development of special visuo-constructive and spatial skills. Not a bad take for one generation’s worth of brain work! However, Wolf (2007) makes the point that this rapid-fire information “scanning” does not promote deep and reflective discourse.

You don’t have to burn books to destroy a culture. Just get people to stop reading them…                                                                                               Ray Bradbury

The collective brain, an amalgam of all of our ideas, may be what is to come. Already, we can use open platforms to cooperate in the development of technologies. Although I have already argued that cooperation was evolutionally advantageous, I wonder if there can be too much of a good thing?

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s