Amanda Garrett

Stacey Smith

Thomas Valencia

 

The Development of Human Cognition

 

Klix, Friedhart (2001). The evolution of cognition. Journal of Structural Learning &   Intelligent Systems, 14(1), p 415-433.

 

 

                The development of human cognition is seen to have developed in two separate neural networks of the brain; the Wernicke’s area and the Broca’s area. The beginning of the development of human cognition has been traced to the early Hominids. During the Pleistocene Age there was a major decline in annual temperature by 10-15 degrees Celsius, a constant rise in cold glaciers, and sea levels dropped 120 meters, with the rivers and lakes drying up. These climatic changes severely lowered the food resources for all organisms; those who survived had to expand their living areas in order to obtain necessary sources of energy. These early Hominids, mostly in Eastern Africa, needed to expand their living areas, which would ultimately produce great achievements in the development of human cognition. During this period of living expansion, social groups started to emerge, thus communication also started to emerge as a way for early Hominids to coordinate these social groups into productive entities. The use of voices and hand gestures were probably the first traces of language. Crude stone tools also developed as a way to secure sources of protein.  This protein allowed for sustained energy needed for travel. These larger areas of living, beginnings of communication, and the development of tools would thus need larger amounts of brain capacity to function correctly. Yet, it wasn’t until the Miocene period (roughly 35 million years ago) that actual brain volume increased from 350cm cubed to 1400-1500cm cubed.

            The early Hominids, along with H. Hablis, H. Ergaster, and H. Erectus, probably developed a type of proto-language. This proto-language started in the area of the brain known as Heschl sulcus where sounds and their meanings are recognized.  The needs for storage and reactivating sounds within the brain caused the brain to further develop.  In addition to storage, words required a new connection and coordination between the tongue muscles, larynx, and mouth. This early proto-language would take another step in its development during the “Eem warming up time” about 180-120,000 years ago. It was at this time that the Hominids’ social culture started to emerge with certain rules, rituals, myths, and a hierarchy. This increased social structure also made it necessary for sounds to contain distinct and variable meanings in order to facilitate the demands of this evolving hierarchy.

                During this time of extensive travel towards abundant lands, learning and memory had to further develop. The increased ability to learn and remember developed out of a necessity to remember locations, landmarks, and routes back to camp. The process of finding food, then learning how to get back home is called the inversion of a learned sequence. This new form of learning was essential for continually finding food and returning to the main tribe.  Another form of learning is based upon the need to change materials such as stones into useful tools or objects. This kind of learning involved being able to set a mental goal, then execute it through a series of various actions.  Individuals learned to alter the external appearances of stones and other objects of nature. Consequently, these new forms of learning had a great impact on the development of the brain.

            As tools became more sophisticated, the brain, too, enlarged to twice its original size.   The growth in brain size is mainly due to the fact that social structures stabilized while simultaneously dealing with an extremely challenging environment, and needing strategies for hunting and protection.  However, the process of growth was slow moving.  It took approximately one million years for technology, such as the construction of hand axes, to become more refined. This also required that individuals realized that each object could have numerous functions.  Moreover, new combinations of actions could be utilized in order to make more complicated instruments.  In this way, tools could be modified for different purposes in order to accomplish new goals. Ultimately, both social structure and brain size contributed to increasing technology especially in the arena of tool construction. 

            Complex social living conditions led to the creation of and need for language. The foundation in the development of language is the basic association between sounds and objects. To further that simple association, individuals had to learn to make connections between sound arrangements (or words) and event dependent objects.  An example of this is the word pig for the living animal and the word pork or ham for that same animal, but cooked.  These are two very different descriptions of the same object, but they explain the animal’s condition or event dependent state.  Along with event dependence, is the need for event concepts or, as they are known today, verbs.  Verbs describe the action that takes place with the various objects early humans were attempting to define.  The last aspect of language is discrimination learning.  This means having slightly different names or sounds for objects based on their use.  For example, in modern terms, the word knife implies an object that cuts relatively simple substances, but the word meat-cleaver indicates that it is a knife that cuts tough, large pieces of meat. This increased learning helped classify objects in relation to events and their various uses.

The use of tools further helped establish the use of language through the properties that a tool possesses. First, the ability to distinguish between the properties of the tool, such as its weight, led to the need to establish a way to create a comparative relation between the tool and its use. Second, tools require a way of distinguishing how it is to be used in reality. Thus, some kind of action (verb/event concept) was needed to describe the relationship between what the tool was and its function. Finally, every tool had steps in its production and a way of expressing those steps was needed. Hence, sounds and meanings needed to be constructed in order to express the information for the creation of a specific tool, establishing a way to connect sounds with the event at hand.

            Finally, the creation of language over time can be concentrated in two main neural areas. These two areas are known as Wernicke’s area and Broca’s area.  Wernicke’s area is concerned with naming objects whereas Broca’s area is concerned with combining terms into sentences.  It is argued that the development of Wernicke’s area was present during the time of Homo Erectus about 1.6-1.8 million years ago.  During this time, word-object associations were necessary, but they were only utilized in a very basic way. At this point, Homo Erectus language was grammar free. The emergence of Broca’s area would later emerge during the era of the Cro-Magnons. This is largely associated with the emergence of highly organized tools and social networks.  The use of basic sentences began to take form by making use of subjects, verbs, and objects all together. As mentioned before, the use of tools created a need for words that would describe the tools (subjects), their characteristics (adjectives), their functions (verb), and what they were to be made out of (nouns).  The author makes note that problems in either the Wernicke or Broca areas greatly impairs speech.  With Wernicke’s aphasia, the individual is unable to think of the target word, so a substitution word is used.  Homo Ercetus relied solely on this mechanism to make basic communications so, perhaps, Homo Erectus would have had no verbal communication without this area of the brain.  With Broca’s aphasia, only simple sentences can be constructed.  This means that Cro-Magnon language would be the only language we had if this area of the brain did not develop.

With the formation of actual sentences, the emergence of many languages could take place.  Therefore, the major separation in languages took place 150,000 to 120,000 years ago during the time of Cro-Magnons also known as the Eem warming period. Therefore, early forms of language were constructed at different time periods in different ways.  Of course, the Cro-Magnons prevailed and our language became more complex with greater combinations of words in formal sentences.  These concepts were passed on through the concept of Darwinian selection and, in the end, those who formed sentences had the selective advantage. 

From environmental changes and challenges to complex social hierarchies, the development of cognition is seen to have facilitated much memory and language acquisition.  We are a people who are based on the use of communication and learning.  It took many years and a lot of neural expansion for us to reach where our mental capacities are today.  Luckily, we continue to grow and it may just be, that where we are today, will be the new ancestral comparison to even greater neural capacities in the future.   

 

I           The Early Hominids

A.     Climate Changes in the Pleistocene Age

1.      Lowered temperatures, glacier encroachment, and dried lakes and rivers.

2.      A major decrease in food resources.

B.     The Survivors of Climate Change

1.      Hominids 4 million years ago in Eastern Africa.

2.      Travel in groups with coordination of people requiring communication

a.       Use of voices.

b.      Use of hand gestures promoted walking upright.

3.      Need for protein for energy in travel – hunting.

4.      Need for tools.

C.     The Process of Increased Cognition

1.      Began 35 million years ago in Miocene period.

2.      Brain volume from 350 cm cubed to 1400 – 1500 cm cubed.

3.      Developed a proto-language

a.       Heschl sulcus – recognition of sounds with meanings.

b.      Began storing and reactivating sounds.

c.       Connection between mouth, larynx, and tongue muscle.

D.     “Eem warming up time” (180-120,000 years ago)

1.      Time of new social order with nomadic groups.

2.      Tribes with roles, ie. Elders

3.      Formulation of myths, rituals, and rules.

4.      A need for differentiation in sounds and meanings.

II          Learning and Memory

A.     Demands of Environment

1.      Had to find areas with abundant food sources.

2.      Had to remember how to reach areas and how to return home.

a.       Inversion of learned sequence.

b.      This indicates the established capacity of the CNS.

3.      Had to learn to change surface appearances.

a.       Set a goal, ie. Make a spear.

b.      Reach goal through series of actions.

4.      Memory requires storage in the brain.

III        Tools and Mental Action Programs

A.     Brain increases to 2 times its size.

1.      Due to stable social organization.

2.      Due to extreme environmental conditions.

3.      Due to the need for strategies in hunting and protection.

B.     Progress in Technology

1.      Took over 1 million years to go from basic stone tool to sophisticated hand axe.

2.      Refinement of tools meant a combination of actions, ie. Drill hole, use microliths.

IV        Evolution of Language

A.     Concepts for Language

1.      Pre-human primate time included associations between sounds and objects.

2.      New associations of sound patterns with event dependent objects, ie. Different name for animal alive and animal cooked.

3.      Discrimination learning meant having object properties change based on experience or use.

4.      Event concepts involve the use of verbs.

B.     Tools and Language

1.      Define objects through comparative language, ie. Heavy vs. light.

2.      Define the function of objects with adverbs.

3.      Define the sequence of actions necessary to make or use tools.

C.     Evolution of Language and Disturbance

1.      Two neural networks: Wernicke’s area and Broca’s area.

2.      Wernicke aphasia – cannot find target word, so uses substitution.

3.      Broca aphasia – can only make simple sentences with gestures (ealry proto-language).

D.     Conclusions

1.      Wernicke’s area and Broca’s area both evolved at different times in different conditions.

2.      Wernicke’s area mainly used by Homo erectus, 1.6 –1.8 million years ago, and was grammar free.

3.      Broca’s area mainly used by early Cro-Magnun in northern Africa.

4.      Oldest language combined subject, verbs, and objects.

5.      Language separation took place 150,000 to 120,000 years ago in Eem period.

6.      Cro-Magnun tools represent construction of plans that facilitated sentence structure.

E.      Author’s Main Points

1.      The challenging environmental conditions forced surviving ancestors to form a complex social structure (tribe).

2.      A stable social structure facilitated expansion of the brain.

a.       Had to communicate within the tribe.

b.      Had to learn to use various tools for various situations.

3.      The naming of objects with sounds/words and the use of sentences developed at different times.