I once tried to learn a simple form of a Bantu language and failed (not surprising as I always fail to learn a new language). One of the problems with this particular attempt was classes of nouns. There were 10 or so classes, each with their own rules. Actually it works like the gender of nouns in most European languages, but it is much more complex and unlike gender it is less arbitrary. The nouns are grouped in somewhat descriptive groups like animals, people, places, tools etc. Besides the Bantu languages there are a number of other groups that have extensive noun classes, twenty or more.
Years ago I found the noun classes inexplicable. Why did they exist? But there has been a number of hints that it is a quite natural way for concepts to be stored in the brain – faces stored here, tools stored there, places stored somewhere else.
A recent paper (Andrew James Bauer, Marcel Adam Just. Monitoring the growth of the neural representations of new animal concepts. Human Brain Mapping, 2015; DOI: 10.1002/hbm.22842) studies how and where new concepts are stored.
Their review of previous finds illustrates the idea. “Research to date has revealed that object concepts (such as the concept of a hammer) are neurally represented in multiple brain regions, corresponding to the various brain systems that are involved in the physical and mental interaction with the concept. The concept of a hammer entails what it looks like, what it is used for, how one holds and wields it, etc., resulting in a neural representation distributed over sensory, motor, and association areas. There is a large literature that documents the responsiveness (activation) of sets of brain regions to the perception or contemplation of different object concepts, including animals (animate natural objects), tools, and fruits and vegetables. For example, fMRI research has shown that nouns that refer to physically manipulable objects such as tools elicit activity in left premotor cortex in right-handers, and activity has also been observed in a variety of other regions to a lesser extent. Clinical studies of object category-specific knowledge deficits have uncovered results compatible with those of fMRI studies. For example, damage to the inferior parietal lobule can result in a relatively selective knowledge deficit about the purpose and the manner of use of a tool. The significance of such findings is enhanced by the commonality of neural representations of object concepts across individuals. For example, pattern classifiers of multi-voxel brain activity trained on the data from a set of participants can reliably predict which object noun a new test participant is contemplating. Similarity in neural representation across individuals may indicate that there exist domain-specific brain networks that process information that is important to survival, such as information about food and eating or about enclosures that provide shelter.”
Their study is concerned with how new concepts are formed (they have a keen interest in education). “Collectively, the results show that before instruction about a feature, there were no stored representations of the new feature knowledge; and after instruction, the feature information had been acquired and stored in the critical brain regions. The activation patterns in the regions that encode the semantic information that was taught (habitat and diet) changed, reflecting the specific new concept knowledge. This study provides a novel form of evidence (i.e. the emergence of new multi-voxel representations) that newly acquired concept knowledge comes to reside in brain regions previously shown to underlie a particular type of knowledge. Furthermore, this study provides a foundation for brain research to trace how a new concept makes its way from the words and graphics used to teach it, to a neural representation of that concept in a learner’s brain.”
This is a different type of learning. It is conceptual knowledge learning rather than learning an intellectual skill such as reading or a motor skill such as juggling.
The storage of conceptual knowledge appears to be quite carefully structured rather than higgly piggly.
Here is the abstract. “Although enormous progress has recently been made in identifying the neural representations of individual object concepts, relatively little is known about the growth of a neural knowledge representation as a novel object concept is being learned. In this fMRI study, the growth of the neural representations of eight individual extinct animal concepts was monitored as participants learned two features of each animal, namely its habitat (i.e., a natural dwelling or scene) and its diet or eating habits. Dwelling/scene information and diet/eating-related information have each been shown to activate their own characteristic brain regions. Several converging methods were used here to capture the emergence of the neural representation of a new animal feature within these characteristic, a priori-specified brain regions. These methods include statistically reliable identification (classification) of the eight newly acquired multivoxel patterns, analysis of the neural representational similarity among the newly learned animal concepts, and conventional GLM assessments of the activation in the critical regions. Moreover, the representation of a recently learned feature showed some durability, remaining intact after another feature had been learned. This study provides a foundation for brain research to trace how a new concept makes its way from the words and graphics used to teach it, to a neural representation of that concept in a learner’s brain.”