The human brain is the most highly advanced data processor in terms of the speed volume and complexity of the data it processes. One could therefore say that it is the epitome of the evolutionary process. At any given moment the brain is exposed to a deluge of data. The sense organs are generating terabytes of data each moment, being constantly shovelled into the brain real time by transmitting pathways or neurons.
What determines prioritisation of data processing? Which data is to be assimilated and which is to be discarded? Cognition can fluctuate between a general background unfocused awareness to sharp focusing on a specific target.
The brain has the amazing ability to process and sieve through this incoming barrage of data. One of the mechanisms deployed is called Latent Inhibition. Data (LID) that is repetitive in nature.
LID causes neurons carrying this data to suppress adjacent neurons carrying the same information. These neurons are deployed to transmit other signals or at least not transmit "more of the same." An adaptation by neural pathways which narrows the bandwidth and accords a lower priority or inhibits data is meant to prevent crowding on the cognitive horizon.
An example is the tactile sensation of clothes touching the skin which is constantly being relayed to the brain. The neurons keep this data in a "Standby" mode, relegating its transmission to a lower priority. This phenomenon becomes even more important in increasing the accuracy of visual perception.
Different photoreceptors in the eye respond to varying degrees of light. When one cell activates in response to light, its activity impairs or prevents neighbouring cells from getting activated. This causes the edges between light and dark areas to appear more prominent than they would otherwise. In the absence of lateral inhibition, the border between a black tile and a white tile would appear less obvious. Perception is greatly impacted by the content of the delivered data.
When the filtered data arrives on the cognitive screen, the data is tagged with an emotion- byte. This emotion- byte is unique to each individual. This emotion tagged data is transcribed into samskaras or anagrams for encryption, storage and subsequent retrieval. This emotion- byte tagged database (samskaras) is unique to each individual.
This emotion tag could be pain, fear, grief, pleasure or joy and becomes vritti or the software- that determines one's inclinations or aversions.
The concept of vritti is central to the main definition of Yoga- "yoga chitta vritti nirodha" given in Sutra 1.2 of the Yoga Sutras by the great sage Patanjali.
Vrittis refer to the different tendencies, or psycho-physical propensities. They are an expression of stored anagrams or samskaras. Collectively they represent motivation, behavioural patterns, desires, repulsions, predispositions and complexes.
The software thereafter not only shapes or personalises but also operates the hardware, the physical form with its identity. The eightfold path of Ashtanga Yoga aims to disconnect (nirodha) this database (vritti) from the personalised consciousness (chitta) to effect a pure, impersonal awareness. It ceases the generation of new software obviating the need for any appropriate hardware -- liberation "from" the person rather than "of" the person.