“Between stimulus and response there is a space. In that space is our power to choose our response. In our response lies our growth and our freedom.” Victor E Frankl
As per the spiritual tradition of India, Mind (or Antahkaran) is made up of four functions or parts. These are Manas, Chitta, Ahamkar and Buddhi. These are typically translated as sensory-motor mind, memory bank, ego and intellect respectively. As an interesting aside, Buddha derives from the common root of Buddhi (budh- to know) and stands for the enlightened one.
Here is a brief description of the four functions:
Manas is ordinary, indeterminate thinking — just being aware that something is there and automatically registers the facts which the senses perceive.
The subconscious action, memory, etc., is caused by chitta. The function of chitta is chinta (contemplation), the faculty whereby the Mind in its widest sense raises for itself the subject of its thought and dwells thereon.
Buddhi determines, decides and logically comes to a conclusion that something is such-and-such a thing. That is another aspect of the operation of the psyche — buddhi or intellect. buddhi, on attending to such registration, discriminates, determines, and cognizes the object registered, which is set over and against the subjective self by aha?k?ra.
Ahamkara — ego, affirmation, assertion, ‘I know’. “I know that there is some object in front of me, and I also know that I know. I know that I am existing as this so-and-so.” This kind of affirmation attributed to one’s own individuality is the work of ahamkara, known as egoism.
There is also a hierarchical relation between these with Buddhi at the top and Manas at the bottom. Now, lets look at each of these more closely.
Manas, or sensory-motor mind, is not just registering stimulus but also responsible for executing actions and may be equated with the sensory/ motor cortical functions of the brain. It controls the 10 Indriyas (5 senses and 5 action-oriented faculties). Its important to note that Manas is doing both the functions associated with stimulus as well as the response, though its the first one when it comes to stimulus processing (registering the stimulus) and the last one when it comes to executing responses/actions ( it blindly executes the action that has been decided / chosen upstream). Of course one could just have a reflex action where a stimulus leads to response, but in majority of human action, there is a space between the two. That space is provided by the rest of the mind functions.
Chitta, or memory-prospecting mind, may be typically equated with the association cortex part pf the brain. Many refer to chitta as the memory or impressions bank, but forget to mention the future oriented part of it. Here is a quote:
The part of the Mind thinking and visualizing the objects, events and experiences from the past or the future (emphasis mine) is called the Chitta and this act is called Chintan.
Its thus evident that Chitta drives Manas not only based on past memories, but also based on future expectations or predictions. From brain studies , we know that the same part of the brain is used for memory as well as prospection. Chitta using past memories to drive manas (and thus behavior or motivated cognition) I view as being conditioned by classical conditioning processes. Chitaa using future expectations/ predictions to drive behavior and motivated cognition, I view as being conditioned by operant conditioning processes. In many philosophical and spiritual traditions, one of the aims is to get over (social) conditioning. Chitta hinders spiritual awakening by using habits, which is an integral pat of chitta function. The habits are nothing but the conditioning, but again one in stimulus path and the other in response/action path.
Ahamkara, or experiential-agentic self, may be typically equated with consciousness/ conscious and ego-driven self. It knows and say ‘I am’ Conscious entities typically have two functions- experience and agency. It is something it is to be like that conscious entity (experience) and the entity has volition or ability to do things (agency). The concept of self as a conscious entity that has experience (in the stimulus path) and agency (in the response/ action path) is important for this notion of ahamkara. With self comes concepts like real self and ideal self which drive and are driven by experience and agency respectively. The less the discrepancy between the two the better your spiritual growth. An interesting concept here is that of coloring or external decorations- your coloring or how you see your self do lead to downward impact on chitta and manas by contaminating the stimulus/ action.
Buddhi, or knowing-deciding mind, is the final frontier on your path to spirituality. The typical functions associated with Buddhi are knowing, discriminating, judging and deciding. I think knowing/ discriminating (between stimuli/ actions etc) is a stimulus path function, while judging/ deciding (between actions/ responses/ attending to a stimuli) is a response path function. However I also believe they converge to a great extent here or else we will have a problem of turtles all the way down. Once you start to see things as they are, you are also able to choose wisely. At least that is what the scriptures say and what Boddhisattvas aspire or achieve.
To me this increasingly fine-grained control of what we perceive and how we act , from the gross actions and perceptions of manas to the discriminating decisions of buddhi are very intuitively appealing and also appear to be grounded in psychological and neural processes.
Mindfulness (Buddhism based) has become all the rage nowadays, yet if we look at the spiritual traditions of India, perhaps while Yoga defined as Chitta vritti nirodaha (or “Yoga is the silencing of the modifications of the mind”) does refer to being in the present (here-and-now) and not to be disturbed by the perturbations of chitta (memories of past or expectations of future), one also needs to go beyond just Chitta vritti, to addressing the Ahamkara coloring and finally to try achieving the Buddha nature where there is little disparity in doing and being. (Mindfulness) Meditation needs to move beyond being curious, non-judgemental and in the present to where one doe shave a judgement function, but one that is perfectly attuned.