Perception theory in India and the West

In the last post, we saw how the concept of consciousness has some fundamental differences between Indian thought, and Western thought that is now the mainstream method of scientific inquiry. 

In this post, let us look at how the concept of perception, or our interaction with the world outside, is modelled in Indian thought and in Western science. 

In Cognitive Science today, perception is defined as the process by which we segment raw signals received by our sense organs into semantic objects and relationships between them. Sometimes, perception is distinguished from cognition in the following way: perception is a recognition process where we identify objects and relationships, while cognition is a process of sense making where we try to interpret what we have perceived. 

For example, suppose we see something like the following picture: 

Image Source: Google image search

Our perception mechanism recognises a dog in the picture, standing up behind a fence, and looking somewhat sad. Our cognition mechanism provides one or more explanations or interpretations for what we have seen-- maybe the dog waiting for its owner, maybe it is calling for help, maybe it is abused, or maybe it is just missing its friend on the other side of the fence, and so on. 

Cognition is greatly influenced by our mental model, which in turn is influenced by our emotional state. If we are in an angry or sad emotional state, we are much more likely to value negative interpretations, and if we are in a happy mental state, we are much more likely to value positive interpretations. (The reality of course, may be independent of our emotional state). 

Perception is also aided by our attention mechanism-- which decides which signal to keep among the several raw signals that are coming in. Attention attenuates most of the raw signals, and focuses the perception to segment only that part of the signal on which, we are paying attention to. 

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Let us now turn to how perception is understood in Indian philosophy. 

In Indian philosophy, the essence of our being is pure awareness-- called by different names in different contexts. The awareness that is us, uses our mind-body complex to interact with the world around us (called Prakriti).

Our mind is said to cast a field of perception around us. This field of perception experiences a disturbance or "whorl" (called Vritti) either through external or internal stimuli. For instance, if an object comes into our field of vision, it forms a Vritti in our minds. 

Vrittis can also be caused by internal stimuli-- from our memories. Be it external or internal, the mind experiences a whorl which is the beginning of the perception process. Note that, there is no specific mention of sense organs or the different kinds of signals (vision, speech, touch, etc.) Vrittis are considered to be "multi-modal" in nature. A stimuli on our mind's field creates whorls that have all sense components-- vision, sound, emotion, touch, etc. This holistic unit of signal (that is called a "chunk" in Cognitive Science) is the fundamental building block. Raw signals of a particular type-- like vision, sound, etc. are just components of the holistic signal, which by themselves have no meaning. 

Vrittis are also called avidya (non-knowledge). It is only when they are interpreted by our awareness, can Vrittis be converted to knowledge. 

There are multiple models of how Vrittis are interpreted. But all of them agree that the interpretation of Vrittis depends on the "modulation" of our mind. The Upanishads mention five forms of modulations for our mind: Pramana, Viparyaya, Vikalpa, Smriti, and Nidra. 

In a Pramana state of mind, we are in a state of inquiry-- we want to explore, examine, ask questions, etc. In Viparyaya, we are in a distracted frame of mind-- we cannot decide which of the whorls to focus upon, and keep switching contexts. In Vikalpa, our mind is in a deluded state-- it has already decided the interpretation, and tries to cherry-pick for confirming signals from the different Vrittis. In Smriti, we are in a state of nostalgia or reminiscence-- every Vritti is interpreted for what it reminds us of from our episodic memories. And in the state of Nidra, we are asleep-- and ignore all the Vrittis. 

Patanjali's Yoga Sutra proposes another model mentioning the following five modes of our mind: Mudha, Kshipta, Vikshipta, Ekagra, and Nirudha. 

Image Source: Google image search

The above slide explains the five modulations of mind, each of which, affects the way in which we interpret our Vrittis. 

Note that Vrittis can be formed from internal stimuli as well-- from our memories. By "memory" what we mean is some cognitive element that is stored in our minds-- not necessarily an exact replica of a past event. Memories in the human mind are not passive data banks, they are active, autonomous units, that can generate Vrittis in our minds, leading to downstream mental (and even physical) activity. 

Memory elements that are repeatedly encountered, and which become deeply embedded in our minds, are called Samskara. These refer to hermeneutic elements that drive our thinking and interpretation. We are most often, not even aware of our Samskara and how it may be affecting or even biasing the way we interpret our world. 

For the mind, there is only a theoretical knowledge that distinguishes between internally induced and externally induced Vrittis. If this knowledge signal is weak, or the Vrittis are too strong, the mind may be unable to determine whether this Vritti is being caused by something external or internal. This often happens in a state of trauma or paranoia, where a person be experiencing real pain within, from internally induced Vrittis, even though there is no external stimuli. 

The more deep-rooted such memories are, the tougher it is to recognise them and remove them from our memories. 

Similarly, dreams are made from internally induced Vrittis. In a state of dream, the mind feels that the dream is as real as the real thing. As the Upanishads say: Dreams are real as long as they last-- so is life.