Perception
Objective aspects of perception- Perception is the process by which animals acquire information about their environment: What's out there? Where is it? What is it doing? Where is it going?
Stages in that process:
-
•Physical stimuli ( e.g. light particles, sound waves) act on sense organs to create nerve signals brain process the signals to extract information; perception = end product
-
•Different types of animals have different nervous systems - hence, perceive the world differently, e.g., dog whistles we can't hear.
-
•We are only ‘tuned in’ to certain information, and even only receptive to a narrow range (e.g. just the ‘visible spectrum’ from the entire electromagnetic spectrum).
02. What is ‘Perception’?
1:39 PM
Defining perception is difficult, because the concept is so basic (like, “What is Consciousness”?) There are two ways to approach the definition, both are correct, but from different points of view. There is the ‘objective’ definition, and the ‘subjective’ definition.
Subjective aspects of perception- Perception is our internal, mental, representation of the world. Some consequences:
-
•Sensory process generally give rise to conscious mental experiences: sights, sounds, tastes, smells, etc.
-
•Perception is "symbolic" or "representational" : the brain constructs neural "icons" of the outside world based on data supplied by the sense organs. That data is often ambiguous. Hence, brain often has to guess, guided by built-in biases and past experience.
-
•One consequence is that the same stimulus can be perceived differently by different people, or different creatures, or even the same person at different times.
-
•Subjective perceptual experiences are hard to study scientifically because they are unobservable by other people - is your "red" the same as mine? Why does ‘red’ look red anyway? (this is the famous ‘inverted spectrum’ problem). But we try anyway. For instance:
The ‘blind spot’: Most of the inside surface of the back of the eye is lined with photoreceptor cells that absorb incoming light particles and turn them into nerve signals. But in one region, called the "blind spot", the photoreceptors are absent. If the image of an object falls within this blind spot region, that object cannot be seen. But, most people report that the blind spot portion of their visual field appears to be filled in with the color or texture that surrounds the blind spot. We know this from asking people about their perceptions, but there's no way to directly check this experimentally.