ABSTRACT
Contrary to popular belief, the brain does not operate like a camera taking in a whole scene, but operates more like a feature detector. Despite the fact that each person’s brain constructs its own perceptions, the results are not specific to each individual. ‘Bottom-up’ processing refers to how individual sensory stimuli activate brain cells and how simple individual features of the environment are co-ordinated with one another and built into more complex features of the environment at a neuronal level. The cortex is richly endowed with cortico-cortical dendritic pathways that link neurons in the superficial layers of the cortex. Perception is very sensitive to the sensory context in which a stimulus is encountered. This means that a stimulus can be perceived differently depending on what other environmental stimuli are close by. Different stimulus features of the same object are processed by cortical neurons in different brain areas.
