As an individual we stand in a world that pulsates with energy. Within us is the silent darkness of the brain; how does the world get in there, what is it we see? There are three sets of tools, illustrated in Figure 4.1, that work together to help us make sense of our world.

Senses – through stimulation of receptors by our sense organs we detect physical energy directly from the external or internal environment; we encode that energy into neural signals.

Perception – processes by which the brain organises and interprets sensory information.

Attention – through selective attention we choose what we need or want to take notice of, homing in on stimuli that may be important and cutting out the interference of background effects; it is the root of both our restlessness and our concentration.