Perception is the use of your physical senses (including cybernetic) and awareness of the physical world around you. Perception differs from Investigation in that it is noticing things by chance, rather than actively searching for something.
Use Perception whenever you want to take a detailed account of your surroundings (see Detailed Perception, p. 190). Perception can also be considered an Automatic Action (see Basic Perception, p. 190) and so the gamemaster may call for a Perception Test to determine if you notice something; it is recommended that such tests be rolled secretly by the gamemaster. Perception is also used as an Opposed Test whenever someone around you is trying to be sneaky with Infiltration or Palming.
Example (optional) specializations include Aural, Olfactory, Tactile, Taste, Visual.