Sensory memory

Sensory memory is the brief retention of raw sensory information in a modality-specific form before it is either attended to and transferred to short-term memory or lost to decay. It serves as a precategorical buffer that holds the sensory trace just long enough for the cognitive system to decide what deserves further processing — a filter that determines what the mind will ever become aware of. Despite its brevity, sensory memory is not a passive echo; its characteristics are shaped by top-down attention and bottom-up salience, making it an active gatekeeper rather than a mere recording device.

The two best-studied forms are iconic memory (visual) and echoic memory (auditory), though haptic and olfactory analogs likely exist. Sensory memory sits at the boundary between the physical world and the cognitive system: it is the last stage at which information is still out