aftereffect

An aftereffect is a secondary or residual consequence that persists after the initial cause, event, or stimulus has ceased. Aftereffects can arise from physical, physiological, perceptual, or social processes and may be beneficial, harmful, or neutral. They can be brief or endure for extended periods, from moments to years.

In perception and sensory science, aftereffects are common outcomes of neural adaptation. Classic examples include optical afterimages, where staring at a bright color or pattern can produce a lingering perception of a complementary color after the stimulus ends, or motion aftereffects, where continued perception of motion occurs after viewing a moving image.

In health and medicine, aftereffects refer to consequences that follow illness, injury, treatment, or exposure to substances. This can include fatigue, weakness, pain, withdrawal symptoms, or delayed complications. Some aftereffects resolve quickly, while others require ongoing management or medical attention.

In psychology and related fields, aftereffects describe lasting changes in attitude, mood, or behavior following exposure to stimuli, experiences, or persuasive messaging. These effects may influence decision making, risk perception, or social attitudes beyond the immediate context of the original event.

In broader usage, aftereffects can denote residual impacts of a disaster, policy, or industry change on communities or economies. The term is sometimes used metaphorically to describe lingering behavioral or cultural shifts after a notable incident.

The term may be confused with brand names such as Adobe After Effects, a software package for post-production visual effects. The general concept of an aftereffect is separate from specific tools or products.