are presented below. Distractor inhibition model Distractor inhibition model is the oldest model that explains the negative priming effect as the result of selective attention to a target stimulus. When we pay attention to a particular stimulus, we perceive other stimuli surrounding the target as distractors in order to help focus. But when one of those distractors becomes the new target of attention, our response to the target is hampered due to immediate residual inhibition. Selective attention is the ability to respond to a specific object when there are other distractors that also compete for a response. To explain this selective attention, the distractor inhibition model proposes a dual mechanism involving excitation to boost target signal and inhibition to suppress distractors. This inhibition is triggered when there is a mismatch between the internal representations of the target and a distractor. Inhibition of the distractor's internal representation is a way of helping to selectively attend to the target stimulus. This inhibition decays gradually when the stimulus is no longer present to help with the next target. However, if a distractor stimulus is re-encountered as the target, the internal representation of the distractor stimulus may continue to be suppressed because it is too soon for the decay to dissipate already. This is referred to as the transient residual inhibition. This inhibition also impairs the processing of an appropriate response to the new target stimulus and results in greater reaction time. There are a few problems associated with this inhibition model. This model accounts for negative priming only when the stimuli are repetitively ignored as distractors during a goal directed behavior of selecting the target stimulus. This model does not support negative priming effects found in cases short of goal directed behavior. Another issue is that negative priming effects have been found to be long-term contradicting to the proposed transient residual inhibition. Long-term persistence of negative priming questions the validity of the distractor inhibition model. Episodic retrieval model The episodic retrieval model is the current popular model and explains that negative priming occurs due to memory retrieval. This model theorizes that each encounter with a stimulus is encoded and stored separately as an individual episode. Each episode includes perceptual details of both the stimuli and the response developed for that stimulus. When a stimulus is encountered the second time, the previous episode regarding that stimulus along with its tags of perceptual details, role