Negative priming is an implicit memory effect in which prior exposure to a stimulus unfavorably influences the response to the same stimulus. It falls under the category of priming, which refers to the change in the response towards a stimulus due to a subconscious memory effect. Negative priming describes the slow and error-prone reaction to a stimulus that is previously ignored.Mayr, S. & A. Buchner (2007) Negative priming as a memory phenomenon—A review of 20 years of negative priming research. Zeitschrift für Psychologie, 215, 35–51. For example, a subject may be imagined trying to pick a red pen from a pen holder. The red pen becomes the target of attention, so the subject responds by moving their hand towards it. At this time, they mentally block out all other pens as distractors to aid in closing in on just the red pen. After repeatedly picking the red pen over the others, switching to the blue pen results in a momentary delay picking the pen out (however, there is a decline in the negative priming effect when there is more than one nontarget item that is selected againstNeumann, E. & DeSchepper, B.G. (1992). An inhibition-based fan effect: Evidence for an active suppression mechanism in selective attention. Canadian Journal of Psychology, 46 (1), 1-40.). The slow reaction due to the change of the distractor stimulus to target stimulus is called the negative priming effect.
Negative priming is believed to play a crucial role in attention and memory retrieval processes. When stimuli are perceived through the senses, all the stimuli are encoded within the brain, where each stimulus has its own internal representation. In this perceiving process, some of the stimuli receive more attention than others. Similarly, only some of them are stored in short-term memory. Negative priming is highly related to the selective nature of attention and memory.
Broadly, negative priming is also known as the mechanism by which inhibitory control is applied to cognition. This refers only to the inhibition stimuli that can interfere with the current short-term goal of creating a response.Dempster, Frank N. (Ed); Brainerd, Charles J. (Ed), (1995). Interference and inhibition in cognition. San Diego, CA, US: Academic Press. The effectiveness of inhibiting the interferences depends on the cognitive control mechanism as a higher number of distractors yields higher load on working memory. Increased load on working memory can in turn result in slower perceptual processing leading to delayed reaction. Therefore, negative priming effect depends on the amount of distractors, effectiveness of the cognitive control mechanism and the availability of the cognitive control resources.de Fockert, J. W., Mizon, G. A., & D'Ubaldo, M. (2010). No Negative Priming Without Cognitive Control. Journal of Experimental Psychology–Human Perception and Performance, 36(6), 1333–1341.
Theories and classic models There are a number of theories and models that try to explain the reason behind negative priming. They all try to reason negative priming's role in cognition and justify why it occurs. A few of the well-known models 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.Tipper, S.P. (2001). Does negative priming reflect inhibitory mechanisms? A review and integration of conflicting views. Quarterly Journal of Experimental Psychology: Human Experimental Psychology, 54A, 321–343.Tipper, S.P. (1985). The negative priming effect: Inhibitory priming by ignored objects. Quarterly Journal of Experimental Psychology: Human Experimental Psychology, 37A, 571–590. 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.Houghton, G., & Tipper, S. P. (1994). A model of inhibitory mechanisms in selective attention. In D. Dagenbach & T. H. Carr (Eds.), Inhibitory processes in attention memory and language (pp. 53–112). San Diego, CA, US: Academic Press, xiv.
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.Grison, S., Tipper, S. P., & Hewitt, O. (2005). Long-term negative priming: Support for retrieval of prior attentional processes. Quarterly Journal of Experimental Psychology Section a-Human Experimental Psychology, 58(7), 1199–1224. 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 in selective attention, and response given are all retrieved automatically. When the repetitively ignored distractor stimulus is encountered as the target, a tag associated with the response to the stimulus is also retrieved. This response tag of a distractor will likely be "do-not-respond" tag as opposed to the "respond" tag of the target stimulus. Retrieval of the previous "do-not respond" tag of the stimulus conflicts with the current "respond" tag. This presents a problem of whether to respond or not. Resolving this conflict takes time and produces negative priming effect.Neill, W.T., Valdes, L.A., Terry, K.M., & Gorfein, D.S. (1992). Persistence of negative priming: II. Evidence for episodic trace retrieval. Journal of Experimental Psychology: Learning, Memory, and Cognition, 18, 993–1000.
Episode retrieval model has gained more popularity over the last decade compared to the distractor inhibition model due to the issues with long-term negative priming. Episode retrieval varies from the distractor inhibition model because it claims that the negative priming occurs only when the memory of the stimuli is retrieved and not during the encoding of the distractor stimuli. Recent findings lean towards this model but the model itself is not entirely complete. Its idea of association tags like the "do-not-respond" tag is vague and needs concrete evidence to support this model.
Houghton–Tipper model
Due to the issues found with the distractor inhibition model, Tipper and Houghton modified the distractor inhibition model to account for long-term negative priming effects. The original inhibition account proposed that inhibition occurs only when the distractors are suppressed. The Houghton–Tipper model revised this proposition and claims that inhibition occurs during both the encoding of distractors and the retrieval of that memory. The main reason for this change is to explain the long-term negative priming and justify it using the new combined model. When a repeated distractor becomes the target, processing of this stimulus automatically retrieves the memory of the stimulus being inhibited as a distractor. This model suggests that inhibition occurs when ignoring the distractor and during the memory retrieval of the previous ignorance of the stimulus. Therefore, it incorporates the inhibition account in selective attention and the episode retrieval model.
Feature mismatch hypothesis This theory proposes that negative priming effect is the result of interference due to the target being located where the distractor was once located. When the target stimulus and distractor stimulus are repeatedly placed in the same location, we know their respective location and pay attention more to the location of the target than the target itself. Our response to the target is also faster because we have already identified where to pay attention. This is called Simon effect, which refers our innate tendency to respond faster and more accurately when stimuli occur in the same location. This can be explained by neuroscience in terms of neural facilitation and short-term plasticity. However, if the positions of the stimuli are not the same as before, it is no longer easy to attend to the target as it once was. The feature mismatch hypothesis states that inhibition occurs when there is a mismatch between the target and its location. This theory is explains the effects of location specific negative priming but lacks in its justification of negative priming when location is not involved.Park, J., & Kanwisher, N. (1994). Negative priming for spatial locations: Identity mismatching, not distractor inhibition. Journal of Experimental Psychology: Human Perception and Performance, 20, 613–623. It deviates from the distractor inhibition model to describe location specific negative priming but has more loop holes than the other models.
Temporal discrimination model