Interference refers to a phenomenon in cognitive psychology where competing information can hinder the storage and retrieval of memories. It is commonly segmented into two types: proactive interference and retroactive interference.
Proactive interference arises when older memories disrupt the recall of new information. Conversely, retroactive interference occurs when new information causes difficulties in retrieving older memories. Both types of interference can affect long-term memory and short-term memory, though they generally have a more pronounced impact on long-term recollection.
To illustrate proactive interference, imagine a person who has just learned a new password for their email account. If they previously had a different password for years, the old password may interfere with the recall of the new one. One documented influence of proactive interference is the reduced accuracy of recalling the latest of similar tasks or lists.
For an example of retroactive interference, consider someone who has just learned to play a song on the guitar. If they immediately start learning a new song, the recent practice may hamper their ability to play the first song they learned. Research has shown that by manipulating sublists, proactive and retroactive events were measurable and distinct.
The mechanisms that underpin memory interference theory involve complex cognitive processes. The theory posits that the brain has a finite capacity for information storage and processing, which leads to competition between memories.
Both types of interference underscore the dynamic and sometimes competitive nature of human memory systems, highlighting the importance of understanding these processes for enhancing memory retention and retrieval.
Proactive Interference
When compared to retroactive interference, proactive interference is the less common and less harmful of the two interference theory effects. Previously, it was assumed that losing functioning memories would be impossible if not for purposeful interference.
Proactive interference accumulates when memories are learned in similar settings. A common example is seeing previous motor abilities from one talent interfering with a new set of motor abilities being learned in another skill from the first.
Proactive interference is also linked to poorer list discrimination, which happens when participants are asked to decide whether an item appears on a previously learned list. If the items or pairs to be learned are conceptually connected, proactive interference works better.
Delos Wickens found that proactive interference build-up is released when the category of things being learnt changes, resulting in greater processing in short-term memory. Presenting new abilities later in practice can significantly reduce proactive interference, allowing participants to have the best chance to store fresh new memories into long-term memory.
Retroactive Interference
In retroactive interference, also known as retroactive inhibition, the effect takes place when any type of skill has not been rehearsed over long periods. When compared to proactive interference, retroactive interference is thought to be the more prevalent and problematic of the two effects of interference theory.
Since the German psychologist Hermann Ebbinghaus conducted the first scientific work on forgetting in the late nineteenth century, following research on the pace of forgetting presented knowledge has revealed a steep curve. While many factors influence the rate of forgetting, the overall conclusion is that 70% of originally recalled material is lost within 24 hours of a practice session, followed by 80% within 48 hours.
Regardless of the figures, retroactive interference can be considerably decreased by employing over-learning practice schedules, frequent rest sessions when practicing skills, and skill rehearsal time during inactive periods of practice. Continuous skills are more resistant to forgetting than discrete abilities, implying that the types of skills practiced and retroactive interference have a substantial interaction.
The subject of retroactive interference has spawned a long-standing controversy in memory research about whether the process of forgetting is caused by the interference of other competing stimuli or by the unlearning of the forgotten material. The crucial conclusion one can draw from RI, Robert Bjork wrote, is that “forgetting is not simply a failure or weakness of the memory system,” but rather an essential component of our stored knowledge repertoire.
Effects of Interference on Long-Term Memories
In terms of long-term memory, proactive interference can lead to difficulties during the memory consolidation phase, a critical period when memories are stabilized and integrated into existing knowledge. Misremembering details or mixing up information are common symptoms of recall difficulties due to interference.
This is especially prominent when a person frequently encounters similar types of information, which can blend into older memories, leading to a distortion of facts. Long-term memories, particularly those that are not rehearsed or frequently recalled, are more susceptible to such distortions.
Retrieval failure refers to the inability to access a memory that is believed to still exist within one’s memory store. Interference can exacerbate this issue, making it challenging to retrieve specific information amidst the clutter of similar but irrelevant memories. For instance, a person who has learned multiple programming languages may struggle to recall a particular coding syntax when the languages have many commonalities.
Interference Theory History
Interference theory, rooted in early psychological studies, posits that the capability to remember can be affected by subsequent learning experiences. Initial examinations into interference date back to the late 19th and early 20th centuries, where researchers began observing the phenomena of retroactive and proactive interference. These observations led to further inquiries and systematic investigations, laying the groundwork for modern understanding of memory interference.
John A. Bergström is recognized for conducting the first interference study in 1892. His experiment was comparable to the Stroop task in that subjects had to sort two decks of cards containing words into two piles.
When the placement of the second pile was moved, sorting became slower, indicating that the first set of sorting rules interfered with learning the new set. His research contributed to the establishment of a more structured approach to studying memory processing and played a crucial role in the development of interference theory.
In 1900, German psychologists Georg Elias Müller and Pilzecker continued studies into retroactive interference. Müller used “associative Hemmung” (inhibition) as a blanket term for retroactive and proactive inhibition, which caused confusion among Americans later on.
In 1924, John G. Jenkins and Karl Dallenbach demonstrated that everyday activities can interfere with memory by conducting an experiment that revealed that retention was better during sleep than during the same amount of time devoted to activity. In 1932, the United States made more progress when John A. McGeoch proposed that decay theory be replaced by an interference theory.
Benton J. Underwood, an American psychologist, made the next significant improvement in 1957. Underwood reviewed the traditional Ebbinghaus learning curve and concluded that most of the forgetting was caused by interference from previously learned information.
More recently, Wohldmann, Healey, and Bourne demonstrated that Retroactive Interference affects motor movement retention. Researchers found that retroactive interference impacts the performance of old motor motions when freshly acquired motor movements are exercised.
Physical repetition of newly accomplished motor movements reduced memory and recall of previously taught actions. Despite the retroactive interference seen by Wohldmann et al., researchers have observed that mental exercise reduced the degree of retroactive interference, implying that mental practice is more adaptable and enduring over time.
References:
- Bjork, R. A. (1992). Interference and memory. In L. R. Squire (Ed.), Encyclopedia of learning and memory. New York: Macmillan
- Izawa, C. (1980). Proactive versus retroactive interference in recognition memory. The Journal of General Psychology, 102(1), 53-73
- Rieber, Robert W., ed (1998). Psychology theoretical-historical perspectives (2nd ed.). Washington, DC: American Psychological Association. ISBN 978-1-55798-524-8
- Underwood, Benton J. (1969). Attributes of memory. Psychological Review. 76 (6): 559–573. doi: 10.1037/h0028143
- Unsworth, N., Brewer, G. A., & Spillers, G. J. (2013). Focusing the search: Proactive and retroactive interference and the dynamics of free recall. Journal of Experimental Psychology: Learning, Memory, and Cognition, 39(6), 1742–1756
- Wickens, D.; Moody, M.; Shearer, P. (1976). Lack of Memory for Unattended Items in Dichotic Listening. Journal of Experimental Psychology. 2 (6): 712–719. doi: 10.1037/0278-7393.2.6.712
- Wohldmann, E.L.; Healy, A.F.; Bourne, Jr. (2008). A mental practice superiority effect: Less retroactive interference and more transfer than physical practice. Journal of Experimental Psychology: Learning, Memory, and Cognition. 34 (4): 823–833. doi:10.1037/0278-7393.34.4.823