Interference theory

Interference theory is a theory regarding human memory. Interference occurs in learning; it is the notion that memories encoded in long-term memory (LTM) are forgotten, and cannot be retrieved into short-term memory (STM) effectively due to either memories interfering, or hampering, one another. As there are an immense number of comparably encoded memories within the storage of LTM, the challenge for memory retrieval is recalling the specific memory to be retrieved and worked upon in the temporary workspace provided in STM. The retention of information with respect to the relevant time of encoding memories into LTM has an effect on the degree of interference strength. There are two types of interference effects: Interference theory is a theory regarding human memory. Interference occurs in learning; it is the notion that memories encoded in long-term memory (LTM) are forgotten, and cannot be retrieved into short-term memory (STM) effectively due to either memories interfering, or hampering, one another. As there are an immense number of comparably encoded memories within the storage of LTM, the challenge for memory retrieval is recalling the specific memory to be retrieved and worked upon in the temporary workspace provided in STM. The retention of information with respect to the relevant time of encoding memories into LTM has an effect on the degree of interference strength. There are two types of interference effects: John A. Bergström is credited as conducting the first study regarding interference in 1892. His experiment was similar to the Stroop task and required subjects to sort two decks of card with words into two piles. When the location was changed for the second pile, sorting was slower, demonstrating that the first set of sorting rules interfered with learning the new set. German psychologists continued in the field with Georg Elias Müller and Pilzecker in 1900 studying retroactive interference. To the confusion of Americans at a later date, Müller used 'associative Hemmung' (inhibition) as a blanket term for retroactive and proactive inhibition. The next major advancement came from American psychologist Benton J. Underwood in 1957. Underwood revisited the classic Ebbinghaus learning curve and found that much of the forgetting was due to interference from previously learned materials In 1924, James J. Jenkins and Karl Dallenbach showed that everyday experiences can interfere with memory with an experiment that resulted in retention being better over a period of sleep than over the same amount of time devoted to activity. The United States again made headway in 1932 with John A. McGeoch suggesting that decay theory should be replaced by an interference theory. The most recent major paradigm shift came when Underwood proposed that proactive inhibition is more important or meaningful than retroactive inhibition in accounting for forgetting. Proactive interference, also known as Proactive inhibition, is the interference of older memories with the retrieval of newer memories. Of the two effects of interference theory, proactive interference is considered the less common and less problematic type of interference compared to retroactive interference. It has been hypothesized that forgetting working memories would be non-existent if not for proactive interference. Proactive interference build up occurs with memories being learned in similar contexts. A common example is observing previous motor abilities from one skill interfering with a new set of motor abilities being learned in another skill from the initial. Proactive interference is also associated with poorer list discrimination, which occurs when participants are asked to judge whether an item has appeared on a previously learned list. If the items or pairs to be learned are conceptually related to one another, then proactive interference has a greater effect. Delos Wickens discovered that proactive interference build up is released when there is a change to the category of items being learned, leading to increased processing in STM. Presenting new skills later in practice can considerably reduce proactive interference desirable for participants to have the best opportunity to encode fresh new memories into LTM. The leading experimental technique for studying proactive interference in the brain is the 'recent-probes' task, in which participants must commit a given set of items to memory and they are asked to recall a specific item indicated by a probe. Using the recent-probes task and fMRIs, the brain mechanisms involved in the resolution of proactive interference have been identified as the ventrolateral prefrontal cortex and the left anterior prefrontal cortex. Researchers have studied the joint influence of proactive and retroactive interference using a list of items to be remembered. As expected, recall was hampered by increasing the number items in a given list. Proactive interference also affected learning when dealing with multiple lists. Researchers had participants learn a list of 10 paired adjectives. The experimenters would consider a list to be learned if the participant could correctly recall eight of the ten items. After two days, participants could recall close to 70% of the items. However, those asked to memorize a new list the day after learning the first one had a recall of only 40%. Those who learned a third list recalled 25% of the items. Therefore, Proactive interference affected the correct recall of the last list learned, because of the previous one, or two. In terms of forgetting, the effect of Proactive interference was supported by further studies using different methods. The effect of proactive interference was reduced when the test was immediate and when the new target list was obviously different from the previously learned lists. Span performance refers to working memory capacity. It is hypothesized that span performance is limited in language comprehension, problem solving, and memory. Proactive Interference affects susceptibility to span performance limitations, as span performance in later experimental trials were worse than performance in earlier trials. With single tasks, proactive interference had less effect on participants with high working memory spans than those with low ones. With dual tasks, both types were similarly susceptible.