The purpose of the present study was to explore whether note-taking as a memory aid may provide a naturalistic example of intentional forgetting. One might predict that the note-taking group should show evidence of having better memory for the identity and location of the cards, as it could be argued that the form of studying that they were engaged in was more active and elaborative than the forms used by the study group (Di Vesta & Gray, 1972). The first experiment replicated the findings of Eskritt et al. (2001), however, demonstrating that participants in the note-taking group remembered significantly less location information than did participants in the study group. These results are suggestive that note-takers intentionally forgot the location information.
The results of the second experiment provided converging evidence for this interpretation. Note-taking provided a release from proactive interference when the Concentration game was played multiple times. Note-takers did not suffer from proactive interference either when using notes during the memory task or in the last game, when they played without using notes. It is important to note that note-takers were required to attend to and process the identity and location information in order to make and then use their notes each turn. Yet, their performance on the fifth game was more similar to the control group’s performance on their first game. Not unlike a person using a day planner to keep track of appointments, the results indicate that participants relied on their notes as an external store for the cards’ locations.
That location information was the type of information intentionally forgotten is in and of itself interesting, independent of the context in which it occurred. It could be argued that Golding and Keenan (1985) examined intentional forgetting for location information as well. They wanted to see whether participants would show intentional forgetting for a set of verbal directions, in which the to-be-forgotten information was presented as making a mistake in the directions. They found evidence for directed forgetting when participants’ memories were tested with a drawing task, but not with a verbal test.
Another task somewhat similar to the present task was conducted by Sparrow et al. (2011). They examined participants’ memory for facts that they typed into a computer and for the different folders where the facts were saved. When the researchers tested participants’ location and fact memory, they found that participants were able to recall the location where the information was saved better than the facts themselves. It was not the case that participants could not remember the facts on their own; in another experiment, Sparrow et al. found that participants were able to remember more facts when they thought that the computer had not saved what they had typed, as compared with facts that they thought had been successfully saved. Sparrow et al. suggested that this situation was similar to directed-forgetting studies, with participants thinking that they were free to forget the information that had been saved on the computer, but that they needed to remember information that had been erased.
That these participants were more proficient at recalling location information (i.e., the folders in which facts were saved) may appear to be the opposite of what we found. On the surface it is, but in both cases, participants were remembering the easier information and relying on an external memory store for the more difficult information. In Sparrow et al.’s study, participants had considerably fewer folders to keep track of, relative to the number of facts, making the “where” information easier to recall. In the present study, identity information would have been easier to remember for a number of reasons, including that each pair consisted of two identical cards in different locations and that distinguishing between the identities of the cards would have been easier than differentiating between the various locations. Therefore, it appears likely that participants do not intentionally forget only one specific type of information, independent of the task at hand, but rather can use intentional forgetting flexibly when employing external resources to lessen their cognitive load and enhance memory performance. They will rely on the external store for the more difficult information, and use the easier information to help access or organize the externally stored information (Eskritt et al., 2001; Sparrow et al., 2011).
The use of more naturalistic stimuli means that the present paradigm is some different from typical directed-forgetting paradigms using words as stimuli. One important difference has to do with the relevance of the information to be forgotten (Golding & Keenan, 1985). When participants are asked to forget a word in a list, the word can be considered no longer relevant to the task. On the other hand, the location information in the present experiment was still necessary for the task. Other studies looking at intentional forgetting in naturalistic contexts have found that when to-be-forgotten information is relevant to the task, participants are likely still to be influenced by that information. For example, when a judge tells jurors that some evidence is inadmissible, jurors tend still to be influenced by that information in their decision-making (Golding & Long, 1998). When more naturalistic studies try to control for relevance, evidence for intentional forgetting tends to be found again (Golding & Keenan, 1985).
So, why were participants able to intentionally forget relevant information in the present study? A number of different processes have been offered to explain intentional forgetting, such as differential rehearsal (Basden, Basden, & Gargano, 1993), retrieval inhibition (Geiselman, Bjork, & Fishman, 1983) and contextual change (Sahakyan & Kelley, 2002). In comparing the results of our first experiment to those from the two traditional methods of examining intentional forgetting, our results are more similar to those from studies using the item method. Participants in the note-taking group demonstrated poorer memory for location information, regardless of whether they were tested using a recall or recognition task. Typically, only studies using the item method reveal an intentional-forgetting effect with a recognition test (MacLeod, 1998). It is generally thought that differential rehearsal is involved with intentional forgetting for the item method (Basden et al., 1993). Participants maintain the presented word in memory until they receive the “forget” or “remember” cue, in order to determine whether or not they should actively rehearse the item. Likewise, the participants in the present study needed to process and consider location information to produce their notes, but if they intended their notes as an external memory store, they did not need to actively rehearse that information afterward.
However, the list and item methods are just procedures that are typically used to observe intentional forgetting. The different processes that theorists debate being involved in the two methods are likely involved in intentional forgetting (and remembering) to different degrees that vary with the task demands. For example, Fawcett et al. (2013) recently introduced the event method for testing directed forgetting, which uses videotaped events as stimuli. They found that participants were less likely to show intentional forgetting for more general information about the events, as opposed to more specific details, which we would argue is similar to our suggestion that participants remember the easier information, which they can then use to access the more difficult information in an external store. Although Fawcett et al.’s task is too recently developed for the underlying processes to have yet been identified, they argued that the combination of processes is likely to be different from the combinations involved in either the list or the item method.
Therefore, the paradigm used in the present study may not be directly analogous to either the list or the item method. Differential rehearsal seems to be the most likely explanation for the process involved for intentional forgetting when external storage is involved (Sparrow et al., 2011). As in an incidental-learning task, participants process the required information to make their notes, but then do not attend to it further. However, rehearsal may not be the only process to consider. Participants in the present study also demonstrated that they could selectively remember one type of information over another, which might be explained by the contextual-change hypothesis. This hypothesis has been suggested to play a role with the list method of testing, in that the items in the list to remember are proposed to be easier to recall because participants generate an internal context change between the two lists (Sahakyan & Kelley, 2002). Cues at retrieval match the encoding cues for the to-be-remembered list better than those for the to-be-forgotten list of words. Typically, selectively forgetting only some information within a list is not found with the list method (Geiselman et al., 1983; Sahakyan, 2004). However, Delaney, Nghiem, and Waldum (2009) reported that a selective intentional-forgetting effect is possible under some conditions. In particular, the ability to group information together within the list, separate from other information, appears to influence the ability to intentionally forget. Participants in the first study were able to remember one class of information, the identity of the cards, and to intentionally forget another type, the location information. Perhaps the use of notes helps provide support for the use of context to better separate the type of information to intentionally forget.
Research has suggested that inhibition may also play a role in intentional forgetting for both the list (Geiselman et al., 1983) and item (Lee, Lee, & Fawcett, 2013) methods. It may potentially do so with the present paradigm, as well. Eskritt (2005) reported that, whereas 9- to 10-year-olds are capable of producing notes that are just as functional as those of undergraduates, they are not as hampered by the notes’ removal as undergraduates are: Children’s ability to remember location suffered when they lost access to their notes, but they could recall more location information than could the undergraduates. This finding might be explained by the children not being as capable of inhibiting location information, which benefits their performance when access to notes is lost. On the other hand, the findings may also be explained by the contextual-change hypothesis, in that the children were not as able to separate the location information from the identity information as adults could.
Therefore, further research will be necessary to directly test what processes may be involved with intentional forgetting with note-taking. To further complicate the issue, note-taking can also aid in the encoding of information (Di Vesta & Gray, 1972), depending on its purpose. One issue that tends to be overlooked in the literature on intentional forgetting is the purpose for intentional forgetting. The assumption is often that the information to be forgotten can be forgotten permanently, like forgetting an old phone number after getting a new one, and this is frequently how intentional forgetting is tested. However, intentional forgetting may occur to stop some information from interfering with the present task (Lehman & Malmberg, 2011). Such information may still be useful at a future time—for example, the location information in the present experiment. In the literature, it is recognized that different explanations may account for list-method as opposed to item-method intentional forgetting, but otherwise, theorists rarely explicitly consider the different roles that intentional forgetting may play in memory. Perhaps the types of processes involved will vary, depending on the purpose for intentionally forgetting in different situations.
In the present study, we investigated the relationship between external memory use and intentional forgetting. However, that participants used intentional forgetting as part of their note-taking strategy for our task does not mean that individuals always do so. A large literature within educational psychology concerns the use of note-taking as an aid to encoding information better, versus using the notes as an external memory store (Eskritt & Lee, 2007), and the purpose for note-taking may influence whether or not intentional forgetting is involved. Because external memory aids are so common, memory research needs to explore further how their use incorporates different memory processes. Furthermore, individual differences in reliance on intentional forgetting are likely to emerge as part of using notes. As participants played the Concentration game with notes in the second experiment, almost all of them would turn over a card, and if they recognized the card, would check their notes for its pair’s location. However, a couple of participants used their notes as a “back-up”; they frequently relied on their own memory for a card’s location, unless they could not remember it or made a mistake. They were less likely to have been using intentional forgetting, but this distinction would have been lost in the group data. The results of the present study indicate that note-taking for memory purposes may provide a naturalistic example of intentional forgetting, but further exploration will be necessary in order for researchers to fully understand the role that intentional forgetting plays, individual differences in its use, and the processes it involves.