Pay Attention! Divided Attention Impairs Memory Processes
Have you ever been certain a friend said something when they’re certain that they didn’t? How about remembering it completely differently from how they actually said it? If you have, chances are you had a false memory! Don’t worry, you’re not the only one. False memories occur when we remember events that didn’t happen or remember them very differently from how they actually happened (Schacter, 1999). Although it may be unsettling to hear, false memories are very common and hard to detect. As far as you’re concerned, these don’t seem like false memories at all! False memories can be very similar in nature to true memories, which makes them all the more difficult to distinguish. Psychologists interested in memory often study false memories to learn more about the underlying processes that drive memory.
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Cognitive psychologists have developed a few different methods of inducing false memories. Perhaps the most reliable and widely used is the Deese-Roediger-McDermott (DRM; Roediger & McDermott, 1995) paradigm. In this paradigm, participants are presented with lists of words that are semantically associated, or related by meaning. For example, the words beach and ocean are semantically associated because people typically have strong connections between the ocean and the beach. After studying these words, participants take a memory test in which they have to decide whether they studied certain words or not. The DRM uses these types of associates to create false memories for words that are never presented, but are highly related to the words that are. One typical DRM list includes words such as banner, American, symbol, stars, and anthem, all of which converge upon the word flag. In this case, the word flag is called the critical lure. After studying this list of words, participants frequently remember seeing flag, even though it was never presented, because it is highly related to the words on the presented list.
One of the main theories to explain the DRM paradigm is called Activation Monitoring Theory (AMT; Roediger, Balota, & Watson, 2001). This theory poses two complementary processes that lead to false memories: automatic activation of critical lures and a breakdown in source monitoring. When participants study DRM lists, the words in the list are activated within one’s semantic network, or a mental grid of related concepts and words. The activation of these list items automatically spreads to other words in this network, including the critical lure. When tested, participants have to engage in source monitoring, during which they discern whether activated words were actually presented in the list, or were merely related to those that were. The familiarity of the critical lure, and its relatedness to the list words, makes this monitoring difficult. When monitoring fails, participants falsely remember having seen the critical lure in the study list. In other words, they have a false memory for the critical lure!
Over the past 20 years, researchers have manipulated the DRM in various ways to show the ease with which false memories can be induced and examine what factors increase or reduce false memories. One of these factors is attention. Researchers manipulate attention during the DRM procedure by distracting participants as they study DRM lists. In this type of manipulation, researchers are interested in observing how divided attention affects false memory. Presumably, divided attention should not affect automatic processes. Therefore, divided attention should not affect false memory rates, given that the activation of the critical lures is theoretically automatic. However, previous studies have found that divided attention can have mixed effects on false memory rates in the DRM paradigm. Some studies have found that divided attention increases false memory whereas others have found that it decreases false memory (Gallo, 2006). To read about how divided attention might affect false memory in children and adults, click here. We were interested in resolving these discrepancies by examining the effects of divided attention on recognition in the DRM paradigm.
Participants who agreed to take our study studied 18 DRM lists – nine under full attention conditions and nine under divided attention conditions. Under full attention conditions, participants simply studied the DRM lists. When studying under divided attention, participants were asked to pay attention to the study list words while also determining whether a number presented on either side of each word was odd or even. They pressed one of two keys to indicate their response. Each study list was comprised of 12 related words and four filler items. The last five items in each list were all related to the critical lure. Immediately after studying each list, they were asked to complete a recognition test for the words in that list. During this test, participants were presented with items and had to determine whether they were in the study list (“old”) or not (“new”) by pressing keys on the keyboard. In each test, the primed critical lure – related to the study list – was the second item tested. The critical lure for a non-studied list was the third item, and studied and non-studied words were mixed throughout the test list.
Our results showed that after studying under divided attention, participants had less false memories for related critical lures compared to when they studied under full attention. In other words, participants were less likely to respond “old” to the related critical lure if they had studied the list under divided attention compared to under full. Additionally, after studying under divided attention, participants had more false memories for unrelated critical lures compared to when they studied under full attention. We found a similar pattern for the recognition of studied list items. Participants had lower correct recognition rates of studied list words following study under divided attention compared to under full attention. Participants also had higher false recognition rates, or “false alarms,” for non-studied words on the test list following study under divided attention compared to full attention.
This pattern of results showed us that dividing attention during study decreased both false recognition of related critical lures and correct recognition of studied list items. These results suggest that divided attention impairs the formation of a strong semantic network at study. When studying under divided attention conditions, the critical lure for each study list was less likely to be activated and then falsely recognized during the test. Additionally, the list items were weakly activated and thus were less likely to send activation to the critical lure. As mentioned, the activation of critical lures is theoretically automatic and should therefore not be affected by divided attention at study. However, our results suggest otherwise!
Our study was designed so that participants would be tested on the related critical lure when activation for that lure was at its peak. The last five items studied were all related to the critical lure and recognition tests were presented immediately after each study list. Even under these conditions, participants falsely recognized related critical lures less if they had studied the previous list under divided attention compared to full attention. This suggests that dividing attention had an effect on the activation of critical lures, and thus activation may not be entirely automatic. The results from our study also have implications concerning memory more broadly. They further emphasize the close relationship between attention and memory. Not only does divided attention reduce memory for things that actually occurred, but also for things that never even happened!
This research was conducted by Cole Walsh, Nathan Huebschmann, and Liam Wilson with the assistance of Jen Coane and Yi Feng.
References
Gallo, D. A. (2006). Processes that cause false memory. In Associative illusions of memory (pp. 131-155). New York, NY: Psychology Press.
Roediger, H. L., Balota, D. A., & Watson, J. M. (2001). Spreading activation and arousal of false memories. In H. L. Roediger, III, J. S. Nairne, I. Neath, & A. M. Surprenant (Eds.), The nature of remembering: Essays in honor of Robert G. Crowder (pp. 95–115). Washington, DC: American Psychological Association Press.
Roediger, H. L. & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, 21(4), 803-814. doi:10.1037/0278-7393.21.4.803
Stadler, M. A., Roediger, H. I., & McDermott, K. B. (1999). Norms for word lists that create false memories. Memory & Cognition, 27(3), 494-500. doi:10.3758/BF03211543
Quite an interesting post about false memory! You provide thorough background about the DRM paradigm and false memory research. I am also impressed with your own study on the DRM paradigm under divided attention and full attention conditions. I would have been interested in hearing your thoughts as to why you think your results contrasted with the original theories on false memory (how the activation of critical lures is theoretically automatic). Why do you suppose your results don’t support this theory?