رشد معکوس در حافظه کاذب: اثر ظرفیتی هیجانی و برانگیختگی

Do the emotional valence and arousal of events distort children’s memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can be manipulated factorially. False memories increased with age for unpresented semantic associates of word lists, and net accuracy (the ratio of true memory to total memory) decreased with age. These surprising developmental trends were more pronounced for negatively valenced materials than for positively valenced materials, they were more pronounced for high-arousal materials than for low-arousal materials, and developmental increases in the effects of arousal were small in comparison with developmental increases in the effects of valence. These findings have ramifications for legal applications of false memory research; materials that share the emotional hallmark of crimes (events that are negatively valenced and arousing) produced the largest age increases in false memory and the largest age declines in net accuracy.

Developmental reversals in false memory are surprising age increases in children’s tendency to remember things that did not happen to them. Such increases are remarkable because it has been thought for more than a century that false memory declines sharply between early childhood and young adulthood (e.g., Binet, 1900, Small, 1896, Stern, 1910 and Whipple, 1909). There is a large literature of recent vintage that supports this long-standing belief (for reviews, see Bruck and Ceci, 1999, Ceci and Bruck, 1995, Ceci and Bruck, 1993, Goodman, 2006, Goodman and Schaaf, 1997, Poole and Lamb, 1998, Quas et al., 1997 and Reyna et al., 2007). For instance, age declines in false memory have been reported in many studies of memory suggestion, a paradigm that is designed to parallel the coercive forensic interviewing techniques that first focused scientific attention on children’s false memories (e.g., Bjorklund et al., 1998, Bjorklund et al., 2000, Eisen et al., 2002, Goodman et al., 1994, Holliday and Hayes, 2000, Holliday and Hayes, 2001, Marche, 1999 and Marche and Howe, 1995). Likewise, age declines have been detected with false memory paradigms that do not provide children with memory suggestions. Examples include free and cued recall of live events (e.g., Pipe et al., 1999 and Poole and White, 1991), free and cued recall of word lists (e.g., Bjorklund & Muir, 1988), memory for mathematical propositions (Brainerd & Reyna, 1995), memory for narratives (e.g., Ackerman, 1992 and Ackerman, 1994), sentence recognition (e.g., Reyna and Kiernan, 1994 and Reyna and Kiernan, 1995), and word recognition (e.g., Brainerd, Reyna, & Kneer, 1995). However, Brainerd, Reyna, and Ceci (2008a) recently concluded that despite extensive documentation of age declines in false memory, there is mounting evidence of reversals of that pattern under conditions that are both theoretically and pragmatically important. Brainerd and colleagues reviewed more than 30 experiments in which such reversals were identified. In some, age increases in false memory were more pronounced than corresponding increases in true memory, so that the net accuracy of memory (the ratio of true memory to total memory) actually declined between childhood and adulthood (e.g., Metzger et al., 2008). Brainerd and colleagues noted that although such findings are surprising, the developmental reversal effect is not a serendipitous discovery because it was predicted on theoretical grounds some years before relevant studies were conducted. Specifically, the effect was predicted by fuzzy trace theory (FTT) (see Brainerd and Reyna, 1998 and Ceci and Bruck, 1998), which posits that age increases in false memory are apt to occur in situations that have two features, namely that (a) false memories arise from people’s propensity to connect meaning across distinct events that share meaning and (b) it is difficult to use verbatim traces of actual events to suppress those distortions. In the developmental studies that Brainerd and colleagues (2008a) reviewed, Deese/Roediger/McDermott (DRM) lists (Deese, 1959 and Roediger and McDermott, 1995) were the most frequently used example of a task that exhibits both of these properties. With respect to the first property, a DRM list consists of a series of familiar words that share meaning with each other (e.g., nurse, sick, ill, hospital, medicine) and for which there is a missing word that is a semantic associate of all the list words (doctor in this instance). When adults are exposed to such lists and respond to immediate recognition or recall tests, missing words (usually called critical distractors or critical lures) are falsely recognized more than 70% of the time and falsely recalled more than 20% of the time on average. Concerning the second property, after being exposed to such a list, it is difficult to suppress false memories of unpresented words such as doctor by recalling presented words such as ill, hospital, and nurse because participants are well aware that there are many other presented medical words that they cannot recall and doctor could easily be one of them ( Brainerd, Reyna, Wright, & Mojardin, 2003). Several experiments have confirmed FTT’s prediction that false memories of DRM critical distractors should increase during child-to-adult development. In the initial confirmation, Brainerd, Reyna, and Forrest (2002) found that both false recall and false recognition of critical distractors increased between early childhood and young adulthood, with floor levels of false recall being observed under 7 years of age. In their literature review, Brainerd and colleagues (2008a) surveyed 26 published experiments in which DRM lists had been administered to participants ranging in age from young children to young adults, 25 of which detected reliable age increases in false memory. Brainerd and colleagues also found that the accumulated literature showed that the formation of meaning connections between list words is both necessary and sufficient to produce age increases in DRM false memory. Regarding necessity, manipulations that interfere with older participants’ greater ability to form meaning connections have been found to reduce or eliminate age increases (e.g., Connolly and Price, 2006 and Holliday and Weekes, 2006). Regarding sufficiency, manipulations that enhance younger participants’ lesser ability to form such connections have likewise been shown to reduce or eliminate age increases (e.g., Brainerd et al., 2006, Brainerd et al., 2008b, Lampinen et al., 2006 and Odegard et al., 2008). Of course, the fact that meaning connection is necessary and sufficient for age increases in false memory does not rule out the possibility that there are other mechanisms that contribute to such increases (Ghetti, 2008 and Howe, 2008)