Working memory affects false memory production for emotional events

ABSTRACT

Whereas a link between working memory (WM) and memory distortions has been demonstrated, its influence on emotional false memories is unclear. In two experiments, a verbal WM task and a false memory paradigm for negative, positive or neutral events were employed. In Experiment 1, we investigated individual differences in verbal WM and found that the interaction between valence and WM predicted false recognition, with negative and positive material protecting high WM individuals against false remembering; the beneficial effect of negative material disappeared in low WM participants. In Experiment 2, we lowered the WM capacity of half of the participants with a double task request, which led to an overall increase in false memories; furthermore, consistent with Experiment 1, the increase in negative false memories was larger than that of neutral or positive ones. It is concluded that WM plays a critical role in determining false memory production, specifically influencing the processing of negative material.

KEYWORDS:

• Working memory
• false memories
• emotional content

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Erratum

Acknowledgements

We are grateful to Cinzia Montefinese for helping with data collection.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

¹The scripts were the following: waking up (i.e., typical morning routine before going to school), going shopping (i.e., young boy going grocery shopping with his mother), dating/meeting a friend (see attached example for this script), bike trip (i.e., girl going on a bike trip in a downtown area), rock climbing (i.e., boy climbing a mountain, a quite typical sport in Northern Italy), track competition (i.e., young girls getting ready for and performing a competition), coming back from a long trip (i.e., girl coming back by train from a trip, and entering her home, see Toffalini, Bellavitis, & Cornoldi, 2015, for the pictorial example of this script), slot machine (i.e., boy playing at a slot machine), and a birthday party (i.e., adolescents having a birthday party).

²Valence and arousal levels of the photographs representing the negative, positive, and neutral outcomes were rated by 18 independent judges using the SAM (Self-Assessment Manikin) scale (Bradley & Lang, 1994). Responses for both valence and arousal are provided through a 9-point rating scale. Nine refers to high valence / high arousal, and 1 to low valence / low arousal. A series of paired-samples t-tests showed that the outcomes significantly differed as expected: negative outcomes had lower valence (M = 2.22, SD = 0.94), t(16) = 12.62, p < .001, and positive outcomes had higher valence (M = 7.67, SD = 0.79), t(16) = −15.04, p < .001, than neutral outcomes (M = 5.04, SD = 0.45). Furthermore, arousal was significantly higher in both negative (M = 7.40, SD = 0.88), t(16) = −8.74, p < .001, and positive outcomes (M = 6.90, SD = 0.93), t(16) = −12.92, p < .001, than in neutral outcomes (M = 3.89, SD = 1.30). Finally, although arousal was slightly higher in the negative than in the positive outcomes, the difference did not reach significance, t(16) = 1.64, p = .12.

³The WM score was respectively 24.15 (SD = 3.39) for the low WM group and 36.00 (SD = 1.66) for the high WM group. The two groups did not differ in terms of either anxiety or depression scores (high WM group, anxiety score: M = 20.33, SD = 5.47; depression score: M = 11.70, SD = 3.62. Low WM group: anxiety score: M = 21.18, SD = 6.26; depression score: M = 11.97, SD = 4.59).

⁴We tentatively explored whether a pattern similar to that of Experiment 1 would emerge after dichotomizing participants based on high vs. low WM scores at the CWMS task. Both experimental groups were thus divided into sub-groups using the same criteria as Exp.1. Interestingly, the 15 participants with high WM capacity within the WM-load group produced fewer negative false memories (M = 0.49, SD = 28) than the 12 participants with low WM capacity in the same group (M = 0.64, SD = 22); the same happened also in the no-WM load group, with the 14 participants having high WM capacity producing fewer negative false memories (M = 0.21, SD = 0.25) than the 10 participants having low WM capacity (M = 0.43, SD = 0.27). No inferential statistics were calculated due to the very limited number of participants involved in these comparisons.