Alexithymia impairs the cognitive control of negative material while facilitating the recall of neutral material in both younger and older adults

Abstract

We investigated the moderating impact of the personality construct alexithymia on the ability of younger and older adults to control the recall of negative and neutral material. We conducted two experiments using the directed forgetting paradigm with younger and older adults. Participants studied negative (Experiment 1) or neutral (Experiment 2) words. Participants were instructed to forget the first half and remember the second half of an entire list of words. Overall, we found that alexithymia impairs the ability of both younger and older adults to cognitively control negative material (through both recall and inhibition). The “externally oriented thinking” factor of alexithymia appears to play a particularly pertinent role in terms of inhibiting negative material. Furthermore, older adults recalled fewer sought after negative items, but this was not evident in terms of inhibition. In contrast, only age (older adults) negatively impacted the recall of sought after neutral items. Interestingly, alexithymia had the opposite effect: the “difficulty in identifying emotions” factor of alexithymia was associated with an increased recall of neutral items. We discuss these results in terms of alexithymia and its impact on cognitive control.

Keywords :

• Age
• Alexithymia
• Cognitive control
• Directed forgetting
• Emotion
• Externally oriented thinking
• Negative
• Neutral
• Recall

Notes

¹ Traditionally, this type of cognitive control has been couched in terms of inhibition (Barnier et al., 2007; Basden et al., 1993; Bjork, 1989; Bjork & Bjork, 2003; Geiselman & Bagheri, 1985; MacLeod, 1998, 1999; Power et al., 2000; Wilson & Kipp, 1998). This inhibition, according to the direct-suppression model, is an executive control process whereby target items inhibited directly (Levy & Anderson, 2002). However, recent research suggests that the impaired recall of TBF items may better be framed in terms of context change (Sahakyan & Foster, 2009; Sahakyan & Kelley, 2002; Sahakyan et al., 2008). That is, the participants make a mental context change between items instructed to be forgotten and those instructed to be remembered. As the final recall test context better matches the to-be-remembered items, individuals are better able to recall these, while forgetting the others. Here, however, we remain agnostic to the ultimate mechanisms driving the directed forgetting effect. Rather, we are primarily interested in whether, when instructed to forget, participants are able to forget (by whichever mechanism) the items instructed to be forgotten.

² Given our low Cronbach's α scores for the depression and anxiety scales comprising the HADS measure, we entered them into our regression models separately.

³ See note 2.

⁴ It is worth mentioning, though, that the evidence suggesting that EOT also influences the ability to control neutral material is based upon our correlational analyses. All results from our correlational analyses, especially those that differ from our regression analyses, should be interpreted with caution. Unlike our regression analyses, our correlational analyses fail to control for anxiety and depression.