The role of alexithymia in memory and executive functioning across the lifespan

Abstract

Alexithymia is a personality trait characterised by difficulties identifying feelings (DIF), describing feelings (DDF), and externally oriented thinking (EOT). Alexithymia has been associated with poorer memory, at least for emotive materials, and recently, with executive and neural dysfunction. Aging is also accompanied by poorer memory and executive functioning (EF), neural dysfunction, and increasing alexithymia. Thus, the hypothesis of a general cognitive impairment in alexithymia, particularly in elders, needs investigation. Three large, independent, cross-sectional experiments (n = 296, 139 and 121, respectively) investigated memory and EF in healthy adults, ranging from young to old adulthood, with age, sex, and the three Toronto Alexithymia Scale-20 subscales (DIF, DDF, EOT) as predictors in hierarchical regressions. Across studies, alexithymia contributed to poorer memory (via EOT) and EF (via DIF), in younger and older adults. Additionally, these effects occurred in non-emotive contexts with neutral stimuli. Moreover, although memory was worse with greater age and poor EF contributed to poor memory, those who had both high EOT and poor EF had particularly poor memory. Thus, alexithymia (particularly via high DIF or high EOT) is a risk factor for age-related cognitive decline. Further research should clarify the direction and nature of these complex relationships.

The influence of alexithymia on memory for emotional faces and realistic social interactions

“…The current findings for neutral faces were congruent with these predictions, as none of the memory metrics for neutral faces were associated with alexithymia. This is consistent with previous studies using words (Luminet et al, 2006;Suslow et al, 2003;Vermeulen & Luminet, 2009) and neutral faces (Di Stefano & Koven, 2012), but differs from Correro et al (2019), who reported evidence of impaired memory for neutral words and stories in high alexithymia scorers. Memory performance for emotional faces was also consistent with our predictions, as d' scores and the number of hits for emotional faces were negatively related to scores on the DDF subscale of the TAS-20.…”

“…These findings are consistent with Study 1 and with studies examining memory for neutral faces (Di Stefano & Koven, 2012) and words (Luminet et al, 2006;Suslow et al, 2003;Vermeulen et al, 2009). However, they differ from recent evidence of an alexithymia-related deficit in memory for neutral stimuli (Correro et al, 2019). The finding that higher alexithymia scores (DIF and EOT) were associated with poorer memory (hits) for emotional videos also supports our hypotheses.…”

“…For example, Ridout et al (2007) demonstrated that emotion recognition from these videos was related to performance on measures of inhibitory function. This is notable, as recent evidence (Correro et al, 2019) confirmed that DIF, and not DDF, scores were negatively associated with scores on an executive factor (extracted from a battery of executive tasks). Therefore, assuming that individuals with high DIF scores also exhibit impaired executive function, this would explain the observed negative relationship between DIF scores and emotion recognition from the videos (in line with Ridout et al, 2007) and the negative association between DIF scores and memory for the videos, as these individuals would have had fewer resources to allocate to the encoding of the videos.…”

“…For example, examined retrieval times on the autobiographical memory test (AMT; Williams and Broadbent, 1986), whereas studies reporting a memory deficit in alexithymia have tended to examine memory content. Furthermore, although studies have tended show intact memory for neutral material in high alexithymia scorers (Luminet et al, 2006;Suslow et al, 2003;Vermeulen & Luminet, 2009), Correro, Paitel, Byers and Nielson (2019) provided evidence of impaired memory for neutral material in participants with elevated alexithymia scores.…”

“…This was thought to reflect the need to inhibit the task irrelevant elements of these complex social interactions in order to make the correct emotion recognition judgements. With this in mind it is notable that facets of alexithymia have been associated with deficits in executive function, including inhibition and conflict processing (Correro et al, 2019;Koven & Thomas, 2010;Zhang et al, 2011), thus the observed deficit in anger recognition might plausibly be a consequence of impaired executive function in those with high alexithymia.…”