Psychosocial stress impairs working memory at high loads: An association with cortisol levels and memory retrieval

Abstract

Stress and cortisol are known to impair memory retrieval of well-consolidated declarative material. The effects of cortisol on memory retrieval may in particular be due to glucocorticoid (GC) receptors in the hippocampus and prefrontal cortex (PFC). Therefore, effects of stress and cortisol should be observable on both hippocampal-dependent declarative memory retrieval and PFC-dependent working memory (WM). In the present study, it was tested whether psychosocial stress would impair both WM and memory retrieval in 20 young healthy men. In addition, the association between cortisol levels and cognitive performance was assessed. It was found that stress impaired WM at high loads, but not at low loads in a Sternberg paradigm. High cortisol levels at the time of testing were associated with slow WM performance at high loads, and with impaired recall of moderately emotional, but not of highly emotional paragraphs. Furthermore, performance at high WM loads was associated with memory retrieval. These data extend previous results of pharmacological studies in finding WM impairments after acute stress at high workloads and cortisol-related retrieval impairments.

Hydrocortisone reduces emotional distracter interference in working memory

“…These results are inconsistent with several studies that found WM impairments after stress and GC administration (Lupien et al, 1999;Oei et al, 2006;Schoofs et al, 2008). However, it is in line with the one doseresponse study that found evidence for both GC-induced WM impairment and enhancement (Lupien et al, 1999).…”

“…Consistent with cognitive load theory, individual differences in WM capacity have found to be related to the ability to suppress self-relevant intrusive thought (Brewin and Smart, 2005), vulnerability to intrusions in general, and the ability to intentionally suppress intrusions (Schelstraete and Hupet, 2002). Interestingly, acute stress and GCs have shown to impair WM performance particularly at high loads and not low loads (Lupien et al, 1999;Oei et al, 2006). Stress might make individuals especially vulnerable to distractions when cognitive load is high.…”

“…Working memory was measured using an adapted version of the Sternberg item-recognition task (Sternberg, 1966) previously used and described by Oei et al (2006). The WM processing load was manipulated by varying the numbers of uppercase letters (1-4 targets) that had to be held in memory (1000 ms) for later recognition, and by varying the number of letters (1-4 displayed) presented in the recognition display after a short delay (1500 ms), which led to a load of 2, 4, 12 or 16 comparisons.…”

“…The delay-phase between target and recognition display originally contained a fixation cross (Lupien et al, 1999;Oei et al, 2006). In the current task version, distracters were presented during the delay-phase that consisted of pictures selected from the International Affective Pictures System (Lang et al, 2001).…”

“…In humans, both chronic (Young et al, 1999) and acute GC administration (Lupien et al, 1999;Wolf et al, 2001) led to impaired WM. In addition, several studies in healthy people found that acute stressinduced GC elevations are related to impaired WM performance (Elzinga and Roelofs, 2005;Oei et al, 2006;Schoofs et al, 2008).…”