A mismatch between early and recent life stress predicts better response inhibition, but not cognitive inhibition.

A growing body of work has found that a mismatch between early and recent life stress, more than a cumulative influence of stress, contributes to detrimental stress-related health outcomes. To date, however, no work has examined how such a mismatch might relate to stress-related cognitive outcomes. We addressed this gap in the current study by assessing participants' (N = 154, Mage = 18.7, 104 female) early and recent life stress using the same inventory, and subsequently assessing their inhibitory control in a hybrid stop-signal/flanker task. Surprisingly, we found that a greater degree of stressor mismatch was associated with better response inhibition (i.e. smaller stop-signal reaction time) across a number of analytic approaches. Cognitive inhibition (i.e. the flanker interference effect) was not associated with stressor mismatch. These results thus show that a greater degree of mismatch between early and recent life stress is related to response inhibition in the same way as acute stress affects response inhibition, suggesting that response inhibition may be an important cognitive process for navigating both acute stress and general environmental conditions that do not match the conditions in which expected stress occurrence was established.

Acute stress influences the emotional foundations of executive control: Distinct effects on control-related affective and cognitive processes.

Acute stress is known to influence performance on various task outcomes indicative of executive functioning (i.e., the top-down, goal-directed control of cognition and behavior). The most common interpretation of these effects is that stress influences control processes themselves. Another possibility, though, is that stress does not impair control per se, but instead alters the affective dynamics underlying the recruitment of control (e.g., reducing the extent to which making an error is aversive), resulting in less recruitment of control and thus poor performance. To date, however, no work has examined whether stress effects on executive function outcomes are driven by affective dynamics related to the recruitment of control. In the current study, we found that acute stress influenced-and cortisol responses related to-both executive control-related performance outcomes (e.g., post-error slowing) and control-related affective dynamics (e.g., negative affect following recruitment of control) in a modified Stroop task, but that these effects appeared to be independent of each other: The effects of stress on, and associations of cortisol with, control-related cognitive outcomes were not statistically mediated by task- or control-related affective dynamics. These results thus suggest that although stress influences affective dynamics underlying executive function, the effects of stress on executive function outcomes appear to be at least partially dependent on nonaffective processes, such as control processes themselves.

Writing about a stressful experience improves semantic clustering of memory in men, not women.

Writing about negative experiences can produce multiple benefits, including improvements in mental and emotional health. However, writing about negative experiences potentially be detrimental, as reliving and reexperiencing a negative memory can be painful. Although the emotional effects of writing about negative experiences are well established, the cognitive effects are less heavily explored, and no work to date has examined how writing about a stressful experience might influence episodic memory. We addressed this issue in the present study (N = 520) by having participants encode a list of 16 words that were organised around four semantic clusters, randomly assigning participants to write about an unresolved stressful experience (n = 263) or the events of the previous day (n = 257), and assessing their memory in a free recall task. Writing about a stressful experience did not influence overall memory performance; however, the stressful writing manipulation increased semantic clustering of information within memory for men, whereas the stressful writing manipulation did not influence semantic clustering of information within memory in women. Additionally, writing with more positive sentiment improved semantic clustering and reduced serial recall. These results provide evidence for unique sex differences in writing about stressful experiences and the role of sentiment in the effects of expressive writing.

(A lack of) effects of acute social stress on attentional bias to threat.

Attentional biases toward or away from emotionally evocative stimuli have been well documented and are known to be clinically relevant, making it important to understand how various factors contribute to them. Some work has suggested that acute stress modulates attentional biases, but this work has produced inconsistent results. For example, many studies have found that stress enhances attentional bias, others that stress decreases attentional bias, and others still that there is no effect of stress at all. Methodological differences may explain these inconsistencies. For example, discrepancies exist between studies in participant sex (e.g., mixed sample vs. all men) and in the type of attentional bias paradigm. We addressed these gaps by examining the effects of an acute social stressor (vs. control) on attentional bias assessed via facial dot probe, focusing on potential sex differences in these effects (N = 141). We found that, overall, participants were significantly biased towards threat, but biases did not differ by stress condition or sex. These findings help to clarify the existing discrepancy in the literature, as we found that stress exerts little if any effect on attentional bias assessed via a facial dot probe.

Stress and memory encoding: What are the roles of the stress-encoding delay and stress relevance?

The effects of acute stress on memory encoding are complex. Recent work has suggested that both the delay between stress and encoding and the relevance of the information learned to the stressor may modulate the effects of stress on memory encoding, but the relative contribution of each of these two factors is unclear. Therefore, in the present study, we manipulated (1) acute stress, (2) the delay between stress and encoding, and (3) the relevance of the information learned to the stressor. The results indicated that stress during encoding led to better memory for study materials that were related to the stressor relative to memory for study materials that were unrelated to the stressor. This effect was numerically reduced for materials that were encoded 40 min after stressor onset (23 min after the stressor had ended) compared with items encoded at the time of the stressor, but this difference was not significant. These results suggest that the relevance of the information learned to the stressor may play a particularly important role in the effects of stress on memory encoding, which has important implications for theories of stress and memory.