Optimal testing time for suppression of competitors during interference resolution

Abstract

Interference between competing memory traces is a common cause of memory failure. Recent research has demonstrated a suppression mechanism that operates at retrieval to resolve interference. Using an adaptation of the suppression paradigm in Healey, Ngo, and Hasher [(2014). Below-baseline suppression of competitors during interference resolution by younger but not older adults. Psychological Science, 25(1), 145-151. doi: 10.1177/0956797613501169 ], we tested whether the ability to suppress competing memory traces varies with the synchrony between optimal arousal period and time of testing. We replicate the below-baseline suppression effect for young adults tested at optimal times of day, and present novel evidence that they do not show competitor suppression during non-optimal times of day. In fact, competitors are actually strengthened at non-optimal times. Our results suggest that the ability to resolve interference by suppression varies with circadian arousal.

Influences of time of day on generalization

“…We speculate that states of lower inhibition at non-optimal times of day (the morning for most young adults; Hasher et al, 1999;May, 1998;May & Hasher, 2017;Yoon et al, 1999) might highlight relatively weak connections between memories, facilitating both generalization and false memory. This is consistent with previous work demonstrating that at non-optimal times of day there is both an increased ability to find remote connections between words (Simor & Polner, 2017;Wieth & Zacks, 2011) and increased memory interference (Ngo & Hasher, 2017).…”

“…A major caveat to this finding is that our sample consisted predominantly of neutral chronotypes ( Supplementary Table 3), whereas studies reporting chronotype-related effects typically sample more densely from extreme morning and evening types (May, 1998;May et al, 2005;Simor & Polner, 2017;Wieth & Zacks, 2011). Though neutral type young adults often fail to show time of day effects (May & Hasher, 2017), morning testing has been classified as a non-optimal time for both evening and neutral type young adults (Ngo et al, 2018;Ngo & Hasher, 2017), so it is likely the morning constituted a non-optimal time for the vast majority of our sample (we had very few morning types). To examine whether an evening benefit could emerge in this task, future work with strong morning types, which could be achieved by sampling older adults (May et al, 2005;Yoon et al, 1999), would be informative.…”

“…Although these effects were mostly considered secondary curious results, there is a rich literature demonstrating time of day effects on cognition. Several cognitive processes vary across the circadian cycle in both animals (Krishnan & Lyons, 2015) and humans (Schmidt et al, 2007), including attention (Matchock & Mordkoff, 2009;Valdez et al, 2005Valdez et al, , 2010, executive functions (Anderson et al, 2014;Barner et al, 2019;García et al, 2012;Hahn et al, 2012;Hasher et al, 1999;Lara et al, 2014;May, 1998;Ngo & Hasher, 2017;Rothen & Meier, 2017;Rowe et al, 2006;West et al, 2002;Yoon et al, 1999), and various forms of long-term memory (Coutanche et al, 2020;Folkard, 1979;Gerstner & Yin, 2010;Hidalgo et al, 2004;Himmer et al, 2017;May et al, 1993May et al, , 2005Petros et al, 1990;Pica et al, 2014;Puttaert et al, 2019;Rothen & Meier, 2016;Smarr, 2014;Winocur & Hasher, 2004;Yang et al, 2007), including semantic memory (Anderson et al, 1991;Dunne et al, 1990;Fabbri et al, 2013;Millar et al, 1980;Tilley & Warren, 1983).…”

“…These optimal times of day are determined by an individual's chronotype (morning or evening preference; Horne & Östberg, 1976), which is typically the evening for young adults (May et al, 1993;May & Hasher, 2017;Yoon et al, 1999). Evidence that off-peak circadian states are associated with low inhibition include impaired performance on tasks with high cognitive control demands (May, 1999;Rothen & Meier, 2016;Rowe et al, 2006) and greater interference between memories (Ngo & Hasher, 2017). Although interference between memories can be deleterious for their veridical preservation, this lower inhibitory state may be beneficial for connecting memories to uncover shared structure.…”

Time of day effects on the use of distraction to minimise forgetting

“…However, there are at least two circumstances under which young adults’ cognitive control has been reported to be reduced: (1) when in a positive mood (e.g., Biss, Hasher, & Thomas, 2010; Fredrickson, 2001; Schmitz, De Rosa, & Anderson, 2009; Vermeulen, 2010) and (2) when tested at off-peak times of day. With respect to time of day, there is substantial evidence that young adults operating at a time that is desynchronised with their circadian preference show reduced control relative to others operating at a peak time (e.g., Hornik & Tal, 2009; Intons-Peterson, Rocchi, West, McLellan, & Hackney, 1999; Lara, Madrid, & Correa, 2014; Lehmann, Marks, & Hanstock, 2013; Ngo & Hasher, 2016; Pica, Pierro, & Kruglanski, 2014; Ramírez, García, & Valdez, 2012; Ramírez et al, 2006; Webb, 1982). For example, in a study by Rowe and colleagues (2006) using a 1-back task on pictures with superimposed distracting words, evening chronotype young adults showed priming for the irrelevant words when tested in the morning, but not when tested in the afternoon.…”