We often organize items in space according to their semantic and/or functional properties (e.g., cookware in the kitchen, clothing in the closet), yet little research has been conducted on the memorial effects of these types of spatial configurations. Across three experiments, we examined how a semantically homogenous display influenced memory for item locations compared to a heterogenous/scrambled display. Participants learned the locations of words in a semantically homogenous display (where all words belonged to a single category), as well as a scrambled display (where the words belonged to an assortment of different categories). While the semantic display improved recall memory for the words themselves (i.e., item memory), it resulted in a cost to item location memory. We hypothesize that semantic structuring can impair memory for item locations by increasing similarity and hence confusability between items from the same category.

We often organize objects around both visual and semantic boundaries in space. Across four experiments, we examined how semantically consistent partitions influenced memory for object locations. Participants learned the locations of items in a semantically partitioned display (where each partition contained objects from a single category), as well as a purely visually partitioned display (where each partition contained a random assortment of objects from different categories). While semantic partitions significantly improved location memory over the purely visually partitioned display, this advantage was significantly reduced when participants were cued to the correct partition during recall. Our results suggest that semantic category information benefits memory via strengthening the association between a given category and a spatial region delineated by a partition. Further, there was some indication that this benefit may come with the drawback of reducing memory precision for objects within a partitioned space.

Offloading to-be-remembered information is a ubiquitous memory strategy, yet in relying on external memory stores,our ability to recall from internal memory is often diminished. In the present investigation, we examine how offloadingimpacts true and false recall. Across three preregistered experiments, participants studied and wrote word lists that wereeach strongly associated with an unstudied critical word. We compared recall in the offloading condition (i.e., when theyexpected to have access to their written lists during recall) with a no-offloading condition (i.e., when they did not expectto have access to their written lists during recall). In the absence of the written external stores, offloading decreased truerecall of the presented words while increasing false recall for the unpresented critical words. Results are discussed in termsof offloadings differential effects on the formation of gist and verbatim traces during encoding.

Offloading cognition to external stores is practiced ubiquitously in daily life (e.g., counting on fingers, writing lists), yet is a relatively new area of investigation within cognitive science. Previous experiments have assessed the benefits and downfalls, including participants’ lowered memory for offloaded information that is no longer available (Gardony et al., 2013; Sparrow et al., 2011). In addition, when offloading, individuals appear susceptible to manipulations of their external store (Risko et al., 2019). We report a series of experiments investigating how the perceived reliability of an external store affects individuals’ susceptibility to manipulation of that store. Consistent with previous research, results suggest that the majority of participants do not notice an item inserted into their external store. However, once cued to this event, individuals do become more likely to subsequently notice a manipulation of their external store. Implications of this research for our understanding of distributed memory systems will be discussed.

Memory is reliably enhanced for information read aloud compared with information read silentlythe production effect.Three preregistered experiments examined whether the production effect arises from a time-consuming recollective processoperating at test that benefits items that were produced at study. To accomplish this, participants were required to respondwithin a short deadline under the assumption that a time-consuming recollective process would be less able to operatewhen less time is available. If so, the production effect under speeded responding instructions should be reduced relativeto a standard nonspeeded condition. Results generally supported this prediction. However, even under speeded respondinginstructions, there was a robust production effect, potentially suggesting that other, more rapid, processes also contributeto the production effect.

Flower senescence is commonly enhanced by the endogenous hormone ethylene and suppressed by the gibberellins (GAs) in plants. However, the detailed mechanisms for the antagonism of these hormones during flower senescence remain elusive. In this study, we characterized one up-regulated gene PhOBF1, belonging to the basic leucine zipper transcription factor family, in senescing petals of petunia (Petunia hybrida). Exogenous treatments with ethylene and GA₃ provoked a dramatic increase in PhOBF1 transcripts. Compared with wild-type plants, PhOBF1-RNAi transgenic petunia plants exhibited shortened flower longevity, while overexpression of PhOBF1 resulted in delayed flower senescence. Transcript abundances of two senescence-related genes PhSAG12 and PhSAG29 were higher in PhOBF1-silenced plants but lower in PhOBF1-overexpressing plants. Silencing and overexpression of PhOBF1 affected expression levels of a few genes involved in the GA biosynthesis and signaling pathways, as well as accumulation levels of bioactive GAs GA₁ and GA₃. Application of GA₃ restored the accelerated petal senescence to normal levels in PhOBF1-RNAi transgenic petunia lines, and reduced ethylene release and transcription of three ethylene biosynthetic genes PhACO1, PhACS1, and PhACS2. Moreover, PhOBF1 was observed to specifically bind to the PhGA20ox3 promoter containing a G-box motif. Transient silencing of PhGA20ox3 in petunia plants through tobacco rattle virus-based virus-induced gene silencing method led to accelerated corolla senescence. Our results suggest that PhOBF1 functions as a negative regulator of ethylene-mediated flower senescence by modulating the GA production.