Long-Term Language Retention for Students of a Second Language: A Review of the Literature

Long-Term Language Retention for Students of a Second Language: A Review of the Literatur

Forget Me Not: Are Stronger Memories More Susceptible to Retrieval-Induced Forgetting?

Successfully retrieving information sometimes causes forgetting of related, but unpracticed, information, termed retrieval-induced forgetting (RIF). One explanatory mechanism of RIF suggests related, but currently irrelevant, information is inhibited during retrieval, resulting in poorer memory for competing representations. Critically, this perspective suggests stronger memories are more susceptible to RIF because stronger representations produce additional competition when unpracticed. To resolve this competition, strong competing items are inhibited, resulting in the counterintuitive prediction that stronger memories are more likely to be forgotten. The aim of the current experiments was to replicate and extend recent work suggesting non-typical objects and own-race faces, both of which are associated with stronger memory traces, are more likely to be forgotten. In Experiment 1, participants studied and practiced typical and non-typical objects before memory was assessed through recognition or measures of perceptual similarity. Results showed object memorability influenced the magnitude of RIF: Non-typical (i.e., highly memorable) objects were more likely to be forgotten than typical (i.e., non-memorable) objects. However, RIF did not correspond with changes in perceived similarity. In Experiment 2, participants studied and practiced own- and other-race faces before memory was assessed, again through either recognition or similarity measures. Experiment 2 revealed no RIF for own- or other-race faces, and no corresponding changes in perceived similarity. These findings suggest that if memory traces are too weak to produce competition, no RIF is observed. Considered together, these results support inhibitory accounts of RIF, and suggest stronger memories produce additional competition that makes them more susceptible to forgetting

The Attentional Mechanisms of Active Forgetting

Recent work has shown that intentional forgetting of distracting, erroneous, or irrelevant information aids memory, and relies on active, effortful processes. Two experiments investigated the underlying attentional mechanisms that are active during directed forgetting (DF). Across both experiments, participants completed a modified item-method DF task, in which they received memory instructions to remember or forget individual images for a subsequent memory test. Participants studied items associated with remember or forget instructions before they were shown a subliminal presentation of target items. Finally, participants responded to probes by identifying briefly shown letters to assess how attention and item identity information are inhibited following forget instructions. In Experiment 1, after studying items, participants completed either an explicit memory test (recognition) or an implicit memory task (perceptual identification). Experiment 2 extended the findings of Experiment 1 by examining how spatial information is inhibited following instructions to forget, given spatial components in many recent investigations of DF (e.g., Fawcett & Taylor, 2008, 2010; Taylor, 2005). Although it was predicted that active forgetting would be associated with attentional inhibition linked to both item identity and spatial location, results revealed no inhibitory effects during speeded probe responses across both experiments. However, clear forgetting effects were observed, with participants exhibiting better memory for items they were cued to remember, relative to items they were cued to forget. The results of both experiments support the hypothesis that some information is lost or degraded by instructions to intentionally forget, but raise further questions about the nature of attentional withdrawal proposed to occur during a DF task

Expectancy effects in the Autonomous Sensory Meridian Response

The Autonomous Sensory Meridian Response (ASMR) is a tingling, almost euphoric, sensation often elicited following certain visual or auditory stimulations (Barratt & Davis, 2015). Despite considerable media attention, little empirical work has investigated the underlying mechanisms. In the present study, ASMR enthusiasts and naïve observers listened to audio clips with and without ASMR-eliciting characteristics. We also manipulated participants’ expectations of ASMR, providing a measure of “placebo effects.” Although naïve participants were susceptible to suggestive instructions, experienced users were not, suggesting that initial exposure to ASMR media may evoke somatosensory responses consistent with one’s expectations. Implications for at-home stress management techniques are discussed

The Use of Flagella and Motility for Plant Colonization and Fitness by Different Strains of the Foodborne Pathogen Listeria monocytogenes

The role of flagella and motility in the attachment of the foodborne pathogen Listeria monocytogenes to various surfaces is mixed with some systems requiring flagella for an interaction and others needing only motility for cells to get to the surface. In nature this bacterium is a saprophyte and contaminated produce is an avenue for infection. Previous studies have documented the ability of this organism to attach to and colonize plant tissue. Motility mutants were generated in three wild type strains of L. monocytogenes by deleting either flaA, the gene encoding flagellin, or motAB, genes encoding part of the flagellar motor, and tested for both the ability to colonize sprouts and for the fitness of that colonization. The motAB mutants were not affected in the colonization of alfalfa, radish, and broccoli sprouts; however, some of the flaA mutants showed reduced colonization ability. The best colonizing wild type strain was reduced in colonization on all three sprout types as a result of a flaA deletion. A mutant in another background was only affected on alfalfa. The third, a poor alfalfa colonizer was not affected in colonization ability by any of the deletions. Fitness of colonization was measured in experiments of competition between mixtures of mutant and parent strains on sprouts. Here the flaA and motAB mutants of the three strain backgrounds were impaired in fitness of colonization of alfalfa and radish sprouts, and one strain background showed reduced fitness of both mutant types on broccoli sprouts. Together these data indicate a role for flagella for some strains to physically colonize some plants, while the fitness of that colonization is positively affected by motility in almost all cases