The symbiotic association between plants and arbuscular mycorrhizal fungi is almost ubiquitous within the plant kingdom 1, and the early stages of the association are controlled by plant-derived ...strigolactones acting as a signal to the fungus in the rhizosphere 2–4 and lipochito-oligosaccharides acting as fungal signals to the plant 5. Hyphopodia form at the root surface, allowing the initial invasion, and this is analogous to appressoria, infection structures of pathogenic fungi and oomycetes. Here, we characterize RAM2, a gene of Medicago truncatula required for colonization of the root by mycorrhizal fungi, which is necessary for appropriate hyphopodia and arbuscule formation. RAM2 encodes a glycerol-3-phosphate acyl transferase (GPAT) and is involved in the production of cutin monomers. Plants defective in RAM2 are unable to be colonized by arbuscular mycorrhizal fungi but also show defects in colonization by an oomycete pathogen, with the absence of appressoria formation. RAM2 defines a direct signaling function, because exogenous addition of the C16 aliphatic fatty acids associated with cutin are sufficient to promote hyphopodia/appressoria formation. Thus, cutin monomers act as plant signals that promote colonization by arbuscular mycorrhizal fungi, and this signaling function has been recruited by pathogenic oomycetes to facilitate their own invasion.
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► A glycerol-3-phosphate acyl transferase is required for mycorrhizal infection ► Cutin monomers act as a chemical signal to promote hyphopodia formation ► Cutin production is induced upon mycorrhizal colonization ► A conserved signaling process in mycorrhizal and pathogenic interactions
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
When people estimate the summative carbon footprint of a sequence of events, how are the individual events integrated? In three experiments, we found that summative carbon footprint judgments of item ...sequences are disproportionately influenced by items at the end of the sequence in comparison with those at the beginning—a recency effect. When, for example, sequences ended with a low carbon footprint item, they were assigned a lower carbon footprint than corresponding sequences with an identical content but different item order. The results also revealed that a green peak (presenting many low carbon footprint items at once) had a relatively large effect on estimates when the peak was contextually distinct from other items in terms of its valence. The results are consistent with an account within which distinctiveness of representations within short‐term memory differentially influences decision‐making and suggest that memory processes bias the perceived environmental footprint of temporally separated instances.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The Deese-Roediger and McDermott (DRM) paradigm and visually guided saccade tasks are both prominent research tools in their own right. This study introduces a novel DRM-Saccade paradigm, merging ...both methodologies. We used rule-based saccadic eye movements whereby participants were presented with items at test and were asked to make a saccade to the left or right of the item to denote a recognition or non-recognition decision. We measured old/new recognition decisions and saccadic latencies. Experiment 1 used a pro/anti saccade task to a single target. We found slower saccadic latencies for correct rejection of critical lures, but no latency difference between correct recognition of studied items and false recognition of critical lures. Experiment 2 used a two-target saccade task and also measured corrective saccades. Findings corroborated those from Experiment 1. Participants adjusted their initial decisions to increase accurate recognition of studied items and rejection of unrelated lures but there were no such corrections for critical lures. We argue that rapid saccades indicate cognitive processing driven by familiarity thresholds. These occur before slower source-monitoring is able to process any conflict. The DRM-Saccade task could effectively track real-time cognitive resource use during recognition decisions.
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Referring to the well-replicated finding that the presence of to-be-ignored sound disrupts short-term memory for serially-presented visual items, the irrelevant sound effect (ISE) is an important ...benchmark finding within cognitive psychology. The ISE has proven useful in evaluating the structure, function and development of short-term memory. This preregistered report focused on a methodological examination of the paradigm typically used to study the ISE and sought to determine whether the ISE can be reliably studied using the increasingly popular method of online testing. Comparing Psychology students tested online, in-person and participants from an online panel, results demonstrated successful reproduction of the key signature effects of auditory distraction (the changing-state effect and the steady-state effect), albeit smaller effects with the online panel. Our results confirmed the viability of online data collection for auditory distraction research and provided important insights for the accumulation and maintenance of high data quality in internet-based experimentation.
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The process-oriented account of auditory distraction suggests that task-disruption is a consequence of the joint action of task- and sound-related processes. Here, four experiments put this view to ...the test by examining the extent to which to-be-ignored melodies (with or without lyrics) influence vocal-motor processing. Using song retrieval tasks (i.e., reproduction of melodies or lyrics from long-term memory), the results revealed a pattern of disruption that was consistent with an interference-by-process view: disruption depended jointly on the nature of the vocal-motor retrieval (e.g., melody retrieval via humming vs. spoken lyrics) and the characteristics of the sound (whether it contained lyrics and was familiar to the participants). Furthermore, the sound properties, influential in disrupting song reproduction, were not influential for disrupting visual-verbal short-term memory-a task that is arguably underpinned by non-semantic vocal-motor planning processes. Generally, these results cohere better with the process-oriented view, in comparison with competing accounts (e.g., interference-by-content).
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Legumes establish mutualistic associations with mycorrhizal fungi and with nitrogen-fixing rhizobial bacteria. These interactions occur following plant recognition of Nod factor from rhizobial ...bacteria and Myc factor from mycorrhizal fungi 1–3. A common symbiosis signaling pathway is involved in the recognition of both Nod factor and Myc factor and is required for the establishment of these two symbioses 4–6. The outcomes of these associations differ, and therefore, despite the commonality in signaling, there must be mechanisms that allow specificity. In Nod factor signaling, a complex of GRAS-domain transcription factors controls gene expression downstream of the symbiosis signaling pathway. Here, we show that a GRAS-domain transcription factor, RAM1, functions in mycorrhizal-specific signaling. Plants mutated in RAM1 are unable to be colonized by mycorrhizal fungi, with a defect in hyphopodia formation on the surface of the root. RAM1 is specifically required for Myc factor signaling and appears to have no role in Nod factor signaling. RAM1 regulates the expression of RAM2, a glycerol-3-phosphate acyl transferase that promotes cutin biosynthesis to enhance hyphopodia formation. We conclude that mycorrhizal signaling downstream of the symbiosis-signaling pathway has parallels with nodulation-specific signaling and functions to promote mycorrhizal colonization by regulating cutin biosynthesis.
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► A GRAS-type transcription factor that functions in the mycorrhizal association ► This transcription factor is not required for nodulation ► The work reveals specific modes of signaling for Myc factors compared to Nod factors ► One target of this transcription factor is the activation of cutin signaling
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Children with inattention and hyperactivity often present difficulties in recognising anger from voices. Research has shown enhanced brain activity (N100) to vocal anger, possibly reflecting ...preattentive hyper-vigilance to vocal anger, in children with ADHD. In this study, we investigated the preattentive processing of vocal anger, by testing whether children with inattention and hyperactivity are distracted by task-irrelevant vocal anger stimuli. A total of 194 participants (50 adults, 51 adolescents, 93 children) participated in a cross-modal oddball paradigm wherein emotional (angry, happy) voices were oddballs and neutral voices were standard in a visual categorisation task. Questionnaires measures screened for inattention and hyperactivity. Reaction times measures demonstrated that overall, hyperactivity predicted slower performance via distraction by threat-related (angry) stimuli. The results suggest that vocal anger can capture attention in a pre-attentive (automatic) way in children with high levels of inattention and hyperactivity. Implications for theory and clinical practice are discussed.
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In this article, we outline our view of how concentration shields against distraction. We argue that higher levels of concentration make people less susceptible to distraction for two reasons. One ...reason is that the undesired processing of the background environment is reduced. For example, when people play a difficult video game, as opposed to an easy game, they are less likely to notice what people in the background are saying. The other reason is that the locus of attention becomes more steadfast. For example, when people are watching an entertaining episode of their favorite television series, as opposed to a less absorbing show, attention is less likely to be diverted away from the screen by a ringing telephone. The theoretical underpinnings of this perspective, and potential implications for applied settings, are addressed.
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BFBNIB, NMLJ, NUK, OILJ, PNG, SAZU, UKNU, UL, UM, UPUK
Automatic information processing has been and still is a debated topic. Traditionally, automatic processes are deemed to take place autonomously and independently of top-down cognitive control. For ...decades, the literature on reading has brought to the fore empirical phenomena such as Stroop and semantic priming effects that provide support for the assumption that semantic information can be accessed automatically. More recently, there has been growing evidence that semantic processing is in fact susceptible to higher-level cognitive influences, suggesting that this form of processing is instead conditionally automatic. The purpose of the present study was to revisit this debate using a novel approach: The automatic access to the meaning of irrelevant auditory stimuli was tested through the assessment of their distractive power. More specifically, we aimed to examine whether a categorical change in the content of to-be-ignored auditory sequences composed of speech items that are personally nonsignificant to participants (e.g., a digit among letters) can disrupt an unrelated visual focal task. In seven experiments, we assessed this categorical deviation effect and its functional properties. We established that distraction by categorical deviation is noncontingent on the activated task set and appears resistant to top-down control manipulations. By suggesting not only that the semantic content of the irrelevant sound can be extracted preattentively, but also that such semantic activation is ineluctable during auditory distraction, these findings shed new light on the automatic nature of semantic processing.
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CEKLJ, FFLJ, NUK, ODKLJ, PEFLJ, UPUK
Two experiments critically examined a predictive-coding based account of the vulnerability of short-term memory (STM) to auditory distraction, particularly the disruptive effect of changing-state ...sound on verbal serial recall. Experiment 1 showed that providing participants with the opportunity to predict the contents of an imminent spoken distractor sentence via a forewarning reduced its particularly disruptive effect but only to the same level of disruption as that produced by simpler changing-state sequences (a sequence of letter-names). Moreover, a postcategorically unpredictable changing-state sequence (e.g., "F, B, H, E, . . .") was no more disruptive than a postcategorically predictable sequence ("A, B, C, D, . . ."). Experiment 2 showed that a sentence distractor was disruptive regardless of whether participants reported adopting a serial rehearsal strategy to perform the focal task (in this case, a missing-item task) whereas, critically, the disruptive effect of simpler changing-state sequences was only found in participants who reported using a serial rehearsal strategy. Moreover, when serial rehearsal was not used to perform the focal task, the disruptive effect of sentences was completely abolished by a forewarning. These results indicate that predictability plays no role in the classical changing-state irrelevant sound effect and that foreknowledge selectively attenuates a functionally distinct stimulus-specific attentional-diversion effect. As such, the results are at odds with a unitary, attentional account of auditory distraction in STM and instead strongly support a duplex-mechanism account.
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CEKLJ, FFLJ, NUK, ODKLJ, PEFLJ, UPUK
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