Effects of Probabilistic Contingencies on Word Processing in an Artificial Lexicon

Artificial lexicons have been used with eye-tracking to study the integration of contextual (top-down) and bottom-up information in lexical processing. The present study utilized these techniques to study the role of probabilistic information in lexical processing. Participants were trained to associate novel nouns and modifiers, with certain combinations occurring more frequently than others. Participants heard a modifier-noun phrase and were asked to select the words in a display. We predicted that participants would make anticipatory eye movements to nouns based on the probabilities they previously learned. While no anticipatory effects were found, delayed effects consistent with our predictions were found

Autoreceptor Control of Peptide/Neurotransmitter Corelease from PDF Neurons Determines Allocation of Circadian Activity in Drosophila

SummaryDrosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral-ventral pacemaker neurons (LNvs) that secrete the neuropeptide PDF (pigment dispersing factor). Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR)-expressing dorsal clock neurons in organizing circadian activity. Although LNvs also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here, we show that (1) PDFR activation in LNvs shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions, and (2) this shift is mediated by stimulation of the Gα,s-cAMP pathway and a consequent change in PDF/neurotransmitter corelease from the LNvs. These results suggest another mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits

Learning homophones in context:Easy cases are favored in the lexicon of natural languages

International audienc

Flexible Use of Phonological and Visual Memory in Language-mediated Visual Search

In language-mediated visual search, memory and attentional resources must be allocated to simultaneously process verbal instructions while navigating a visual scene to locate linguistically specified targets. We investigate when and how listeners use object names in visual-search strategies across three visual world experiments, varying the presence and location of an added visual memory demand. The results suggest that as long as objects in the display can be visually inspected throughout the trial, participants do not linguistically encode those objects. We suggest that instead they use the visual environment as an external memory, mapping the spoken word onto potential referents and using perceptual visual routines automatically triggered by the spoken word. The results are discussed in terms of flexible and efficient allocation of memory resources in natural tasks that combine language and vision

Distal prosody influences lexical interpretation in online sentence processing

Previous work examining prosodic cues in online spoken word recognition has focused primarily on local cues to word identity. However, recent studies have suggested that sentence-level prosodic patterns can also influence the downstream interpretation of lexically ambiguous syllables (Dilley & McAuley, 2008; Dilley, Mattys, & Vinke, 2010). To test the hypothesis that these distal prosody effects are based on expectations about the organization of upcoming material, we conducted a visual world experiment using fixations to competing alternatives such as pan and panda, which differ in the presence or absence of a prosodic boundary after pan(-). As predicted, the acoustic properties of distal sentence material affected the proportion of fixations to the monosyllabic competitor beginning 200 ms after the onset of the target word. These findings support the hypothesis that expectations based on perceived prosodic patterns in the distal context influence lexical segmentation and recognition

<em>In Vivo</em> Circadian Oscillation of dCREB2 and NF-κB Activity in the <em>Drosophila</em> Nervous System

<div><p>cAMP response element-binding protein (CREB) and nuclear factor kappa-B (NF-κB) are two ubiquitous transcription factors involved in a wide number of cellular processes, including the circadian system. Many previous studies on these factors use cellular assays that provide limited information on circadian activity or anatomical specificity. The ability to study transcription factors in defined tissue within intact animals will help to bridge the gap between cellular and <em>in vivo</em> data. We have used the GAL4-UAS and FLP-FRT systems to gain spatial control over reporter gene expression. Using a luciferase-based reporter, we show <em>in vivo</em> that <em>Drosophila</em> dCREB2- and NF-κB-mediated transcription oscillates in neuronal cells, glia, and in the mushroom body, a higher-order brain center in flies. This oscillation is under circadian control, cycling with a 24-hour rhythm, under both light-dark and dark-dark conditions. In light-light conditions, dCREB2 and NF-κB reporter flies exhibit a suppression of rhythmic activity. Furthermore, neuronal cycling of dCREB2 and NF-κB activity are modulated in <em>period</em> mutant flies, indicating these oscillations are controlled through the central clock. This study shows for the first time region-specific circadian oscillation of dCREB2/NF-κB activity in the <em>Drosophila</em> nervous system.</p> </div