Unreliable landmarks disrupt egocentric navigation in desktop virtual environments.

Research using a drug discriminated goal-tracking (DGT) task showed that the N-methyl-D: -aspartate (NMDA) channel blocker MK-801 (dizocilpine) reduced the nicotine-evoked conditioned response (CR). Given the unknown mechanism of the effect, Experiment 1 replicated the MK-801 results and included tests with NMDA receptor ligands. Experiments 2a and 2b tested whether MK-801 pretreatment blocked DGT via a state-dependency effect. In Experiment 1, adult male Sprague-Dawley rats received intermittent access to liquid sucrose following nicotine (0.4mg base/kg); no sucrose was delivered on intermixed saline sessions. Conditioning was indicated by increased anticipatory dipper entries (goal-tracking) on nicotine compared to saline sessions. Antagonism and/or substitution tests were conducted with MK-801, phencyclidine, CGP 39551, d-CPPene (SDZ EAA 494), Ro 25,6981, L-701,324, ACPC, and NMDA. In Experiment 2a, rats received nicotine and sucrose on every session-no intermixed saline sessions without sucrose. Tests combined MK-801 or the non-competitive nicotinic acetylcholine receptor antagonist, mecamylamine with either nicotine or saline. Experiment 2b had sucrose delivered on saline sessions and no sucrose on intermixed nicotine sessions followed by MK-801 antagonism tests of the saline CS. MK-801 and phencyclidine dose-dependently attenuated the CR in Experiment 1. Ro-25,6981 enhanced the CR, but did not substitute for nicotine. Other ligands showed inconsistent effects. In Experiment 2a, MK-801 pretreatment reduced goal-tracking when given before nicotine and saline test sessions; mecamylamine pretreatment had no effect. In Experiment 2b, MK-801 dose-dependently attenuated the saline-evoked CR. Combined, the results suggest that MK-801 blocks discriminated goal-tracking by virtue of state-changing properties.

The influence of emotion on attention has been examined more closely in recent years using a variety of paradigms. Öhman (1993) suggested that participants more readily pay attention to negative information than neutral information. The current work was designed to expand upon these findings by examining both negative and positive emotion word processing in a non-clinical population using the dot probe task. Experiments 1a and 1b examined the supraliminal and subliminal processing of negative and positive emotion words presented in separate blocks. The results revealed that participants responded faster to the probe when it appeared in the same location as the negative emotion word relative to when it appeared in the same location as an emotionally neutral word, but were equally fast at responding to the probe when it appeared in the same location as the positive emotion word or neutral word. These effects occurred regardless of whether the words were presented with or without a mask. These findings suggest that negative emotion words automatically capture attention even for non-clinical samples and even when they are presented below the threshold of conscious awareness, indicating that this is a robust and automatic effect. In Experiments 2a and 2b, the negative and positive words were intermixed within the same block. When the words were masked, the results revealed faster processing of the probe when it appeared in the same location as either a negative word or a positive word, relative to when it appeared in the same location as a neutral word; however, when the words were presented without a mask, the probe was processed equally fast regardless of whether it appeared in the same location as a negative or positive emotion word or a neutral word. The findings from Experiment 2b also indicate that positive words have the ability to automatically capture attention and influence subsequent processing when they are presented below the threshold of awareness. In addition, the hemispheric processing of the two word types was also examined. The results from Experiments 1a and 1b supported the Right Hemisphere Hypothesis (RHH), indicating that the negative and positive words were processed more efficiently in the left visual field (LVF). In Experiments 2a and 2b, the RHH was supported when the words were masked, but the Valence Specific Hypothesis (VSH) was supported when the words were presented without a mask. Specifically, the positive words were processed more efficiently in the right visual

Previous experiments in visual comparison have shown that the spatial congruency bias (SCB), a bias to categorise two targets as "same" if they occupy the same location in successive displays, and the overall bias (OB), the average bias across all trials, vary with visual similarity; and that the OB also varies with the type of task being performed. In four experiments, we explore whether these results are best explained by a visual similarity account, an attentional zoom account, or a combination of the two. Using a shape comparison task, we manipulated the visual similarity and predictability of the target displays by varying the local position of the target letter, either between different blocks (i.e., predictable; Experiments 1a and 2a) or within a block (i.e., unpredictable; Experiments 1b and 2b); additionally, we varied the distractor letters such that they were the same between the to-be-compared displays in most of the trials (Experiments 1a and 1b) or they were different in every trial (Experiments 2a and 2b). Under conditions of low interference, the predictability of visual information has no effect on the OB, or on the SCB, but this may be because attentional demands are low in these conditions. As predicted by the attentional zoom account, the SCB is influenced by predictability when peripheral interference is high. These results suggest that both similarity and attention play a role in visual comparisons.

Introduction Recent studies suggested that the energy delivered by the mechanical ventilator to the lungs termed the mechanical power can induce and increase the risks of ventilator induced lung injury. The components of the mechanical power include the variables delivered by the ventilator: tidal volume, respiratory rate, inspiratory flow, airway pressure. Adaptive Ventilator Mode-2 (AVM-2) is a pressure-controlled mode with an optimal targeting scheme based on the inspiratory power equation that adjusts the respiratory rate and tidal volume to achieve a target minute ventilation. This mode conceptually should reduce the mechanical power delivered to the patients and thus reduce the incidence of ventilator induced lung injury. Methodology A bench study using a lung simulator (TTL, Michigan Instruments, Michigan, USA) was conducted. We constructed a passive single compartment normal respiratory mechanics model with compliance of 50 ml/cmH2O, and resistance of 10 cmH2O/L/s, with IBW 70 kg. We compared three different ventilator modes: Adaptive Ventilation Mode-2 (AVM-2), Pressure Regulated Volume Control (PRVC), and Volume Controlled Ventilation (VCV) in four different scenarios: 2 levels of minute ventilation 7 and 10.5 Lit/min (Experiment 1 and 2 respectively), each with 2 different PEEP levels 5 and 10 cmH2O (Experiment A and B respectively) termed Experiments 1A, 1B, 2A, and 2B respectively. The AVM-2 mode automatically selects the optimal tidal volume, and respiratory rate per the dialed percent minute ventilation with an I:E ratio of 1:1. In the PRVC, VCV we selected target tidal volume 6ml/kg/IBW (420 ml), and respiratory rate adjusted to match the minute ventilation for the AVM-2 mode. I:E ratio was kept 1:2 to avoid intrinsic PEEP. The study was conducted using a bellavista™ 1000 e Ventilator (Vyaire Medical, Illinois, USA). The mechanical power delivered by the ventilator for each mode was computed and compared between the three modes in each experiment. Statistical analysis was done using Kruskal-Wallis test to analyze the difference between the three modes, post HOC Tukey test was used to analyze the difference between each mode with the confidence intervals, P < 0.05 was considered statistically significant. Results There were statistically significant differences between all the three modes regarding the ventilator delivered mechanical power. The AVM-2 mode delivered significantly less mechanical power than VCV which in turn was less than PRVC. Experiment 1A: AVM-2 8.76 土 0.05, VCV 9.78 土 0.04, PRVC 10.82 土 0.08, P < 0.001 Experiment 1B: AVM-2 11.27 ± 0.09 VCV 12.81 ± 0.05, PRVC 13.88 ± 0.06, P < 0.001. Experiment 2A: AVM-2 14.76 ± 0.05, VCV 15.79 ± 0.05, PRVC 18.29 ± 0.07, P < 0.001, Experiment 2B: AVM-2 18.76 ± 0.04, VCV 20.56 ± 0.04, PRVC 21.17 土 0.03, P < 0.001. Discussion AVM2 mode delivered less mechanical power compared to two conventional modes using low tidal volume in a normal lung model. This might reduce the incidence of ventilator induced lung injury. Results need to be validated in more clinical studies.

Intrinsic Laryngeal Muscle Activity During Subvocalization

A critical transition in ovarian follicular development is the selection of a dominant follicle, capable of ovulating, from a cohort of synchronously growing antral follicles. However, little is known about mechanisms and factors that regulate the selection and growth of dominant ovarian follicles. We have investigated whether a component of the insulin-like growth factor (IGF) system, namely IGFBP-4 protease, is associated with the establishment of follicular dominance in cattle. IGFBP proteases degrade IGFBPs, freeing IGFs to interact with their receptors. In experiment 1, follicular fluid from preovulatory follicles (n = 4) degraded about 80% of the added recombinant human (rh) IGFBP-4 within 18 h of incubation. The IGFBP-4 protease exhibited optimal activity at neutral/basic pH and its sensitivity to various protease inhibitors suggested a metalloprotease. The decline in the intensity of the band corresponding to intact rhIGFBP-4 was accompanied by the appearance of immunoreactive fragments of molecular weights approximately 18 and 14 kDa, which were not detectable by ligand blot analysis. In experiment 2, follicular fluid samples were collected from dominant and subordinate follicles on Day 2 or 3 of the first follicular wave, after ovariectomy (experiment 2a, n = 3/day) or by ultrasound-guided follicular aspiration (experiment 2b, n = 4-5/day). Estradiol concentrations in follicular fluid from dominant vs. subordinate follicles confirmed their identities and indicated that the dominant follicle had been selected by Day 2 of the follicular wave. In both experiments 2a and 2b, IGFBP-4 proteolytic activity was 2- to 3.5-fold (P < 0.05) and 5-fold (P < 0.01) higher in follicular fluid from dominant than subordinate follicles on Days 2 and 3 of the follicular wave, respectively. The finding that IGFBP-4 proteolytic activity is higher in dominant, estrogen-active follicles than in subordinate follicles of the same cohort, as early as Day 2 of the follicular wave, strongly suggests a role for IGFBP-4 protease in the establishment of ovarian follicular dominance.

Spatial-frequency-dependent visible persistence and specific reading disability

Research shows that memory for a context generalizes (i.e., becomes less precise) over time. In this series of experiments, we examined the impact of early life stress on context generalization. Early life stress was modeled using a maternal separation procedure, whereby pups were separated from the dam for 3 hr a day from postnatal Day 2 to 14, or reared as normal. In adulthood, rats were trained to fear a context, and were then tested for freezing in either the training context or a generalization context. Across 5 experiments, we found that maternally separated animals showed generalization when tested 1 day after training (Experiments 1a, 2, 3a, 3b), whereas standard reared rats discriminated at this time point (Experiments 1a & 3b). When tested 1 week after training, all rats generalized (Experiment 1b). Furthermore, maternally separated animals froze more to the training context than the generalization context when tested 1 hour after training (Experiment 2), indicating that the increased generalization expressed by these animals when tested after 1 day is not due to a general inability to discriminate. Manipulations that have been found to reduce generalization in standard reared animals failed to enhance memory specificity at the 1-day retention interval in maternally separated animals (i.e., a pretest reminder, Experiment 3a, and context preexposure, Experiment 3b). Thus, early life stress results in faster generalization that is more resistant to treatments designed to enhance memory specificity. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Persistence and drug-induced reinstatement of a morphine-induced conditioned place preference

This study investigated optimism, which is considered a personality trait, from the grounded cognition perspective. Three experiments were conducted to investigate the association between pink and optimism. In Experiment 1A, 22 undergraduates (10 females; Mage = 23.68) were asked to classify words as optimistic or pessimistic as fast as possible. Half the words were presented in pink and half in black. Experiment 1B (N = 24; 14 females; Mage = 22.82) was identical to 1A except for the color of the words-black and light blue instead of pink-to rule out the possible influence of brightness. Experiment 2 exposed 144 participants (74 females; Mage = 25.18) to pink or yellow and then measured their optimism level. The findings for Experiments 1A and 1B indicated an association between pink and optimism regardless of brightness. Experiment 2 found that mere exposure to pink increased optimism levels for females. These results contribute to the dynamic view of personality, current views on optimism, and the growing literature on grounded cognition.

In Experiment 1a, rats trained to escape shock by performing a 2-s inactive response were less impaired on a subsequent 2-way shuttle response than their yoked counterparts that received inescapable shock. In contrast, in Experiment 1b, rats trained to escape shock by performing a longer duration inactive response were more impaired on the subsequent escape task than their inescapably shocked counterparts. In Experiment 2, the results of Experiments 1a and 1b were replicated, and the inactive responses performed during pretreatment by both the escapable and inescapable shock groups were assessed and correlated with test stage 2-way shuttle escape performance. These activity data indicate that inactivity during pretreatment shock in both escapable and inescapable shock groups was a highly reliable predictor of subsequent 2-way shuttle performance, irrespective of the pretreatment shock contingency to which these Ss were exposed.

It has been proposed that representations emerge from a single memory system organized along a continuum of specificity. This continuum is assumed to reflect a scale between the simulation of overlapping and specific features of the traces, which depends on trace distinctiveness. More specifically, higher trace distinctiveness facilitates the simulation of trace-specific features, which increase the discriminability of traces and lead to the emergence of a more specific representation. In two experiments, participants were asked to identify match (low task discrimination demand) or mismatch (high task discrimination demand) associations between actions and characters that were visually either highly or lowly distinctive. The results of Experiment 1show that in the high-distinctiveness context, performance was better when identifying a mismatch rather than a match, while the opposite was true in the low-distinctiveness context. The results of Experiment 2 show that using a dynamic visual noise to interfere with the participants' ability to simulate the features of the characters also reduced the benefit of the high-distinctiveness context for the mismatch trials (Experiment 2a and 2b) and increased the benefit of the low-distinctiveness context for the match trials (Experiment 2b). Taken together, these results suggest that the simulation of trace-specific features underlies the emergence of specific representations, which can be beneficial when the discrimination demand of the task is high and detrimental when this demand is low. Memory might therefore be viewed as a scale of simulation between overlapping and specific trace features.

Kaolin clay intake motivated by lactose ingestion in rats

Strategy compatibility: The time versus money effect on product evaluation strategies

Inferences and expectations evoked by an experience support interpretation and are sometimes misattributed to the experience itself-a constructive error observed in multiple domains (e.g., memory for sentences, stories, and events). Boundary extension (BE), memory beyond the edges of a view, may reflect this type of error (multisource model; Intraub, 2010). In contrast, it may simply reflect a spatial distortion involving good continuation of visible content (Bainbridge & Baker, 2020a). To explore this, we addressed an understudied aspect of BE: its content. In Experiment 1 (n = 156), participants predicted the unseen surroundings beyond close-ups of objects on continuous backgrounds and close-ups of objects cropped to eliminate a surrounding container. Expected-container and expected-continuation pictures were selected based on agreement across predictions. These were presented for 15 s each to naive participants, and the expanse and content of BE was assessed in recognition memory (Experiments 2a and 2b, total n = 394; Experiment 3, n = 184) and free recall (drawings: Experiment 4, n = 66). Expected containment elicited unprecedented false memory for unique content in BE and instances of alternative "readings" of the same views. Remembered expanse was constrained by expected containment, with this constraint being "released" when conditions favored false memory for the container rather than expectation alone (Experiment 2b). Results suggest that prior knowledge (e.g., learned contingencies, object-to-context associations) is leveraged during scene perception, contextualizing a view and simulating anticipated surroundings. These outcomes would have adaptive value for the observer during the dynamics of natural scene perception. (PsycInfo Database Record (c) 2025 APA, all rights reserved).