Paw placement during walking is altered by analgesic doses of opioids and post-surgical injury in mice

Hind paw-directed assays are commonly used to study the analgesic effects of opioids in mice. However, opioid-induced hyper-locomotion can obscure results of such assays. We aimed to overcome this potential confound by using gait analysis to observe hind paw usage during walking in mice. We measured changes in paw print area following induction of post-surgical pain (using the paw incision model) and treatment with oxycodone. Paw incision surgery reduced the paw print area of the injured hind paw as the mice avoided placing the incised section of the paw on the floor. Surprisingly, oxycodone caused a tiptoe-like gait in mice, resulting in a reduced paw print area in both hind paws. Further investigation of this opioid-induced phenotype revealed that analgesic doses of oxycodone or morphine dose-dependently reduced hind paw print area in uninjured mice. The gait changes were not dependent on opioid-induced increases in locomotor activity; speed and paw print area had no correlation in opioid-treated mice, and other analgesic compounds that alter locomotor activity did not affect paw print area. Unfortunately, the opioid-induced 'tiptoe' gait phenotype prevented gait analysis from being a viable metric for demonstrating opioid analgesia in injured mice. However, this work reveals an important, previously uncharacterized effect of treatment with analgesic doses of opioids on paw placement. Our characterization of how opioids affect gait has important implications for the use of mice to study opioid pharmacology and suggests that scientists should use caution when using hind paw-directed nociceptive assays to test opioid analgesia in mice.

Agreement Attraction in Turkish: The Case of Genitive Attractor

Previous studies have shown that speakers may find sentences violating subject-verb agreement grammatical when the sentence contains a feature-matching noun phrase. This so-called agreement attraction effect has also been found in genitive possessive structures such as 'the teacher's brother' in Turkish (Lago et al., 2019), which is in contrast with its absence in similar constructions in English (Nicol et al., 2016). This discrepancy has been hypothesized to be a result of the association between genitive case marking and subjecthood in Turkish, but not in English. In the present research, we test an alternative explanation in which Turkish number agreement attraction effects are due to a potential confound in Lago et al.'s experiment, as a result of which subject head nouns were locally ambiguous between the possessive and the accusative case. We hypothesized that this ambiguity may have inhibited the availability of the head noun as an agreement controller as the accusative is a non-subject case in Turkish. To test this hypothesis, we conducted a speeded acceptability judgment experiment and our results suggest that case-ambiguity does not play a role in agreement attraction, and thus lends credibility to the claim that genitive noun phrases may function as attractors in Turkish due to the association between genitive case and subjecthood.

Eye placement bias is remarkably robust

When drawing faces, people show a systematic bias of placing the eyes higher up the head than they are placed in reality. The current study investigated the development of this phenomenon while removing the potential confound of drawing ability. Participants (N = 124) in three age groups (3-5yo, 10-11yo, and adults) reconstructed two foam faces, one from observation and one from memory. The high eye placement bias was remarkably robust with mean eye placement in every condition significantly higher than the original faces. The same bias was not shown for mouth placement. Eye placement was highest for the youngest participants and for the memory conditions. The results suggest that an eye placement bias is not caused by the motor skill demands required for drawing and lend evidence to the suggestion that an eye placement bias is caused by perceptual and decision-making processes.

Revisiting the Relationship Between Social Distance and Communication Preferences: A Replication and Reinterpretation of Amit et al. (2013, Experiment 2)

Amit et al. (2013) concluded that social distance can influence communication preferences: People prefer communicating with closer others using pictures (which are more concrete) and more distant others using words (which are more abstract). We conducted a high-powered (N = 988) preregistered replication of Amit et al. (2013, Experiment 2) and extended the design by manipulating the presence of a potential confound we detected when examining the original instructions. The original effect successfully replicated using the original instructions but did not replicate after the removal of the confound. Moreover, we demonstrate that the effect obtained with the original instructions likely relies on a different mechanism (comfort with sending personal pictures to close and distant contacts) than that posited in the original study (preference for concrete and abstract communication). These results cast doubt on the original interpretation and highlight the importance of transparent reporting standards in research.

Eye Placement Bias Is Remarkably Robust

When drawing faces, people show a systematic bias of placing the eyes higher up the head than they are placed in reality. This study investigated the development of this phenomenon while removing the potential confound of drawing ability. Participants ( N = 124) in three age groups (3–5 yo, 10–11 yo, and adults) reconstructed two foam faces: one from observation and one from memory. The high eye placement bias was remarkably robust with mean eye placement in every condition significantly higher than the original faces. The same bias was not shown for mouth placement. Eye placement was highest for the youngest participants and for the memory conditions. The results suggest that an eye placement bias is not caused by the motor skill demands required for drawing and lend evidence to the suggestion that an eye placement bias is caused by perceptual and decision-making processes.

Does Brain Lateralization Affect the Performance in Binary Choice Tasks? A Study in the Animal Model Danio rerio

Researchers in behavioral neuroscience commonly observe the behavior of animal subjects in the presence of two alternative stimuli. However, this type of binary choice introduces a potential confound related to side biases. Understanding whether subjects exhibit this bias, and the origin of it (pre-existent or acquired throughout the experimental sessions), is particularly important to interpreting the results. Here, we tested the hypothesis according to which brain lateralization may influence the emergence of side biases in a well-known model of neuroscience, the zebrafish. As a measure of lateralization, individuals were observed in their spontaneous tendencies to monitor a potential predator with either the left or the right eye. Subjects also underwent an operant conditioning task requiring discrimination between two colors placed on the left–right axis. Although the low performance exhibited in the operant conditioning task prevents firm conclusions from being drawn, a positive correlation was found between the direction of lateralization and the tendency to select the stimulus presented on one specific side (e.g., right). The choice for this preferred side did not change throughout the experimental sessions, meaning that this side bias was not the result of the prolonged training. Overall, our study calls for a wider investigation of pre-existing lateralization biases in animal models to set up methodological counterstrategies to test individuals that do not properly work in a binary choice task with stimuli arranged on the left–right axis.

The Influence of Perspective Taking Encouraged by the Audit Committee on Auditor and Client Judgments during Accounting Disputes

SUMMARY We examine the influence of an audit committee (AC) that encourages auditors (partners and managers) and clients (CFOs and controllers) to consider an accounting dispute from the other party's perspective. Experiment 1 suggests this approach leads to a higher likelihood of agreement and greater concessionary behavior than an AC that does not encourage perspective taking. Perspective taking also impacts the negotiators in different ways. Auditors' solution sets (concessions less reservation price) shift closer to the client's desired adjustment, while clients' solution sets get wider, suggesting greater flexibility. When the AC subsequently provides a resolution recommendation to all negotiators, the AC's initial approach carries over and impacts the negotiators' subsequent behavior. We support these findings in Experiment 2, which was designed to rule out a potential confound and to use a different perspective taking manipulation. This paper extends negotiation research and has implications for practitioners, regulators, and those charged with governance. Data Availability: Available upon request from the authors.

Hemodynamic modeling of aspirin effects on BOLD responses at 7T

Aspirin is considered a potential confound for functional magnetic resonance imaging (fMRI) studies. This is because aspirin affects the synthesis of prostaglandin, a vasoactive mediator centrally involved in neurovascular coupling, a process that underlies the blood oxygenated level dependent (BOLD) response. Aspirin-induced changes in BOLD signal are a potential confound for fMRI studies of patients (e.g. with cardiovascular conditions or stroke) who receive low-dose aspirin prophylactically and are compared to healthy controls that do not take aspirin. To examine the severity of this potential confound, we combined high field (7 Tesla) MRI during a simple hand movement task with a biophysically informed hemodynamic model. Comparing elderly volunteers with vs. without aspirin medication, we tested for putative effects of low-dose chronic aspirin on the BOLD response. Specifically, we fitted hemodynamic models to BOLD signal time courses from 14 regions of the human motor system and examined whether model parameter estimates were significantly altered by aspirin. While our analyses indicate that hemodynamics differed across regions, consistent with the known regional variability of the BOLD response, we neither found a significant main effect of aspirin (i.e., an average effect across brain regions) nor an expected drug×region interaction. While our sample size is not sufficiently large to rule out small-to-medium global effects of aspirin, we had adequate statistical power for detecting the expected interaction. Altogether, our analysis suggests that low-dose aspirin, as used for prophylactic purposes, does not strongly affect BOLD signals and may not represent a critical confound for fMRI studies.

Idea Generation and Goal Derived Categories

Semantic search and retrieval of information plays an important role in creative idea generation. This study was designed to examine how semantic and temporal clustering varies when asking participants to generate ideas about uses for objects compared with generating members of goal-derived categories. Participants generated uses for three objects: brick, hammer, picture frame, and also generated members of the following goal-derived categories: things to take in case of a fire, things to sell at a garage sale, and ways to spend lottery winnings. Using response-time analysis and semantic analysis, results illustrated that all six prompts generally led to exponentialcumulative response-time distributions. However, the proportion of temporally clustered responses, defined using the slope-difference algorithm, was higher for goal-derived category responses compared with object uses. Despite that, overall pairwise semantic similarity was higher for object uses than for goal derived exemplars. The effect of prompt on pairwise semantic similarity is likely the result of context-dependency of exemplars from goal-derived categories. However, the current analysis contains a potential confound such that special instructions to give “common and uncommon” responses were provided only for the object-uses prompts. The confound is likely minimal, but future work is necessary to illustrate the robustness of the results.