1,721,050 research outputs found
Open Practices Disclosure, LakensOpenPracticesDisclosure – Equivalence Testing for Psychological Research: A Tutorial
No full textOpen Practices Disclosure, LakensOpenPracticesDisclosure for Equivalence Testing for Psychological Research: A Tutorial by Daniël Lakens, Anne M. Scheel, and Peder M. Isager in Advances in Methods and Practices in Psychological Science</p
Three-Sided Testing to Establish Practical Significance
No full textContains supplementary materials for the article "Three-Sided Testing to Establish Practical Significance: A tutorial" by Peder M Isager and Jack Fitzgerald.
Article abstract: Researchers may want to know whether an observed statistical relationship is either meaningfully negative, meaningfully positive, or small enough to be considered practically equivalent to zero. Such a question can not be addressed with standard null hypothesis significance testing, nor with standard equivalence testing. Three-sided testing (TST) is a procedure to address such questions, by simultaneously testing whether
an estimated relationship is significantly below, within, or above predetermined smallest effect sizes of interest. TST is a natural extension of the standard two one-sided test for equivalence (TOST). TST offers a more comprehensive decision framework than TOST with no penalty to error rates or statistical power. In this paper, we give a non-technical introduction to TST, provide commands for conducting TST in both R
and Jamovi, and provide a Shiny app for easy implementation. Whenever a meaningful smallest effect size of interest can be specified, TST should be combined with null hypothesis significance testing as the default frequentist testing procedure
μ-Opioid Modulation of Reported Wanting of Palatable Food Images: A pharmacological fMRI study in healthy humans
No full textType: Master's thesis
Supervisors: Siri Leknes, Marie Eikemo, Tom Johnstone
Final grade: B (Norwegian grade system). See supplemental materials for grader evaluation document.
The endogenous μ-opioid receptor (MOR) system in the brain is central to reward behaviors across species, and brain areas implicated in reward are dense with μ-opioid receptors. The MOR system has received the most interest through its involvement in pleasure mediation (‘liking’), but there is much evidence to suggest a role for the MOR system in motivated ‘wanting’ as well. Nevertheless, we still know very little about the mechanisms of MOR modulation in reward motivation in healthy humans. Further, it is unclear to what extent the animal research on MOR modulation of reward-processing in the brain can be extended to humans, as very few studies have explored this relationship directly in the human brain. We examined the effects of a low dose (10mg) of per oral morphine (a μ-opioid agonist) on reported food wanting, and of applying a cognitive regulation task to downregulate this wanting, in healthy human participants. We also measured neural activity as approximated by functional magnetic resonance imaging. The study was designed to minimize the risk of potential confound effects of the drug manipulation. In a within-subject, counterbalanced, placebo-controlled, double-blind design, 63 participants (31 male, mean age 27 ±5) were tested in a morphine and placebo session on two separate days. In line with our expectations, morphine did not significantly affect subjective mood or state, respiration- or heart rate, or motor coordination. Morphine also did not appear to alter global BOLD, measured by a simple visual control task. The food wanting task elicited significant activation in reward related regions compared to baseline, and cognitive regulation produced the expected decrease in food wanting, together with increased activity in ventral prefrontal regions. Activation in extrastriate occipital regions was observed across tasks. Preliminary analyses confirmed our hypothesis that MOR agonism would increase food wanting, but did not confirm our hypothesis of associated activity increase in the striatum and medial prefrontal areas. Instead, increased activity in regulation-related regions may be required for successful downregulation of wanting after morphine treatment. In summary, we have now validated the paradigm and task design of this study. Thus, a complete analysis of the drug effects of interest can be conducted and the results interpreted to draw meaningful conclusions regarding the effects of MOR stimulation with morphine on BOLD signals relating to ‘wanting’ for palatable food images
The effect of the presence of others on performance in a jigsaw puzzle solving task: Replication of Agarwal et al. (2016)
No full textScientists have studied the effect of the mere presence of others since the late 1800s (Robert B Zajonc 1965). This phenomenon has frequently been associated with both enhancements and decreases in performance on a variety of tasks, both in humans (e.g. Hollister and Berenson 2009, Kuhn and Solomon 2014, Rittle and Bernard 1976), but also in less cognitively developed species such as the cockroach (Robert B. Zajonc, Heingartner, and Herman 1969). One theoretical explanation for the mere presence effects is that the presence of others facilitates well-known responses in the performer and disrupts less trained responses, although other explanations have been suggested as well (Robert B Zajonc 1965, Guerin and Innes 1982). The current project attempts to replicate a previous experiment investigating the effect of the presence of another participant on performance in a puzzle-solving task (Agarwal et al. 2016). The project was completed in collaboration with undergraduate students from a Dutch university
μ-Opioid Modulation of Reported Wanting of Palatable Food Images: A pharmacological fMRI study in healthy humans
No full textType: Master's thesis
Supervisors: Siri Leknes, Marie Eikemo, Tom Johnstone
Final grade: B (Norwegian grade system)
The endogenous μ-opioid receptor (MOR) system in the brain is central to reward behaviors across species, and brain areas implicated in reward are dense with μ-opioid receptors. The MOR system has received the most interest through its involvement in pleasure mediation (‘liking’), but there is much evidence to suggest a role for the MOR system in motivated ‘wanting’ as well. Nevertheless, we still know very little about the mechanisms of MOR modulation in reward motivation in healthy humans. Further, it is unclear to what extent the animal research on MOR modulation of reward-processing in the brain can be extended to humans, as very few studies have explored this relationship directly in the human brain. We examined the effects of a low dose (10mg) of per oral morphine (a μ-opioid agonist) on reported food wanting, and of applying a cognitive regulation task to downregulate this wanting, in healthy human participants. We also measured neural activity as approximated by functional magnetic resonance imaging. The study was designed to minimize the risk of potential confound effects of the drug manipulation. In a within-subject, counterbalanced, placebo-controlled, double-blind design, 63 participants (31 male, mean age 27 ±5) were tested in a morphine and placebo session on two separate days. In line with our expectations, morphine did not significantly affect subjective mood or state, respiration- or heart rate, or motor coordination. Morphine also did not appear to alter global BOLD, measured by a simple visual control task. The food wanting task elicited significant activation in reward related regions compared to baseline, and cognitive regulation produced the expected decrease in food wanting, together with increased activity in ventral prefrontal regions. Activation in extrastriate occipital regions was observed across tasks. Preliminary analyses confirmed our hypothesis that MOR agonism would increase food wanting, but did not confirm our hypothesis of associated activity increase in the striatum and medial prefrontal areas. Instead, increased activity in regulation-related regions may be required for successful downregulation of wanting after morphine treatment. In summary, we have now validated the paradigm and task design of this study. Thus, a complete analysis of the drug effects of interest can be conducted and the results interpreted to draw meaningful conclusions regarding the effects of MOR stimulation with morphine on BOLD signals relating to ‘wanting’ for palatable food images
A neat OSF project for everyone to see!
No full textThis is an example project intended for demonstration purposes only
On the role of causal direction and feedback in network theories of mental disorder
No full textThe network theory of mental disorder represents a possible paradigm shift in
psychopathological research, and may permanently change the way we study
mental health and illness. This theory has one fundamental assumption:
psychopathology is driven by direct causal relationships between individual
symptoms. Despite this, surprisingly little has been written about the formal
role of causality in driving network dynamics. In this article, I formalize
the principle of direct causal connections from Borsboom (2017, principle 3)
using the framework of structural causal models advanced by Judea Pearl.
I then refine the principle of hysteresis from Borsboom (2017, principle 5)
by identifying causal feedback as the second necessary condition for hysteresis
to occur (in addition to connectivity strength). Finally, I discuss how
these refinements lead to new insights about concepts like ‘treatment’ and
‘comorbidity’. Understanding the causal structure of symptom networks is
integral to understanding how mental disorders develop, and how they may
be treated
Student replication of Coles et al. (2020, doi: 10.31234/osf.io/br4y9) study 2
No full textA reoccurring concern in facial feedback research is that the observed effects are merely an artifact of demand characteristics: cues that participants use to guess and adjust their behavior to fit the researcher’s hypothesis (Schimmack & Chen, 2017; Strack et al., 1988). For example, even if smiling does not increase happiness, participants may guess the hypothesis and adjust their happiness reports accordingly. In the current project we attempted to replicate the procedures of Coles et al. 2020, study 2, doi:10.31234/osf.io/br4y9) to tease apart the effects of demand characteristics from the potential effects of facial feedback
Supplemental materials for preprint: Test validity defined as d-connection between target and measured attribute: Expanding the causal definition of Borsboom et al. (2004)
No full text- …
