Visual Mental Imagery and Visual Perception: Structural Equivalence Revealed by Scanning Processes

The research reported in the present article investigates whether information is represented the same way in both visual mental imagery and the early phases of visual perception. In Experiment 1, the same participants scanned over patterns of dots in a mental image (with images based on a just-seen pattern), during perception, and in an iconic image. The time to scan increasing distances increased at comparable rates in the three tasks. However, in Experiment 2, when mental images were created from information stored in long-term memory, participants scanned more slowly in the mental image condition. Nevertheless, the rates of scanning in the perceptual tasks were highly correlated with the rates of scanning in the imagery tasks in both experiments. The results provide evidence that mental images and perceived stimuli are represented similarly and can be processed in the same way.Psycholog

Fear Selectively Modulates Visual Mental Imagery and Visual Perception

Emotions have been shown to modulate low-level visual processing of simple stimuli. In this study, we investigate whether emotions only modulate processing of visual representations created from direct visual inputs or whether they also modulate representations that underlie visual mental images. Our results demonstrate that when participants visualize or look at the global shape of written words (low-spatial-frequency visual information), the prior brief presentation of fearful faces enhances processing, whereas when participants visualize or look at details of written words (high-spatial-frequency visual information), the prior brief presentation of fearful faces impairs processing. This study demonstrates that emotions have similar effects on low-level processing of visual percepts and of internal representations created on the basis of information stored in long-term memory.Psycholog

Testosterone replacement therapy for older men

Despite intensive research on testosterone therapy for older men, important questions remain unanswered. The evidence clearly indicates that many older men display a partial androgen deficiency. In older men, low circulating testosterone is correlated with low muscle strength, with high adiposity, with insulin resistance and with poor cognitive performance. Testosterone replacement in older men has produced benefits, but not consistently so. The inconsistency may arise from differences in the dose and duration of testosterone treatment, as well as selection of the target population. Generally, studies reporting anabolic responses to testosterone have employed higher doses of testosterone for longer treatment periods and have targeted older men whose baseline circulating bioavailable testosterone levels were low. Most studies of testosterone replacement have reported anabolic that are modest compared to what can be achieved with resistance exercise training. However, several strategies currently under evaluation have the potential to produce greater anabolic effects and to do so in a safe manner. At this time, testosterone therapy can not be recommended for the general population of older men. Older men who are hypogonadal are at greater risk for the catabolic effects associated with a number of acute and chronic medical conditions. Future research is likely to reveal benefits of testosterone therapy for some of these special populations. Testosterone therapy produces a number of adverse effects, including worsening of sleep apnea, gynecomastia, polycythemia and elevation of PSA. Efficacy and adverse effects should be assessed frequently throughout the course of therapy

Mental Rotation is Not Easily Cognitively Penetrable

When participants take part in mental imagery experiments, are they using their "tacit knowledge" of perception to mimic what they believe should occur in the corresponding perceptual task? Two experiments were conducted to examine whether such an account can be applied to mental imagery in general. These experiments both examined tasks that required participants to "mentally rotate" stimuli. In Experiment 1, instructions led participants to believe that they could re-orient shapes in one step or avoid re-orienting the shapes altogether. Regardless of instruction type, response times increased linearly with increasing rotation angles. In Experiment 2, participants first observed novel objects rotating at different speeds, and then performed a mental rotation task with those objects. The speed of perceptually demonstrated rotation did not affect the speed of mental rotation. We argue that tacit knowledge cannot explain mental imagery results in general, and that in particular the mental rotation effect reflects the nature of the underlying internal representation and processes that transform it, rather than participants’ pre-existing knowledge.Psycholog

Mortality in kittens is associated with a shift in ileum mucosa-associated enteroccoci from E. hirae to biofilm-forming E. faecalis and adherent E. coli

Approximately ~15% of foster kittens die before 8-wks of age with most of these kittens demonstrating clinical signs or post-mortem evidence of enteritis. While a specific cause of enteritis is not determined in most cases; these kittens are often empirically administered probiotics that contain enterococci. The enterococci are members of the commensal intestinal microbiota but can also function as opportunistic pathogens. Given the complicated role of enterococci in health and disease, it would be valuable to better understand what constitutes a “healthy” enterococcal community in these kittens and how this microbiota is impacted by severe illness. In this study, we characterize the ileum mucosa-associated enterococcal community of 50 apparently healthy and 50 terminally ill foster kittens. In healthy kittens, E. hirae was the most common species of ileum mucosa-associated enterococci and was often observed to adhere extensively to the small intestinal epithelium. These E. hirae isolates generally lacked virulence traits. In contrast, non-E. hirae enterococci, notably E. faecalis, were more commonly isolated from the ileum mucosa of kittens with terminal illness. Isolates of E. faecalis had numerous virulence traits and multiple antimicrobial resistance. Moreover, attachment of E. coli to the intestinal epithelium was significantly associated with terminal illness and was not observed in any kitten with adherent E. hirae. These findings identify a significant difference in species of enterococci cultured from the ileum mucosa of kittens with terminal illness compared to healthy kittens. In contrast to prior case studies that associate enteroadherent E. hirae with diarrhea in young animals, these controlled studies identified E. hirae as more often isolated from healthy kittens and adherence of E. hirae as more common and extensive in healthy compared to sick kittens

Apoptosis induction by Bid requires unconventional ubiquitination and degradation of its N-terminal fragment

Bcl-2 family member Bid is subject to autoinhibition; in the absence of stimuli, its N-terminal region sequesters the proapoptotic Bcl-2 homology 3 (BH3) domain. Upon proteolytic cleavage in its unstructured loop, Bid is activated, although structural data reveal no apparent resulting conformational change. We found that, upon Bid cleavage, the N-terminal fragment (tBid-N) is ubiquitinated and degraded, thus freeing the BH3 domain in the C-terminal fragment (tBid-C). Ubiquitination of tBid-N is unconventional because acceptor sites are neither lysines nor the N terminus. Chemical approaches implicated thioester and hydroxyester linkage of ubiquitin and mutagenesis implicated serine and possibly threonine as acceptor residues in addition to cysteine. Acceptor sites reside predominantly but not exclusively in helix 1, which is required for ubiquitination and degradation of tBid-N. Rescue of tBid-N from degradation blocked Bid's ability to induce mitochondrial outer membrane permeability but not mitochondrial translocation of the cleaved complex. We conclude that unconventional ubiquitination and proteasome-dependent degradation of tBid-N is required to unleash the proapoptotic activity of tBid-C

Using Radical Adult Education to Map Change in a Globalized World

Radical adult education using a sociological frame can support adult educators to see their roles as change agents within their spheres of influence. Using cultural mapping, adult educators define these spheres, stake claims, set benchmarks, grow networks, or develop participatory action research within the identified community

Expect the unexpected? Challenges of prospectively exploring stakeholder engagement in research

Abstract: Stakeholder engagement in research is increasingly viewed as making a major contribution to assisting impact. This paper draws on a longitudinal, prospective impact study exploring stakeholder engagement in a 3-year tobacco control research project which used stakeholder engagement in the development, testing and dissemination of its return on investment tool. The paper presents the challenges of data collection when undertaking prospective research on stakeholder engagement in health-related research. The impact study used mixed methods of data collection to explore stakeholder engagement in the target project, comprising surveys, interviews and observations of meetings and events involving stakeholders. Stakeholder engagement that actually occurred in the target project, and the data collection methods of stakeholder engagement that were actually used in the impact study, varied substantially from those intended in each case. Data collection for the impact study was dependent on the target project’s stakeholder engagement, which became substantially reduced. Modifications to data collection for the impact study were required. One of the reasons for the reduction of stakeholder engagement was linked to constraints on the target project to meet non-negotiable deadlines. Another factor was concerns about overburdening stakeholders. The knock-on effect of reduced stakeholder engagement highlighted the impact study’s lack of control over its data collection, which was related to the prospective nature of the study. The authors acknowledge that an advantage of a retrospective approach over a prospective one is researchers knowing about data availability and accessibility from the outset. However, the prospective approach of the impact study enabled insight into stakeholder engagement in real-time: how and when it occurred, the challenges, and the experiences of stakeholders and the target project researchers. While the quantity of data gathered was considerably less than anticipated, the quality of data was rich and enabled the impact study objectives to be achieved. With increasing emphasis on public engagement in research and calls for engagement to be evaluated for impact, this paper aims—by highlighting the challenges the impact study experienced—to provide some insight to future research that seeks to respond to those calls

On model selections for repeated measurement data in clinical studies: On model selections for repeated measurement data in clinical studies

Repeated measurement designs have been widely used in various randomized controlled trials for evaluating long term intervention efficacies. For some clinical trials, the primary research question is to compare two treatments at a fixed time, using a t-test. Though simple, robust, and convenient, this type of analysis fails to utilize a large amount of collected information. Alternatively, the mixed effects model is commonly used for repeated measurement data. It models all available data jointly and allows explicit assessment of the overall treatment effects across the entire time spectrum. In this paper, we propose an analytic strategy for longitudinal clinical trial data where the mixed effects model is coupled with a model selection scheme. The proposed test statistics not only make full use of all available data but also utilize the information from the optimal model deemed for the data. The performance of the proposed method under various setups, including different data missing mechanisms, is evaluated via extensive Monte Carlo simulations. Our numerical results demonstrate that the proposed analytic procedure is more powerful than the t-test when the primary interest is to test for the treatment effect at the last time point. Simulations also reveal that the proposed method outperforms the usual mixed effects model for testing the overall treatment effects across time. In addition, the proposed framework is more robust and flexible in dealing with missing data compared to several competing methods. The utility of the proposed method is demonstrated by analyzing a clinical trial on the cognitive effect of testosterone in geriatric men with low baseline testosterone levels