The prevalence of aphantasia (imagery weakness) in the general population.

Visual mental imagery is the ability to create a quasi-perceptual visual picture in the mind's eye. For people with the rare trait of aphantasia, this ability is entirely absent or markedly impaired. Here, we aim to clarify the prevalence of aphantasia in the general population, while overcoming limitations of previous research (e.g., recruitment biases). In Experiment 1, we screened a cohort of undergraduate students (n502) using the Vividness of Visual Imagery Questionnaire (Marks, 1973) and found that 4.2% had aphantasia. To establish the reliability of our estimate, we then screened a new sample of people (n502) at an online crowdsourcing marketplace, again finding that approximately four percent (3.6%) had aphantasia. Overall, our combined prevalence from over a thousand people of 3.9% - which shows no gender bias - provides a useful index for how commonly aphantasia occurs, based on measures and diagnostic thresholds in line with contemporary aphantasia literature.

What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia.

People with aphantasia have impoverished visual imagery so struggle to form mental pictures in the mind's eye. By testing people with and without aphantasia, we investigate the relationship between sensory imagery and sensory sensitivity (i.e., hyper- or hypo-reactivity to incoming signals through the sense organs). In Experiment 1 we first show that people with aphantasia report impaired imagery across multiple domains (e.g., olfactory, gustatory etc.) rather than simply vision. Importantly, we also show that imagery is related to sensory sensitivity: aphantasics reported not only lower imagery, but also lower sensory sensitivity. In Experiment 2, we showed a similar relationship between imagery and sensitivity in the general population. Finally, in Experiment 3 we found behavioural corroboration in a Pattern Glare Task, in which aphantasics experienced less visual discomfort and fewer visual distortions typically associated with sensory sensitivity. Our results suggest for the very first time that sensory imagery and sensory sensitivity are related, and that aphantasics are characterised by both lower imagery, and lower sensitivity. Our results also suggest that aphantasia (absence of visual imagery) may be more accurately defined as a subtype of a broader imagery deficit we name dysikonesia, in which weak or absent imagery occurs across multiple senses.

What is the relationship between Aphantasia, Synaesthesia and Autism?

For people with aphantasia, visual imagery is absent or markedly impaired. Here, we investigated the relationship between aphantasia and two other neurodevelopmental conditions also linked to imagery differences: synaesthesia, and autism. In Experiment 1a and 1b, we asked whether aphantasia and synaesthesia can co-occur, an important question given that synaesthesia is linked to strong imagery. Taking grapheme-colour synaesthesia as a test case, we found that synaesthesia can be objectively diagnosed in aphantasics, suggesting visual imagery is not necessary for synaesthesia to occur. However, aphantasia influenced the type of synaesthesia experienced (favouring 'associator' over 'projector' synaesthesia - a distinction tied to the phenomenology of the synaesthetic experience). In Experiment 2, we asked whether aphantasics have traits associated with autism, an important question given that autism - like aphantasia - is linked to weak imagery. We found that aphantasics reported more autistic traits than controls, with weaknesses in imagination and social skills.

The combined effects of a monotonous diet and exposure to thiamethoxam on the performance of bumblebee micro-colonies.

There is a pressing need to better understand the factors contributing to declines of wild pollinators such as bumblebees. Many different contributors have been postulated including: loss of flower-rich habitats and nesting sites; monotonous diets; impacts of invasive pathogens; exposure to pesticides such as neonicotinoids. Past research has tended to investigate the impacts of these stressors in isolation, despite the increasing recognition that bees are simultaneously exposed to a combination of stressors, with potentially additive or synergistic effects. No studies to date have investigated the combined effects of a monotonous diet and exposure to pesticides. Using queenless micro-colonies of Bombus terrestris audax, we examined this interaction by providing bees with monofloral or polyfloral pollen that was either contaminated with field-realistic levels of thiamethoxam, a commonly used neonicotinoid, or not contaminated. Both treatments were found to have a significant effect on various parameters relating to micro-colony performance. Specifically, both pesticide-treated micro-colonies and those fed monofloral pollen grew more slowly than those given polyfloral pollen or pollen without pesticides. The two factors appeared to act additively. Micro-colonies given monofloral pollens also exhibited lower reproductive efforts and produced smaller drones. Although further research is needed to examine whether similar effects are found in whole colonies, these findings increase our understanding of the likely effects of multiple stressors associated with agricultural intensification on bee declines.

Better practical evaluation for lower limb amputees.

PURPOSE: To avoid wastage of prostheses and unfair selection methods for prosthetic prescription, we aimed to develop a practical assessment tool for amputees with doubtful potential, using refurbished second hand modular prostheses. METHOD: Thirty-seven primary amputees (33 transfemoral, 4 transtibial; 22 males, 15 females; median age 71 years, range 19-91) were considered to have doubtful potential for prosthetic use, due to single or multiple impairments. Amputees were assessed using custom-made socket and refurbished second-hand modular prostheses. Liability issues were fully covered. RESULTS: Two patients died before completing the assessment. Median duration of assessment was 4 weeks (range 1-31 weeks). Among the 35 amputees who completed the trial, 14 (38%) proceeded to final prosthesis successfully and 21 (58%) decided to abandon the prostheses. The main reasons for prostheses rejection identified by the team were: hip flexion deformity (4); frailty (4); bilateral amputations (4); COAD (6), stroke (4), stump pain (3) and contralateral leg problems (2) CONCLUSION: High prosthetic rejection rate was expected and confirmed in this group (58%), but considerable number did proceed to definitive prosthesis. The method is practical and fair for amputees of doubtful potential, with considerable cost saving.

Lipid-induced pore formation of the Bacillus thuringiensis Cry1Aa insecticidal toxin.

After activation, Bacillus thuringiensis (Bt) insecticidal toxin forms pores in larval midgut epithelial cell membranes, leading to host death. Although the crystal structure of the soluble form of Cry1Aa has been determined, the conformation of the pores and the mechanism of toxin interaction with and insertion into membranes are still not clear. Here we show that Cry1Aa spontaneously inserts into lipid mono- and bilayer membranes of appropriate compositions. Fourier Transform InfraRed spectroscopy (FTIR) indicates that insertion is accompanied by conformational changes characterized mainly by an unfolding of the beta-sheet domains. Moreover, Atomic Force Microscopy (AFM) imaging strongly suggests that the pores are composed of four subunits surrounding a 1.5 nm diameter central depression.