Search

Background: Charles Bonnet syndrome (CBS) is a condition in which people with vision loss experience complex visual hallucinations. These complex visual hallucinations may be caused by increased excitability in the visual cortex that are present in some people with vision loss but not others. Objectives: We aimed to evaluate the association between γ-aminobutyric acid (GABA) in the visual cortex and CBS. We also tested the relationship among visually evoked responses, functional connectivity, and CBS. Design: This is a prospective, case-controlled, cross-sectional observational study. Methods: We applied 3-Tesla magnetic resonance spectroscopy, as well as task-based and resting state (RS) connectivity functional magnetic resonance imaging in six participants with CBS and six controls without CBS. GABA+ was measured in the early visual cortex (EVC) and in the lateral occipital cortex (LOC). Participants also completed visual acuity and cognitive tests, and the North-East Visual Hallucinations Interview. Results: The two groups were well-matched for age, gender, visual acuity and cognitive scores. There was no difference in GABA+ levels between groups in the visual cortex. Most participants showed the expected blood oxygenation level dependent (BOLD) activation to images of objects and the phase-scrambled control. Using a fixed effects analysis, we found that BOLD activation was greater in participants with CBS compared to controls. Analysis of RS connectivity with LOC and EVC showed little difference between groups. A fixed effects analysis showed a correlation between the extent of functional connectivity with LOC and hallucination strength. Conclusion: Overall, our results provide no strong evidence for an association between GABAergic inhibition in the visual cortex and CBS. We only found subtle differences in visual function and connectivity between groups. These findings suggest that the neurochemistry and visual connectivity for people with Charles Bonnet hallucinations are comparable to a sight loss population. Differences between groups may emerge when investigating subtle and transient changes that occur at the time of visual hallucinations. Plain language summary: Brain imaging in Charles Bonnet syndrome In Charles Bonnet Syndrome (CBS), people with sight loss start to see hallucinations that they know are not real but can be disturbing. In this study we used MRI scanning to measure how the chemistry in the visual brain differs in people with CBS and those who have sight loss but no hallucinations. Surprisingly we did not find any differences in chemistry between these groups, suggesting that their brains do not differ greatly. Any differences in how their visual brain works may be too small to measure, or only present when people hallucinate. [ABSTRACT FROM AUTHOR]

The hero label has become a pervasive positive stereotype applied to many different groups and occupations, such as nurses, teachers, and members of the military. Although meant to show support, appreciation, and even admiration, we suggest that attaching this label to groups and occupations may actually have problematic consequences. Specifically, we theorize that the hero label may affect beliefs about the internal motivations of these group members that make them more vulnerable to exploitation. These ideas are tested and supported across nine preregistered studies using complementary materials and experimental paradigms. In these studies, we find that: (a) heroization strengthens expectations that teachers, nurses, and military personnel would willingly volunteer for their own exploitation; (b) the hero label and its consequences follow workers even after they transition to a new career (e.g., participants expected a military veteran—relative to a matched nonveteran—to be more willing to volunteer for his own exploitation at his subsequent civilian job, because the veteran was perceived to be more heroic than the matched nonveteran); and (c) occupational heroization—likely because of its impact on beliefs regarding what heroized workers would freely choose to do—reduces opposition to exploitative policies. In short, our studies show that heroization ultimately promotes worse treatment of the very groups that it is meant to venerate. [ABSTRACT FROM AUTHOR]