Caregiving during the Covid-19 pandemic: Factors associated with caregiver stress and cognition

Caregivers are critical in helping persons with dementia (PWD) live at home longer, but the caregiving experience is associated with increased risk of physical (Vitaliano et al., 2003; Son et al., 2007; Fonareva & Oken, 2014) and cognitive decline among caregivers (Pertle et al., 2015; Lathan et al., 2016; Vitaliano et al., 2017). The present study examined the caregiver experience during the time of the Covid-19 pandemic including factors associated with caregiver stress, burden, and self-reported cognition (i.e., prospective and retrospective memory errors). In a sample of 56 caregivers of PWD, caregiver stress was positively associated with reports of greater life change resulting from Covid-19 and a greater frequency of care recipient depressive and disruptive behaviors; however, caregiver stress was not associated with care recipient memory problems. Additionally, caregiver burden was negatively associated with ratings of preparedness for the pandemic, but not with availability of support services or the amount of time spent caregiving. Further, frequencies of prospective and retrospective memory mistakes were positively associated with perceived stress, but not with caregiver burden. These findings reveal that caregivers of PWD report greater experiences of stress associated with the Covid-19 pandemic and other facets of their caregiving responsibilities (e.g., care recipient depressive and disruptive behaviors, frequency of memory mistakes). This work is a first step in identifying areas in which caregivers need assistance and expanding the literature on caregiver cognition by measuring self-reported everyday memory performance.

The Effects of Acute and Binge 3,4-methylenedioxymethamphetamine (MDMA) Exposure on Learning and Memory in Rats

<p>When rats are administered acute doses of MDMA they produce significantly more reference memory errors than working memory errors in the partially baited radial arm maze (Kay et al, 2009). The potential role of serotonin and dopamine in this effect was examined by administering the serotonin agonist Citalopram and the dopamine agonist GBR12909. GBR12909 produced significantly more reference memory errors, while Citalopram tended to produce more working memory errors. Administration of the D1 agonist A68930 and the D2 agonist Quinpirole predominantly produced reference memory errors, but to a lesser extent than acute MDMA administration. Low doses of both drugs produced a synergistic effect, more similar to that seen with acute MDMA administration. These findings suggest dopamine plays a role in the reference memory effect seen with MDMA exposure in the partially baited radial maze. In the second half of the thesis binge regimes of MDMA (4 x 10mg/kg) were administered to rats. When there was a gap of eight weeks between dosing and training the ability to acquire the radial arm maze was not significantly impaired. When this MDMA regime was repeated with a three-day gap between dosing and training it produced a significant but transient deficit in performance. When later challenged with acute doses of MDMA (4.0 mg/kg) the binge treated rats were less impaired than saline controls indicating drug tolerance. In an additional study that used a three-day delay between dosing and training a significant impairment in task acquisition was found. This deficit appeared to be long-term as the MDMA treated rats were impaired when the rules of task were changed suggesting a deficit in cognitive flexibility. Again when subjects were challenged with acute MDMA there was evidence of drug tolerance. The final study examined the effects of repeated MDMA exposure on task acquisition by administering acute doses of MDMA or saline once a week after rats had previously been treated with either a binge regime of MDMA or saline. MDMA exposure significantly impaired task acquisition and produced residual drug effects in the binge treated MDMA group the day after acute drug administration. However evidence of behavioural tolerance in this study was mixed due to a floor effect where performance of the binge MDMA group was so poor at the beginning of the study. In conclusion MDMA exposure impaired accuracy with reference memory processes were more affected than working memory processes. The underlying nature of this impairment remains unclear but it may be due to a long-term memory deficit, an impairment in understanding task rules or a perseverative pattern of responding. These findings imply human Ecstasy users may show deficits in acquiring information and may experience deficits in cognitive flexibility</p>

The Effects of Acute and Binge 3,4-methylenedioxymethamphetamine (MDMA) Exposure on Learning and Memory in Rats

<p>When rats are administered acute doses of MDMA they produce significantly more reference memory errors than working memory errors in the partially baited radial arm maze (Kay et al, 2009). The potential role of serotonin and dopamine in this effect was examined by administering the serotonin agonist Citalopram and the dopamine agonist GBR12909. GBR12909 produced significantly more reference memory errors, while Citalopram tended to produce more working memory errors. Administration of the D1 agonist A68930 and the D2 agonist Quinpirole predominantly produced reference memory errors, but to a lesser extent than acute MDMA administration. Low doses of both drugs produced a synergistic effect, more similar to that seen with acute MDMA administration. These findings suggest dopamine plays a role in the reference memory effect seen with MDMA exposure in the partially baited radial maze. In the second half of the thesis binge regimes of MDMA (4 x 10mg/kg) were administered to rats. When there was a gap of eight weeks between dosing and training the ability to acquire the radial arm maze was not significantly impaired. When this MDMA regime was repeated with a three-day gap between dosing and training it produced a significant but transient deficit in performance. When later challenged with acute doses of MDMA (4.0 mg/kg) the binge treated rats were less impaired than saline controls indicating drug tolerance. In an additional study that used a three-day delay between dosing and training a significant impairment in task acquisition was found. This deficit appeared to be long-term as the MDMA treated rats were impaired when the rules of task were changed suggesting a deficit in cognitive flexibility. Again when subjects were challenged with acute MDMA there was evidence of drug tolerance. The final study examined the effects of repeated MDMA exposure on task acquisition by administering acute doses of MDMA or saline once a week after rats had previously been treated with either a binge regime of MDMA or saline. MDMA exposure significantly impaired task acquisition and produced residual drug effects in the binge treated MDMA group the day after acute drug administration. However evidence of behavioural tolerance in this study was mixed due to a floor effect where performance of the binge MDMA group was so poor at the beginning of the study. In conclusion MDMA exposure impaired accuracy with reference memory processes were more affected than working memory processes. The underlying nature of this impairment remains unclear but it may be due to a long-term memory deficit, an impairment in understanding task rules or a perseverative pattern of responding. These findings imply human Ecstasy users may show deficits in acquiring information and may experience deficits in cognitive flexibility</p>

Social Aspects of Discussions Affect Capitulation and Susceptibility to False Memories

<p>People talk. People talk to entertain each other, to divulge news, and to gain support. Additionally, people talk about shared experiences to figure out what "really" happened. But does talking about the past change what we remember? That is the overarching question of the research presented in this thesis. People remember the same events in different ways; consequently, when people discuss the past, they might come across new information. To examine how discussion affects people's memories, we must know what happened during a target event and must create conflicts in the discussion to see how those conflicts affect people's memories. To overcome these challenges, I used the MORI technique to present different viewers with different movies on the same screen at the same time (Mori, 2003; 2007). The MORI technique allows people to feel that they have shared an experience--they sit side-by-side and ostensibly watch the same--yet systematic differences are introduced into their memories, and the effect of those differences can be tracked through discussion. I report a series of experiments that examine the efficacy of the MORI technique and investigate how different social factors contribute to false memories. Each experiment used a variation of the same basic three-stage procedure. First, pairs of people each unwittingly watched slightly different versions of an event. Next, pairs answered questions about the event together; some questions guided them to discuss details for which they had seen contradictory information. Finally, subjects completed a memory test individually to determine what each person really remembered about the event. In short, when people watched a movie via the MORI technique, they could see and remember the details of the movie (Experiments 1A and 1B), and they did not notice or implicitly remember details from the alternate (blocked) movie version--the version their partner saw (Experiments 3A and 3B). Additionally, discussion corrupted people's memories (Experiments 2A, 2B, 4, 5 and 6). 'People were influenced by their partner's suggestions: they falsely remembered details from their partner's version of the event, even though those details contradicted what they personally saw. Consistent with the Source Monitoring Framework, the corrupting influence of the discussion depended on social factors in the interaction (Johnson, Hashtroudi, & Lindsay, 1993; Lindsay, 2008). For instance, people were more likely to remember false details that their romantic partner suggested than false details that a stranger suggested (Experiment 4). Additionally, leading people to believe that their counterpart's vision was better or worse than their own led them to be more or less influenced by their counterpart's false suggestions (Experiment 6). In sum, when people share an experience and discuss it they can come to remember seeing things that they were only told about after the event. In other words, corroboration does not equal accuracy. I discuss the possible-beneficial-mechanisms underlying these memory errors; draw parallels between my research and research on social influence, group remembering and transactive memory systems; discuss theoretical, methodological and practical implications, and suggest potential applications of my findings and avenues for future research.</p>

Social Aspects of Discussions Affect Capitulation and Susceptibility to False Memories

<p>People talk. People talk to entertain each other, to divulge news, and to gain support. Additionally, people talk about shared experiences to figure out what "really" happened. But does talking about the past change what we remember? That is the overarching question of the research presented in this thesis. People remember the same events in different ways; consequently, when people discuss the past, they might come across new information. To examine how discussion affects people's memories, we must know what happened during a target event and must create conflicts in the discussion to see how those conflicts affect people's memories. To overcome these challenges, I used the MORI technique to present different viewers with different movies on the same screen at the same time (Mori, 2003; 2007). The MORI technique allows people to feel that they have shared an experience--they sit side-by-side and ostensibly watch the same--yet systematic differences are introduced into their memories, and the effect of those differences can be tracked through discussion. I report a series of experiments that examine the efficacy of the MORI technique and investigate how different social factors contribute to false memories. Each experiment used a variation of the same basic three-stage procedure. First, pairs of people each unwittingly watched slightly different versions of an event. Next, pairs answered questions about the event together; some questions guided them to discuss details for which they had seen contradictory information. Finally, subjects completed a memory test individually to determine what each person really remembered about the event. In short, when people watched a movie via the MORI technique, they could see and remember the details of the movie (Experiments 1A and 1B), and they did not notice or implicitly remember details from the alternate (blocked) movie version--the version their partner saw (Experiments 3A and 3B). Additionally, discussion corrupted people's memories (Experiments 2A, 2B, 4, 5 and 6). 'People were influenced by their partner's suggestions: they falsely remembered details from their partner's version of the event, even though those details contradicted what they personally saw. Consistent with the Source Monitoring Framework, the corrupting influence of the discussion depended on social factors in the interaction (Johnson, Hashtroudi, & Lindsay, 1993; Lindsay, 2008). For instance, people were more likely to remember false details that their romantic partner suggested than false details that a stranger suggested (Experiment 4). Additionally, leading people to believe that their counterpart's vision was better or worse than their own led them to be more or less influenced by their counterpart's false suggestions (Experiment 6). In sum, when people share an experience and discuss it they can come to remember seeing things that they were only told about after the event. In other words, corroboration does not equal accuracy. I discuss the possible-beneficial-mechanisms underlying these memory errors; draw parallels between my research and research on social influence, group remembering and transactive memory systems; discuss theoretical, methodological and practical implications, and suggest potential applications of my findings and avenues for future research.</p>

Does wording matter? Examining the effect of phrasing on memory for negated political fact-checks

After encountering negated messages, people may remember the core claim while forgetting the negative evaluation. These memory errors are of particular concern for fact checks on social media, which often use brief affirmations or negations to help the public learn the truth behind questionable claims. Across three experiments, we examined whether these memory errors could be minimized by placing evaluations before the entire claim is stated (e.g., “No, X did not do Y, as A claims”), rather than after (e.g., “A claims X did Y. No, this is false”). Participants remembered whether fact-checked political claims were affirmed or negated immediately (Experiment 1) and one week later (Experiment 2). While participants began to forget these fact-checks after three weeks, this forgetting was similar for before- and after-claim evaluations, contrary to our predictions (Experiment 3). These results suggest that there are multiple, equally memorable formats for communicating affirmations and negations.

Permchecker: a toolchain for debugging memory managers with typestate

Dynamic memory managers are a crucial component of almost every modern software system. In addition to implementing efficient allocation and reclamation, memory managers provide the essential abstraction of memory as distinct objects, which underpins the properties of memory safety and type safety. Bugs in memory managers, while not common, are extremely hard to diagnose and fix. One reason is that their implementations often involve tricky pointer calculations, raw memory manipulation, and complex memory state invariants. While these properties are often documented, they are not specified in any precise, machine-checkable form. A second reason is that memory manager bugs can break the client application in bizarre ways that do not immediately implicate the memory manager at all. A third reason is that existing tools for debugging memory errors, such as Memcheck, cannot help because they rely on correct allocation and deallocation information to work. In this paper we present Permchecker, a tool designed specifically to detect and diagnose bugs in memory managers. The key idea in Permchecker is to make the expected structure of the heap explicit by associating typestates with each piece of memory. Typestate captures elements of both type (e.g., page, block, or cell) and state (e.g., allocated, free, or forwarded). Memory manager developers annotate their implementation with information about the expected typestates of memory and how heap operations change those typestates. At runtime, our system tracks the typestates and ensures that each memory access is consistent with the expected typestates. This technique detects errors quickly, before they corrupt the application or the memory manager itself, and it often provides accurate information about the reason for the error. The implementation of Permchecker uses a combination of compile-time annotation and instrumentation, and dynamic binary instrumentation (DBI). Because the overhead of DBI is fairly high, Permchecker is suitable for a testing and debugging setting and not for deployment. It works on a wide variety of existing systems, including explicit malloc/free memory managers and garbage collectors, such as those found in JikesRVM and OpenJDK. Since bugs in these systems are not numerous, we developed a testing methodology in which we automatically inject bugs into the code using bug patterns derived from real bugs. This technique allows us to test Permchecker on hundreds or thousands of buggy variants of the code. We find that Permchecker effectively detects and localizes errors in the vast majority of cases; without it, these bugs result in strange, incorrect behaviors usually long after the actual error occurs.

False Memories in Native and Foreign Languages

Human memory is prone to memory errors and distortion. Evidence from studies on cognitive functions in bilinguals indicates that they might be prone to different types of memory errors compared to monolinguals; however, the effect of language in false memories is still understudied. Source monitoring processes required for proper memory functioning, presumably, rely on inhibitory control, which is also heavily utilized by bilinguals. Moreover, it is suggested that thinking in a second language leads to more systematic and deliberate reasoning. All these results lead to expect that bilinguals are more analytical when processing information in their second language overcoming some memory errors depending on the language of information. To test this hypothesis, we run a classical misinformation experiment with an explicit source monitoring task with a sample of Russian–English bilinguals. The language of the misinformation presentation did not affect the degree of the misinformation effect between the Russian and English languages. Source monitoring demonstrated an overall higher accuracy for attributions to the English source over the Russian source. Furthermore, analysis on incorrect source attributions showed that when participants misattributed the sources of false information (English or Russian narrative), they favored the Russian source over the not presented condition. Taken together, these results imply that high proficiency in the second language does not affect misinformation and that information processing and memory monitoring in bilinguals can differ depending on the language of the information, which seems to lead to some memory errors and not others.

Current clinical practice in patients with cardiac implantable electronic devices undergoing radiotherapy: a literature review

Patients with cardiac implantable electronic devices (CIED) undergoing radiotherapy (RT) are more common due to the ageing of the population. With newer CIEDs’ implementing the complementary metal-oxide semiconductor (CMOS) technology which allows the miniaturization of CIED, it is also more susceptible to RT. Effects of RT on CIED ranges from device interference, device operational/memory errors of permanent damage. These malfunctions can cause life-threatening clinical effects. Cumulative dose is not the only component of RT that causes CIED malfunction, as neutron use and dose rate effect also affects CIEDs. The management of this patient cohort in clinical practice is inconsistent due to the lack of a consistent guideline from manufacturers and physician specialty societies. Our review will focus on the current clinical practice and the recently updated guidelines of managing patients with CIED undergoing RT. We aim to simplify the evidence and provide a simple and easy to use guide based on the recent guidelines.