Twenty years of load theory—Where are we now, and where should we go next?

Selective attention allows us to ignore what is task-irrelevant and focus on what is task-relevant. The cognitive and neural mechanisms that underlie this process are key topics of investigation in cognitive psychology. One of the more prominent theories of attention is perceptual load theory, which suggests that the efficiency of selective attention is dependent on both perceptual and cognitive load. It is now more than 20 years since the proposal of load theory, and it is a good time to evaluate the evidence in support of this influential model. The present article supplements and extends previous reviews (Lavie, Trends in Cognitive Sciences, 9, 75–82. doi:10.​1016/​j.​tics.​2004.​12.​004, 2005, Current Directions in Psychological Science, 19, 143–148. doi:10.​1177/​0963721410370295​, 2010) by examining more recent research in what appears to be a rapidly expanding area. The article comprises five parts, examining (1) evidence for the effects of perceptual load on attention, (2) cognitive load, (3) individual differences under load, (4) alternative theories and criticisms, and (5) the future of load theory. We argue that the key next step for load theory will be the application of the model to real-world tasks. The potential benefits of applied attention research are numerous, and there is tentative evidence that applied research would provide strong support for the theory itself, as well as real-world benefits related to activities in which attention is crucial, such as driving and education

Fool me twice: How effective is debriefing in false memory studies?

Deception is often necessary in false memory studies, especially when the study aims to explore the effect of misinformation on memory. At the end of the study, participants are debriefed, but does this eliminate the influence of misinformation? In the current study, we followed up 630 participants six months after they participated in a study in which they were exposed to fabricated political news stories. We compared the memories of these â continuing participantsâ for both novel and previously seen news stories to the memories of 474 newly recruited participants. Relative to new recruits, continuing participants were less likely to report a false memory for a story that they had been previously exposed to, and they were also less likely to report a false memory for a novel fake news story. Continuing participants were more likely to report a memory for previously seen true events than novel true events. Both groups of participants reported enjoying the experience and feeling confident that they understood which stories were fabricated. Importantly, this study did not find any negative long-term effects of participating in our false memory experiment, and even exhibited some positive effects

False memories for fake news during Ireland's abortion referendum

The current study examined false memories in the week preceding the 2018 Irish abortion referendum. Participants (N = 3,140) viewed six news stories concerning campaign events—two fabricated and four authentic. Almost half of the sample reported a false memory for at least one fabricated event, with more than one third of participants reporting a specific memory of the event. “Yes” voters (those in favor of legalizing abortion) were more likely than “no” voters to “remember” a fabricated scandal regarding the campaign to vote “no,” and “no” voters were more likely than “yes” voters to “remember” a fabricated scandal regarding the campaign to vote “yes.” This difference was particularly strong for voters of low cognitive ability. A subsequent warning about possible misinformation slightly reduced rates of false memories but did not eliminate these effects. This study suggests that voters in a real-world political campaign are most susceptible to forming false memories for fake news that aligns with their beliefs, in particular if they have low cognitive ability

Best practices for ethical conduct of misinformation research: A scoping review and critical commentary

Misinformation can have noxious impacts on cognition, fostering the formation of false beliefs, retroactively distorting memory for events, and influencing reasoning and decision-making even after it has been credibly corrected. Researchers investigating the impacts of real-world misinformation are therefore faced with an ethical issue: they must consider the immediate and long-term consequences of exposing participants to false claims. In this paper, we first present an overview of the ethical risks associated with real-world misinformation. We then report results from a scoping review of ethical practices in misinformation research. We investigated (1) the extent to which researchers report the details of their ethical practices, including issues of informed consent and debriefing, and (2) the specific steps that researchers report taking to protect participants from the consequences of misinformation exposure. We found that fewer than 30% of misinformation papers report any debriefing, and almost no authors assessed the effectiveness of their debriefing procedure. Building on the findings from this review, we evaluate the balance of risk versus reward currently operating in this field and propose a set of guidelines for best practices. Our ultimate goat is to allow researchers the freedom to investigate questions of considerable scientific and societal impact white meeting their ethical obligations to participants

The implications of Methylphenidate use by healthy medical students and doctors in South Africa

Background: The use of medical stimulants to sustain attention, augment memory and enhance intellectual capacity is increasing in society. The use of Methylphenidate for cognitive enhancement is a subject that has received much attention in the literature and academic circles in recent times globally. Medical doctors and medical students appear to be equally involved in the off-label use of Methylphenidate. This presents a potential harm to society and the individual as the long-term side effect profile of this medication is unknown. Discussion: The implication of the use of Methylphenidate by medical students and doctors has not been fully explored. This article considers the impact of this use on the traditional role of medicine, society, the patient and suggests a way forward. We discuss the salient philosophy surrounding the use of cognitive enhancement. We query whether there are cognitive benefits to the use of Methylphenidate in healthy students and doctors and whether these benefits would outweigh the risks in taking the medication. Could these benefits lead to tangible outcomes for society and could the off label-use of Methylphenidate potentially undermine the medical profession and the treatment of patients? If cognitive benefits are proven then doctors may be coerced explicitly or implicitly to use the drug which may undermine their autonomy. The increased appeal of cognitive enhancement challenges the traditional role of medicine in society, and calls into question the role of a virtuous life as a contributing factor for achievement. In countries with vast economic disparity such as South Africa an enhancement of personal utility that can be bought may lead to greater inequities. Summary: Under the status quo the distribution of methylphenidate is unjust. Regulatory governmental policy must seek to remedy this while minimising the potential for competitive advantage for the enhanced. Public debate on the use of cognitive enhancement is long overdue and must be stimulated. The use of Methylphenidate for cognitive enhancement is philosophically defendable if long-term research can prove that the risks are negligible and the outcomes tangible

Perceptual load affects eyewitness accuracy and susceptibility to leading questions

Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e.,the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator), the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals

Neural repetition effects in the medial temporal lobe complex are modulated by previous encoding experience.

It remains an intriguing question why the medial temporal lobe (MTL) can display either attenuation or enhancement of neural activity following repetition of previously studied items. To isolate the role of encoding experience itself, we assessed neural repetition effects in the absence of any ongoing task demand or intentional orientation to retrieve. Experiment 1 showed that the hippocampus and surrounding MTL regions displayed neural repetition suppression (RS) upon repetition of past items that were merely attended during an earlier study phase but this was not the case following re-occurrence of items that had been encoded into working memory (WM). In this latter case a trend toward neural repetition enhancement (RE) was observed, though this was highly variable across individuals. Interestingly, participants with a higher degree of neural RE in the MTL complex displayed higher memory sensitivity in a later, surprise recognition test. Experiment 2 showed that massive exposure at encoding effected a change in the neural architecture supporting incidental repetition effects, with regions of the posterior parietal and ventral-frontal cortex in addition to the hippocampus displaying neural RE, while no neural RS was observed. The nature of encoding experience therefore modulates the expression of neural repetition effects in the MTL and the neocortex in the absence of memory goals

Neural repetition effects in the medial temporal lobe complex are modulated by previous encoding experience

It remains an intriguing question why the medial temporal lobe (MTL) can display either attenuation or enhancement of neural activity following repetition of previously studied items. To isolate the role of encoding experience itself, we assessed neural repetition effects in the absence of any ongoing task demand or intentional orientation to retrieve. Experiment 1 showed that the hippocampus and surrounding MTL regions displayed neural repetition suppression (RS) upon repetition of past items that were merely attended during an earlier study phase but this was not the case following re-occurrence of items that had been encoded into working memory (WM). In this latter case a trend toward neural repetition enhancement (RE) was observed, though this was highly variable across individuals. Interestingly, participants with a higher degree of neural RE in the MTL complex displayed higher memory sensitivity in a later, surprise recognition test. Experiment 2 showed that massive exposure at encoding effected a change in the neural architecture supporting incidental repetition effects, with regions of the posterior parietal and ventral-frontal cortex in addition to the hippocampus displaying neural RE, while no neural RS was observed. The nature of encoding experience therefore modulates the expression of neural repetition effects in the MTL and the neocortex in the absence of memory goals.Medical Research Counci

Functional connectivity between ventral and dorsal frontoparietal networks underlies stimulus-driven and working memory-driven sources of visual distraction

We investigate the neural basis of two routes to visual distraction: salient stimuli capture attention in a bottom-up fashion and the reappearance of task-irrelevant items that are being actively maintained in working memory can lead to distraction via top-down, but automatic, guidance of attention. Bottom-up, stimulus-driven distraction has typically been associated with a ventral network incorporating the inferior frontal gyrus and temporoparietal junction. A dorsal network including the superior frontal gyrus, superior parietal cortex and intraparietal sulcus is known to underlie the voluntary, top-down control of attention. Here we show that the ventral attention network may be modulated in a top-down manner by task-irrelevant memory signals. Furthermore, we delineate how the biasing of attention by these bottom-up and top-down sources of visual distraction is modulated by changes in connectivity among critical nodes of ventral and dorsal frontoparietal regions. The findings further our understanding of the neural circuitry that mediates the control of human visual attention.Medical Research Counci

Functional connectivity between ventral and dorsal frontoparietal networks underlies stimulus-driven and working memory-driven sources of visual distraction

We investigate the neural basis of two routes to visual distraction: salient stimuli capture attention in a bottom-up fashion and the reappearance of task-irrelevant items that are being actively maintained in working memory can lead to distraction via top-down, but automatic, guidance of attention. Bottom-up, stimulus-driven distraction has typically been associated with a ventral network incorporating the inferior frontal gyrus and temporoparietal junction. A dorsal network including the superior frontal gyrus, superior parietal cortex and intraparietal sulcus is known to underlie the voluntary, top-down control of attention. Here we show that the ventral attention network may be modulated in a top-down manner by task-irrelevant memory signals. Furthermore, we delineate how the biasing of attention by these bottom-up and top-down sources of visual distraction is modulated by changes in connectivity among critical nodes of ventral and dorsal frontoparietal regions. The findings further our understanding of the neural circuitry that mediates the control of human visual attention.Medical Research Counci