How well do online, self-administered measures correspond to in-lab assessments? A preliminary examination of three measures in healthy older adults.

The COVID-19 pandemic unexpectedly plunged investigators around the world into "digital neuropsychology" and online testing, and clinicians into telemedicine. OBJECTIVE: The objective of the present study was to examine the correspondence between previously collected in-lab scores and online scores administered using a fully-automated platform, and identify issues that should be considered for automated testing. METHOD: We examined correspondence between in-lab and online scores for three types of measures often used as cognitive screeners in studies of older adults: A performance test, a subjective symptom-rating scale, and vocabulary test. Participants were a community sample of healthy older adults (n = 55). RESULTS: Both preregistered and exploratory analyses found only modest correspondence for the performance test (Cronbach's α .604), but relatively good correspondence for the subjective rating (.821) and vocabulary test (.952). Additional analyses identified issues with specific items on the performance test, as well as potential indicators of problematic cases such as the use of external aids on the vocabulary test. CONCLUSION: Our results identify several pitfalls when adapting tests for online testing, but the relatively strong correspondence for some measures suggests a promising outlook for the validity of online testing once these are resolved. We make suggestions for how the identified pitfalls might be addressed in future studies attempting to adapt performance measures for online testing. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Opposite reactions to loss incentive by young and older adults: Insights from diffusion modeling.

The prospect of loss becomes more salient in later life, and the opportunity to avoid loss is often used to motivate older adults. We examined the effect of loss incentive on working memory in young and older adults. Diffusion-modeling analyses, manipulation of task parameters, and self-report measures identified which aspects of cognitive-motivational processing were most affected within each group. As predicted, loss incentive increased working memory performance and self-reported motivation in young adults, but, consistent with prior work, had the opposite effect in older adults. Diffusion-modeling analyses suggested the primary effect was on the quality of the memory representation (drift rate). Incentive did not interact with retention interval or the number of items in the memory set. Instead, longer retention intervals led to better performance, potentially by improved differentiation between studied items and the unstudied probe as a function of temporal context. Overall, the results do not support theories suggesting that older adults are either more motivated by loss or that they ignore it. Instead, the loss incentive increased young adults' performance and subjective motivation, with opposite effects for older adults. The specific impact on drift rate and lack of interactions with set size or retention interval suggest that rather than affecting load-dependent or strategic processes, the effects occur at a relatively global level related to overall task engagement. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Cholinergic systems, attentional-motor integration, and cognitive control in Parkinson's disease.

Dysfunction and degeneration of CNS cholinergic systems is a significant component of multi-system pathology in Parkinson's disease (PD). We review the basic architecture of human CNS cholinergic systems and the tools available for studying changes in human cholinergic systems. Earlier post-mortem studies implicated abnormalities of basal forebrain corticopetal cholinergic (BFCC) and pedunculopontine-laterodorsal tegmental (PPN-LDT) cholinergic projections in cognitive deficits and gait-balance deficits, respectively. Recent application of imaging methods, particularly molecular imaging, allowed more sophisticated correlation of clinical features with regional cholinergic deficits. BFCC projection deficits correlate with general and domain specific cognitive deficits, particularly for attentional and executive functions. Detailed analyses suggest that cholinergic deficits within the salience and cingulo-opercular task control networks, including both neocortical, thalamic, and striatal nodes, are a significant component of cognitive deficits in non-demented PD subjects. Both BFCC and PPN-LDT cholinergic projection systems, and striatal cholinergic interneuron (SChI), abnormalities are implicated in PD gait-balance disorders. In the context of experimental studies, these results indicate that disrupted attentional functions of BFCC and PPN-LDT cholinergic systems underlie impaired gait-balance functions. SChI dysfunction likely impairs intra-striatal integration of attentional and motor information. Thalamic and entorhinal cortex cholinergic deficits may impair multi-sensory integration. Overt degeneration of CNS systems may be preceded by increased activity of cholinergic neurons compensating for nigrostriatal dopaminergic deficits. Subsequent dysfunction and degeneration of cholinergic systems unmasks and exacerbates functional deficits secondary to dopaminergic denervation. Research on CNS cholinergic systems dysfunctions in PD requires a systems-level approach to understanding PD pathophysiology.

α4ß2* Nicotinic Cholinergic Receptor Target Engagement in Parkinson Disease Gait-Balance Disorders.

OBJECTIVE: Attentional deficits following degeneration of brain cholinergic systems contribute to gait-balance deficits in Parkinson disease (PD). As a step toward assessing whether α4ß2* nicotinic acetylcholine receptor (nAChR) stimulation improves gait-balance function, we assessed target engagement of the α4ß2* nAChR partial agonist varenicline. METHODS: Nondemented PD participants with cholinergic deficits were identified with [18 F]fluoroethoxybenzovesamicol positron emission tomography (PET). α4ß2* nAChR occupancy after subacute oral varenicline treatment was measured with [18 F]flubatine PET. With a dose selected from the nAChR occupancy experiment, varenicline effects on gait, balance, and cognition were assessed in a double-masked placebo-controlled crossover study. Primary endpoints were normal pace gait speed and a measure of postural stability. RESULTS: Varenicline doses (0.25mg per day, 0.25mg twice daily [b.i.d.], 0.5mg b.i.d., and 1.0mg b.i.d.) produced 60 to 70% receptor occupancy. We selected 0.5mg orally b.i.d for the crossover study. Thirty-three participants completed the crossover study with excellent tolerability. Varenicline had no significant impact on the postural stability measure and caused slower normal pace gait speed. Varenicline narrowed the difference in normal pace gait speed between dual task and no dual task gait conditions, reduced dual task cost, and improved sustained attention test performance. We obtained identical conclusions in 28 participants with treatment compliance confirmed by plasma varenicline measurements. INTERPRETATION: Varenicline occupied α4ß2* nicotinic acetylcholine receptors, was tolerated well, enhanced attention, and altered gait performance. These results are consistent with target engagement. α4ß2* agonists may be worth further evaluation for mitigation of gait and balance disorders in PD. ANN NEUROL 2021;90:130-142.

Aging and inhibition: Introduction to the special issue.

Inhibitory theory suggests that a major determinant of individual differences in cognitive performance (including differences that are typically observed with increasing age) is the ability to dampen down goal-irrelevant stimuli, thoughts, and actions. While this theory has garnered a lot of support over the years, it has also seen several challenges. This special issue of Psychology and Aging entitled "Aging and Inhibition: The View Ahead" continues with this theme and includes 14 articles by top researchers in the field of cognitive aging. While most of the articles included here lend support to the theory, some challenge it or provide limiting conditions. We organize our overview of these articles according to the different functions, or stages, of inhibition, which we refer to as access, deletion, and restraint, followed by a discussion of potential moderators, including practice, motivation, and arousal. In our view, these articles contribute to our understanding of how and when age differences in inhibitory control are observed and the wider implications (both positive and negative) for cognition. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Losing Money and Motivation: Effects of Loss Incentives on Motivation and Metacognition in Younger and Older Adults.

Incentives are usually expected to increase motivation and cognitive control and to thereby improve performance. A small but growing number of studies have begun to investigate whether the effects of incentive on cognitive performance differ for younger vs. older adults. Most have used attention and cognitive control paradigms, trial-wise implementation of incentive condition, and gain incentives (reward), with only a very few investigating the effects of loss incentives. The present study takes a complementary approach: We tested younger and older adults in a working memory paradigm with loss incentives implemented session-wide (between subjects). We also included self-report measures to ask how loss incentive affected participants' perceptions of the mental demand of the task, as well as their perceived effort, frustration, motivation, distraction, and metacognitive judgments of how well they had performed. This allowed us to test the disparate predictions of different theoretical views: the intuitive hypothesis that incentive should increase motivation and performance, the motivational shift proposal that older adults are especially motivated to avoid losses (Freund and Ebner, 2005), a heuristic "positivity effect" perspective that older adults ignore losses (Brassen et al., 2012; Williams et al., 2017), and a more nuanced view that suggests that when negative information is unavoidable and increases perceived costs, older adults may instead disengage from the situation (Charles, 2010; Hess, 2014). The results seemed most consistent with the more nuanced view of the positivity effect. While neither group showed incentive-related performance differences, both younger and older adults reported greater perceived demand and frustration under loss incentive, especially in the most challenging conditions. Loss incentive increased the accuracy of immediate metacognitive judgments, but reduced the accuracy of later, more global judgments of competency for older adults. Self-report measures suggested that the loss incentive manipulation was distracting to young adults and demotivating for older adults. The results suggest a need for caution in generalizing from existing studies to everyday life, and that additional studies parameterizing critical aspects of task design and incentive manipulation are needed to fully understand how incentives affect cognition and motivation in younger and older adults.

Forebrain Cholinergic Signaling: Wired and Phasic, Not Tonic, and Causing Behavior.

Conceptualizations of cholinergic signaling as primarily spatially diffuse and slow-acting are based largely on measures of extracellular brain ACh levels that require several minutes to generate a single data point. In addition, most such studies inhibited the highly potent catalytic enzyme for ACh, AChE, to facilitate measurement of ACh. Absent such inhibition, AChE limits the presence of ambient ACh and thus renders it unlikely that ACh influences target regions via slow changes in extracellular ACh concentrations. We describe an alternative view by which forebrain signaling in cortex driving cognition is largely phasic (milliseconds to perhaps seconds), and unlikely to be volume-transmitted. This alternative is supported by new evidence from real-time amperometric recordings of cholinergic signaling indicating a specific function of rapid, phasic, transient cholinergic signaling in attentional contexts. Previous neurochemical evidence may be reinterpreted in terms of integrated phasic cholinergic activity that mediates specific behavioral and cognitive operations; this reinterpretation fits well with recent computational models. Optogenetic studies support a causal relationship between cholinergic transients and behavior. This occurs in part via transient-evoked muscarinic receptor-mediated high-frequency oscillations in cortical regions. Such oscillations outlast cholinergic transients and thus link transient ACh signaling with more sustained postsynaptic activity patterns to support relatively persistent attentional biases. Reconceptualizing cholinergic function as spatially specific, phasic, and modulating specific cognitive operations is theoretically powerful and may lead to pharmacologic treatments more effective than those based on traditional views.Dual Perspectives Companion Paper: Diverse Spatiotemporal Scales of Cholinergic Signaling in the Neocortex, by Anita A. Disney and Michael J. Higley.

Poor Sleep Quality and Compromised Visual Working Memory Capacity.

OBJECTIVES: Reduction in the amount of information (storage capacity) retained in working memory (WM) has been associated with sleep loss. The present study examined whether reduced WM capacity is also related to poor everyday sleep quality and, more importantly, whether the effects of sleep quality could be dissociated from the effects of depressed mood and age on WM. METHODS: In two studies, WM was assessed using a short-term recall task, producing behavioral measures for both the amount of retained WM information (capacity) and how precise the retained WM representations were (precision). Self-report measures of sleep quality and depressed mood were obtained using questionnaires. RESULTS: In a sample of college students, Study 1 found that poor sleep quality and depressed mood could independently predict reduced WM capacity, but not WM precision. Study 2 generalized these sleep- and mood-related WM capacity effects to a community sample (aged 21-77 years) and further showed that age was associated with reduced WM precision. CONCLUSIONS: Together, these findings demonstrate dissociable effects of three health-related factors (sleep, mood, and age) on WM representations and highlighte the importance of assessing different aspects of WM representations (e.g., capacity and precision) in future neuropsychological research.

Cholinergic double duty: cue detection and attentional control.

Cholinergic signaling in the cortex involves fast or transient signaling as well as a relatively slower neuromodulatory component. These two components of cholinergic activity mediate separate yet interacting aspects of cue detection and attentional control. The transient component appears to support the activation of cue-associated task or response sets, whereas the slower modulatory component stabilizes task-set and context representations, therefore potentially facilitating top-down control. Evidence from humans expressing genetic variants of the choline transporter as well as from patients with degenerating cholinergic systems supports the hypothesis that attentional control capacities depend on levels of cholinergic neuromodulation. Deficits in cholinergic-attentional control impact diverse cognitive functions, including timing, working memory, and complex movement control.

Compensatory dopaminergic-cholinergic interactions in conflict processing: Evidence from patients with Parkinson's disease.

Executive functions are complex both in the cognitive operations involved and in the neural structures and functions that support those operations. This complexity makes executive function highly vulnerable to the detrimental effects of aging, brain injury, and disease, but may also open paths to compensation. Neural compensation is often used to explain findings of additional or altered patterns of brain activations by older adults or patient populations compared to young adults or healthy controls, especially when associated with relatively preserved performance. Here we test the hypothesis of an alternative form of compensation, between different neuromodulator systems. 135 patients with Parkinson's Disease (PD) completed vesicular monoamine transporter type2 (VMAT2) and acetylcholinesterase PET scanning to assess the integrity of nigrostriatal dopaminergic, thalamic cholinergic, and cortical cholinergic pathways, and a behavioral test (Stroop + task-switching) that puts high demands on conflict processing, an important aspect of executive control. Supporting the compensatory hypothesis, regression models controlling for age and other covariates revealed an interaction between caudate dopamine and cortical cholinergic integrity: Cortical cholinergic integrity was a stronger predictor of conflict processing in patients with relatively low caudate dopaminergic function. These results suggest that although frontostriatal dopaminergic function plays a central role in executive control, cholinergic systems may also make an important contribution. The present results suggest potential pathways for remediation, and that the appropriate interventions for each patient may depend on their particular profile of decline. Furthermore, they help to elucidate the brain systems that underlie executive control, which may be important for understanding other disorders as well as executive function in healthy adults.

The cortical cholinergic system contributes to the top-down control of distraction: Evidence from patients with Parkinson's disease.

Past animal and human studies robustly report that the cholinergic system plays an essential role in both top-down and bottom-up attentional control, as well as other aspects of cognition (see Ballinger et al., 2016 for a recent review). However, current understanding of how two major cholinergic pathways in the human brain (the basal forebrain-cortical pathway, and the brainstem pedunculopontine-thalamic pathway) contribute to specific cognitive functions remains somewhat limited. To address this issue, we examine how individual variation in the integrity of striatal-dopaminergic, thalamic-cholinergic, and cortical-cholinergic pathways (measured using Positron Emission Tomography in patients with Parkinson's disease) was associated with individual variation in the initial goal-directed focus of attention, the ability to sustain attentional performance over time, and the ability to avoid distraction from a highly-salient, but irrelevant, environmental stimulus. Compared to healthy controls, PD patients performed similarly in the precision of attention-dependent judgments of duration, and in sustaining attention over time. However, PD patients' performance was strikingly more impaired by the distractor. More critically, regression analyses indicated that only cortical-cholinergic integrity, not thalamic-cholinergic or striatal-dopaminergic integrity, made a specific contribution to the ability to resist distraction after controlling for the other variables. These results demonstrate that the basal forebrain cortical cholinergic system serves a specific role in executing top-down control to resist external distraction.

Addiction vulnerability trait impacts complex movement control: Evidence from sign-trackers.

Cognitive-motivational vulnerability traits are associated with increased risk for substance addiction and relapse. Sign-tracking (ST) behavior in rats is associated with poor attentional control, mediated by an unresponsive basal forebrain cholinergic system, and an increased risk for substance addiction/relapse. A separate literature links poor attentional control and cholinergic losses to increased fall risk in Parkinson's disease. Here we tested the hypothesis that the relatively inferior attentional control of STs extends to complex movement control and a propensity for falls. STs were found to fall more often than goal-trackers (GTs) while traversing a straight rotating rod and, similar to human fallers, when taxed by a secondary task. Furthermore, STs fell more often while traversing a rotating zig-zag rod. GTs exhibited fewer falls from this rod by avoiding entry to the rotating zig-zag sections when in, or rotating toward, a difficult traversal state. Goal-tracking rats approached risky movement situations using strategies indicative of superior top-down control. These results suggest that the impact of opponent cognitive-cholinergic traits extends to complex movement control, and that impairments in the cognitive-motor interface are likely to be comorbid with addiction vulnerability. Sign-tracking indexes an endophenotype that may increase the risk for a wide range of neurobehavioral disorders.

Distinct Frontoparietal Networks Underlying Attentional Effort and Cognitive Control.

We investigated the brain activity patterns associated with stabilizing performance during challenges to attention. Our findings revealed distinct patterns of frontoparietal activity and functional connectivity associated with increased attentional effort versus preserved performance during challenged attention. Participants performed a visual signal detection task with and without presentation of a perceptual-attention challenge (changing background). The challenge condition increased activation in frontoparietal regions including right mid-dorsal/dorsolateral PFC (RPFC), approximating Brodmann's area 9, and superior parietal cortex. We found that greater behavioral impact of the challenge condition was correlated with greater RPFC activation, suggesting that increased engagement of cognitive control regions is not always sufficient to maintain high levels of performance. Functional connectivity between RPFC and ACC increased during the challenge condition and was also associated with performance declines, suggesting that the level of synchronized engagement of these regions reflects individual differences in attentional effort. Pretask, resting-state RPFC-ACC connectivity did not predict subsequent performance, suggesting that RPFC-ACC connectivity increased dynamically during task performance in response to performance decrement and error feedback. In contrast, functional connectivity between RPFC and superior parietal cortex not only during the task but also during pretask rest was associated with preserved performance in the challenge condition. Together, these data suggest that resting frontoparietal connectivity predicts performance on attention tasks that rely on those same cognitive control networks and that, under challenging conditions, other control regions dynamically couple with this network to initiate the engagement of cognitive control.

Thalamic cholinergic innervation makes a specific bottom-up contribution to signal detection: Evidence from Parkinson's disease patients with defined cholinergic losses.

Successful behavior depends on the ability to detect and respond to relevant cues, especially under challenging conditions. This essential component of attention has been hypothesized to be mediated by multiple neuromodulator systems, but the contributions of individual systems (e.g., cholinergic, dopaminergic) have remained unclear. The present study addresses this issue by leveraging individual variation in regionally-specific cholinergic denervation in Parkinson's disease (PD) patients, while controlling for variation in dopaminergic denervation. Patients whose dopaminergic and cholinergic nerve terminal integrity had been previously assessed using Positron Emission Tomography (Bohnen et al., 2012) and controls were tested in a signal detection task that manipulates attentional-perceptual challenge and has been used extensively in both rodents and humans to investigate the cholinergic system's role in responding to such challenges (Demeter et al., 2008; McGaughy and Sarter, 1995; see Hasselmo and Sarter 2011 for review). In simple correlation analyses, measures of midbrain dopaminergic, and both cortical and thalamic cholinergic innervation all predicted preserved signal detection under challenge. However, regression analyses also controlling for age, disease severity, and other variables showed that the only significant independent neurotransmitter-related predictor over and above the other variables in the model was thalamic cholinergic integrity. Furthermore, thalamic cholinergic innervation exclusively predicted hits, not correct rejections, indicating a specific contribution to bottom-up salience processing. These results help define regionally-specific contributions of cholinergic function to different aspects of attention and behavior.

Attention and the Cholinergic System: Relevance to Schizophrenia.

Traditional methods of drug discovery often rely on a unidirectional, "bottom-up" approach: A search for molecular compounds that target a particular neurobiological substrate (e.g., a receptor type), the refinement of those compounds, testing in animal models using high-throughput behavioral screening methods, and then human testing for safety and effectiveness. Many attempts have found the "effectiveness" criterion to be a major stumbling block, and we and others have suggested that success may be improved by an alternative approach that considers the neural circuits mediating the effects of genetic and molecular manipulations on behavior and cognition. We describe our efforts to understand the cholinergic system's role in attention using parallel approaches to test main hypotheses in both rodents and humans as well as generating converging evidence using methods and levels of analysis tailored to each species. The close back-and-forth between these methods has enhanced our understanding of the cholinergic system's role in attention both "bottom-up" and "top-down"-that is, the basic neuroscience identifies potential neuronal circuit-based mechanisms of clinical symptoms, and the patient and genetic populations serve as natural experiments to test and refine hypotheses about its contribution to specific processes. Together, these studies have identified (at least) two major and potentially independent contributions of the cholinergic system to attention: a neuromodulatory component that influences cognitive control in response to challenges from distractors that either make detection more difficult or draw attention away from the distractor, and a phasic or transient cholinergic signal that instigates a shift from ongoing behavior and the activation of cue-associated response. Right prefrontal cortex appears to play a particularly important role in the neuromodulatory component integrating motivational and cognitive influences for top-down control across populations, whereas the transient cholinergic signal involves orbitofrontal regions associated with shifts between internal and external attention. Understanding how these two modes of cholinergic function interact and are perturbed in schizophrenia will be an important prerequisite for developing effective treatments.

Cholinergic genetics of visual attention: Human and mouse choline transporter capacity variants influence distractibility.

The basal forebrain cholinergic projection system to the cortex mediates essential aspects of visual attention performance, including the detection of cues and the response to performance challenges (top-down control of attention). Higher levels of top-down control are mediated via elevated levels of cholinergic neuromodulation. The neuronal choline transporter (CHT) strongly influences the synthesis and release of acetylcholine (ACh). As the capacity of the CHT to import choline into the neuron is a major, presynaptic determinant of cholinergic neuromodulation, we hypothesize that genetically-imposed CHT capacity variation impacts the balance of bottom-up versus top-down control of visual attention. Following a brief review of the cognitive concepts relevant for this hypothesis, we describe the key results from our research in mice and humans that possess genetically-imposed changes in choline uptake capacity. CHT subcapacity is associated with poor top-down attentional control and attenuated (cholinergic) activation of right frontal regions. Conversely, mice overexpressing the CHT, and humans expressing a CHT variant hypothesized to enhance choline transporter function, are relatively resistant to challenges of visual attention performance. Genetic or environmental modulation of CHT expression and function may be associated with vulnerabilities for cognitive disorders.

Cognitive Aging and Time Perception: Roles of Bayesian Optimization and Degeneracy.

This review outlines the basic psychological and neurobiological processes associated with age-related distortions in timing and time perception in the hundredths of milliseconds-to-minutes range. The difficulty in separating indirect effects of impairments in attention and memory from direct effects on timing mechanisms is addressed. The main premise is that normal aging is commonly associated with increased noise and temporal uncertainty as a result of impairments in attention and memory as well as the possible reduction in the accuracy and precision of a central timing mechanism supported by dopamine-glutamate interactions in cortico-striatal circuits. Pertinent to these findings, potential interventions that may reduce the likelihood of observing age-related declines in timing are discussed. Bayesian optimization models are able to account for the adaptive changes observed in time perception by assuming that older adults are more likely to base their temporal judgments on statistical inferences derived from multiple trials than on a single trial's clock reading, which is more susceptible to distortion. We propose that the timing functions assigned to the age-sensitive fronto-striatal network can be subserved by other neural networks typically associated with finely-tuned perceptuo-motor adjustments, through degeneracy principles (different structures serving a common function).

What do phasic cholinergic signals do?

In addition to the neuromodulatory role of cholinergic systems, brief, temporally discrete cholinergic release events, or "transients", have been associated with the detection of cues in attention tasks. Here we review four main findings about cholinergic transients during cognitive processing. Cholinergic transients are: (1) associated with the detection of a cue and influenced by cognitive state; (2) not dependent on reward outcome, although the timing of the transient peak co-varies with the temporal relationship between detection and reward delivery; (3) correlated with the mobilization of the cue-evoked response; (4) causal mediators of shifts from monitoring to cue detection. We next discuss some of the key questions concerning the timing and occurrence of transients within the framework of available evidence including: (1) Why does the shift from monitoring to cue detection require a transient? (2) What determines whether a cholinergic transient will be generated? (3) How can cognitive state influence transient occurrence? (4) Why do cholinergic transients peak at around the time of reward delivery? (5) Is there evidence of cholinergic transients in humans? We conclude by outlining future research studies necessary to more fully understand the role of cholinergic transients in mediating cue detection.

You can go your own way: effectiveness of participant-driven versus experimenter-driven processing strategies in memory training and transfer.

Cognitive training programs that instruct specific strategies frequently show limited transfer. Open-ended approaches can achieve greater transfer, but may fail to benefit many older adults due to age deficits in self-initiated processing. We examined whether a compromise that encourages effort at encoding without an experimenter-prescribed strategy might yield better results. Older adults completed memory training under conditions that either (1) mandated a specific strategy to increase deep, associative encoding, (2) attempted to suppress such encoding by mandating rote rehearsal, or (3) encouraged time and effort toward encoding but allowed for strategy choice. The experimenter-enforced associative encoding strategy succeeded in creating integrated representations of studied items, but training-task progress was related to pre-existing ability. Independent of condition assignment, self-reported deep encoding was associated with positive training and transfer effects, suggesting that the most beneficial outcomes occur when environmental support guiding effort is provided but participants generate their own strategies.

A ten-year follow-up of a study of memory for the attack of September 11, 2001: Flashbulb memories and memories for flashbulb events.

Within a week of the attack of September 11, 2001, a consortium of researchers from across the United States distributed a survey asking about the circumstances in which respondents learned of the attack (their flashbulb memories) and the facts about the attack itself (their event memories). Follow-up surveys were distributed 11, 25, and 119 months after the attack. The study, therefore, examines retention of flashbulb memories and event memories at a substantially longer retention interval than any previous study using a test-retest methodology, allowing for the study of such memories over the long term. There was rapid forgetting of both flashbulb and event memories within the first year, but the forgetting curves leveled off after that, not significantly changing even after a 10-year delay. Despite the initial rapid forgetting, confidence remained high throughout the 10-year period. Five putative factors affecting flashbulb memory consistency and event memory accuracy were examined: (a) attention to media, (b) the amount of discussion, (c) residency, (d) personal loss and/or inconvenience, and (e) emotional intensity. After 10 years, none of these factors predicted flashbulb memory consistency; media attention and ensuing conversation predicted event memory accuracy. Inconsistent flashbulb memories were more likely to be repeated rather than corrected over the 10-year period; inaccurate event memories, however, were more likely to be corrected. The findings suggest that even traumatic memories and those implicated in a community's collective identity may be inconsistent over time and these inconsistencies can persist without the corrective force of external influences.