The current study aims to deepen understanding of the symptom dimension of negative overgeneralization in anxiety. Specifically, the study examines the malleability of memory processes that are known to occur during sleep that may underlie negative overgeneralization.
Up to 50% of peripubertal youth with anxiety have unmet clinical needs, leaving these youth at high risk for suicide, depression and substance abuse across adolescence. In accord with the NIMH strategic plan, the proposal aims to deepen mechanistic understanding of anxiety during the sensitive period of peripuberty to inform novel treatments and reduce health risks. The focus is on negative overgeneralization, which is a core dimension of anxiety that is poorly understood, and refers to the tendency to generalize aversive responses from one context (house fire) to other contexts (camp-fire) that share features. Amygdala activity, induced by heightened emotional arousal, enhances plasticity in associative learning mechanisms, facilitating the binding of contextual features in memory that are only loosely related. The proposal posits that sleep plays a critical role in negative overgeneralization. Specifically, the proposal draws from basic neuroscience to posit a model by which heightened amygdala reactivity during wakefulness, induced by increased emotional arousal, facilitates replay of negative memories during sleep. This facilitated replay leads to the stabilization and integration (consolidation) of negative memories into long-term memory networks via slow wave oscillatory events during NREM sleep. The proposal further posits that facilitated replay of negative memories during sleep promotes generalization by influencing underlying neurocomputational mechanisms (i.e., pattern completion - a computational process that makes neural representations similar). Finally, the proposal posits that sleep-dependent consolidation is malleable, such that Targeted Memory Reactivation (TMR) of positive memories during sleep can competitively displace consolidation of negative memories. This model is tested using a novel multi-method approach combining neuroimaging, polysomnography, and a memory task that captures behavioral generalization and its underlying neural mechanisms (i.e. pattern completion). Aims 1 and 2 do not involve a clinical trial. Aim 1 examines 200 peripubertal youth (ages 10-13 years) across a full continuum of anxious symptoms in a randomized sleep (n=140) versus wake (n=60) design to demonstrate sleep-dependent effects on behavioral and neural mechanisms of negative overgeneralization. Aim 2 focuses on the 140 youth in the sleep condition to evaluate amygdala reactivity at encoding and sleep neurophysiology during post-encoding sleep as mediators between anxiety and negative overgeneralization. Aim 3 is the clinical trial to which this registration refers. In Aim 3, the same design as the sleep condition (above) is used, but a new sample of youth with elevated anxiety (n=60) is recruited to enroll in a randomized trial in which neutral memories are cued during sleep (TMR, n=30), or sham cues are presented during sleep (n=30), to examine malleability of sleep-dependent mechanisms of negative overgeneralization. This project will set the stage for the long-term goal of developing novel interventions that manipulate sleep (e.g. via TMR) not only to improve existing symptoms, but also to positively shape neurodevelopment and reduce risk in the sensitive period of peripuberty.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
58
Experimental manipulation to observe effects on memory for learned material.
Sham manipulation
Center for Children and Families, Florida International University
Miami, Florida, United States
Nicklaus Children's Hospital
Miami, Florida, United States
Scores on the Lure Generalization Index (a Behavioral Measure of Generalization)
Emotional Mnemonic Similarity Task. Participants view pictures depicting negative or neutral objects/scenes. After a delay period (1 week) they are presented with a second set of pictures that are the same (targets), slightly different (lures), or completely different (foils) from the first series of pictures. They are told to indicate by button press if images they are currently viewing are "old" or "new". Responding to the lures as old ("false alarms") provides a signature of generalization for each participant. To correct for response biases (i.e., a tendency to label items as "old") a Lure Generalization Index (LGI) is calculated which reflects corrected memory generalization by subtracting false alarm rates to foils from false alarm rates to lures. Larger LGI values indicate greater generalization (i.e., greater tendency to misidentify similar items as previously seen, accounting for overall biases to identify any items as previously seen). Minimum value -1 and maximum value =1
Time frame: Delayed recall, 1 week
Scores on the Lure Generalization Index (a Behavioral Measure of Generalization)
Emotional Mnemonic Similarity Task. Participants view pictures depicting negative or neutral objects/scenes. After a delay period (12 hours) they are presented with a second set of pictures that are the same (targets), slightly different (lures), or completely different (foils) from the first series of pictures. They are told to indicate by button press if images they are currently viewing are "old" or "new". Responding to the lures as old ("false alarms") provides a signature of generalization for each participant. To correct for response biases (i.e., a tendency to label items as "old") a Lure Generalization Index (LGI) is calculated which reflects corrected memory generalization by subtracting false alarm rates to foils from false alarm rates to lures. Larger LGI values indicate greater generalization (i.e., greater tendency to misidentify similar items as previously seen, accounting for overall biases to identify any items as previously seen). Minimum value -1 and maximum value =1
Time frame: Recall, 12 hours
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