Spatially organized striatum-wide acetylcholine dynamics for the learning and extinction of Pavlovian cues and actions.

Striatal acetylcholine (ACh) has been linked to behavioral flexibility. A key component of flexibility is down-regulating responding as valued cues and actions become decoupled from positive outcomes. We used array fiber photometry in mice to investigate how ACh release across the striatum evolves during learning and extinction of Pavlovian associations. Changes in multi-phasic release to cues and consummatory actions were bi-directional and region-specific. Following extinction, increases in cue-evoked ACh release emerged in the anterior dorsal striatum (aDS) which preceded a down-regulation of anticipatory behavior. Silencing ACh release from cholinergic interneurons in the aDS blocked behavioral extinction. Dopamine release dipped below baseline for down-shifted cues, but glutamate input onto cholinergic interneurons did not change, suggesting an intrastriatal mechanism for the emergence of ACh increases. Our large- scale mapping of striatal ACh dynamics during learning pinpoints region-specific elevations in ACh release positioned to down-regulate behavior during extinction, a central feature of flexible behavior.

Targeted micro-fiber arrays for measuring and manipulating localized multi-scale neural dynamics over large, deep brain volumes during behavior.

Neural population dynamics relevant to behavior vary over multiple spatial and temporal scales across three-dimensional volumes. Current optical approaches lack the spatial coverage and resolution necessary to measure and manipulate naturally occurring patterns of large-scale, distributed dynamics within and across deep brain regions such as the striatum. We designed a new micro-fiber array approach capable of chronically measuring and optogenetically manipulating local dynamics across over 100 targeted locations simultaneously in head-fixed and freely moving mice, enabling the investigation of cell-type- and neurotransmitter-specific signals over arbitrary 3D volumes at a spatial resolution and coverage previously inaccessible. We applied this method to resolve rapid dopamine release dynamics across the striatum, revealing distinct, modality-specific spatiotemporal patterns in response to salient sensory stimuli extending over millimeters of tissue. Targeted optogenetics enabled flexible control of neural signaling on multiple spatial scales, better matching endogenous signaling patterns, and the spatial localization of behavioral function across large circuits.

True and false memory priming of perceptual closure problems in healthy older adults and older adults with Alzheimer's disease.

OBJECTIVE: The present study set out to investigate whether false memories for pictures exhibit priming effects in older adult controls (OACs) and people with early onset Alzheimer's disease (AD). We conducted two studies to examine whether false memories for pictures had a priming effect on a perceptual closure task (PCT). METHOD: In Experiment 1, OACs and people with early onset AD were presented with pictorial versions of the Deese/Rodiger-McDermott lists and took part in a recognition task. This followed with a PCT, where both groups were shown degraded pictures that became clearer over time and participants had to identify the picture as quickly as possible. In Experiment 2, we manipulated the modality-verbal versus pictorial in both the study phase and PCT phase. RESULTS: Experiment 1 results indicated false memories for pictures did not serve as effective primes in the PCT. Experiment 2 results revealed pictorial false memories primed the PCT significantly slower than pictorial true memories in the visual PCT task, but the reverse finding was shown for the verbal PCT task. Finally, verbal false memories primed the verbal PCT reliably faster than true memories. CONCLUSIONS: Our findings show when solving pictorial problems, for both older adults and people with AD false memories may not activate the appropriate representation in memory for solving a pictorial problems whereas actually presented items do. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Creating false rewarding memories guides novel decision making.

When memories of past rewarding experiences are distorted, are relevant decision-making preferences impacted? Although recent research has demonstrated the important role of episodic memory in value-based decision making, very few have examined the role of false memory in guiding novel decision making. The current study combined the pictorial Deese/Roediger-McDermott false memory paradigm with a reward learning task, where participants learned that items from some related lists gained reward and items from other lists led to no reward. Later, participants' memories and decision-making preferences were tested. With three experiments conducted in three countries, we successfully created false memories of rewarding experiences in which participants falsely remembered seeing a nonpresented lure picture bring them reward thereby confirming our constructive association hypothesis. Such false memories led participants to prefer the lure pictures and respond faster in a follow-up decision-making task, and the more false memories they formed, the higher preferences for the lure items they displayed (Experiment 2). Finally, results were replicated with or without a memory test before the decision-making task, showing that the impact of false memory on decision making was not cued by a memory test (Experiment 3). Our data suggest that the reconstructive nature of memory enables individuals to create new memory episodes to guide decision making in novel situations. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Targeted micro-fiber arrays for measuring and manipulating localized multi-scale neural dynamics over large, deep brain volumes during behavior.

Neural population dynamics relevant for behavior vary over multiple spatial and temporal scales across 3-dimensional volumes. Current optical approaches lack the spatial coverage and resolution necessary to measure and manipulate naturally occurring patterns of large-scale, distributed dynamics within and across deep brain regions such as the striatum. We designed a new micro-fiber array and imaging approach capable of chronically measuring and optogenetically manipulating local dynamics across over 100 targeted locations simultaneously in head-fixed and freely moving mice. We developed a semi-automated micro-CT based strategy to precisely localize positions of each optical fiber. This highly-customizable approach enables investigation of multi-scale spatial and temporal patterns of cell-type and neurotransmitter specific signals over arbitrary 3-D volumes at a spatial resolution and coverage previously inaccessible. We applied this method to resolve rapid dopamine release dynamics across the striatum volume which revealed distinct, modality specific spatiotemporal patterns in response to salient sensory stimuli extending over millimeters of tissue. Targeted optogenetics through our fiber arrays enabled flexible control of neural signaling on multiple spatial scales, better matching endogenous signaling patterns, and spatial localization of behavioral function across large circuits.

External and internal influences yield similar memory effects: the role of deception and suggestion.

In legal cases, testimonies can become contaminated because of an amalgam of external and internal influences on memory. It is well-established that external influences (e.g., suggestive interviews) can hurt memory. However, less focus has been placed on the impact of internal influences (e.g., lying) on memory. In the current review, we show that the available evidence suggests that both external and internal influences exert similar effects on memory. That is, we review studies showing that suggesting non-occurrences and suggesting non-experiences can lead to omission errors and false memories, respectively. Likewise, these memory effects are also observed when focusing on internal influences. That is, false denials, feigning amnesia and fabrication have been shown to affect memory in terms of forgetting (i.e., omissions) and false memories (i.e., commissions). Also, we show that both external and internal influences can lead to changes in the belief that an event occurred. We argue that in legal cases, triers of fact should concentrate on whether both types of influences might have affected testimonial accuracy in witnesses, victims, and suspects.

Oversimplifications and Misrepresentations in the Repressed Memory Debate: A Reply to Ross.

Ross argued that false memory researchers misunderstand the concepts of repression and dissociation, as well as the writings of Freud. In this commentary, we show that Ross is wrong. He oversimplifies and misrepresents the literature on repressed and false memory. We rebut Ross by showing the fallacies underlying his arguments. For example, we adduce evidence showing that the notions of dissociation or repression are unnecessary to explain how people may forget and then remember childhood sexual abuse, stressing that abuse survivors may reinterpret childhood events later in life. Also, Ross overlooks previous critiques concerning dissociation. Finally, we will demonstrate that Ross misrepresents work by Freud and Loftus in the area of repressed and false memory. His article confuses, not clarifies, an already heated debate on the existence of repressed memory.

Early Childhood Memories Are not Repressed: Either They Were Never Formed or Were Quickly Forgotten.

Early childhood events are rarely remembered in adulthood. In fact, memory for these early experiences declines during childhood itself. This holds regardless of whether these memories of autobiographical experiences are traumatic or mundane, everyday experiences. Indeed, what people tend to remember from their childhoods involves relatively innocuous experiences, ones often devoid of emotion. In this article, I provide an overview of the types of memories adults recall from their childhoods and the ages at which these memories are believed to have been formed. Along the way, I provide a brief exegesis of the neurobiological and cognitive underpinnings of early memory development. I will show that changes and growth in neural interconnectivity as well as the development of various cognitive structures (e.g., the inception of the cognitive self) help propel the emergence of a mature autobiographical memory system, one that can and does serve as a reconstructive base for remembering events that occur in later childhood and adulthood. During the course of this review, I detail the nature of early memories, their fragility, and the adaptive consequences of forgetting and supplanting these memories with newer, more age-appropriate experiences throughout childhood.

Generative processing and emotional false memories: a generation "cost" for negative false memory formation but only after delay.

Previous research shows that manipulations (e.g. levels-of-processing) that facilitate true memory often increase susceptibility to false memory. An exception is the generation effect. Using the Deese/Roediger-McDermott (DRM) paradigm, Soraci et al. found that generating rather than reading list items led to an increase in true but not false memories. They argued that generation led to enhanced item-distinctiveness that drove down false memory production. In the current study, we investigated the effects of generative processing on valenced stimuli and after a delayed retention interval to examine factors that may lead to a generation effect that increases false memories. At the immediate test, false recognition rates for both negative and neutral valanced critical lures were similar across read and generate conditions. However, after a one-week delay, we saw a valence differentiation, with a generation effect for false recognition but only for negative stimuli. The roles of item-specific and relational processing during encoding and their interaction with long-term retention are discussed.

Memory construction: a brief and selective history.

In this short article, we provide a brief introduction to the idea that memory involves constructive processes. The importance of constructive processes in memory has a rich history, one that stretches back more than 125 years. This historical context provides a backdrop for the articles appearing in this special issue of Memory, articles that outline the current thinking about the constructive nature of memory. We argue that memory construction, either implicitly or explicitly, represents the current framework in which modern memory research is embedded.

Self-Enhanced False Memory Across the Life Span.

OBJECTIVES: The role of self in veridical memory has been extensively studied, but what is the role of self in false memory development across the life span? The current study examined the impact of self-reference on associative false memory in children, younger adults, and older adults, and further investigated possible mechanisms concerning how self-reference might affect false memory in different age groups. METHODS: Combining a self-reference manipulation with the Deese/Roediger-McDermott (DRM) paradigm, children, younger adults, and older adults encoded DRM word lists as paired with their own name, another person's name, or a red square. Later their true and false recognition memory as well as recollection and familiarity were measured. RESULTS: A self-enhanced false memory effect was found in all age groups. That is, participants generated more false memories in the self-reference condition relative to the other-reference and neutral conditions. Furthermore, when examining its underlying memory mechanisms, we found that self-reference mainly increased false recollection in younger adults but facilitated familiarity of critical lures in older adults. DISCUSSION: Although self-reference increases false memory in both younger and older adults, the underlying mechanisms are different in that older adults have more self-relevant false familiarity while younger adults generate more self-relevant phantom recollection. The current study also has implications for eyewitness reports, suggesting that the self-relevance of memory may be one relevant factor to consider when evaluating potential risk factors of false memory.

What science tells us about false and repressed memories.

What does science tell us about memory phenomena such as false and repressed memories? This issue is highly pressing as incorrect knowledge about these memory phenomena might contribute to egregious effects in the courtroom such as false accusations of abuse. In the current article, we provide a succinct review of the scientific nature of false and repressed memories. We demonstrate that research has shown that about 30% of tested subjects formed false memories of autobiographical experiences. Furthermore, this empirical work has also revealed that such false memories can even be implanted for negative events and events that allegedly occurred repeatedly. Concerning the controversial topic of repressed memories, we show that plausible alternative explanations exist for why people claim to have forgotten traumatic experiences; explanations that do not require special memory mechanisms such as the unconscious blockage of traumatic memories. Finally, we demonstrate that people continue to believe that unconscious repression of traumatic incidents can exist. Disseminating scientifically articulated knowledge on the functioning of memory to contexts such as the courtroom is necessary as to prevent the occurrence of false accusations and miscarriages of justice.

Manipulating Memory Associations Minimizes Avoidance Behavior.

Memories of the past can guide humans to avoid harm. The logical consequence of this is if memories are changed, avoidance behavior should be affected. More than 80 years of false memory research has shown that people's memory can be re-constructed or distorted by receiving suggestive false feedback. The current study examined whether manipulating people's memories of learned associations would impact fear related behavior. A modified sensory preconditioning paradigm of fear learning was used. Critically, in a memory test after fear learning, participants received verbal false feedback to change their memory associations. After receiving the false feedback, participants' beliefs and memories ratings for learned associations decreased significantly compared to the no feedback condition. Furthermore, in the false feedback condition, participants no longer showed avoidance to fear conditioned stimuli and relevant subjective fear ratings dropped significantly. Our results suggest that manipulating memory associations might minimize avoidance behavior in fear conditioning. These data also highlight the role of memory in higher order conditioning.