Using Imagination to Understand the Neural Basis of Episodic Memory

“…2005), episodic future thinking (Atance and O’Neill, 2001; Addis et al., 2007; Schacter and Addis, 2007; Szpunar et al., 2007), the default mode (Raichle et al., 2001) and daydreaming (Mason et al., 2007), leading to suggestions that it performs a general function (Buckner and Carroll, 2007;…”

“…theory of mind (Kumaran and Maguire, 2005; Amodio and Frith, 2006) and episodic future thinking (Addis et al., 2007) suggesting that the amPFC and PCC might be supporting pro- cesses related to the self (Conway and Pleydell-Pearce, 2000) and mental time travel (Wheeler et al., 1997; Tulving, 2002).”

“…a purely created imagined experience does not have the same reliance or effect on the imaginer’s self-schema compared with a real episodic memory (Conway and Pleydell-Pearce, 2000; Gallagher, 2000) although both likely involve the adoption of an egocentric viewpoint (Burgess, 2006) on the part…”

“…bears a striking resemblance to networks found to support self-reflection (Johnson et al., 2002), theory of mind (Kumaran and Maguire, 2005; Amodio and Frith, 2006) and episodic future thinking (Addis et al., 2007) suggesting that the amPFC and PCC might be supporting pro- cesses related…”

“Moreover, by using rich imaginary memories as a well matched comparison task we were able to isolate processes specific to episodic memory, such as the use of self-schema (Conway and Pleydell-Pearce, 2000; Gallagher, 2000), a sense of familiarity and mental time travel (Tulving, 2002).”

“, 2001), and perhaps even daydreaming (Mason et al., 2007).”

“…network (also replicated in this study with the RM RO contrast) has also been activated in a variety of other circumstances including navigation (Burgess et al., 2002; Hartley et al., 2003; Spiers and Maguire, 2006), spatial tasks (Maguire et al., 2003; Kumaran and Maguire, 2005), episodic…”

“…a key component of episodic memory recall lends additional support to constructive theories of episodic memory (Bartlett, 1932; Schacter et al., 1998) and the recently proposed constructive episodic simulation function of the episodic memory system (Schacter and Addis, 2007; Schacter et al., 2007).”

“Activity in the default network has been found to increase during tasks of theory of mind, mind wandering, and memory [50,51].”

“In contrast, imagined-future events contain many features regarding the thoughts and reasoning processes (cognitive operations), as well as feelings of emotion and of importance (Addis, Wong, & Schacter, 2008; D’Argembeau & Van der Linden, 2004; Hassabis et al., 2007; McDonough & Gallo, 2010).”

“As alluded to previously, a common process underlying imagination, past and future thinking may be the mental construction of scene imagery (Barry & Maguire, 2019a, 2019b; Hassabis & Maguire, 2007; Maguire & Mullally, 2013).”

“Many of these regions, including the precuneus, are known to be part of a generic, core memory network for objects and are known to be recruited into various object recognition tasks in a task-specific manner (Cavanna and Trimble, 2006; Hassabis et al., 2007; Roth and Courtney, 2007; Spreng et al., 2009).”

“…Rugg and Vilberg, 2012; Kim, 2016) and simulating future (Addis et al., 2007; Szpunar et al., 2014; McCormick et al., 2018) or fictitious events (Hassabis et al., 2007a), and it therefore seems vital for mental construction (Schacter and Addis, 2007; Hassabis and Maguire, 2009; Bird et al.,…”

“During the resting state, the default mode regions may continuously and spontaneously encode internal thoughts and self-representations, consolidate recent memory traces, retrieve representations in memory and flexibly generate predictions about the present and relevant future (Bar, 2007; Buckner and Carroll, 2007; Ha…”

“Interestingly, the precuneus has been associated with scene construction (Hassabis et al., 2007) as well as first-person perspective taking (Vogeley & Fink, 2003).”

“A related possibility is that downstream imagery and retrieval of episodic memories related to the acoustic scene may have preferentially led to activation of these midline regions (Hassabis et al., 2007).”

“, 2012), while bilateral HC damage associated with anterograde amnesia leads to difficulty imagining scenes and objects (Hassabis et al., 2007; Mullally et al., 2012).”

“Although prior studies have also investigated imagination about future events (for review, see Hassabis and Maguire, 2009), these studies did not include trait information nor did they ask participants to generate sequences of future social actions (Addis et al., 2007; Hassabis et al., 2007) and did not reveal activat…”

“In the absence of such a context, the encoding of strong (a-contextual egocentric) sensory and affective representations of traumatic events can lead to an increased incidence of subsequent intrusive imagery.”

“On the one hand, there is evidence that the hippocampus is activated when imagining events or scenes that are not located at particular times in the past or future (Summerfield et al., 2010; Hassabis et al., 2007), and a recent study failed to detect significant hippocampal activity when participants placed an imagine…”

“…reported a largely overlapping collection of brain regions that appears to support both the reconstruction of past events and the novel construction of hypothetical future scenarios (Addis et al., 2007, 2009; Hassabis et al., 2007; Szpunar et al., 2007, 2009; see also Benoit and Schacter, 2015).”

“250–251) noted substantial overlap between the concepts of “scene construction” and “event construction,” but nonetheless drew a distinction between them, noting that: “one of the key measures of scene construction, the spatial coherence index, assesses the spatial integrity of a constructed scene (Hassabis et al., 20…”

“, 2014), atemporal fictitious events (Hassabis et al., 2007; Summerfield et al., 2009, 2010) and counter-factual events (De Brigard et al.”

“…data, we would like to suggest that emphasis put on the role of MVI in AbM and, by the same token, on the posterior cerebral regions (Hassabis et al., 2007), could have compensated for the weakness of the retrieval strategy processes supported by the prefrontal cortex (Botzung et…”

“…the amount of detail generated for each event (1= not vivid . . . 4= very vivid) and the other scale assessed the spatial coherence of each event (contiguousness of the spatial context: 1= fragmented scenes . . . 4= continuous scene; Hassabis et al., 2007; not reported in the current study).”

“…us from inhabiting our imagination (Hassabis et al. 2007b; Mullally et al. 2012) and contemplating the future (Tulving, 1985; Klein et al. 2002; Hassabis et al. 2007b; Rosenbaum et al. 2009; Andelman et al. 2010; Race et al. 2011), as well as impairing the ability to navigate effectively in…”

“Self-schemas are part of the structure of the self and influence both self and interpersonal functioning (Conway & Pleydell-Pearce, 2000; Hassabis et al., 2007; Horowitz, 1991; Nelson & Fivush, 2004).”

“To conclude, in spite of some evident limitation such as the restricted capability of mental simulation due to the accumulation of errors, the lack of realistic modelfree behaviour, the simplified value-based computation mechanism and the approximated mapping to anatomical structures, the presented architecture could…”

“Moreover, a variety of studies indicate that the brain makes a distinction between imagining real and fictitious persons or events, as demonstrated by the specific areas that are activated (Abraham et al., 2008; Benoit et al., 2010; Daselaar et al., 2010; Harris et al., 2008; Hassabis et al., 2007).”

“…2007, 2020), where episodic memory retrieval and imagery generation are held to involve common constructive and simulative processes (Pearson, 2019; Hassabis, Kumaran, & Maguire, 2007; Hassabis & Maguire, 2007), by adding hip-pocampally based memory indices that point to the storage locations of…”

“, 2016]; mental scene construction [Hassabis et al., 2007; Palombo et al., 2018]; as well as large-scale spatial navigation in virtual reality environments [Ekstrom et al.”

“Activation patterns in the brain evoked by these tasks all show involvement of the PPC (Hassabis et al., 2007).”

“, 2002) and episodic memory (Hassabis et al., 2007), may promote greater readiness state for high-level inference-based metalizing processes about self (Kelley et al.”

“The mechanism of decision making and reasoning has attracted a lot of attention in the neuroscience field [3, 20].”

“…(2009) hypothesized that the hippocampus, which is involved in episodic memory retrieval, prefrontal cortices involved in top–down processing and the retrosplenial complex involved in associative processing, are regions which retain prior experiences of a person [see also Hassabis et al. (2007)].”

“…beenassociated with the regeneration of rich contextual associations, with correct source retrieval ([ − 6 − 70 60] Lundstrom et al., 2005), as well as with complex mental imagery, implying re-construction, maintenance and visualisation of complex scenes ([6 − 66 60] Hassabis et al., 2007).”

“For example, commonalities between retrieving AM and performing higher-order spatial navigation (Hassabis et al., 2007; Spreng et al., 2009) and spatial retrieval tasks (Greenberg et al., 2009; Hoscheidt et al., 2010; Sheldon and Moscovitch, 2012) are typically reported in posterior aspects of the…”

“Indeed, patients with hippocampal amnesia lose the ability to imagine novel experiences [77], reducing their ability to make optimal decisions [78].”

“, 2005), which has been linked to familiarity (Hassabis et al., 2007).”

“The MT subsystem reliably showed activation in bilateral medial temporal regions, consistent with previous studies showing these regions are important for thinking about events that happened in a speci fi c place and time during episodic retrieval (Hassabis and Maguire, 2007; Hassabis et al., 2007).”

“Results demonstrated that children aged 4 and 5 were capable of answering the question while only a minority 3-year-old children could successfully complete the task, suggesting that the development of memory facilitates the development of prospection to some extent.”

“In humans, the capacity to represent space and time together has resulted in a rich capacity for episodic memory –memory for life events [32]– aswell as the ability to formulate detailed representations of things that have not happened yet (planning) or may never happen (imagination [33,34]).”

“Hassabis and Maguire (2007) have suggested that each of these abilities rely on the capacity for “scene construction”, which refers to the generation and maintenance of a coherent, multimodal spatial representation. They also suggest that scene construction may be involved in certain forms of navigation (Hassabis & Ma…”

“…of processes, including episodic and visuospatial memory functions (Aggleton and Pearce, 2001; Epstein et al., 2007; Rudge and Warrington , 1991), spatial attention (Small et al., 2003), visual imagery (Burgess, 2008; Hassabis et al., 2007), and others (Buckner et al., 2008; Vogt et al., 2006).”

“Both neuroimaging evidence (Hassabis et al. 2007; Summerfield et al. 2010) and neuropsychological evidence on patients with amnesia due to hippocampal damage (Hassabis et al.”

“However, the functional distinctions –both behavioral, neuroimaging, and neurochemical-between the hippocampus and RSC are still suggestive of a cooperative dynamic [2,13,30].”

“…and imagining scenes are also associated with increased hippocampal activity compared to similar tasks involving objects, and to some extent, faces (Hassabis et al. 2007a; Zeidman et al. 2015a,b; Hodgetts et al. 2016; Ross et al. 2018; www.learnmem.org 257 Learning & Memory Dalton et al. 2018;…”

“Theta activity is related to novelty detection [118] and to the imagination of fictitious scenes [119].”

“001 with 10 or more contiguous voxels (for a similar approach, see [27]).”

“…processing and/or social cognition (Bedny et al., 2009; Buckner and Carroll, 2007; Cabeza et al., 2008; Carter and Huettel, 2013; Cavanna and Trimble, 2006; Hassabis and Maguire, 2007; Hassabis et al., 2007; Lepage et al., 2000; Maguire et al., 2001; Sestieri et al., 2011; Svoboda et al., 2006).”

“…network, such as resting-state tasks, [Binder et al., 1999; Greicius et al., 2003; Greicius et al., 2009], tasks requiring episodic memory [Hassabis et al., 2007; Hassabis and Maguire, 2007; Shallice et al., 1994], and even tasks that incorporate semantic memory and processing [Binder and…”

“…2009, 26 (6) “scene construction”, involving the generation, maintenance, and visualization of complex spatial contexts (Hassabis & Maguire, 2007), which has also been shown to be critically reliant on the hippocampus and other medial temporal lobe structures (Hassabis et al., 2007a, 2007b).”

“Imaginative processes are oftenhighly integrated states (Schlichting & Preston, 2015): Thinking about the future, for example relies on both episodic (Hassabis et al, 2007a, 2007b) and semantic memory (Irish & Piguet, 2013), as well as affective processes (MacLeod & Byrne, 1996).”