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).”

“We also did not find an interaction between training time and environment [F(3, 82) = 0.”

“In the Hassabis et al. (2007a) measure, the atemporal and future scenario conditions have similar scene construction demands but in the narrative condition, these demands are substantially reduced because the scenario structure is provided in this condition but has to be self-generated in the other…”

“Preferential activation of the right hippocampus has been observed during future simulation relative to past retrieval (Addis et al., 2007) and for the imagination of vivid scenes relative to objects (Hassabis et al., 2007a), offering important clues regarding potential laterality effects.”

“Neurally, both processes are supported by a “core” network, including the medial temporal lobes, ventromedial prefrontal cortex, and lateral temporal and parietal regions (Hassabis et al., 2007; Schacter et al., 2007; Stawarczyk & D’Argembeau, 2015).”

“As highlighted above, Hassabis, Kumaran, and Maguire (2007) and Hassabis, Kumaran, Vann et al. (2007) have offered evidence for the role of the MTL in imag-”

“The hippocampus is also heavily implicated in the construction of spatially coherent scenes or layouts, which provide the spatial backdrop for past and future event constructions [50], yet has further been suggested to represent temporal order information and to support the temporal organization of memories [53,54].”

“The fact that our patients had hippocampal volume reductions similar to what has been reported for P01 and Jon (40%–50”

“We applied an imaginability task introduced by Hassabis et al. (2007).”

“…of scenes’ spatial properties (Aguirre et al. 1998; Epstein and Kanwisher 1998; Kravitz et al. 2011; Mullally and Maguire 2011, 2013; Park et al. 2011), as well as processing of scenes’ contextual associations (Aminoff et al. 2007; Hassabis et al. 2007; Summerfield et al. 2010; Howard et al. 2011).”

“This is perhaps most strikingly demonstrated in natural scene understanding tasks, such as imagining novel viewpoints, in which HC and mPFC are causally engaged (Hassabis et al., 2007; Hassabis & Maguire, 2009; Lee, Buckley, et al., 2005; Lee, Bussey, et al., 2005).”

“…hippocampal navigational system for generic short-term memory as a way-station to manipulation and long-term consolidation (and reconsolidation) in the neocortex (Buzsaki, 2005; Samsonovich and Ascoli, 2005), and possibly even human creativity (Balter, 2010) and imagination (Hassabis et al., 2007).”

“At the cognitive level, humans tend to use experience to build a model at the spiritual level (induction) and deduce the future through the learned model (deduction) [42,43].”

“An important question is how SG managed to construct complex fictitious experiences, a task amnesic patients cannot do (Hassabis et al., 2007).”

“…interdigitated with, those associated with scene construction (Figure 2b), which canonically include ventral medial parietal cortex (sometimes referred to as the retrosplenial complex or retrosplenial cortex), parahippocampal cortex, and portions of the angular gyrus (e.g., Hassabis et al., 2007).”

“Volumes were centred on peak voxels identified in prior motivational and episodic future imagination studies ([29,30,31], Methods in S1 File).”

“The scene construction task described by Hassabis, Kumaran, and Maguire (2007), and used by Lind et al. (2014) among individuals with ASD, was used as a measure of imagination.”

“On the other hand, a general function of default network regions may be to support mental imagery (Daselaar et al., 2010; Hassabis et al., 2007).”

“Whereas, early studies of memory functions focused on the hippocampus, various studies have since established the existence of a largescale brain network supporting MTT-related processes (Buckner and Carroll, 2007; Hassabis et al., 2007a; Arzy et al., 2009a; Schacter and Addis, 2009; Spreng et al., 2009; Nyberg et al.…”

“Associative processes in episodic memory involve mental visual reconstruction (Tulving 2002; Hassabis et al. 2007; Karanian and Slotnick 2015; St-Laurent et al. 2015; Wing et al. 2015).”

“Given this context, it is not surprising that individuals with Alzheimer’s disease experience disturbances in episodic autobiographical memory for past experiences 7,67,68 and face challenges in imagining novel scenarios that may occur in the future 13,66,69 .”

“However, we note that part of this network (AG, precuneus, PCC) is active during high-level language processing and participates in a slow semantic integration system which is thought to store the meanings of passages or movies in episodic memory (60, 61) and replay them in imagination (62).”

“[38], in which five patients with hippocampal amnesia showed profoundly impoverished mental simulations when it came to imagining new experiences.”

“No, it’s like I’m kind of floating : : : (Hassabis et al., 2007, p. 1727) In Extract 1, P03 begins by stating that he can see the sky.”

“2003), imagining fictitious experiences (Hassabis et al. 2007), and it is a part of the default mode network (Raichle et al.”

“This is consistent with results showing that the ability to simulate future autobiographical scenarios is based on the activity of medial temporal lobes [99–101], which is the earliest area affected by the neuropathological process in AD.”

“one that is synchronous with the dynamics of an unobserved external process, which may be computationally distinct from “offline” or 475 asynchronous simulation processes thought to be relevant for imagination (Hassabis et al., 2007; Shepard & Metzler, 1971) or counterfactual reasoning (Gerstenberg & Tenenbaum, 2017).”

“As in Experiment 1, creativity was assessed using the AUT (George and Wiley, 2019; Guildford, 1967), imaginability using Hassabis et al.’s scene construction task (2007), openness to new evidence using a trait hypothesis-testing task (Galinsky & Moskowitz, 2000), and cognitive flexibility using the…”

“, 2016), as well as in imagination of novel scenarios and situations (Buckner and Carroll, 2007; Hassabis et al., 2007; Buckner et al., 2008; Buckner, 2010), and in constructing new spatial scenes (Hassabis and Maguire, 2009) and finally in imagining potential future experiences (Schacter et al.”

“The hippocampus is believed to form a spatio-temporally extended multi-modal representation of ongoing experience and recent events (Eichenbaum, 2004; Hassabis et al., 2007).”

“This subsystem is also implicated in constructing scenes during imagined experiences of plausible personal events (Hassabis et al., 2007) and immersing in imagined, multimodal emotional situations (Wilson-Mendenhall et al.”

“Moreover, the PCC is recruited during the recollection processing on recognition tasks [49] and on retrieval of real episodic memories rather than constructed ones [50].”

“Previous studies have referred to the process of imagining the future by various names, including “imagination” (Hassabis et al., 2007), “episodic foresight” (Hudson et al., 2011), “future thoughts” (P. M. Szpunar & Szpunar, 2016), and “mental time travel” (Suddendorf et al., 2009); this study…”

“In contrast, scene construction, thought to be a key component of episodic recollection, is associated with a medial temporal (MT) subsystem ( Andrews-Hanna et al., 2010b ; D’Argembeau et al., 2010 ; Hassabis et al., 2007 ; Zhang et al., 2022 ).”

“Core areas of the DMN, including the posterior cingulate cortex, inferior parietal lobules, and medial temporal lobes, have also been shown to be involved in scene construction of past and fictitious events (Hassabis et al., 2007; Kim, 2012; Andrews-Hanna et al., 2014).”

“In contrast, the scene construction task (Hassabis et al., 2007) involves provision of the general scenario and the participant is required to build upon the pre‐constructed scene, at times receiving prompts about visuospatial information (Berryhill et al., 2010; Hurley, Maguire, and Vargha‐Khadem,…”

“…2003; Schacter and Addis, 2007; Szpunar et al., 2007; Addis et al., 2007), and hippocampal amnesics are typically quite impaired in episodic prospection (Talland, 1965; Klein et al., 2002; Hassabis et al., 2007; Addis et al., 2009; Andelman et al., 2010; Kwan et al., 2010; Race et al., 2011, 2013).”

“This is consistent with work demonstrating hippocampal activity during episodic recall and prospective simulation of the future (e.g. Addis et al., 2007), and also in imagination of an event without any specified time (Hassabis et al., 2007a).”

“Yaoi et al./Journal of Physiology - Paris 107 (2013) 517– 525 (Maddock, 1999) and in the retrieval or encoding of autobiographical memory (Hassabis et al., 2007; Maguire and Mummery, 1999).”

“Prospection is theorized to rely on functional interactions between a multi-regional network across the brain (Hassabis et al., 2007; Schacter et al., 2012; Brown et al., 2016).”

“…2019a,b; Steel et al., 2021), visual scene perception (Baldassano et al., 2013; Epstein and Baker, 2019; Silson et al., 2019a), scene construction (Hassabis et al., 2007), processing of spatial and other contextual associations (Bar and Aminoff, 2003), navigation (Epstein, 2008; Epstein and…”

“…by neuroimaging studies, which have proved that both recalling the past and anticipating the future activate the same areas of the brain (Addis et al. 2007; Botzung et al. 2008; Buckner and Carroll 2007; Hassabis et al. 2007; Okuda et al. 2003; Schacter et al. 2007, 2008; Szpunar et al. 2007).”

“Additionally, the posterior cingulate, inferior parietal cortex, and lateral temporal cortex were recruited during the construction of the mental scenes, which is the process that could be required in the memory encoding (Hassabis et al., 2007).”

“Neuropsychological investigations have found parallel deficits in episodic future thinking and episodic memory (e.g. Hassabis et al., 2007b; Levine et al., 1998; Tulving, 1985, 2000).”