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).”

“To successfully engage with such interventions, participants must comprehend the verbal sentences while engaging in simultaneous scene construction, maintenance, updating, and visualization (Hassabis et al. 2007).”

“Functional magnetic resonance imaging brain studies showed increased activity in a brain network, including the hippocampus, when people recalled episodic memory and imagined future episodes [8].”

“Note that the type of design we employed has been widely and successfully used in research of selfgeneration cognition and autobiographical memory (Gilboa et al. 2004; Addis et al. 2007, 2009; Hassabis et al. 2007; Spreng and Grady 2009; Weiler et al. 2010; Gerlach et al. 2011; Palombo et al. 2018).”

“, 2011), and also when they simply construct imaginary scenes (Hassabis et al., 2007).”

“Hassabis et al. (2007), for instance, used advanced brain scanning technology to trace similarities and differences in pre-frontal cortical activity between imagined fictitious experiences and episodic memory.”

“Here, in addition to playing a role in constructing imagined future scenarios [43], the explicit representation of events or episodes in the past may be essential for updating beliefs about current and future states or learning time-invariant properties of an agent’s environment [17].”

“Hassabis, Kumaran, and Maguire (2007), in a functional MRI study, demonstrated that the construction of new scenes involves a network comprising the hippocampus, the parahippocampal gyrus, the retrosplenial cortex and the posterior parietal cortex.”

“One strong candidate for a network of structures is the DMN, which is implicated in tasks that require drawing on internally - constructed information such as autobiographical memory (23), abstract thought (24, 25), and narrative interpretation (17, 20).”

“…relies on a distributed memory network involving the hippocampus, the parahippocampal gyrus and the retrosplenial cortex, which supports not only memory register and retrieval but also is involved in the generation, maintenance and visualization of complex spatial context and imagination 15 .”

“[19, 20] revealed that episodic memory and imagery shared the same neural basis.”

“Episodic memory formation, while dependent on HPC, nevertheless appears to be a process distributed across multiple brain regions (Hassabis et al., 2007).”

“402 Neuroimaging studies have also documented hippocampal engagement during the 403 construction of scene imagery (Hassabis et al., 2007b; Zeidman and Maguire, 2016; Barry et 404 al., 2018; Clark et al., 2018; Dalton et al., 2018).”

“Imaginability was assessed using an episodic future thinking task devised by Hassabis et al. (2007).”

“, 2010) and given the shared neural substrates for recall and imagination (Hassabis et al., 2007), we predict that similar changes in connectivity of brain networks regardless of how much the odor-evoked recalled episodes overlap with reality.”

“As stated earlier, the implication of the parietal cortex in recalling scenes from an egocentric point of view (Spiers and Maguire, 2007b), as well as the implication of the parahippocampus in landmark processing and scene construction of imagined scenes in fMRI studies (Rosenbaum et al., 2004; Hassabis et al., 2007;…”

“When recal-ling personal past events, scenes are generated to package information and once these scenes are created, then multimodal descriptions of the events are integrated into a cohesive whole (Hassabis et al., 2007).”

“Indeed, multiple prior studies of event imagination have successfully employed approaches similar to the current study (Addis et al. 2007; Hassabis et al. 2007; D’Argembeau et al. 2008; D’Argembeau et al. 2010; Addis et al. 2011).”

“This assumption is supported by research demonstrating how future thinking is typically more effortful and involves more cognitive processing and reconstruction time than past thinking [31,32].”

“…Places1/2, like the ventral component, are associated with scene-construction or contextual association, whereas People1/2, like the dorsal component, are associated with more social and potentially semantic processing ( Andrews-Hanna et al., 2010; Bar & Aminoff, 2003; Hassabis et al., 2007).”

“FPC activation has been consistently associated with episodic retrieval (Düzel et al., 1999; Hassabis et al., 2007; Henson et al., 1999; Johnson and Rugg, 2007; Kapur et al., 1995; Lepage et al., 2000; Okuda et al., 2003; Rugg et al., 2002).”

“According to Hassabis et al. (2007), episodic simulation of atemporal, fictitious scenes which are not self-relevant does not require self-projection.”

“Our results support a number of neuroimaging studies that suggest a role for the rostral medial prefrontal cortex in “internal” or self-referential signals (Gilbert et al. 2006; Burgess et al. 2007; Hassabis et al. 2007; Mason et al. 2007; Raichle and Snyder 2007; Boorman et al. 2009), but further contributes to the l…”

“…possible scenarios (Schacter et al., 2007, 2012; Hamrick, 2019) The hippocampus is a brain region that is critical for memory and imagination (Hassabis et al., 2007a, 2007b; Addis et al., 2007; Schacter et al., 2007) and it holds a model of the environment (also called a cognitive map…”

“They noted that brain regions involved in visual imagery are also active during tasks that have been linked to creative imagination (e. g., Fulford et al., 2018; Hassabis et al., 2007).”

“…of an experiment in which patients with amnesia associated with bilateral hippo campal damage were compared to a controlled group in their ability to construct imag inary experiences, Hassabis et al. (2007) note that patients with hippocampal amnesia show deficit in imagining novel experiences.”

“Following the procedure of Lind et al. (2014b), the task was rated according to the scoring scheme of (Hassabis, Kumaran, & Maguire, 2007a).”

“…particular the hippocampus, in not only the perception of scenes (for reviews, see Epstein and Baker, 2019; Lee et al., 2012a,b), but also in the use of imagination to construct fictitious experiences (Hassabis et al., 2007a), future scenes, and events (Addis et al., 2007; Staresina et al., 2011).”

“Episodic memory and scene construction are closely connected, as reflected by the significant overlap of their neural substrates [1,5] and parallel impairments observed in clinical populations ([9], but see [10]).”

“…spatial scenes in memory (Hassabis, Kumaran, Vann, & Maguire, 2007b; Ross et al., 2018; Taylor et al., 2007; Zeidman & Maguire, 2016), imagination (Hassabis, Kumaran, & Maguire, 2007a; Hassabis, Kumaran, Vann, & Maguire, 2007b; Zeidman & Maguire, 2016), and visual perception (Barense et al.,…”

“More generally, Hassabis et al. 30,31 proposed a distributed memory network involving the hippocampus, the parahippocampal gyrus and the retrosplenial cortex, which not only supports memory register and retrieval but also is involved in the generation, maintenance and visualization of complex…”

“However, we note that part of this network (angular gyrus, 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 (58, 59) and replay them in imagination (60).”

“…the anterior division, AV nuclei are linked to the visual cortex via connections to the retrospinal cortex ( Lomi et al., 2023), which is thought to contribute to spatial organization in imagination ( Botzung et al., 2008; D’Argembeau et al., 2008; Hassabis et al., 2007; Szpunar et al., 2007).”

“As also noted in Aydin et al. (2023), this is important for the scene construction arguments, stating that an image of the location serves as a scaffold for elaboration with additional details (Hassabis & Maguire, 2007; Rubin et al., 2019).”

“…in the cluster that emerged in the current exploratory analysis, recall success effects in the critical versus control tasks covered locations within the right posterior AnG, typically observed in episodic recall tasks 30,58–60 , and particularly when episodic events are remembered vividly 61 .”

“…the pictures-unlinked and patterns-unlinked conditions, since the hippocampus is known to respond strongly to scenes relative to nonscene stimuli (Hassabis et al., 2007a; Graham et al., 2010; Zeidman et al., 2015; Hodgetts et al., 2016; Monk et al., 2021); however, no difference was apparent.”

“This subsystem facilitates memory-based scene construction and the process of peering into the future (Hassabis et al., 2007).”

“Supporting research shows that hippocampal lesion leads to an inability to construct spatially coherent scenes [33], and fMRI studies support the involvement of the hippocampus especially in tasks which require a 3D spatial layout [29,30,34–36].”

“We interpret the activation of the parahippocampal regions as reflecting the mental construction of event representations (Hassabis et al. 2007; Hassabis and Maguire 2009).”

“The precuneus plays a role in mental imagery (Burgess, 2008; Hassabis et al., 2007; Johnson et al., 2007), including shifting attentional resources to different object features and targets within space (Cavanna & Trimble, 2006; Le et al., 1998; Nagahama et al., 1999), which may facilitate the…”

“…et al., 2008, 2007; Spreng et al., 2015; Svoboda et al., 2006; Yang et al., 2013), mental simulation and scene construction (Gerlach et al., 2011; Hassabis et al., 2007; Hassabis and Maguire, 2007; Spreng and Grady, 2010), theory of mind (ToM) and social cognition (Amft et al., 2015; Mar, 2011;…”