Sharing mental simulations and stories: hippocampal contributions to discourse integration

Narrative identity in addictive disorders: a conceptual review

Narrative identity allows individuals to integrate their personal experiences into a coherent and meaningful life story. Addictive disorders appear to be associated with a disturbed sense of self, reflected in problematic and disorganized self-narratives. In recent literature, a growing body of research has highlighted how narrative approaches can make a dual contribution to the understanding of addiction: on the one hand, by revealing crucial aspects of self structure, and, on the other, by supporting the idea that addiction is a disorder related to unintegrated self-states in which dissociative phenomena and the resulting sense of 'loss of self' are maladaptive strategies for coping with distress. This conceptual review identified the main measures of narrative identity, i.e., narrative coherence and complexity, agency, and emotions, and critically examines 9 quantitative and qualitative studies (out of 18 identified in literature), that have investigated the narrative dimension in people with an addictive disorder in order to provide a synthesis of the relationship between self, narrative and addiction. These studies revealed a difficulty in the organization of narrative identity of people with an addictive disorder, which is reflected in less coherent and less complex autobiographical narratives, in a prevalence of passivity and negative emotions, and in a widespread presence of themes related to a lack of self-efficacy. This review points out important conceptual, methodological and clinical implications encouraging further investigation of narrative dimension in addiction.

On the influence of thought on language: a naturalistic framework for the pantomimic origins of human communication

This paper focuses on the idea that pantomime is a privileged lens for investigating the origin of language in a naturalistic framework. Two reasons support this claim. The first one concerns the motivated and iconic character of pantomime compared to the arbitrary and abstract features of linguistic signs emphasized by the conventionalist thesis. The second reason is that a pantomimic account of language origin paves the way for a rethinking of the traditional hypothesis on the relationship between thought and language. Specifically, it leads to a revision of the thesis of the unidirectional influence of language on thought in favor of a bidirectional influence. Indeed, looking at the relationship between thought and language in its nascent stage means investigating the role of thought in shaping language rather than the role of language in shaping thought. A bidirectional perspective of this type hinges on the twofold idea that thought has primarily a narrative foundation and that pantomime represents an ideal expressive means for bootstrapping the evolutionary foundations of language origins in a naturalistic framework.

An evolutionary account of impairment of self in cognitive disorders

Recent research has proposed that certain aspects of psychosis, as experienced in, e.g., schizophrenia (SCZ), but also aspects of other cognitive conditions, such as autism spectrum disorders (ASD) and synesthesia, can be related to a shattered sense of the notion of self. In this paper, our goal is to show that altered processing of self can be attributed to an abnormal functioning of cortico-striatal brain networks supporting, among other, one key human distinctive cognitive ability, namely cross-modality, which plays multiple roles in human cognition and language. Specifically, our hypothesis is that this cognitive mechanism sheds light both on some basic aspects of the minimal self and on some aspects related to higher forms of self, such as the narrative self. We further link the atypical functioning in these conditions to some recent evolutionary changes in our species, specifically, an atypical presentation of human self-domestication (HSD) features. In doing so, we also lean on previous work concerning the link between cognitive disorders and language evolution under the effects of HSD. We further show that this approach can unify both linguistic and non-linguistic symptoms of these conditions through deficits in the notion of self. Our considerations provide further support for the hypothesis that SCZ and ASD are diametrically opposed cognitive conditions, as well for the hypothesis that their etiology is associated with recent human evolution, leading to a deeper understanding of the causes and symptoms of these disorders, and providing new cues, which can be used for an earlier and more accurate diagnostics.

Persuasive conversation as a new form of communication in Homo sapiens

The aim of this paper is twofold: to propose that conversation is the distinctive feature of Homo sapiens' communication; and to show that the emergence of modern language is tied to the transition from pantomime to verbal and grammatically complex forms of narrative. It is suggested that (animal and human) communication is a form of persuasion and that storytelling was the best tool developed by humans to convince others. In the early stage of communication, archaic hominins used forms of pantomimic storytelling to persuade others. Although pantomime is a powerful tool for persuasive communication, it is proposed that it is not an effective tool for persuasive conversation: conversation is characterized by a form of reciprocal persuasion among peers; instead, pantomime has a mainly asymmetrical character. The selective pressure towards persuasive reciprocity of the conversational level is the evolutionary reason that allowed the transition from pantomime to grammatically complex codes in H. sapiens, which favoured the evolution of speech. This article is part of the theme issue 'Reconstructing prehistoric languages'.

Narrativity and Referential Activity Predict Episodic Memory Strength in Autobiographical Memories

Narrativity has been proposed as an indicator of episodic memory strength when people discuss their past (Nelson and Horowitz in Discourse Processes 31:307-324, 2001. https://doi.org/10.1207/S15326950dp31-3_5 ). Referential Activity, the extent to which words convey a speaker's experience of being present in the event being described, has been independently hypothesized to indicate episodic memory strength (Maskit in J Psycholinguist Res, 2021. https://doi.org/10.1007/s10936-021-09761-8 ). These hypotheses are tested using a linguistic measure of narrativity and a computerized measure of referential activity to predict previous independent ratings of episodic memory strength that used the Levine et al. (Psychol Aging 17(4):677-689, 2002. https://doi.org/10.1037//0882-7974.17.4.677 ) measure of internal details in retold personal memories provided by Schacter (Addis et al. in Psychol Sci 19(1):33-41, 2008. https://doi.org/10.1111/j.1467-9280.2008.02043.x ). Raters scored narrativity on four brief near and far past memories elicited from 32 subjects, using Nelson's narrative temporal sequence method based on Labov's (J Narrat Life Hist 7(1-4):395-415, 1997. https://doi.org/10.1075/jnlh.7.49som ) analysis of spoken narratives of personal experience; computerized weighted scores of referential activity (WRAD) were obtained on these same 128 memories. Data analysis showed that narrative temporal sequences predict internal details and WRAD predict internal details. Adding WRAD to narrative temporal sequences improved the prediction of internal details.

The language of mental images: Characterizing hippocampal contributions to imageable word use during event construction

Accumulating evidence suggests that the hippocampus plays a critical role in the creative and flexible use of language at the sentence or discourse level. Yet it is currently unclear whether the hippocampus also supports language use at the level of single words. A recent study by Hilverman et al. (2017) found that amnesic patients with hippocampal damage use less imageable words when describing autobiographical episodes compared to healthy controls, but this deficit was attributed to patients' deficits in episodic memory rather than impairments in linguistic functions of the hippocampus per se. Yet, in addition to affecting word use by way of its role in memory, the hippocampus could also impact language use more directly. The current study aimed to test this hypothesis by investigating the status of imageable word use in amnesia during two different types of language production tasks. In Experiment 1, participants constructed narratives about events depicted in visually presented pictures (picture narratives). In Experiment 2, participants constructed verbal narratives about remembered events from the past or simulated events in the future (past/future narratives). Across all types of narratives, patients produced words that were rated as having similar levels of imageability compared to controls. Importantly, this was the case both in patients' picture narratives, which did not require generating details from episodic memory and were matched to those of controls with respect to narrative content, and in patients' narratives about past/future events, which required generating details from memory and which were reduced in narrative content compared to those of controls. These results distinguish between the quantity and quality of individual linguistic details produced in amnesia during narrative construction, and suggest that the use of imageable linguistic representations does not depend on intact episodic memory and can be supported by regions outside the hippocampus.

Getting better without memory

Does the tendency to adjust appraisals of ourselves in the past and future in order to maintain a favourable view of ourselves in the present require episodic memory? A developmental amnesic person with impaired episodic memory (HC) was compared with two groups of age-matched controls on tasks assessing the Big Five personality traits and social competence in relation to the past, present and future. Consistent with previous research, controls believed that their personality had changed more in the past 5 years than it will change in the next 5 years (i.e. the end-of-history illusion), and rated their present and future selves as more socially competent than their past selves (i.e. social improvement illusion), although this was moderated by self-esteem. Despite her lifelong episodic memory impairment, HC also showed these biases of temporal self-appraisal. Together, these findings do not support the theory that the temporal extension of the self-concept requires the ability to recollect richly detailed memories of the self in the past and future.

Temporal integration of narrative information in a hippocampal amnesic patient

Default network regions appear to integrate information over time windows of 30 ​s or more during narrative listening. Does this long-timescale capability require the hippocampus? Amnesic behavior suggests that regions other than the hippocampus can independently support some online processing when input is continuous and semantically rich: amnesics can participate in conversations and tell stories spanning minutes, and when tested immediately on recently heard prose they are able to retain some information. We hypothesized that default network regions can integrate the semantically coherent information of a narrative across long time windows, even in the absence of an intact hippocampus. To test this prediction, we measured BOLD activity in the brain of a hippocampal amnesic patient (D.A.) and healthy control participants while they listened to a 7 min narrative. The narrative was played either in its intact form, or as a paragraph-scrambled version, which has been previously shown to interfere with the long-range temporal dependencies in default network activity. In the intact story condition, D.A.'s moment-by-moment BOLD activity spatial patterns were similar to those of controls in low-level auditory cortex as well as in some high-level default network regions (including lateral and medial posterior parietal cortex). Moreover, as in controls, D.A.'s response patterns in medial and lateral posterior parietal cortex were disrupted when paragraphs of the story were presented in a shuffled order, suggesting that activity in these areas did depend on information from 30 ​s or more in the past. Together, these results suggest that some default network cortical areas can integrate information across long timescales, even when the hippocampus is severely damaged.

Discourse Measures to Differentiate Between Mild Cognitive Impairment and Healthy Aging

Although subtle discourse declines in people with mild cognitive impairment (MCI) have been reported, heterogeneous measures and tasks among the MCI discourse studies have yielded widely varying outcomes. The present study aimed to first, identify discourse measures that aid the differentiation among people with amnestic MCI (aMCI), people with non-amnestic MCI (naMCI), and cognitively healthy control (HC) participants, and second, delineate the cognitive functions related to such discourse measures. Three discourse tasks (an episodic narrative, a planning task, and a picture description) were performed by 30 aMCI, 22 naMCI, and 21 HC participants. Samples were analyzed using six categories of 15 measures, namely coherence, cohesion, proposition, grammaticality, lexicality, and fluency. The statistical analyses included (1) a multivariate analysis of variance for group comparison; (2) binary simple logistic regression and receiver operating characteristic curve analysis for differentiation between two groups; (3) binary multiple logistic regression for being diagnosed with naMCI or aMCI with the minimum number of predictors; and (4) Pearson correlation analysis for identifying the cognitive functions associated with the discourse measures. The proportion of cohesive words and propositional density in aMCI participants were worse than those in naMCI participants. Global coherence, the proportion of cohesive words, and the proportion of dysfluencies and pauses in naMCI participants were lower than those in the HC participants. Global and local coherence and the proportion of cohesive words, cohesive ties per utterances, propositional density, and dysfluencies and pauses in aMCI participants were worse than those in the HC participants. The aforementioned measures were demonstrated to be effective predictors for classifying groups by receiver operating characteristic curve analysis. In addition, the proportions of cohesive words and pauses were common discourse measures for differentiation between naMCI and HC participants or between aMCI and HC participants using binary multiple logistic regression. According to the correlation analysis, memory and executive functions are needed for coherent, cohesive, and efficient discourse productions in MCI. The detailed description of discourse performances in this study will aid the characterization of the declined language abilities of MCI participants and also the understanding of the cognitive functions involved in discourse performance in MCI.

The nature of recollection across months and years and after medial temporal lobe damage

We studied the narrative recollections of memory-impaired patients with medial temporal lobe (MTL) damage who took a 25-min guided walk during which 11 planned events occurred. The recollections of the patients, recorded directly after the walk, were compared with the recollections of controls tested directly after the walk (C1), after one month (C2), or after 2.6 years (C3). With respect to memory for the walk, the narrative recollections of the patients were impoverished compared with C1 but resembled the recollections of volunteers tested after long delays (C2 and C3). In addition, how language was used by the patients in their recollections resembled how language was used by groups C2 and C3 (higher-frequency words, less concrete words, fewer nouns, more adverbs, more pronouns, and more indefinite articles). These findings appear to reflect how individuals, either memory-impaired patients or controls, typically speak about the past when memory is weak and lacks detail and need not have special implications about language use and MTL function beyond the domain of memory. A notable exception to the similarity between patient narratives and the narratives of C2 and C3 was that the control groups reported the events of the walk in correct chronological order, whereas the order in which patients reported events bore no relationship to the order in which events occurred. We suggest that the MTL is especially important for accessing global information about events and the relationships among their elements.

Boundary extension is attenuated in patients with ventromedial prefrontal cortex damage

The ventromedial prefrontal cortex (vmPFC) and hippocampus have been implicated in the mental construction of scenes and events. However, little is known about their specific contributions to these cognitive functions. Boundary extension (BE) is a robust indicator of fast, automatic, and implicit scene construction. BE occurs when individuals who are viewing scenes automatically imagine what might be beyond the view, and consequently later misremember having seen a greater expanse of the scene. Patients with hippocampal damage show attenuated BE because of their scene construction impairment. In the current study, we administered BE tasks to patients with vmPFC damage, brain-damaged control patients, and healthy control participants. We also contrasted the performance of these patients to the previously-published data from patients with hippocampal lesions (Mullally, Intraub, & Maguire, 2012). We found that vmPFC-damaged patients showed reduced BE compared to brain-damaged and healthy controls. Indeed, BE attenuation was similar following vmPFC or hippocampal damage. Notably, however, whereas hippocampal damage seems to particularly impair the spatial coherence of scenes, vmPFC damage leads to a difficulty constructing scenes in a broader sense, with the prediction of what should be in a scene, and the monitoring or integration of the scene elements being particularly compromised. We conclude that vmPFC and hippocampus play important and complementary roles in scene construction.

Changes in discourse structure over time following traumatic brain injury

The objective of the present study was to investigate structural changes in the narrative discourse of individuals with penetrating traumatic brain injury (pTBI) following immediate and delayed story retellings. Additionally, the potential influence of immediate memory, working memory, and executive functions on narrative discourse performance were examined. The narrative discourse of two groups, 123 with pTBI and 44 non-brain injured (NBI), was sampled. Participants were asked to retell a wordless picture story immediately after viewing it and again 30-min later. Story narratives were analyzed using a variety of microlinguistic and macrostructural measures. Results revealed significant group differences of both microlinguistic and macrostructural measures following the immediate retell, but not following the delayed retell. Regression analyses revealed that immediate memory accounted for a modest degree of the explained variance for the production of critical content during narrative discourse. The observed deficits were relatively stable over a short delay (30 min) and appeared attributable, in part, to difficulty with the encoding and consolidation of story content.

Time and Narrative: An Investigation of Storytelling Abilities in Children With Autism Spectrum Disorder

This study analyzed the relation between mental time travel (MTT) and the ability to produce a storytelling focusing on global coherence, which is one of the most notable characteristics of narrative discourse. As global coherence is strictly tied to the temporal sequence of the events narrated in a story, we hypothesized that the construction of coherent narratives would rely on the ability to mentally navigate in time. To test such a hypothesis, we investigated the relation between one component of MTT—namely, episodic future thinking (EFT)—and narrative production skills by comparing the narratives uttered by 66 children with high-functioning autism spectrum disorder (ASD) with those produced by 66 children with typical development. EFT was assessed by administering a task with minimal narrative demands, whereas storytelling production skills were assessed by administering two narrative production tasks that required children to generate future or past episodes with respect to the target stimuli. The results showed that EFT skills were impaired only in a subgroup of children with ASD and that such subgroup performed significantly worse on the narrative production task than ASD participants with high EFT skills and participants with typical development. The practical and theoretical implications of these findings are discussed.

The Social Brain Is Not Enough: On the Importance of the Ecological Brain for the Origin of Language

In this paper, I assume that the study of the origin of language is strictly connected to the analysis of the traits that distinguish human language from animal communication. Usually, human language is said to be unique in the animal kingdom because it enables and/or requires intentionality or mindreading. By emphasizing the importance of mindreading, the social brain hypothesis has provided major insights within the origin of language debate. However, as studies on non-human primates have demonstrated that intentional forms of communication are already present in these species to a greater or lesser extent, I maintain that the social brain is a necessary but not a sufficient condition to explain the uniqueness of language. In this paper, I suggest that the distinctive feature of human communication resides in the ability to tell stories, and that the origin of language should be traced with respect to the capacity to produce discourses, rather than phrases or words. As narrative requires the ability to link events distant from one another in space and time, my proposal is that in order to explain the origin of language, we need to appeal to both the social brain and the ecological brain - that is, the cognitive devices which allow us to mentally travel in space and time.

Episodic Memory and Beyond: The Hippocampus and Neocortex in Transformation

The last decade has seen dramatic technological and conceptual changes in research on episodic memory and the brain. New technologies, and increased use of more naturalistic observations, have enabled investigators to delve deeply into the structures that mediate episodic memory, particularly the hippocampus, and to track functional and structural interactions among brain regions that support it. Conceptually, episodic memory is increasingly being viewed as subject to lifelong transformations that are reflected in the neural substrates that mediate it. In keeping with this dynamic perspective, research on episodic memory (and the hippocampus) has infiltrated domains, from perception to language and from empathy to problem solving, that were once considered outside its boundaries. Using the component process model as a framework, and focusing on the hippocampus, its subfields, and specialization along its longitudinal axis, along with its interaction with other brain regions, we consider these new developments and their implications for the organization of episodic memory and its contribution to functions in other domains.

Amnesia and future thinking: Exploring the role of memory in the quantity and quality of episodic future thoughts

OBJECTIVES

To examine the impact of memory accessibility on episodic future thinking.

DESIGN

Single-case study of neurological patient HCM and an age-matched comparison group of neurologically Healthy Controls.

METHODS

We administered a full battery of tests assessing general intelligence, memory, and executive functioning. To assess autobiographical memory, the Autobiographical Memory Interview (Kopelman, Wilson, & Baddeley, 1990. The Autobiographical Memory Interview. Bury St. Edmunds, UK: Thames Valley Test Company) was administered. The Past Episodic and Future Episodic sections of Dalla Barba's Confabulation Battery (Dalla Barba, 1993, Cogn. Neuropsychol., 1, 1) and a specifically tailored Mental Time Travel Questionnaire were administered to assess future thinking in HCM and age-matched controls.

RESULTS

HCM presented with a deficit in forming new memories (anterograde amnesia) and recalling events from before the onset of neurological impairment (retrograde amnesia). HCM's autobiographical memory impairments are characterized by a paucity of memories from Recent Life. In comparison with controls, two features of his future thoughts are apparent: Reduced episodic future thinking and outdated content of his episodic future thoughts.

CONCLUSIONS

This article suggests neuropsychologists should look beyond popular conceptualizations of the past-future relation in amnesia via focussing on reduced future thinking. Investigating both the quantity and quality of future thoughts produced by amnesic patients may lead to developments in understanding the complex nature of future thinking disorders resulting from memory impairments.

PRACTITIONER POINTS

We highlight the clinical importance of examining the content of future thoughts in amnesic patients, rather than only its quantitative reduction. We propose an explanation of how quantitative and qualitative aspects of future thinking could be affected by amnesia. This could provide a useful approach to understand clinical cases of impaired prospection.

LIMITATIONS

Systematic group investigations are required to fully examine our hypothesis. Although the current study utilized typical future thinking measures, these may be limited and we highlight the need to develop clinically relevant measures of prospection.

Alterations in autobiographical memory for a blast event in Operation Enduring Freedom and Operation Iraqi Freedom veterans with mild traumatic brain injury

OBJECTIVE

Although loss of consciousness associated with moderate or severe traumatic brain injury (TBI) is thought to interfere with encoding of the TBI event, little is known about the effects of mild TBI (mTBI), which typically involves only transient disruption in consciousness.

METHOD

Blast-exposed Afghanistan and Iraq War veterans were asked to recall the blast event. Participants were stratified based on whether the blast was associated with probable mTBI (n = 50) or not (n = 25). Narratives were scored for organizational structure (i.e., coherence) using the Narrative Coherence Coding Scheme (Reese et al., 2011) and episodic recollection using the Autobiographical Interview Coding Procedures (Levine et al., 2002).

RESULTS

The mTBI group produced narratives that were less coherent but contained more episodic details than those of the no-TBI group.

CONCLUSION

These results suggest that mTBI interferes with the organizational quality of memory in a manner that is independent of episodic detail generation.