Metacognitive deficits in categorization tasks in a population with impaired inner speech

Inner speech in the daily lives of people with aphasia

Introduction

This exploratory, preliminary, feasibility study evaluated the extent to which adults with chronic aphasia (N = 23) report experiencing inner speech in their daily lives by leveraging experience sampling and survey methodology.

Methods

The presence of inner speech was assessed at 30 time-points and themes of inner speech at three time-points, over the course of three weeks. The relationship of inner speech to aphasia severity, demographic information (age, sex, years post-stroke), and insight into language impairment was evaluated.

Results

There was low attrition (<8%) and high compliance (>94%) for the study procedures, and inner speech was experienced in most sampled instances (>78%). The most common themes of inner speech experience across the weeks were 'when remembering', 'to plan', and 'to motivate oneself'. There was no significant relationship identified between inner speech and aphasia severity, insight into language impairment, or demographic information. In conclusion, adults with aphasia tend to report experiencing inner speech often, with some shared themes (e.g., remembering, planning), and use inner speech to explore themes that are uncommon in young adults in other studies (e.g., to talk to themselves about health).

Discussion

High compliance and low attrition suggest design feasibility, and results emphasize the importance of collecting data in age-similar, non-brain-damaged peers as well as in adults with other neurogenic communication disorders to fully understand the experience and use of inner speech in daily life. Clinical implications and future directions are discussed.

Two models of mind blanking

Mind blanking is a mental state in which attention does not bring any perceptual input into conscious awareness. As this state is still largely unexplored, we suggest that a comprehensive understanding of mind blanking can be achieved through a multifaceted approach combining self-assessment methods, neuroimaging and neuromodulation. In this article, we explain how electroencephalography and transcranial magnetic stimulation could be combined to help determine whether mind blanking is associated with a lack of mental content or a lack of linguistically or conceptually determinable mental content. We also question whether mind blanking occurs spontaneously or intentionally and whether these two forms are instantiated by the same or different neural correlates.

Bridging phenomenology and neural mechanisms of inner speech: ALE meta-analysis on egocentricity and spontaneity in a dual-mechanistic framework

The neural mechanisms of inner speech remain unclear despite its importance in a variety of cognitive processes and its implication in aberrant perceptions such as auditory verbal hallucinations. Previous research has proposed a corollary discharge model in which inner speech is a truncated form of overt speech, relying on speech production-related regions (e.g. left inferior frontal gyrus). This model does not fully capture the diverse phenomenology of inner speech and recent research suggesting alternative perception-related mechanisms of generation. Therefore, we present and test a framework in which inner speech can be generated by two separate mechanisms, depending on its phenomenological qualities: a corollary discharge mechanism relying on speech production regions and a perceptual simulation mechanism within speech perceptual regions. The results of the activation likelihood estimation meta-analysis examining inner speech studies support the idea that varieties of inner speech recruit different neural mechanisms.

What can neurodiversity tell us about inner speech, and vice versa? A theoretical perspective

Inner speech refers to the experience of talking to oneself in one's head. While notoriously challenging to investigate, it has also been central to a range of questions concerning mind, brain, and behaviour. Posited as a key component in executive function and self-regulation, inner speech has been claimed to be crucial in higher cognitive operations, self-knowledge and self-awareness. Such arguments have traditionally been supported with examples of atypical development. But variations in inner speech - and in some cases, significant diversity - in fact pose several key challenges to such claims, and raises many more questions for, language, thought and mental health more generally. In this review, we will summarise evidence on the experience and operation of inner speech in child and adult neurotypical populations, autistic people and other neurodivergent groups, and people with diverse experiences of linguistic and sensory development, including deafness. We will demonstrate that the relationship between inner speech and cognitive operations may be more complex than first assumed when explored through the lens of cognitive and neurological diversity, and the implications of that for understanding the developing brain in all populations. We discuss why and how the experience of inner speech in neurodivergent groups has often been assumed rather than investigated, making it an important opportunity for researchers to develop innovative future work that integrates participatory insights with cognitive methodology. Finally, we will outline why variations in inner speech - in neurotypical and neurodivergent populations alike - nevertheless have a range of important implications for mental health vulnerability and unmet need. In this sense, the example of inner speech offers us both a way of looking back at the logic of developmental psychology and neuropsychology, and a clue to its future in a neurodiverse world.

Which blueberries are better value? The development and validation of the functional numeracy assessment for adults with aphasia

BACKGROUND

People with aphasia (PWA) can experience functional numeracy difficulties, that is, problems understanding or using numbers in everyday life, which can have numerous negative impacts on their daily lives. There is growing interest in designing functional numeracy interventions for PWA; however, there are limited suitable assessments available to monitor the impact of these interventions. Existing functional numeracy assessments lack breadth and are not designed to be accessible for PWA, potentially confounding their performance. Additionally, they do not include real-life demands, such as time pressure, which may affect their ecological validity. Thus, there is a crucial need for a new assessment to facilitate further research of PWA's functional numeracy.

AIMS

To develop, validate and pilot a wide-ranging, aphasia-friendly functional numeracy assessment to investigate how functional numeracy is impacted by aphasia severity and time pressure demands, and to explore predictors of PWA's functional numeracy.

METHODS & PROCEDURES

To develop the Functional Numeracy Assessment (FNA), 38 items inspired by the General Health Numeracy Test (GHNT) and Excellence Gateway were adapted for suitability for PWA and entered in a computerized psychometric-style test. The final 23 items (FNA23) were selected based on 213 neurotypical controls' performance, and controlled for difficulty, response modality and required numeracy skills. Aphasia-friendly adaptations of the GHNT and Subjective Numeracy Scale were used to examine the FNA23's concurrent validity. Internal consistency reliability and interrater reliability (for spoken responses) were also examined. A novel Time Pressure Task was created by slight adaptation of seven FNA23 questions to explore the effects of time pressure on functional numeracy performance. A total of 20 PWA and 102 controls completed all measures on an online testing platform.

OUTCOMES & RESULTS

The FNA23 demonstrated acceptable internal consistency reliability (KR-20 = 0.81) and perfect interrater reliability (for spoken responses). FNA23 and GHNT scores were positively associated, suggesting satisfactory concurrent validity. PWA demonstrated poorer functional numeracy than controls and took longer to complete assessments, indicating that aphasia impacts functional numeracy. Time pressure did not significantly impact performance. PWA demonstrated a wide range of functional numeracy abilities, with some performing similarly to controls.

CONCLUSIONS & IMPLICATIONS

The FNA23 is a wide-ranging, valid and reliable assessment which, with further development, will be a useful tool to identify and monitor PWA's functional numeracy difficulties in research and clinical practice. Considering PWA's widespread functional numeracy difficulties evidenced by this study, all PWA would likely benefit from routine evaluation for functional numeracy difficulties as part of their neurorehabilitation journeys.

WHAT THIS PAPER ADDS

What is already known on this subject Few studies have investigated functional numeracy difficulties in PWA. No published functional numeracy assessments exist that have been specifically designed to be accessible for PWA. What this paper adds to existing knowledge The newly developed FNA23 is a valid and reliable tool to extensively assess PWA's functional numeracy. This study confirmed previous findings of widespread functional numeracy difficulties in PWA that are related to their aphasia severity. What are the potential or actual clinical implications of this work? The FNA23 can be used to assess PWA's functional numeracy to inform areas of strengths and difficulties to target in intervention, and to monitor progress towards achieving intervention objectives. All PWA should be routinely evaluated for functional numeracy difficulties.

A context-sensitive and non-linguistic approach to abstract concepts

Despite the recent upsurge in research on abstract concepts, there remain puzzles at the foundation of their empirical study. These are most evident when we consider what is required to assess a person's abstract conceptual abilities without using language as a prompt or requiring it as a response-as in classic non-verbal categorization tasks, which are standardly considered tests of conceptual understanding. After distinguishing two divergent strands in the most common conception of what it is for a concept to be abstract, we argue that neither reliably captures the kind of abstraction required to successfully categorize in non-verbal tasks. We then present a new conception of concept abstractness-termed 'trial concreteness'-that is keyed to individual categorization trials. It has advantages in capturing the context-relativity of the degree of abstraction required for the application of a concept and fittingly correlates with participant success in recent experiments. This article is part of the theme issue 'Concepts in interaction: social engagement and inner experiences'.

What is mind blanking: a conceptual clarification

The investigation of so-called mind blanking has been recently established in the context of mind wandering research. Unfortunately, the description of the term "mind blanking" and its experimental assessment are often ambiguous. More specifically, two distinct phenomena have been conceptually blended and both characterized using the term "mind blanking" in experimental studies: the absence of task-focus and thought, versus complete lack of conscious experiences. At least in part, this confusion can be traced back to the writings of William James, who referred to "thought" as a superordinate term to address different conscious experiences. Applying the technique of so-called experience sampling, experimental studies, up to now, probably assessed the absence of thought, but not a complete lack of conscious experiences. There is no clear evidence yet for instances of the latter phenomenon occurring during non-pathological waking state. Possibly, such evidence could be revealed in the future using a conceptually more refined experience sampling.

A voice without a mouth no more: The neurobiology of language and consciousness

Most research on the neurobiology of language ignores consciousness and vice versa. Here, language, with an emphasis on inner speech, is hypothesised to generate and sustain self-awareness, i.e., higher-order consciousness. Converging evidence supporting this hypothesis is reviewed. To account for these findings, a 'HOLISTIC' model of neurobiology of language, inner speech, and consciousness is proposed. It involves a 'core' set of inner speech production regions that initiate the experience of feeling and hearing words. These take on affective qualities, deriving from activation of associated sensory, motor, and emotional representations, involving a largely unconscious dynamic 'periphery', distributed throughout the whole brain. Responding to those words forms the basis for sustained network activity, involving 'default mode' activation and prefrontal and thalamic/brainstem selection of contextually relevant responses. Evidence for the model is reviewed, supporting neuroimaging meta-analyses conducted, and comparisons with other theories of consciousness made. The HOLISTIC model constitutes a more parsimonious and complete account of the 'neural correlates of consciousness' that has implications for a mechanistic account of mental health and wellbeing.

Assessing abstract thought and its relation to language with a new nonverbal paradigm: Evidence from aphasia

In recent years, language has been shown to play a number of important cognitive roles over and above the communication of thoughts. One hypothesis gaining support is that language facilitates thought about abstract categories, such as democracy or prediction. To test this proposal, a novel set of semantic memory task trials, designed for assessing abstract thought non-linguistically, were normed for levels of abstractness. The trials were rated as more or less abstract to the degree that answering them required the participant to abstract away from both perceptual features and common setting associations corresponding to the target image. The normed materials were then used with a population of people with aphasia to assess the relationship of abstract thought to language. While the language-impaired group with aphasia showed lower overall accuracy and longer response times than controls in general, of special note is that their response times were significantly longer as a function of a trial's degree of abstractness. Further, the aphasia group's response times in reporting their degree of confidence (a separate, metacognitive measure) were negatively correlated with their language production abilities, with lower language scores predicting longer metacognitive response times. These results provide some support for the hypothesis that language is an important aid to abstract thought and to metacognition about abstract thought.

Inner speech

Inner speech travels under many aliases: the inner voice, verbal thought, thinking in words, internal verbalization, "talking in your head," the "little voice in the head," and so on. It is both a familiar element of first-person experience and a psychological phenomenon whose complex cognitive components and distributed neural bases are increasingly well understood. There is evidence that inner speech plays a variety of cognitive roles, from enabling abstract thought, to supporting metacognition, memory, and executive function. One active area of controversy concerns the relation of inner speech to auditory verbal hallucinations (AVHs) in schizophrenia, with a common proposal being that sufferers of AVH misidentify their own inner speech as being generated by someone else. Recently, researchers have used artificial intelligence to translate the neural and neuromuscular signatures of inner speech into corresponding outer speech signals, laying the groundwork for a variety of new applications and interventions. This article is categorized under: Philosophy > Foundations of Cognitive Science Linguistics > Language in Mind and Brain Philosophy > Consciousness Philosophy > Psychological Capacities.

The ConDialInt Model: Condensation, Dialogality, and Intentionality Dimensions of Inner Speech Within a Hierarchical Predictive Control Framework

Inner speech has been shown to vary in form along several dimensions. Along condensation, condensed inner speech forms have been described, that are supposed to be deprived of acoustic, phonological and even syntactic qualities. Expanded forms, on the other extreme, display articulatory and auditory properties. Along dialogality, inner speech can be monologal, when we engage in internal soliloquy, or dialogal, when we recall past conversations or imagine future dialogs involving our own voice as well as that of others addressing us. Along intentionality, it can be intentional (when we deliberately rehearse material in short-term memory) or it can arise unintentionally (during mind wandering). We introduce the ConDialInt model, a neurocognitive predictive control model of inner speech that accounts for its varieties along these three dimensions. ConDialInt spells out the condensation dimension by including inhibitory control at the conceptualization, formulation or articulatory planning stage. It accounts for dialogality, by assuming internal model adaptations and by speculating on neural processes underlying perspective switching. It explains the differences between intentional and spontaneous varieties in terms of monitoring. We present an fMRI study in which we probed varieties of inner speech along dialogality and intentionality, to examine the validity of the neuroanatomical correlates posited in ConDialInt. Condensation was also informally tackled. Our data support the hypothesis that expanded inner speech recruits speech production processes down to articulatory planning, resulting in a predicted signal, the inner voice, with auditory qualities. Along dialogality, covertly using an avatar's voice resulted in the activation of right hemisphere homologs of the regions involved in internal own-voice soliloquy and in reduced cerebellar activation, consistent with internal model adaptation. Switching from first-person to third-person perspective resulted in activations in precuneus and parietal lobules. Along intentionality, compared with intentional inner speech, mind wandering with inner speech episodes was associated with greater bilateral inferior frontal activation and decreased activation in left temporal regions. This is consistent with the reported subjective evanescence and presumably reflects condensation processes. Our results provide neuroanatomical evidence compatible with predictive control and in favor of the assumptions made in the ConDialInt model.

The neural correlates of "mind blanking": When the mind goes away

Mind blanking (MB) is the state where our minds are seemingly "nowhere," and attention calls no perceptual input into conscious awareness. It is little investigated, perhaps partly because it is difficult to detect the mysterious periods of blanking. In this study, we found that our participants could intentionally produce a state of MB whose neural correlates were deactivation of Broca's area and parts of the default mode network (namely, the hippocampus) which would be active during mind wandering (MW), in addition to activity in another region in the default mode network (namely, anterior cingulate cortex). Because the behavioral finding replicates a previous report of ours, we suggest that the simple instructions that we used to induce MB should be effective. From the neuroimaging data, we conclude that we cannot define the content of our thoughts during MB because our inner speech system does not work at that time. Another possibility is that we actually think of nothing in the MB state. Although more sophisticated studies would be needed to uncover the mechanism of such a phenomenon, the present study provides a methodology and clues for understanding MB and related concepts such as MW, awareness, and metacognitive ability.