ABSTRACT
Within the past decade, the term "phantasia" has been increasingly used to describe the human capacity, faculty, or power of visual mental imagery, with extremes of imagery vividness characterised as "aphantasia" and "hyperphantasia". A substantial volume of empirical research addressing these constructs has now been published, including attempts to find inductive correlates of behaviourally defined aphantasia, for example using research questionnaires and functional magnetic resonance imaging. Mental imagery has long been noted as a source of conceptual confusions but no specific conceptual analysis of the new formulation of phantasia, aphantasia, and hyperphantasia has been undertaken hitherto. We offer some conceptual considerations on phantasia, noting the ongoing confusion of perceptual with mental images, and the ubiquitous use of unvalidated subjective assessment instruments such as the Vividness of Visual Imagery Questionnaire (VVIQ) in diagnosis and assessment, development of which was predicated on these conceptual confusions. We offer some suggestions for a conceptual framework for future empirical studies in this field, circumventing these conceptual confusions.
Subject(s)
Imagination , Humans , Imagination/physiology , Aphasia/physiopathology , Visual Perception/physiologyABSTRACT
Matthew Baillie was born in Shotts, Lanarkshire, Scotland in 1761 and died at Duntisbourne Abbots, Gloucestershire, England in 1823. In the intervening years he established himself as one of the foremost anatomists of his day, publishing one of the earliest treatises on pathological anatomy, and then as physician, eventually ministering to the Royal household and other notable patients and earning a considerable fortune in the process. Amongst his many honours he received an Honorary Fellowship of the Royal College of Physicians of Edinburgh, where he is commemorated in the frieze in the Great Hall. This article follows the trajectory of his career, introducing material not found in previous biographies.
Subject(s)
Universities , England , Humans , ScotlandABSTRACT
Introduction: Whilst the empirical understanding of functional cognitive disorders (FCD) has advanced in recent years, theoretical and conceptual models have evolved more slowly. Existing frameworks for FCD are based on models of other functional neurological disorders or of metacognitive processes and are recognised to lack mechanistic precision.Methods: In this article, a novel application to FCD of Hoel's Overfitted Brain Hypothesis of the evolved function of dreaming is attempted.Results: This posits that the empirically observed sleep disturbance in FCD entails impaired dreaming which causes the brain to be overfitted and hence unable to generalise appropriately, producing mismatch between memory expectations and memory performance.Conclusions: This formulation of FCD is based on considerations derived from the study of neural networks and shares commonalities with Bayesian models of functional neurological disorders. Additionally, it has implications for future hypothesis-driven research in FCD and suggests a pragmatic basis for management strategies.
Subject(s)
Brain , Cognition Disorders , Bayes Theorem , Cognition , Humans , Neural Networks, ComputerSubject(s)
Cognition Disorders , Dementia , Cognition , Cognition Disorders/etiology , Dementia/complications , HumansABSTRACT
Some recent authors have claimed that Théodule-Armand Ribot described transient global amnesia in the nineteenth century in his monograph, Diseases of memory, An examination of this work was undertaken to determine whether or not this claim is true. Whilst Ribot cites Koempfen's thorough report of a case of transient amnesia, dating from 1835, this does not conform to current understanding of transient global amnesia.
Subject(s)
Amnesia, Transient Global , Amnesia , Humans , MemoryABSTRACT
In the mid-1970s, the psychiatrist Edward Hare published two accounts of Michael Faraday's memory symptoms, based upon which he suggested the diagnostic possibilities of an amnesic syndrome related to a transient ischemic attack in the vertebrobasilar cerebrovascular system. This article revisits the contemporary evidence of Faraday's letters and the notes of his physician, Peter Mere Latham, and considers subsequent responses to and shortcomings of Hare's analysis. In light of more recent conceptualizations of memory disorders, a new formulation for Faraday's memory symptoms is suggested: namely, that he manifested a functional cognitive disorder.
Subject(s)
Hearing Loss , Female , Hearing Loss/diagnosis , Hearing Loss/etiology , Humans , Middle AgedSubject(s)
Medicine in Literature/history , Famous Persons , History, 19th Century , Humans , Literature, Modern , MaleABSTRACT
Many patients referred to cognitive disorders clinics are not found to have evidence of any neurological disorder(s) to account for their symptoms. Many demonstrate incongruence between their subjective cognitive symptoms and preserved social and occupational functions. The term 'functional cognitive disorders' (FCD) has been used to denote this diagnostic category. This article aims to review the current state of knowledge regarding FCD. Studies of FCD are in their infancy, but available evidence suggests positive diagnosis may be made based on typical clinical profiles, including language discourse and simple clinical signs. Concurrent mood disorder and sleep disturbance are common, as well as other functional disorders. Pathogenesis is yet to be determined, but a disorder of metamemory has been suggested.
Subject(s)
Cognition Disorders/diagnosis , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Young AdultABSTRACT
Objectives: To examine the diagnostic utility of the 'attended alone' (AA) and 'attended with' (AW) signs for the diagnosis of major and minor neurocognitive disorder. Methods: Consecutive unselected new outpatient referrals (N = 1209) to a dedicated cognitive disorders clinic over a 5-year period (2015-2019 inclusive) were observed for the AA and AW signs. Criterion diagnoses were by usual clinic assessment using standard (DSM-5) diagnostic criteria. Results: AW proved to be very sensitive for the identification of major and minor neurocognitive disorder but with generally low positive predictive values. In the subgroup of patients attending with more than one informant, the AW2+ sign, positive predictive value was higher and likewise with increasing patient age where the prevalence of AW was higher. Diagnostic utility of AW and AA was independent of patient gender. Conclusion: AW and AA are easily observed and categorized signs. AW has a high sensitivity for cognitive impairment while AA has a high positive predictive value for its absence.