Visual imagery and depersonalisation

Aphantasia and hyperphantasia: exploring imagery vividness extremes

The vividness of imagery varies between individuals. However, the existence of people in whom conscious, wakeful imagery is markedly reduced, or absent entirely, was neglected by psychology until the recent coinage of 'aphantasia' to describe this phenomenon. 'Hyperphantasia' denotes the converse - imagery whose vividness rivals perceptual experience. Around 1% and 3% of the population experience extreme aphantasia and hyperphantasia, respectively. Aphantasia runs in families, often affects imagery across several sense modalities, and is variably associated with reduced autobiographical memory, face recognition difficulty, and autism. Visual dreaming is often preserved. Subtypes of extreme imagery appear to be likely but are not yet well defined. Initial results suggest that alterations in connectivity between the frontoparietal and visual networks may provide the neural substrate for visual imagery extremes.

Aphantasia and psychological disorder: Current connections, defining the imagery deficit and future directions

Aphantasia is a condition characterized by a deficit of mental imagery. Since several psychopathologies are partially maintained by mental imagery, it may be illuminating to consider the condition against the background of psychological disorder. After outlining current findings and hypotheses regarding aphantasia and psychopathology, this paper suggests that some support for defining aphantasia as a lack of voluntary imagery may be found here. The paper then outlines potentially fruitful directions for future research into aphantasia in general and its relation to psychopathology in particular, including rethinking use of the SUIS to measure involuntary imagery, whether aphantasia offers protection against addiction, and whether hyperphantasia is a potential risk factor for maladaptive daydreaming, among others.

Assessing responsiveness to direct verbal suggestions in depersonalization-derealization disorder

The dissociative disorders and germane conditions are reliably characterized by elevated responsiveness to direct verbal suggestions. However, it remains unclear whether atypical responsiveness to suggestion is similarly present in depersonalization-derealization disorder (DDD). 55 DDD patients and 36 healthy controls completed a standardised behavioural measure of direct verbal suggestibility that includes a correction for compliant responding (BSS-C), and psychometric measures of depersonalization-derealization (CDS), mindfulness (FFMQ), imagery vividness (VVIQ), and anxiety (GAD-7). Relative to controls, patients did not exhibit elevated suggestibility (g = 0.26, BF₁₀ = .11) but displayed significantly lower mindfulness (g = 1.38), and imagery vividness (g = 0.63), and significantly greater anxiety (g = 1.39). Although suggestibility did not correlate with severity of depersonalization-derealization symptoms in controls, r = -.03 [95% CI: -.36, .30], there was a weak tendency for a positive association in patients, r = .25, [95% CI: -.03, .48]. Exploratory analyses revealed that patients with more severe anomalous bodily experiences were also more responsive to suggestion, an effect not seen in controls. This study demonstrates that DDD is not characterized by elevated responsiveness to direct verbal suggestions. These results have implications for the aetiology and treatment of this condition, as well as its classification as a dissociative disorder in psychiatric nosology.

The clear and not so clear signatures of perceptual reality in the Bayesian brain

In a Bayesian brain, every perceptual decision will take into account internal priors as well as new incoming evidence. A reality monitoring system-eventually providing the agent us with a subjective sense of reality avoids us them being confused about whether our experience is perceptual or imagined. Yet not all confusions we experience mean that we wonder wonder whether we may be imagining: some confused experiences feel clearly perceptual but still feel not right. What happens in such confused perceptions, and can the Bayesian brain explain this kind of confusion? In this paper, we offer a characterisation of perceptual confusion and argue that it requires our subjective sense of reality to be a composite of several subjective markers, including a categorical one that can clearly identify an experience as perceptual and connecting us to reality. Our composite account makes new predictions regarding the robustness, the non-linear development and the possible breakdowns of the sense of reality in perception.

Aphantasia: The science of visual imagery extremes

Visual imagery allows us to revisit the appearance of things in their absence and to test out virtual combinations of sensory experience. Visual imagery has been linked to many cognitive processes, such as autobiographical and visual working memory. Imagery also plays symptomatic and mechanistic roles in neurologic and mental disorders and is utilized in treatment. A large network of brain activity spanning frontal, parietal, temporal, and visual cortex is involved in generating and maintain images in mind. The ability to visualize has extreme variations, ranging from completely absent (aphantasia) to photo-like (hyperphantasia). The anatomy and functionality of visual cortex, including primary visual cortex, have been associated with individual differences in visual imagery ability, pointing to a potential correlate for both aphantasia and hyperphantasia. Preliminary evidence suggests that lifelong aphantasia is associated with prosopagnosia and reduction in autobiographical memory; hyperphantasia is associated with synesthesia. Aphantasic individuals can also be highly imaginative and are able to complete many tasks that were previously thought to rely on visual imagery, demonstrating that visualization is only one of many ways of representing things in their absence. The study of extreme imagination reminds us how easily invisible differences can escape detection.

Symptoms of depersonalisation/derealisation disorder as measured by brain electrical activity: A systematic review

Depersonalisation/derealisation disorder (DPD) refers to frequent and persistent detachment from bodily self and disengagement from the outside world. As a dissociative disorder, DPD affects 1-2 % of the population, but takes 7-12 years on average to be accurately diagnosed. In this systematic review, we comprehensively describe research targeting the neural correlates of core DPD symptoms, covering publications between 1992 and 2020 that have used electrophysiological techniques. The aim was to investigate the diagnostic potential of these relatively inexpensive and convenient neuroimaging tools. We review the EEG power spectrum, components of the event-related potential (ERP), as well as vestibular and heartbeat evoked potentials as likely electrophysiological biomarkers to study DPD symptoms. We argue that acute anxiety- or trauma-related impairments in the integration of interoceptive and exteroceptive signals play a key role in the formation of DPD symptoms, and that future research needs analysis methods that can take this integration into account. We suggest tools for prospective studies of electrophysiological DPD biomarkers, which are urgently needed to fully develop their diagnostic potential.

Depersonalisation disorder: clinical features of 204 cases

Background

Depersonalisation disorder is a poorly understood and underresearched syndrome.

Aims

To carry out a large and comprehensive clinical and psychopathological survey of a series of patients who made contact with a research clinic.

Method

A total of 204 consecutive eligible referrals were included: 124 had a full psychiatric examination using items of the Present State Examination to define depersonalisation/derealisation and 80 had either a telephone interview (n=22) or filled out a number of self-report questionnaires. Cases assessed were diagnosed according to DSM–IV criteria.

Results

The mean age of onset was 22.8 years; early onset was associated with greater severity There was a slight male preponderance. The disorder tended to be chronic and persistent. Seventy-one per cent met DSM–IV criteria for primary depersonalisation disorder. Depersonalisation symptom scores correlated with both anxiety and depression and a past history of these disorders was commonly reported. ‘Dissociative amnesia’ was not prominent.

Conclusions

Depersonalisation disorder is a recognisable clinical entity but appears to have significant comorbidity with anxiety and depression. Research into its aetiology and treatment is warranted.

Vestibular Function and Depersonalization/Derealization Symptoms

Patients with an acquired sensory dysfunction may experience symptoms of detachment from self or from the environment, which are related primarily to nonspecific symptoms of common mental disorders and secondarily, to the specific sensory dysfunction. This is consistent with the proposal that sensory dysfunction could provoke distress and a discrepancy between the multi-sensory frame given by experience and the actual perception. Both vestibular stimuli and vestibular dysfunction can underlie unreal experiences. Vestibular afferents provide a frame of reference (linear and angular head acceleration) within which spatial information from other senses is interpreted. This paper reviews evidence that symptoms of depersonalization/derealization associated with vestibular dysfunction are a consequence of a sensory mismatch between disordered vestibular input and other sensory signals of orientation.

Altered orientation of spatial attention in depersonalization disorder

Difficulties with concentration are frequent complaints of patients with depersonalization disorder (DPD). Standard neuropsychological tests suggested alterations of the attentional and perceptual systems. To investigate this, the well-validated Spatial Cueing paradigm was used with two different tasks, consisting either in the detection or in the discrimination of visual stimuli. At the start of each trial a cue indicated either the correct (valid) or the incorrect (invalid) position of the upcoming stimulus or was uninformative (neutral). Only under the condition of increased task difficulty (discrimination task) differences between DPD patients and controls were observed. DPD patients showed a smaller total attention directing effect (RT in valid vs. invalid trials) compared to healthy controls only in the discrimination condition. RT costs (i.e., prolonged RT in neutral vs. invalid trials) mainly accounted for this difference. These results indicate that DPD is associated with altered attentional mechanisms, especially with a stronger responsiveness to unexpected events. From an evolutionary perspective this may be advantageous in a dangerous environment, in daily life it may be experienced as high distractibility.

Depersonalization disorder: disconnection of cognitive evaluation from autonomic responses to emotional stimuli

BACKGROUND

Patients with depersonalization disorder (DPD) typically complain about emotional detachment. Previous studies found reduced autonomic responsiveness to emotional stimuli for DPD patients as compared to patients with anxiety disorders. We aimed to investigate autonomic responsiveness to emotional auditory stimuli of DPD patients as compared to patient controls. Furthermore, we examined the modulatory effect of mindful breathing on these responses as well as on depersonalization intensity.

METHODS

22 DPD patients and 15 patient controls balanced for severity of depression and anxiety, age, sex and education, were compared regarding 1) electrodermal and heart rate data during a resting period, and 2) autonomic responses and cognitive appraisal of standardized acoustic affective stimuli in two conditions (normal listening and mindful breathing).

RESULTS

DPD patients rated the emotional sounds as significantly more neutral as compared to patient controls and standardized norm ratings. At the same time, however, they responded more strongly to acoustic emotional stimuli and their electrodermal response pattern was more modulated by valence and arousal as compared to patient controls. Mindful breathing reduced severity of depersonalization in DPD patients and increased the arousal modulation of electrodermal responses in the whole sample. Finally, DPD patients showed an increased electrodermal lability in the rest period as compared to patient controls.

CONCLUSIONS

These findings demonstrated that the cognitive evaluation of emotional sounds in DPD patients is disconnected from their autonomic responses to those emotional stimuli. The increased electrodermal lability in DPD may reflect increased introversion and cognitive control of emotional impulses. The findings have important psychotherapeutic implications.

Is the Charcot and Bernard case (1883) of loss of visual imagery really based on neurological impairment?

INTRODUCTION. The Charcot and Bernard case of visual imagery, Monsieur X, is a classic case in the history of neuropsychology. Published in 1883, it has been considered the first case of visual imagery loss due to brain injury. Also in recent times a neurological valence has been given to it. However, the presence of analogous cases of loss of visual imagery in the psychiatric field have led us to hypothesise functional origins rather than organic. METHODS. In order to assess the validity of such an inference, we have compared the symptomatology of Monsieur X with that found in cases of loss of visual mental images, both psychiatric and neurological, presented in literature. RESULTS. The clinical findings show strong assonances of the Monsieur X case with the symptoms manifested over time by the patients with functionally based loss of visual imagery. CONCLUSION. Although Monsieur X's damage was initially interpreted as neurological, reports of similar symptoms in the psychiatric field lead us to postulate a functional cause for his impairment as well.

[Depersonalisation/derealization - clinical picture, diagnostics and therapy]

The present state of knowledge about depersonalization (DP) and derealization (DR) is reviewed with respect to classification, epidemiology, etiology, and therapy. Mild and transient DP-DR are considered to be common phenomena. The prevalence of depersonalization-derealization disorder (DP-DR-D) is estimated to be approx. 1-2% of the general population in the Western hemisphere. DP-DR-D is probably severely underdiagnosed. DP-DR-D is strongly associated with depression and anxiety disorders. It is suggested that symptoms of DP-DR indicate disease severity and negatively predict therapy outcome. Neurobiological and psychological models have shown that a disordered body schema and emotional and autonomic blunting are essential components of the disorder. Despite the frequency of DPDR and its clinical relevance, there is a considerable lack of empirical research on DP-DR with respect to the health-care situation of depersonalized patients and with regard to treatment options.

Narcissistic regulation of the self and interpersonal problems in depersonalized patients

BACKGROUND

Psychoanalytical theories coincide in understanding depersonalization (DP) as a disorder of narcissistic self-regulation. DP is described as an ego defense against overwhelming shame resulting in a splitting of an observing ego detached from the experiencing self. In contrast to a behavioral-cognitive theory on DP, which suggests that the catastrophic appraisal of normal transient DP maintains the disorder, psychodynamic approaches stress that DP is an important defensive function for the individual. We examine this psychodynamic aspect more closely as it relates to narcissistic self-regulation and interpersonal behavior in depersonalized patients.

SAMPLING AND METHODS

Thirty-five patients with pathological DP are compared with 28 patient controls concerning their narcissistic self-regulation and interpersonal behavior. For the assessment, we used the German Narcissism Inventory and the Inventory of Interpersonal Problems. The two groups were controlled for sociodemographic data, comorbidity with a personality disorder, and the General Severity Index of the Symptom Check List-90-R.

RESULTS

Bonferroni-corrected group comparison showed that the depersonalized patients are characterized by perceiving themselves as helpless, hopeless, socially isolated and worthless, perceiving others as bad and disappointing, and that they avoid interpersonal relations and reality significantly more than other patients with equal symptom severity.

CONCLUSIONS

Treatment approaches on DP should take the issue of low self-esteem, pervasive shame and the related defensive social avoidance into account. Further empirical research on psychodynamic concepts of DP is warranted also for the sake of linking modern neurobiological findings with clinical experience.

Die Erfassung des Depersonalisations- Derealisationssyndroms mit dem Fragebogen zu Dissoziativen Symptoment

OBJECTIVES

The goal of this study is to investigate the applicability of the German adaptation of the Dissociative Experiences Scale, the "Fragebogen zu dissoziativen Symptomen (FDS)", for research on depersonalization (DP) and derealization (DR), and to elucidate the phenomenology of DP / DR.

METHODS

101 consecutively recruited inpatients were diagnosed with the German version of the Structured Clinical Interview for DSM-IV Dissociative Disorders for depersonalization/derealization. Furthermore, the FDS and the SCL-90-R were administered.

RESULTS

47 of 101 Patients were diagnosed with pathological DP / DR. The mean score of the DES scale of the FDS was 32.00 +/- 15.52. A cut-off score of 17.5 for the DES scale of the FDS yielded a 83.0 % sensitivity and 77.8 % specificity. Depressive disorders, anxiety disorders and trauma-associated disorders were the most common comorbidity.

CONCLUSIONS

The findings are comparable to the Anglo-American samples. The FDS was found to be quite effective for screening of DP / DR. The three-factor solution of the FDS was not well supported in this sample.