Aphantasia within the framework of neurodivergence: Some preliminary data and the curse of the confidence gap.

Aphantasia is a neurocognitive phenomenon affecting voluntary visual imagery, such that it is either entirely absent, or markedly impaired. Using both the social and medical models of disability, this article discusses the extent to which aphantasia can be understood as a disorder or just a form of neutral neurodivergence, given that imagery plays a central role in thinking and memory for most other people. Preliminary school performance data are presented, showing that low imagery does not necessarily complicate life, especially given compensatory strategies and low societal barriers. In addition, we discuss the consequences of labelling aphantasia a disorder with regard to self- and public stigma, and we provide further data regarding a confidence gap, by which aphantasics perceive themselves as performing worse than they objectively do. We conclude that aphantasia should be understood as neutral neurodivergence and that labelling it a disorder is not only wrong, but potentially harmful.

Mental Health Difficulties in Children who Develop Misophonia: An Examination of ADHD, Depression & Anxiety.

Misophonia is a sound sensitivity disorder characterized by unusually strong aversions to a specific class of sounds (e.g., eating sounds). Here we demonstrate the mental health profile in children who develop misophonia, examining depression, anxiety and ADHD. Our participants were members of the birth cohort ALSPAC (Avon Longitudinal Study of Parents and Children). We screened them for misophonia as adults, then analysed their retrospective mental health data from ages 7 to 16 years inclusive, reported from both children and parents. Data from their Development and Wellbeing Assessments (7-15 years) and their Short Mood and Feelings Questionnaires (9-16 years) show that our misophonia group had a greater likelihood of childhood anxiety disorder and depression in childhood (but not ADHD). Our data provide the first evidence from a large general population sample of the types of mental health co-morbidities found in children who develop misophonia.

A symptom network model of misophonia: From heightened sensory sensitivity to clinical comorbidity.

OBJECTIVES: Misophonia-an unusually strong intolerance of certain sounds-can cause significant distress and disruption to those who have it but is an enigma in terms of our scientific understanding. A key challenge for explaining misophonia is that, as with other disorders, it is likely to emerge from an interaction of traits that also occur in the general population (e.g., sensory sensitivity and anxiety) and that are transdiagnostic in nature (i.e., shared with other disorders). METHODS: In this preregistered study with a large sample of participants (N = 1430), we performed a cluster analysis (based on responses to questions relating to misophonia) and identified two misophonia subgroups differing in severity, as well as a third group without misophonia. A subset of this sample (N = 419) then completed a battery of measures designed to assess sensory sensitivity and clinical comorbidities. RESULTS: Clinical symptoms were limited to the most severe group of misophonics (including autistic traits, migraine with visual aura, anxiety sensitivity, obsessive-compulsive traits). Both the moderate and severe groups showed elevated attention-to-detail and hypersensitivity (across multiple senses). A novel symptom network model of the data shows the presence of a central hub linking misophonia to sensory sensitivity which, in turn, connects to other symptoms in the network (relating to autism, anxiety, etc.). CONCLUSION: The core features of misophonia are sensory-attentional in nature with severity linked strongly to comorbidities.

How do Different Types of Synesthesia Cluster Together? Implications for Causal Mechanisms.

It is unclear whether synesthesia is one condition or many, and this has implications for whether theories should postulate a single cause or multiple independent causes. Study 1 analyses data from a large sample of self-referred synesthetes (N = 2,925), who answered a questionnaire about N = 164 potential types of synesthesia. Clustering and factor analysis methods identified around seven coherent groupings of synesthesia, as well as showing that some common types of synesthesia do not fall into any grouping at all (mirror-touch, hearing-motion, tickertape). There was a residual positive correlation between clusters (they tend to associate rather than compete). Moreover, we observed a "snowball effect" whereby the chances of having a given cluster of synesthesia go up in proportion to the number of other clusters a person has (again suggesting non-independence). Clusters tended to be distinguished by shared concurrent experiences rather than shared triggering stimuli (inducers). We speculate that modulatory feedback pathways from the concurrent to inducers may play a key role in the emergence of synesthesia. Study 2 assessed the external validity of these clusters by showing that they predict performance on other measures known to be linked to synesthesia.

Using a new video rating tool to crowd-source analysis of behavioural reaction to stimuli.

Quantifying the intensity of animals' reaction to stimuli is notoriously difficult as classic unidimensional measures of responses such as latency or duration of looking can fail to capture the overall strength of behavioural responses. More holistic rating can be useful but have the inherent risks of subjective bias and lack of repeatability. Here, we explored whether crowdsourcing could be used to efficiently and reliably overcome these potential flaws. A total of 396 participants watched online videos of dogs reacting to auditory stimuli and provided 23,248 ratings of the strength of the dogs' responses from zero (default) to 100 using an online survey form. We found that raters achieved very high inter-rater reliability across multiple datasets (although their responses were affected by their sex, age, and attitude towards animals) and that as few as 10 raters could be used to achieve a reliable result. A linear mixed model applied to PCA components of behaviours discovered that the dogs' facial expressions and head orientation influenced the strength of behaviour ratings the most. Further linear mixed models showed that that strength of behaviour ratings was moderately correlated to the duration of dogs' reactions but not to dogs' reaction latency (from the stimulus onset). This suggests that observers' ratings captured consistent dimensions of animals' responses that are not fully represented by more classic unidimensional metrics. Finally, we report that overall participants strongly enjoyed the experience. Thus, we suggest that using crowdsourcing can offer a useful, repeatable tool to assess behavioural intensity in experimental or observational studies where unidimensional coding may miss nuance, or where coding multiple dimensions may be too time-consuming.

Do the Colors of Educational Number Tools Improve Children's Mathematics and Numerosity?

This study examined how colored educational tools improve children's numerosity ("number sense") and/or mathematics. We tested children 6-10 years (n = 3,236) who had been exposed to colored numbers from the educational tools Numicon (Oxford University Press, 2018) or Numberjacks (Ellis, 2006), which map colors to magnitudes or Arabic numerals, respectively. In a free association task pairing numbers with colors, a subset of children spontaneously provided colors matching one of these schemas. These children, who had internalized Numicon (colored magnitude), showed significantly better numerosity but not mathematics compared to peers. There was no similar benefit from internalizing Numberjacks (colored numerals). These data support a model in which colored number tools provide benefits at different levels of numerical cognition, according to their different levels of cross-modal mappings.

The MULTISENSE Test of Lexical-Gustatory Synaesthesia: An automated online diagnostic.

Lexical-gustatory (LG) synesthesia is an intriguing neurological condition in which individuals experience phantom tastes when hearing, speaking, reading, or thinking about words. For example, the word "society" might flood the mouth of an LG synesthete with the flavor of fried onion. The condition is usually verified in individuals by obtaining verbal descriptions of their word-flavor associations on more than one occasion, separated by several months. Their flavor associations are significantly more consistent over time than are those of controls (who are asked to invent associations by intuition and to recall them from memory). Although this test reliably dissociates synesthetes from nonsynesthetes, it suffers from practical and methodological limitations. Here we present a novel, automated, online consistency test, which can be administered in just 30 min in order to instantly and objectively verify LG synesthesia. We present data from two versions of our diagnostic test, in which synesthetes report their synesthetic flavors either from a hierarchical set of food categories (Exp. 1) or by specifying their basic component tastes (sweet, salty, bitter, etc.). We tested the largest sample of self-declared LG synesthetes studied to date and used receiver operating characteristic analysis to assess the discriminant power of our tests. Although both our methods discriminated synesthetes from controls, our second test (Exp. 2) has greater discriminatory power with a threshold cutoff. We suggest that our novel diagnostic for LG synesthesia has unprecedented benefits in its automated and objective scoring, its ease of use for participants and researchers, its short testing time, and its online platform.

The prevalence and cognitive profile of sequence-space synaesthesia.

People with sequence-space synaesthesia visualize sequential concepts such as numbers and time as an ordered pattern extending through space. Unlike other types of synaesthesia, there is no generally agreed objective method for diagnosing this variant or separating it from potentially related aspects of cognition. We use a recently-developed spatial consistency test together with a novel questionnaire on naïve samples and estimate the prevalence of sequence-space synaesthesia to be around 8.1% (Study 1) to 12.8% (Study 2). We validate our test by showing that participants classified as having sequence-space synaesthesia perform differently on lab-based tasks. They show a spatial Stroop-like interference response, they show enhanced detection of low visibility Gabor stimuli, they report more use of visual imagery, and improved memory for certain types of public events. We suggest that sequence-space synaesthesia develops from a particular neurocognitive profile linked both to greater visual imagery and enhanced visual perception.

Phonological and orthographic influences in the bouba-kiki effect.

We examine a high-profile phenomenon known as the bouba-kiki effect, in which non-word names are assigned to abstract shapes in systematic ways (e.g. rounded shapes are preferentially labelled bouba over kiki). In a detailed evaluation of the literature, we show that most accounts of the effect point to predominantly or entirely iconic cross-sensory mappings between acoustic or articulatory properties of sound and shape as the mechanism underlying the effect. However, these accounts have tended to confound the acoustic or articulatory properties of non-words with another fundamental property: their written form. We compare traditional accounts of direct audio or articulatory-visual mapping with an account in which the effect is heavily influenced by matching between the shapes of graphemes and the abstract shape targets. The results of our two studies suggest that the dominant mechanism underlying the effect for literate subjects is matching based on aligning letter curvature and shape roundedness (i.e. non-words with curved letters are matched to round shapes). We show that letter curvature is strong enough to significantly influence word-shape associations even in auditory tasks, where written word forms are never presented to participants. However, we also find an additional phonological influence in that voiced sounds are preferentially linked with rounded shapes, although this arises only in a purely auditory word-shape association task. We conclude that many previous investigations of the bouba-kiki effect may not have given appropriate consideration or weight to the influence of orthography among literate subjects.

Rates of white matter hyperintensities compatible with the radiological profile of multiple sclerosis within self-referred synesthete populations.

Synesthesia is an inherited condition causing unusual secondary sensations (e.g, sounds might be experienced as both auditory and visual percepts). The condition has been linked with cognitive and perceptual benefits and is considered a benign alternative form of perception. Here, we investigate self-referred synesthete populations and their rates of radiologically determined white matter hyperintensities (WMH) of a type compatible with the McDonald imaging criteria for the diagnosis of multiple sclerosis (MS). MS is a chronic condition resulting in damage to myelination surrounding nerve fibers of the central nervous system (CNS). Magnetic resonance imaging (MRI) features highly suggestive of MS without overt clinical symptoms are termed radiologically isolated syndrome (RIS). We present data showing that the shared MRI profile of MS and RIS has been significantly overrepresented in synesthetes who have participated in neuroimaging research. We present validation of the clinical and MRI status of these synesthetes and an analysis showing the significant probability their unusual numbers may not have arisen by chance. We discuss how to interpret significant data based on small case numbers and consider the implications of our findings for synesthesia's clinical status.

Beyond visual imagery: how modality-specific is enhanced mental imagery in synesthesia?

Synesthesia based in visual modalities has been associated with reports of vivid visual imagery. We extend this finding to consider whether other forms of synesthesia are also associated with enhanced imagery, and whether this enhancement reflects the modality of synesthesia. We used self-report imagery measures across multiple sensory modalities, comparing synesthetes' responses (with a variety of forms of synesthesia) to those of non-synesthete matched controls. Synesthetes reported higher levels of visual, auditory, gustatory, olfactory and tactile imagery and a greater level of imagery use. Furthermore, their reported enhanced imagery is restricted to the modalities involved in the individual's synesthesia. There was also a relationship between the number of forms of synesthesia an individual has, and the reported vividness of their imagery, highlighting the need for future research to consider the impact of multiple forms of synesthesia. We also recommend the use of behavioral measures to validate these self-report findings.

Do sequence-space synaesthetes have better spatial imagery skills? Yes, but there are individual differences.

People with sequence-space synaesthesia perceive sequences (e.g. numbers, months, letters) as spatially extended forms. Here, we ask whether sequence-space synaesthetes have advantages in visuo-spatial skills such as mental rotation. Previous studies addressing this question have produced mixed results with some showing mental rotation advantages (Simner et al. in Cortex 45:1246-1260, 2009; Brang et al. in Cogn Process, 2013), but one that did not (Rizza and Price in Cogn Process 13:299-303, 2012). We tested this hypothesis again with a new group of sequence-space synaesthetes, and we also tested a range of individual differences that might have caused this conflict across previous studies. Specifically, we tested: years of education, visual imagery ability, nature of forms (2D or 3D representation of sequences), number of forms (e.g. for months, days, numbers), and tendency to project sequences into external space versus the mind's eye. We found yet again that synaesthetes had enhanced abilities in mental rotation compared to controls, but that one individual difference in synaesthetes (the ability to project forms into space) was especially linked to performance. We also found that synaesthetes self-reported higher visual imagery than controls (Price in Cortex 45:1229-1245, 2009; Mann et al. in Conscious Cognit 18:619-627, 2009; Rizza and Price 2012). Overall, our data support previous studies showing superior imagery reports (Price 2009) and mental rotation (Simner et al. 2009; Brang et al. 2013) in sequence-space synaesthetes, and we suggest that one previous failure to replicate (Rizza and Price 2012) might be explained by individual differences among synaesthetes recruited for testing.

Sound symbolism in synesthesia: evidence from a lexical-gustatory synesthete.

Synesthesia is a condition in which perceptual or cognitive stimuli (e.g., a written letter) trigger atypical additional percepts (e.g., the color yellow). Although these cross-modal pairings appear idiosyncratic in that they superficially differ from synesthete to synesthete, underlying patterns do exist and these can, in some circumstances, reflect the cross-modal intuitions of nonsynesthetes (e.g., higher pitch sounds tend to be "seen" in lighter colors by synesthetes and are also paired to lighter colors by nonsynesthetes in cross-modal matching tasks). We recently showed that grapheme-color synesthetes are more sensitive to sound symbolism (i.e., cross-modal sound-meaning correspondences) in natural language compared to nonsynesthetes. Accordingly, we hypothesize that sound symbolism may be a guiding force in synesthesia to dictate what types of synesthetic experiences are triggered by words. We tested this hypothesis by examining the cross-modal mappings of lexical-gustatory synesthete, JIW, for whom words trigger flavor experiences. We show that certain phonological features (e.g., front vowels) systematically trigger particular categories of taste (e.g., bitter) in his synesthesia. Some of these associations agree with sound symbolic patterns in natural language. This supports the view that synesthesia may be an exaggeration of cross-modal associations found in the general population and that sound symbolic properties of language may arise from similar mechanisms as those found in synesthesia.

Synaesthesia in Chinese characters: the role of radical function and position.

Grapheme-colour synaesthetes experience unusual colour percepts when they encounter letters and/or digits. Studies of English-speaking grapheme-colour synaesthetes have shown that synaesthetic colours are sometimes triggered by rule-based linguistic mechanisms (e.g., B might be blue). In contrast, little is known about synaesthesia in logographic languages such as Chinese. The current study shows the mechanisms by which synaesthetic speakers of Chinese colour their language. One hypothesis is that Chinese characters might be coloured by their constituent morphological units, known as radicals, and we tested this by eliciting synaesthetic colours for characters while manipulating features of the radicals within them. We found that both the function (semantic vs. phonetic) and position (left vs. right) of radicals influence the nature of the synaesthetic colour generated. Our data show that in Chinese, as in English, synaesthetic colours are influenced by systematic rules, rather than by random associations, and that these rules are based on existing psycholinguistic mechanisms of language processing.

An Automated Online Measure for Misophonia: The Sussex Misophonia Scale for Adults.

Misophonia is a sound sensitivity disorder characterized by a strong aversion to specific sounds (e.g., chewing). Here we present the Sussex Misophonia Scale for Adults (SMS-Adult), within an online open-access portal, with automated scoring and results that can be shared ethically with users and professionals. Receiver operator characteristics show our questionnaire to be "excellent" and "good-to-excellent" at classifying misophonia, both when dividing our n = 501 adult participants by recruitment stream (self-declared misophonics vs. general population), and again when dividing them with by a prior measure of misophonia (as misophonics vs. non-misophonics). Factor analyses identified a five-factor structure in our 39 Likert-type items, and these were Feelings/Isolation, Life consequences, Intersocial reactivity, Avoidance/Repulsion, and Pain. Our measure also elicits misophonia triggers, each rated for their commonness in misophonia. We offer our open-access online tool for wider use (www.misophonia-hub.org), embedded within a well-stocked library of resources for misophonics, researchers, and clinicians.

Investigating the effect of providing monetary incentives to participants on completion rates of referred co-respondents: An embedded randomized controlled trial.

Background: The use of a second informant (co-respondent) is a common method of identifying potential bias in outcome data (e.g., parent-report child outcomes). There is, however, limited evidence regarding methods of increasing response rates from co-respondents. The use of financial incentives is associated with higher levels of engagement and follow-up data collection in online surveys. This study investigated whether financial incentives paid to index participants in an online trial of a parenting-focused intervention, would lead to higher levels of co-respondent data collection. Methods: A study within a trial (SWAT) using a parallel group RCT design. Participants in the host study (an RCT of an online intervention) were randomised into one of two SWAT arms: received/did not receive a £15 voucher when referred co-respondent completed baseline measures. Primary outcome was completion (No/Yes) of Spence Children's Anxiety Scale (SCAS or SCAS-Pre) at baseline. Additional analysis explored impact of incentives on data quality. Results: Intention to treat analysis of 899 parents (183 co-respondents) in the no-incentive arm, and 911 parents (199 co-respondents) in incentive arm. Nomination of co-respondents was similar between incentive arms. The RR for the incentive arm compared to the no incentive arm was 1.13 (95% CI: 0.91 to 1.41, p = 0.264) indicating that incentives did not impact completion of outcomes by consented co-respondents. There were no indications of different data quality between arms. Discussion: The finding that payment of financial incentives to index participant does not lead to greater levels of co-respondent outcome completion suggests that careful consideration should be made before allocating resources in this way in future trials. Trial registration: The host study was registered at Study Record | ClinicalTrials.gov and the SWAT study was registered in the SWAT Store | The Northern Ireland Network for Trials Methodology Research (qub.ac.uk): SWAT number 143: Filetoupload,1099612,en.pdf (qub.ac.uk).

Misophonia, self-harm and suicidal ideation.

Aim: Misophonia is a sound sensitivity disorder characterized by an unusually strong aversion to a specific class of sounds-often human bodily sounds (e.g., chewing). These sounds can cause intense negative emotions which can cause profound difficulties in everyday life. The condition is linked with higher rates of anxiety and depression, and here we ask whether it co-occurs with elevated self-harm and suicidal thinking. Methods: We measured self-harm and misophonia in the general population by examining a birth cohort sample from the Avon Longitudinal Study of Parents and Children (ALSPAC). We screened them for misophonia as adults, then analyzed their earlier data on well-being, self-harm, and suicidal thinking. Results: Adults with misophonia had significantly higher rates of self-harm and suicidal ideation, as well as poorer well-being in a number of different measures at ages 16-17 and 23-24 years. Female misophonics were particularly at risk, from as early as their teenage years, though males, too, show elevated self-harm at 24 years compared to nonmisophonic peers. Conclusion: Our data provide evidence of elevated risks of self-harm associated with misophonia and suggest the need for greater recognition and treatment pathways.

The role of visual imagery in face recognition and the construction of facial composites. Evidence from Aphantasia.

People with aphantasia have a markedly impaired ability to form visual images in the mind's eye. Here, by testing people with and without aphantasia, we examine the relationship between visual imagery and face processing. We show that aphantasics have weaker face recognition than people with visual imagery, using both self-report (Prosopagnosia Index) and behavioural measures (Cambridge Face Memory Test). However, aphantasics nonetheless have a fully intact ability to construct facial composites from memory (i.e., composites produced using EFIT6 by aphantasics and imagers were rated as equally accurate in terms of their resemblance to a target face). Additionally, we show that aphantasics were less able than imagers to see the resemblance between composites and a target face, suggestive of potential issues with face matching (perception). Finally, we show that holistic and featural methods of composite construction using EFIT6 produce equally accurate composites. Our results suggest that face recognition, but not face composite construction, is facilitated by the ability to represent visual properties as 'pictures in the mind'. Our findings have implications for the study of aphantasia, and also for forensic settings, where face composite systems are commonly used to aid criminal investigations.

A phenomenological cartography of misophonia and other forms of sound intolerance.

People with misophonia have strong aversive reactions to specific "trigger" sounds. Here we challenge this key idea of specificity. Machine learning was used to identify a misophonic profile from a multivariate sound-response pattern. Misophonia could be classified from most sounds (traditional triggers and non-triggers) and, moreover, cross-classification showed that the profile was largely transferable across sounds (rather than idiosyncratic for each sound). By splitting our participants in other ways, we were able to show-using the same approach-a differential diagnostic profile factoring in potential co-morbidities (autism, hyperacusis, ASMR). The broad autism phenotype was classified via aversions to repetitive sounds rather than the eating sounds most easily classified in misophonia. Within misophonia, the presence of hyperacusis and sound-induced pain had widespread effects across all sounds. Overall, we show that misophonia is characterized by a distinctive reaction to most sounds that ultimately becomes most noticeable for a sub-set of those sounds.

Mental imagery and visual attentional templates: A dissociation.

There is a growing interest in the relationship between mental images and attentional templates as both are considered pictorial representations that involve similar neural mechanisms. Here, we investigated the role of mental imagery in the automatic implementation of attentional templates and their effect on involuntary attention. We developed a novel version of the contingent capture paradigm designed to encourage the generation of a new template on each trial and measure contingent spatial capture by a template-matching visual feature (color). Participants were required to search at four different locations for a specific object indicated at the start of each trial. Immediately prior to the search display, color cues were presented surrounding the potential target locations, one of which matched the target color (e.g., red for strawberry). Across three experiments, our task induced a robust contingent capture effect, reflected by faster responses when the target appeared in the location previously occupied by the target-matching cue. Contrary to our predictions, this effect remained consistent regardless of self-reported individual differences in visual mental imagery (Experiment 1, N = 216) or trial-by-trial variation of voluntary imagery vividness (Experiment 2, N = 121). Moreover, contingent capture was observed even among aphantasic participants, who report no imagery (Experiment 3, N = 91). The magnitude of the effect was not reduced in aphantasics compared to a control sample of non-aphantasics, although the two groups reported substantial differences in their search strategy and exhibited differences in overall speed and accuracy. Our results hence establish a dissociation between the generation and implementation of attentional templates for a visual feature (color) and subjectively experienced imagery.