Mental imagery and synaesthesia: Is synaesthesia from internally-generated stimuli possible?

Previous studies provide empirical support for the reported colour experience in grapheme-colour synaesthesia by measuring the synaesthetic experience from an externally presented grapheme. The current study explored the synaesthetic experience resulting from a visual mental image of a grapheme. Grapheme-colour synaesthetes (N=6) and matched controls (N=10 per synaesthete) completed a visual mental imagery task that involved visualising a letter and making a size-based decision about it. The background colour that the grapheme was visualised against was manipulated so that it was congruent or incongruent with the synaesthetic colour for the grapheme being visualised. Compared to matched controls, an effect of colour condition was found for four of the six synaesthetes, although importantly the direction of the effect varied between synaesthetes. In addition, a significant effect of group was found, as the synaesthetes were all faster than the matched controls at the imagery task, regardless of background colour. We conclude that there is some support for subjective reports of imagery-induced synaesthesia, but there are important individual differences. These findings are discussed in relation to both the visual imagery and synaesthesia literature.     

Can synaesthesia research inform cognitive science?

The renaissance of synaesthesia research has produced many insights regarding the aetiology and mechanisms that might underlie this intriguing phenomenon, which abnormally binds features between and within modalities. Synaesthesia is interesting in its own right, but whether it contributes to our knowledge of neurocognitive systems that underlie non-synaesthete experience is an open question. In this review, we show that results from the field of synaesthesia can constrain cognitive theories in numerical cognition, automaticity, crossmodal interaction and awareness. Therefore, research of synaesthesia provides a unique window into other domains of cognitive neuroscience. We conclude that the study of synaesthesia could advance our understanding of the normal and abnormal human brain and cognition.     

Do children with grapheme-colour synaesthesia show cognitive benefits?

Grapheme-colour synaesthesia is characterized by conscious and consistent associations between letters and colours, or between numbers and colours (e.g., synaesthetes might see A as red, 7 as green). Our study explored the development of this condition in a group of randomly sampled child synaesthetes. Two previous studies (Simner & Bain, 2013, Frontiers in Human Neuroscience, 7, 603; Simner, Harrold, Creed, Monro, & Foulkes, 2009, Brain, 132, 57) had screened over 600 primary school children to find the first randomly sampled cohort of child synaesthetes. In this study, we evaluate this cohort to ask whether their synaesthesia is associated with a particular cognitive profile of strengths and/or weaknesses. We tested our child synaesthetes at age 10–11 years in a series of cognitive tests, in comparison with matched controls and baseline norms. One previous study (Green & Goswami, 2008, Cognition, 106, 463) had suggested that child synaesthetes might perform differently to non-synaesthetes in such tasks, although those participants may have been a special type of population independent of their synaesthesia. In our own study of randomly sampled child synaesthetes, we found no significant advantages or disadvantages in a receptive vocabulary test and a memory matrix task. However, we found that synaesthetes demonstrated above-average performance in a processing-speed task and a near-significant advantage in a letter-span task (i.e., memory/recall task of letters). Our findings point to advantages for synaesthetes that go beyond those expected from enhanced coding accounts and we present the first picture of the broader cognitive profile of a randomly sampled population of child synaesthetes.     

Time–space synaesthesia – A cognitive advantage?

Is synaesthesia cognitively useful? Individuals with time–space synaesthesia experience time units (such as months of the year) as idiosyncratic spatial forms, and report that these forms aid them in mentally organising their time. In the present study, we hypothesised that time–space synaesthesia would facilitate performance on a time-related cognitive task. Synaesthetes were not specifically recruited for participation; instead, likelihood of time–space synaesthesia was assessed on a continuous scale based on participants’ responses during a semi-structured interview. Participants performed a month-manipulation task, which involved naming every second month or every third month in reverse-chronological order, beginning and ending with a target month. Using hierarchical multiple regression, we found that time–space synaesthesia corresponded with faster performance on both versions of the task. We propose that time–space synaesthesia may expedite the cognitive manipulation of time-based information. Our results also indicate that synaesthesia is far less unusual than widely believed.     

Is the sky 2? Contextual priming in grapheme-color synaesthesia

Grapheme-color synaesthesia is a neurological phenomenon in which particular graphemes, such as the numeral 9, automatically induce the simultaneous perception of a particular color, such as the color red. To test whether the concurrent color sensations in grapheme-color synaesthesia are treated as meaningful stimuli, we recorded event-related brain potentials as 8 synaesthetes and 8 matched control subjects read sentences such as "Looking very clear, the lake was the most beautiful hue of 7." In synaesthetes, but not control subjects, congruous graphemes, compared with incongruous graphemes, elicited a more negative N1 component, a less positive P2 component, and a less negative N400 component. Thus, contextual congruity of synaesthetically induced colors altered the brain response to achromatic graphemes beginning 100 ms postonset, affecting pattern-recognition, perceptual, and meaning-integration processes. The results suggest that grapheme-color synaesthesia is automatic and perceptual in nature and also suggest that the connections between colors and numbers are bidirectional.     

Is synaesthesia an X-linked dominant trait with lethality in males?

In previous research the inheritance patterns of synaesthesia (eg experiencing colours from graphemes) has been studied and it was concluded that synaesthesia is most likely to be the outcome of a single gene passed on the X chromosome in a dominant fashion. In addition, it has been reported that the female-male ratio of synaesthetes is as high as 6:1 and the families of synaesthetes contain more female than male members. This raises the possibility that the gene may be associated with lethality in males. In this study we replicate and extend previous research by investigating the female-male ratio and inheritance patterns in a large sample of synaesthetic families (N = 85). We were able to verify the authenticity of grapheme-colour associates in at least one proband from each family using internal consistency. As before, our results show a female-male bias and are broadly consistent with an X-linked dominant mode of inheritance. However, there was no evidence of male lethality (eg synaesthetes are just as likely to give birth to sons as to daughters). Moreover, our female-male ratio of synaesthetes within families was 2:1--considerably lower than previous estimates. We speculate that men may be more reluctant to disclose synaesthesia than women (indeed, our female-male ratio based on self-referral was 3.7: 1). Finally, we discuss how the genotype may give rise to the phenotype in terms of changes in synaptogenesis or plasticity extending into childhood, to be subsequently shaped by the environment.     

What is the relationship between synaesthesia and visuo-spatial number forms?

This study compares the tendency for numerals to elicit spontaneous perceptions of colour or taste (synaesthesia) with the tendency to visualise numbers as occupying particular visuo-spatial configurations (number forms). The prevalence of number forms was found to be significantly higher in synaesthetes experiencing colour compared both to synaesthetes experiencing taste and to control participants lacking any synaesthetic experience. This suggests that the presence of synaesthetic colour sensations enhances the tendency to explicitly represent numbers in a visuo-spatial format although the two symptoms may nevertheless be logically independent (i.e. it is possible to have number forms without colour, and coloured numbers without forms). Number forms are equally common in men and women, unlike previous reports of synaesthesia that have suggested a strong female bias. Individuals who possess a number form are also likely to possess visuo-spatial forms for other ordinal sequences (e.g. days, months, letters) which suggests that it is the ordinal nature of numbers rather than numerical quantity that gives rise to this particular mode of representation. Finally, we also describe some consequences of number forms for performance in a number comparison task.     

Congruence or coherence? Emotional and physiological responses to colours in synaesthesia

Lexical–chromatic synaesthesia is a condition in which letters and/or words elicit percepts of synaesthetic colours, termed photisms. Anecdotal data suggest that synaesthetes are particularly sensitive to inconsistencies between their synaesthetic percepts and the real world, e.g., it can be annoying and unpleasant for them to see a letter printed in a colour different than the respective photism colour. For R, a synaesthete subject who participated in the present study, the photisms possess specific emotional values (a red photism is pleasing and attractive, green is repulsive and unpleasant, etc.). In contrast to the anecdotal data, R does not always find the colour–photism incongruence to be disturbing. More importantly, he states that it is the emotional coherence between the stimulus and the corresponding photism that matters. In a series of experiments, we studied this new concept of emotional coherence on three levels—subjective (self-report), behavioural, and physiological, corroborating R's introspective statements. Besides the implications of the concept of coherence itself, the results presented here suggest that even highly subjective cognitive constructs can be approached and measured experimentally, uncovering the workings of the underlying psychophysiological mechanisms.     

Is synaesthesia one condition or many? A large-scale analysis reveals subgroups

Synaesthesia is a broadly defined neural phenomenon in which stimulation of a sense or concept triggers a second perception not normally associated with the stimulus. For example, letters or numbers may trigger a colour experience, sounds may trigger a taste sensation, or tastes may trigger a feeling of touch. Dozens of forms of synaesthesia have been reported, but the relationship between the different forms has not been studied: is someone with a particular form of synaesthesia likely to possess other types? If so, which ones? As an inroad to illuminating underlying mechanisms, we here examine which different synaesthesia types tend to co-occur. We analyzed reports of the forms of synaesthesia experienced by 19,133 participants who completed the Synaesthesia Battery (Eagleman, Kagan, Nelson, Sagaram, & Sarma, 2007), using correlation analysis, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and multidimensional scaling (MDS). Our analyses converged on the finding of five distinct groupings of synaesthesia forms. We label these coloured sequence synaesthesias (CSSs), coloured music synaesthesias, non-visual sequela synaesthesias, spatial sequence synaesthesia (SSS), and coloured sensation synaesthesias. Collectively, our findings reveal that synaesthesia is an umbrella term that encompasses several distinct groups with independent probabilities of expression, and this may in turn suggest distinct underlying mechanisms and the possibility of different genetic bases.     

Personality traits in people with synaesthesia: Do synaesthetes have an atypical personality profile?

People with synaesthesia not only have – by definition – unusual experiences (e.g., numbers triggering colour), they also have a different cognitive profile (e.g., in terms of their memory and perceptual abilities) and a bias towards certain interests and activities (e.g., towards the arts). However, virtually nothing is known about whether synaesthetes have an atypical personality profile. In this study, a standard measure of personality was administered (Big Five Inventory) along with two questionnaire measures of empathy. Synaesthetes, relative to demographically matched controls, reported higher levels of ‘Openness to Experience’ which is known to be related to imagination and artistic tendencies. They also reported higher levels of ‘Fantasizing’ on one of the empathy measures, which is conceptually related to Openness, although their self-reported empathy did not differ in other respects. In addition, synaesthetes reported lower levels of Agreeableness which we did not predict in advance.     

Is there a burden attached to synaesthesia? Health screening of synaesthetes in the general population

Synaesthesia has long been considered a benign alternative form of perception most often associated with positive rather than negative outcomes. The condition has been associated with a variety of cognitive and perceptual advantages, including benefits in memory, processing speed, and creativity. It is not currently recognized in the DSM‐IV. Recently, however, several studies have raised the question of a possible link between synaesthesia and clinical conditions. Here, we present the first large‐scale screening of the general population in which we (1) objectively identified grapheme‐colour synaesthetes and (2) elicited information from our participants about a range of clinical conditions. We compared the prevalence rates of these conditions in synaesthetes versus non‐synaesthetes to establish whether any conditions were found at a higher rate among synaesthetes. In our initial study, screening 3,742 people (95 synaesthetes and 3,647 controls), we found initially that grapheme‐colour was significantly comorbid with two conditions (anxiety disorder and obsessive compulsive disorder). In our second study, screening a new population of 120 synaesthetes and 166 non‐synaesthetes, we replicated our finding that grapheme‐colour synaesthesia is comorbid with anxiety disorder. At the same time, we also addressed a methodological concern that likely elevated rates of OCD in Study 1. We consider the aetiology of synaesthesia to determine whether there may be a shared genetic or neurological basis with anxiety disorder, and we question the status of synaesthesia within a mental health framework.     

Redefining super recognition in the real world: Skilled face or person identity recognizers?

While there has been growing interest in the deployment of superior face recognizers in policing and security settings, it is likely that most real‐world tasks tap person rather than face recognition skills. We suggest that changes in real‐world screening tasks and terminology are required to distinguish these individuals from laboratory‐identified superior face recognizers, who have more potential in developing our theoretical understanding of the face recognition system.     

Colours sometimes count: Awareness and bidirectionality in grapheme–colour synaesthesia

Three experiments were conducted with 10 grapheme–colour synaesthetes and 10 matched controls to investigate (a) whether awareness of the inducer grapheme is necessary for synaesthetic colour induction and (b) whether grapheme–colour synaesthesia may be bidirectional in the sense that not only do graphemes induce colours, but that colours influence the processing of graphemes. Using attentional blink and Stroop paradigms with digit targets, we found that some synaesthetes did report “seeing” synaesthetic colours even when they were not able to report the inducing digit. Moreover, congruency effects (effects of matching the colour of digit presentation with the synaesthetic colour associated with that digit) suggested that grapheme–colour synaesthesia can be bidirectional, at least for some synaesthetes.     

What Kind of Society Does the School Need? Redefining the Democratic Work of Education in Impatient Times

Studies in Philosophy and Education - In many places around the world the modern school is under a relentless pressure to perform and the standards for such performance are increasingly being set...     

Redefining dementia care barriers for ethnic minorities: the religion–culture distinction

Barriers to healthcare services experienced by black and minority ethnic (BME) persons with dementia are labelled as “cultural” in existing research. This is a promising shift from an ethno-centric approach to dementia care provision, yet very little research is dedicated to specifically how religion – as distinct from culture – influences healthcare practice. Further consideration of the religion–culture distinction is required; religion and culture are two distinct entities, which inevitably interlink. Cultural themes such as “God's will”, “Religious Ritual” and “Religious Duty”, warrant re-categorisation as “religious”. Sensitivity to the nuances between cultural and religious themes will provide clearer knowledge of how and why BME persons with dementia experience barriers to accessing care services. Further research is needed with regard to the role of religion specifically on dementia care access for BME persons to aim to improve care provision for this underrepresented demographic.     

Redefining unforgiveness: Exploring victims’ experiences in the wake of unforgiven interpersonal transgressions

This study explored victims’ experiences in the aftermath of unforgiven offenses. Semi-structured interviews with 13 individuals discussing two unforgiven offenses revealed considerable variability in the experiences of unforgiveness, suggesting that unforgiveness may be more multifaceted than previously believed. In addition to the negative emotions and rumination previously posited to characterize unforgiveness, novel themes emerged describing unforgiving cognitions (e.g., the offense is unforgiveable) and construals of the offender. Participants varied along each dimension, resulting in a range of outcomes (e.g., forgiveness, lingering personal distress, finding peace without forgiving). Implications for conceptualizing unforgiveness and counseling those who struggle with unforgiven offenses are discussed.     

Grapheme–colour synaesthesia yields an ordinary rather than extraordinary memory advantage: Evidence from a group study

In synaesthesia, the input of one sensory modality automatically triggers an additional experience, not normally triggered by the input of that modality. Therefore, compared to non-synaesthetes, additional experiences exist and these may be used as retrieval cues when memory is tested. Previous case studies have suggested that synaesthesia may yield even extraordinary memory abilities. However, group studies found either a task-specific memory advantage or no performance advantage at all. The aim of the present study was to test whether grapheme–colour synaesthesia gives rise to a general memory benefit using a standardised memory test (Wechsler Memory Scale). The synaesthetes showed a performance advantage in episodic memory tests, but not in short-term memory tests. However, performance was still within the ordinary range. The results support the hypothesis that synaesthesia provides for a richer world of experience and as a consequence additional retrieval cues may be available and beneficial but not to the point of extraordinary memory ability.     

Redefining Queer: Women’s Relationships and Identity in an Age of Sexual Fluidity

This paper examines ways some women work to define their sexual identities outside of or between traditional binary categories today. How does one’s own gender and the gender of one’s sexual and relationship partners through the life course affect the creation and maintenance of a sexual identity? Does our current system of sexual categories fit women’s experiences and identities? This study looks at women’s sexual experiences through an examination of female sex store patrons. Using Anthony Giddens theories of the pure relationship and plastic sexuality and ideas from queer theory alongside qualitative data about women’s sexual and relationship experiences, this paper sheds light on relationship and identity choices some American women are making today around their sexuality and provides new views on identity maintenance, gender, and sexual relationships.