Enhanced associative memory for colour (but not shape or location) in synaesthesia

People with grapheme-colour synaesthesia have been shown to have enhanced memory on a range of tasks using both stimuli that induce synaesthesia (e.g. words) and, more surprisingly, stimuli that do not (e.g. certain abstract visual stimuli). This study examines the latter by using multi-featured stimuli consisting of shape, colour and location conjunctions (e.g. shape A + colour A + location A; shape B + colour B + location B) presented in a recognition memory paradigm. This enables distractor items to be created in which one of these features is ‘unbound’ with respect to the others (e.g. shape A + colour B + location A; shape A + colour A + location C). Synaesthetes had higher recognition rates suggesting an enhanced ability to bind certain visual features together into memory. Importantly, synaesthetes’ false alarm rates were lower only when colour was the unbound feature, not shape or location. We suggest that synaesthetes are “colour experts” and that enhanced perception can lead to enhanced memory in very specific ways; but, not for instance, an enhanced ability to form associations per se. The results support contemporary models that propose a continuum between perception and memory.

Diagnosing synaesthesia with online colour pickers: Maximising sensitivity and specificity

The most commonly used method for formally assessing grapheme-colour synaesthesia (i.e., experiencing colours in response to letter and/or number stimuli) involves selecting colours from a large colour palette on several occasions and measuring consistency of the colours selected. However, the ability to diagnose synaesthesia using this method depends on several factors that have not been directly contrasted. These include the type of colour space used (e.g., RGB, HSV, CIELUV, CIELAB) and different measures of consistency (e.g., city block and Euclidean distance in colour space). This study aims to find the most reliable way of diagnosing grapheme-colour synaesthesia based on maximising sensitivity (i.e., ability of a test to identify true synaesthetes) and specificity (i.e., ability of a test to identify true non-synaesthetes). We show, applying ROC (Receiver Operating Characteristics) to binary classification of a large sample of self-declared synaesthetes and non-synaesthetes, that the consistency criterion (i.e., cut-off value) for diagnosing synaesthesia is considerably higher than the current standard in the field. We also show that methods based on perceptual CIELUV and CIELAB colour models (rather than RGB and HSV colour representations) and Euclidean distances offer an even greater sensitivity and specificity than most currently used measures. Together, these findings offer improved heuristics for the behavioural assessment of grapheme-colour synaesthesia.

Correcting misconceptions about synaesthesia

In the annals of cognitive neuroscience there are examples of fantastic memory abilities (e.g., Luria, 1968) that befuddle the vast majority of us with normal mnemonic skills. Although such feats have yet to be demonstrated in other species, extraordinary memory may not be unique to humans. One possible example comes from a study by Inoue and Matsuzawa (2007), which showed that following extensive training, a chimpanzee, Ayumu, displayed superior working memory than human volunteers. Recently, Humphrey (2012) hypothesized that Ayumu outperformed the human participants because he had synaesthesia, a condition in which a stimulus (an inducer) will involuntarily elicit an atypical ancillary experience (a concurrent) (e.g., graphemes eliciting color photisms) (Ward, 2013). Specifically, Humphrey posits that Ayumu spontaneously developed grapheme-colour synaesthesia through “cross-cortical leakage” (p. 354) between the parietal cortex, which may support the storage of overlearned sequences, and adjacent colour-coding regions, during working memory training. Humphrey speculates that the synaesthetic associations elicited colour after-images during training with numerals, and, in turn, facilitated superior performance. Here we challenge this hypothesis and argue that it makes a number of assumptions that are not supported by current research.

Le potentiel musical des analyses sonores et autres phénomènes vibratoires

La version intégrale de cette thèse est disponible uniquement pour consultation individuelle à la Bibliothèque de l'Université de Montréal (www.bib.umontreal.ca/MU).

Mitempfindung in synaesthetes: co-incidence or meaningful association?

Mitempfindung is the referral of a tactile sensation to a location far away from the stimulation site. This brief note reports a 40% incidence of Mitempfindung in a sample of 20 digit-color synaesthetes which contrasts with a 10% incidence in two control groups of non-synaesthetes. Phenomenological similarities between Mitempfindung and synaesthesia are discussed, and we propose that an erratic neural connectivity underlies both phenomena. To better characterize the nature of the purported neurophysiological peculiarities, prospective studies are needed that characterize Mitempfindung in synaesthetes and nonsynaesthetes.

Blue bananas: development of a task to investigate the representation of synaesthetic experiences

Research has mainly focussed on the perceptual nature of synaesthesia. However, synaesthetic experiences are also semantically represented. It was our aim to develop a task to investigate the semantic representation of the concurrent and its relation to the inducer in grapheme-colour synaesthesia. Non-synaesthetes were either tested with a lexical-decision (i.e., word / non-word) or a semantic-classification (i.e., edibility decision) task. Targets consisted of words which were strongly associated with a specific colour (e.g., banana - yellow) and words which were neutral and not associated with a specific colour (e.g., aunt). Target words were primed with colours: the prime target relationship was either intramodal (i.e., word - word) or crossmodal (colour patch - word). Each of the four task versions consisted of three conditions: congruent (same colour for prime and target), incongruent (different colour), and unrelated (neutral target). For both tasks (i.e., lexical and semantic) and both versions of the task (i.e., intramodal and crossmodal), we expected faster reaction times (RTs) in the congruent condition than in the neutral condition and slower RTs in the incongruent condition than the neutral condition. Stronger effects were expected in the intramodal condition due to the overlap in the prime target modality. The results suggest that the hypotheses were partly confirmed. We conclude that the tasks and hypotheses can be readily adopted to investigate the nature of the representation of the synaesthetic experiences.

Evidence for a perception memory continuum: an EEG study in a healthy population

In line with current memory theories of a perception-memory continuum along the ventral visual pathway, there is evidence that the specific profile of enhanced memory in special populations (e.g. synaesthesia) is based on increased perceptual sensitivity. The main goal of this study was to test in a more general population, if increased perceptual sensitivity is indeed associated with enhanced memory performance. We measured ERPs in response to simple perceptual stimuli biasing either the ventral or the dorsal route and established if perceptual sensitivity in response to ventrally (but not dorsally) processed stimuli is associated with visual short term memory performance in a change detection task. Preliminary results confirm the hypothesis and strengthen the assumption of a perceptual-memory-continuum.

Metáforas del amor en la poesía de la Grecia antigua (I): la épica y la lírica arcaicas

Partiendo del concepto de metáfora cognitiva, que complementa al más conocido de metáfora literaria, y analizando la base conceptual que a ambas subyace, pretendemos un cuidadoso análisis de los textos de poesía épica y lírica arcaicas, sin olvidar la importancia fundamental del contexto cultural en que estos surgen, para obtener una mejor comprensión de la forma en que los griegos conceptualizaban el sentimiento amoroso.

Criteria for graphic representation in musical scores: Visual elements in musical scores

A interdisciplinaridade entre a música e as artes visuais tem sido explorado por conceituados teóricos e filósofos, embora não exista muito na área da interpretação visual do grafismo de partituras musicais. Este estudo investiga como os grafismos na notação e símbolos musicais afectam o intérprete na sua transformação em som, com referência especial a partituras contemporâneas, que utilizam notação menos convencional para a criação de uma interpretação por sugestão. Outras relações entre o som e o visual são exploradas, incluindo a sinestesia, a temporalidade e a relação entre obra de arte e público. O objectivo desta dissertação é a de constituir um estudo inovativo sobre partituras musicais contemporâneas, simultaneamente do ponto de vista musical e visual. Finalmente, também vai mais longe, incluindo desenhos da própria autora inspirados e motivados pela música. Estes já não cumprem uma função de notação convencional para o músico, embora existe uma constante possibilidade de uma reinterpretação. ABSTRACT; The inter-disciplinarity between music and visual art has been explored by leading theorists and philosophers, though very little exists in the area of the visual interpretation of graphic musical scores. This study looks at how the graphics of musical notation and symbols affect the performer in transforming them into sound, with particular reference to contemporary scores that use non¬conventional notation to create an interpretation through suggestion. Other sound-visual relationships are explored, including synaesthesia, temporality and the interconnection between work of art and audience or public. This dissertation aims to be an innovative study of contemporary musical scores, from a musical as well as visual perspective. Finally, it takes a step further with drawings of my own, directly inspired and motivated by the music. These no longer fulfil a conventionally notational function for the musician, yet the potential for a re-interpretation is ever-present.

Alexander Scriabin: the definition of a new sound space in the crisis of tonality

This dissertation describes the new compositional system introduced by Scriabin in 1909– 1910, focusing on Feuillet d’Album op. 58, Poème op. 59, nº1, Prélude op. 59, nº2 and Promethée op. 60. Based upon exhaustive pitch and formal analysis the present study (a) claims the inexistence of non-functional pitches in all analysed works, (b) shows that transpositional procedures have structural consequences on the “basic chord”, and (c) for the first time advances an explanation on the intrinsic relation between the sonata form and the slow Luce line in Promethée op. 60; RESUMO: Sob o título de “Alexander Scriabin: a definição dum novo espaço sonoro na crise da Tonalidade”, a presente tese descreve o novo sistema compositivo introduzido por Scriabin em 1909– 1910, tomando como ponto de partida o estudo de Feuillet d’Album op. 58, Poème op. 59, nº1, Prélude op. 59, nº2 e Promethée op. 60. Baseando-se numa análise exaustiva das alturas e da forma, este estudo (a) conclui pela inexistência de alturas não funcionais em qualquer das obras analisadas, (b) mostra que os procedimentos transpositivos têm consequências estruturais no “acorde básico”, e (c) pela primeira vez explica a estrutura formal de Promethée op. 60 a partir da relação intrínseca entre a sua forma sonata e a linha lenta de Luce.