Musical space synesthesia: Automatic, explicit and conceptual connections between musical stimuli and space

Perceiving depth beyond sight: Evaluating intrinsic and learned cues via a proof of concept sensory substitution method in the visually impaired and sighted

This study explores spatial perception of depth by employing a novel proof of concept sensory substitution algorithm. The algorithm taps into existing cognitive scaffolds such as language and cross modal correspondences by naming objects in the scene while representing their elevation and depth by manipulation of the auditory properties for each axis. While the representation of verticality utilized a previously tested correspondence with pitch, the representation of depth employed an ecologically inspired manipulation, based on the loss of gain and filtration of higher frequency sounds over distance. The study, involving 40 participants, seven of which were blind (5) or visually impaired (2), investigates the intrinsicness of an ecologically inspired mapping of auditory cues for depth by comparing it to an interchanged condition where the mappings of the two axes are swapped. All participants successfully learned to use the algorithm following a very brief period of training, with the blind and visually impaired participants showing similar levels of success for learning to use the algorithm as did their sighted counterparts. A significant difference was found at baseline between the two conditions, indicating the intuitiveness of the original ecologically inspired mapping. Despite this, participants were able to achieve similar success rates following the training in both conditions. The findings indicate that both intrinsic and learned cues come into play with respect to depth perception. Moreover, they suggest that by employing perceptual learning, novel sensory mappings can be trained in adulthood. Regarding the blind and visually impaired, the results also support the convergence view, which claims that with training, their spatial abilities can converge with those of the sighted. Finally, we discuss how the algorithm can open new avenues for accessibility technologies, virtual reality, and other practical applications.

Effects of musical expertise on line section and line extension

Background

This study investigated whether music training led to better length estimation and/or rightward bias by comparing the performance of musicians (pianists) and non-musicians on performance of line sections and line extensions.

Methods

One hundred and sixteen participants, among them 62 musicians and 54 non-musicians, participated in the present study, completed line section and line extension task under three conditions: 1/2, 1/3 and 2/3.

Results

The mixed repeated measures ANOVA analysis revealed a significant group × condition interaction, that the musicians were more accurate than non-musicians in all the line section tasks and showed no obvious pseudoneglect, while their overall performance on the line extension tasks was comparable to the non-musicians, and only performed more accurately in the 1/2 line extension condition.

Conclusion

These findings indicated that there was a dissociation between the effects of music training on line section and line extension. This dissociation does not support the view that music training has a general beneficial effect on line estimation, and provides insight into a potentially important limit on the effects of music training on spatial cognition.

The left dorsal stream causally mediates the tone labeling in absolute pitch

Absolute pitch (AP) refers to the ability to effortlessly identify given pitches without any reference. Correlative evidence suggests that the left posterior dorsolateral prefrontal cortex (DLPFC) is responsible for the process underlying pitch labeling in AP. Here, we measured the sight‐reading performance of right‐handed AP possessors and matched controls under cathodal and sham transcranial direct current stimulation of the left DLPFC. The participants were instructed to report notations as accurately and as fast as possible by playing with their right hand on a piano. The notations were simultaneously presented with distracting auditory stimuli that either matched or mismatched them in different semitone degrees. Unlike the controls, AP possessors revealed an interference effect in that they responded slower in mismatching conditions than in the matching one. Under cathodal stimulation, this interference effect disappeared. These findings confirm that the pitch‐labeling process underlying AP occurs automatically and is largely nonsuppressible when triggered by tone exposure. The improvement of the AP possessors’ sight‐reading performances in response to the suppression of the left DLPFC using cathodal stimulation confirms a causal relationship between this brain structure and pitch labeling.

Consistency and strength of grapheme-color associations are separable aspects of synesthetic experience

Consistency of synesthetic associations over time is a widely used test of synesthesia. Since many studies suggest that consistency is not a completely reliable feature, we compared the consistency and strength of synesthetes' grapheme-color associations. Consistency was measured by scores on the Synesthesia Battery and by the Euclidean distance in color space for the specific graphemes tested for each participant. Strength was measured by congruency magnitudes on the Implicit Association Test. The strength of associations was substantially greater for synesthetes than non-synesthetes, suggesting that this is a novel, objective marker of synesthesia. Although, intuitively, strong associations should also be consistent, consistency and strength were uncorrelated, indicating that they are likely independent, at least for grapheme-color synesthesia. These findings have implications for our understanding of synesthesia and for estimates of its prevalence since synesthetes who experience strong, but inconsistent, associations may not be identified by tests that focus solely on consistency.

Musical-Space Synaesthesia: Visualisation of Musical Texture

I, Svetlana Rudenko, am a concert pianist. I am also a synaesthete and for me, sound is visual. It has shape. According to recent research (Akiva-Kabiri et al., 2014, pp. 17-29): "In musical-space synaesthesia, …unlike the vertical and horizontal representation of musical pitch tones in the general population, synaesthetes describe a linear diagonal organisation of pitch tones." Different piano sounds have aroma and texture. The forms I have lived with since childhood are what I call 'sound landscapes'. I am not alone. Composers such as Liszt, Scriabin, Gubaidulina and Messiaen, as well as artists such as de Córdoba Serrano and Ninghui Xiong, also experienced these impressions. This paper will explore synaesthetic experiences of musical texture, visualisation of sound and tactile sensations of musical texture as well as enhanced cross-modal associations. On the basis of my experiences, I argue that the visualisation of musical texture influences sound perception and even timing: phrases, dynamics and the whole interpretation.