Poster Sessions: Addendum (Errata & Additions)


1) The following poster titles and authors were erroneously omitted from the list of posters contained in the online version of the ASSC 17 Program Book (pp. 8-13). The omitted poster titles and authors will appear in the print edition of the program book We sincerely apologize for these omissions.


Neural signatures of perceptual transitions for a novel bistable auditory stimulus

Gray Davidson, Michael Pitts

P2-081 July 15th, 14:30-16:30


Joint action, joint consciousness: A psychological study of the interaction dynamics of intersubjective experience 

Tom Froese, Hiroyuki Iizuka, Takashi Ikegami

P2-082, July 15th, 14.30 – 16.30 


2) The following poster abstracts were erroneously omitted from the ASSC 17 Program Book (both online and print editions). These abstracts will be included in an Addendum page insert in the print edition of the program book. We sincerely apologize for these omissions.

A new perspective on the debate on synesthesia

Yi-Chen Lin [1], Allen Y. Houng [2]

[1] National Taiwan University

[2] National Yang-Ming University

P1-016, July 14th, 13:30 – 15:30  

There exists a hot debate on whether synesthesia is a perceptual or cognitive phenomenon. In this paper, I will propose a new perspective on grapheme-color synesthesia, one of the most common variants of the phenomenon, to make these two theories compatible. In fact, the two groups are discussing about different issues about synesthesia. The “perceptual group”(Ramachandran and Hubbard, 2001) focuses on “how the synesthetic experience be induced” whereas the “cognitive group”, who asserts that learning and cognition have a profound effect on synesthesia (Mroczko et al.,2009; Witthoft and Winawer, 2013), focuses on “the linkage between visual stimuli and the synesthetic experience”. To set up or adjust the linkage between the visual stimuli and synesthetic experience is cognition-involved, however, once the linkage is connected, such synesthetic experience can be induced by perception only. According to Victor Lamme’s theory (2010), the stimuli evoke a localized recurrent processing in visual cortex will become phenomenal conscious while some evoke the widespread recurrent processing, involving the frontoparietal network, will become access conscious. In the experiment performed by Mroczko et al. (2009), the learning of Glagolitic graphemes is cognition-participated, involving the activation of frontoparietal. The linkage between Glagolitic grapheme and synesthetic experience is set up after training. Therefore, when Glagolitic graphemes were presented again, the stimuli are unnecessary to be sent to frontoparietal area but being processed in the localized recurrent loop, which is perception-involved only, to induce the synesthetic experience. With this new perspective on synesthesia, the two views can be compatible, solving the problem that exist for several decades.


Fronto-parietal cortex mediates perceptual transitions in bistable perception

Weilnhammer, V. A. [1], Ludwig, K. [1,2], Hesselmann, G. [1], Sterzer, P. [1]

[1] Visual Perception Laboratory, Department of Psychiatry and Psychotherapy – Charité Universitätsmedizin Berlin, Germany

[2] Klinische Psychologie, Institut für Psychologie, Mathematisch-Naturwissenschaftliche Fakultät II, Humboldt-Universität zu Berlin, Germany

P1-038, July 14th, 13.30-15.30 (Nautilus 4 & 5)

During bistable vision, perception oscillates between two mutually exclusive percepts while the incoming sensory information remains constant. Greater blood oxygen level dependent (BOLD) responses in fronto-parietal cortex have been shown to be associated with perceptual transitions as compared to “replay” events designed to closely match bistability in both perceptual quality and timing. It has remained controversial, however, whether this enhanced activity reflects causal influences of these regions on processing at the sensory level or, alternatively, an effect of stimulus differences that result, e.g., in longer durations of perceptual transitions in bistable perception compared to replay conditions. Using a rotating Lissajous figure in a functional magnetic resonance imaging (fMRI) experiment, we controlled for potential confounds of differences in transition duration and confirmed previous findings of greater activity in frontal and parietal brain areas for transitions during bistable perception. In addition, we applied Dynamic Causal Modeling (DCM) to identify the neural model that best explains the observed BOLD signals in terms of effective connectivity. We found that enhanced activity for ambiguous events is most likely mediated by a modulation of top-down connectivity from frontal to visual cortex, thus arguing for a causal role of fronto-parietal cortex in perceptual transitions during bistable perception.


Joint action, joint consciousness: A psychological study of the interaction dynamics of intersubjective experience 

Tom Froese [1,3], Hiroyuki Iizuka [2], Takashi Ikegami [3]

[1] Universidad Nacional Autónoma de México

[2] University of Osaka

[3] University of Tokyo

P2-082, July 15th, 14.30 – 16.30

The study of social cognition in interactive settings is gaining in prominence, and second-person neuroscience has begun to reveal different neural mechanisms in contrast to passive spectator settings. We contribute to these developments with a psychological study of the effects of social interaction on consciousness. Pairs of adults controlled their avatars in a 1D virtual space and interacted with each other using nothing but a computer mouse and binary tactile feedback interface. They were instructed to avoid two distractor objects that only differed from the other’s avatar in their lack of responsive movement (one was static; the other precisely copied the avatar’s movements at a distance). They clicked to signal the experimenter when they felt to be interacting with the other’s avatar. We tested 18 teams (36 participants), each for 15 trials of one-minute duration. We thereby replicated the setup of Auvray et al. (2009), but with one crucial difference: we explicitly asked participants to help each other. We confirmed Auvray’s finding that participants clicked successfully (88% correct); additionally, our statistics indicated conscious recognition. The best strategies involved the development of interactions that required mutual participation for their realization, e.g. imitative turn-taking. We assessed the clarity of experience of the other’s presence with post-trial questionnaires, including a perceptual awareness scale and confidence ratings. Subjective clarity significantly correlated with objective clicking success. Moreover, highest scores were significantly correlated with each other and with joint success (indeed, clicks often happened nearly concurrently), indicating that intersubjective experience results from a co-creative process.


Late Addition

 The following poster abstract was accepted after the ASSC 17 Program Book went to press, and is therefore not included in the poster listings or the body of the main text.


Neural discrimination of sequences of sounds during acute coma

Alexandre Simonin [1]*, Athina Tzovara [2,3] *, Natacha Cossy [2,3], Andrea O. Rossetti [1], Mauro Oddo [4], Marzia De Lucia [2,3]

*Equal contributions.


[1] Department of Clinical Neurosciences, [2] Electroencephalography Brain Mapping Core, Center for Biomedical Imaging (CIBM), [3] Department of Radiology, [4] Adult intensive care medicine, Hospitalier Universitaire Vaudois (CHUV), CH-1011 Lausanne, Switzerland


P2-080, July 15th, 14:30 – 16:30 (Nautilus 4 & 5)


Auditory evoked potentials (AEPs) are informative of intact neural functions of comatose patients. One marker is provided by the differential AEPs responses to standard and rare sounds in a standard mismatch negativity (MMN) paradigm. A rich literature interprets this effect as a pre-attentive and unconscious processing of the incoming stimuli. By contrast, an MMN-like effect induced by the identical repetition of groups of sounds has been typically reported when subjects were aware of the sound regularity. Here we tested this hypothesis in twenty-four post-anoxic comatose patients who underwent therapeutic hypothermia (TH). We recorded AEPs during TH and after rewarming to normal temperature (NT) while delivering sequences of five sounds. Stimuli were either groups of five sounds in which four were identical and one different in duration, or five identical sounds. Each of these types of stimuli was used either as standard or as deviant stimulus in a way that we could test an MMN-like effect induced by the repetition of groups of five sounds. We carried out a multivariate topographic analysis which decodes single trial AEPs in response to sound types. Results show that eight patients could track the sound regularity largely independently of their final outcome. The progression of the decoding performance from TH to NT was highly informative of their chance of awakening, providing 89% positive predictive power. These results suggest that active maintenance of perceptual representation does not require consciousness and that the progression over time of the neural auditory discrimination predicts chance of awakening.