Synesthetic experiences of color have been traditionally conceptualized as a perceptual phenomenon. However, recent evidence suggests a role of higher order cognition in the formation of synesthetic experiences. Here, we discuss how synesthetic experiences of color differ from and influence veridical color processing, and how non-perceptual processes such as imagery and color memory might play a role in eliciting synesthetic color experience.

In 2021, 193 Member States at UNESCO’s General Conference adopted the Recommendation on the Ethics of Artificial Intelligence as the first important step towards a future global standard-setting instrument on the subject. The text reflects an emerging consensus among the international community about the growing ethical concerns with artificial intelligence (AI). Among these concerns are also serious risks and dangers attributed to the manipulative effects of AI, which can be further exacerbated by the creative combination of AI with other innovative (...) technologies or applications, such as brain–computer interfaces (BCIs), functional magnetic resonance imaging (fMRI), robotics, and big data. The risks for individuals and society as a whole caused by manipulation through AI are already well known and have recently also been addressed by the European Union having released a proposal for an Artificial Intelligence Act (AIA). Among multiple risks related to AI, the AIA singles out the specific dangers related to AI systems that deploy “subliminal techniques beyond a person’s consciousness to materially distort a person’s behaviour in a manner that causes or is likely to cause that person or another person physical or psychological harm”. The present article thus aims to highlight the known and potential dangers related to AI systems manipulating human thoughts and behaviour through subliminal and supraliminal means and methods. To this end, it advocates the joint study of law and the senses captured by the concept of legal synaesthesia to correspond to the need for an interdisciplinary debate covering the complexity of the links between AI, related technologies, human perception based on the senses and the mind, as well as the role and instruments of law in the future organization of societies in this world. (shrink)

Studies have shown that both serotonin and glutamate receptor systems play a crucial role in the mechanisms underlying drug-induced synesthesia. The specific nature of these mechanisms, however, continues to remain elusive. Here we propose two distinct hypotheses for how synesthesia triggered by hallucinogens in the serotonin-agonist family may occur. One hypothesis is that the drug-induced destabilization of thalamic projections via GABAergic neuronal circuits from sensory areas leads to a disruption of low-level, spontaneous integration of multisensory stimuli. This sort of integration (...) regularly occurs when spatial and temporal attributes match. Destabilization of feedback loops, however, can result in incongruent experiences or binding of random thalamus activation with sensory input in a particular sensory modality. The second hypothesis builds on embodied cognition, cases in which visual images of external stimuli activate task-related neural regions. On this proposal, binding processes that do not normally generate awareness become accessible to consciousness as a result of decreased attentional discrimination among incoming stimuli. (shrink)

Developmental synesthesia typically involves either the stimulation of one sensory modality which gives rise to an experience in a different modality (when a sound, for example, evokes a colour) or the stimulation of a single sensory modality giving rise to different qualitative aspects of experience (when the sight of a number, for example, evokes a colour). These occurrences seem to support Grice’s (1989) argument that sense modalities cannot be individuated without reference to the introspective-character of experience. This, however, threatens intentionalism (...) which maintains that the qualitative character of experience is exhausted, or fully determined by, its intentional content. Ross (2001) attempts to defuse Grice’s argument by proposing an account that does not appeal to the qualitative character of experience to individuate sense modalities. I argue that his account is unsuccessful. (shrink)