Across three main work packages, we used behavioral and functional magnetic resonance imaging (fMRI) to address how emotions are represented in the absence of vision.
The first group of research work packages (WP4-6) was based on behavioral evaluations (Study 1). First, using semi-structured interviews and computational linguistics, we tested whether congenitally and late blind and sighted subjects share the same semantic representation of emotion. Specifically, we used a natural language approach, where blind and sighted individuals were asked to describe in three minutes a specific affective word (e.g. sadness) in terms of bodily sensations, events and related concepts. The procedure has been repeated for 30 emotion categories, providing a total of about 2 hours of descriptions for each subject. Our preliminary findings provide the first emotion taxonomy of sensory deprivation, showing how blind individuals conceive emotions and how differently they process affective states in comparison with sighted people.
The second group of work packages (WP7-9) also relied on a behavioral task (Study 2). We translated a previously validated paradigm for the investigation of bodily maps of emotion to the haptic modality. Congenitally and late blind and blindfolded sighted subjects interacted with a 50cm mannequin representing a human body mounted on a wooden platform. For the same emotion categories employed in Study 1, participants were asked where in the body they perceived changes associated to each state. Results show that for emotional states significantly related to visual cues (e.g. redness of the face for aggressiveness), both congenital and late blind individuals focus on other bodily sensations and identify those as more crucial in the experience (e.g. highlight of the mouth for aggressiveness). At the same time, there are also emotional states in which bodily sensations are similar between sensory deprived and typically developed individuals. The work of Study 2 has been presented at the IMRF (International Multisensory Research forum) 2023 meeting and the AIP (Italian Association of Psychology) 2023 conference.
The third group of work packages (WP10-12) refers to an fMRI investigation (Study 3). We employed a naturalistic stimulation to explore how emotions are represented in sighted, blind and deaf brains. In this regard, ecological stimuli as movies, constitute an ideal proxy of our social daily life and condense a variety of emotional events in a short time. We built different versions of the same movie (i.e. only audio, only video or audio and video) and asked sighted subjects to report their affective experience during the watching or listening of the stimulus. Then, we collected brain data from sensory deprived and typically developed individuals to unveil the role of sensory experience in the cortical representation of affect. Our findings highlight how the ventromedial prefrontal cortex stores a categorical representation of emotion independent of stimulus modality and previous sensory experience. The work of Study 3 has been presented to the BAPS (Belgian Association for Psychological Sciences) 2022 meeting, the CERE (Consortium of European Research on Emotion) 2022 conference, the OHBM (Organization for Human Brain Mapping) 2022 meeting, and the SIPF (Italian Society of Psychophysiology) 2022 meeting.
