Subject-independent decoding of affective states using functional near-infrared spectroscopy

Author(s)

Trambaiolli, Lucas R. ^[1] ; Tossato, Juliana ^[2] ; Cravo, Andre M. ^[2] ; Biazoli, Jr., Claudinei E. ^[2] ; Sato, Joao R. ^[2]

Affiliation

^[1] Harvard Med Sch, McLean Hosp, Div Basic Neurosci, Boston, MA 02115 - USA

^[2] Fed Univ ABC, Ctr Math Comp & Cognit, Sao Bernardo Do Campo, SP - Brazil

• Document type: Journal article
• Source: PLoS One; v. 16, n. 1 JAN 7 2021.
• Web of Science Citations: 0

Abstract

Affective decoding is the inference of human emotional states using brain signal measurements. This approach is crucial to develop new therapeutic approaches for psychiatric rehabilitation, such as affective neurofeedback protocols. To reduce the training duration and optimize the clinical outputs, an ideal clinical neurofeedback could be trained using data from an independent group of volunteers before being used by new patients. Here, we investigated if this subject-independent design of affective decoding can be achieved using functional near-infrared spectroscopy (fNIRS) signals from frontal and occipital areas. For this purpose, a linear discriminant analysis classifier was first trained in a dataset (49 participants, 24.65 +/- 3.23 years) and then tested in a completely independent one (20 participants, 24.00 +/- 3.92 years). Significant balanced accuracies between classes were found for positive vs. negative (64.50 +/- 12.03%, p<0.01) and negative vs. neutral (68.25 +/- 12.97%, p<0.01) affective states discrimination during a reactive block consisting in viewing affective-loaded images. For an active block, in which volunteers were instructed to recollect personal affective experiences, significant accuracy was found for positive vs. neutral affect classification (71.25 +/- 18.02%, p<0.01). In this last case, only three fNIRS channels were enough to discriminate between neutral and positive affective states. Although more research is needed, for example focusing on better combinations of features and classifiers, our results highlight fNIRS as a possible technique for subject-independent affective decoding, reaching significant classification accuracies of emotional states using only a few but biologically relevant features. (AU)

• FAPESP's process: 18/21934-5 - Network statistics: theory, methods, and applications
• Grantee: André Fujita
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/04654-9 - Time series, wavelets and high dimensional data
• Grantee: Pedro Alberto Morettin
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/17406-5 - Emotional decoding and neuromodulation of the prefrontal cortex with NIRS-EEG
• Grantee: Lucas Remoaldo Trambaiolli
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/05225-1 - Decoding affective valence and arousal from prefrontal cortex hemodynamical signals
• Grantee: Juliana França Tossato
• Support Opportunities: Scholarships in Brazil - Scientific Initiation