title: The Multimodal Assessment of Adult Attachment Security: Developing the Biometric Attachment Test.
abstract: Attachment theory has been proven essential for mental health, including psychopathology, development, and interpersonal relationships. Validated psychometric instruments to measure attachment abound but suffer from shortcomings common to traditional psychometrics. Recent developments in multimodal fusion and machine learning pave the way for new automated and objective psychometric instruments for adult attachment that combine psychophysiological, linguistic, and behavioral analyses in the assessment of the construct.
  
  
  
  The aim of this study was to present a new exposure-based, automatic, and objective adult-attachment assessment, the Biometric Attachment Test (BAT), which exposes participants to a short standardized set of visual and music stimuli, whereas their immediate reactions and verbal responses, captured by several computer sense modalities, are automatically analyzed for scoring and classification. We also aimed to empirically validate two of its assumptions: its capacity to measure attachment security and the viability of using themes as placeholders for rotating stimuli.
  
  
  
  A total of 59 French participants from the general population were assessed using the Adult Attachment Questionnaire (AAQ), the Adult Attachment Projective Picture System (AAP), and the Attachment Multiple Model Interview (AMMI) as ground truth for attachment security. They were then exposed to three different BAT stimuli sets, whereas their faces, voices, heart rate (HR), and electrodermal activity (EDA) were recorded. Psychophysiological features, such as skin-conductance response (SCR) and Bayevsky stress index; behavioral features, such as gaze and facial expressions; as well as linguistic and paralinguistic features, were automatically extracted. An exploratory analysis was conducted using correlation matrices to uncover the features that are most associated with attachment security. A confirmatory analysis was conducted by creating a single composite effects index and by testing it for correlations with attachment security. The stability of the theory-consistent features across three different stimuli sets was explored using repeated measures analysis of variances (ANOVAs).
  
  
  
  In total, 46 theory-consistent correlations were found during the exploration (out of 65 total significant correlations). For example, attachment security as measured by the AAP was correlated with positive facial expressions (r=.36, P=.01). AMMI's security with the father was inversely correlated with the low frequency (LF) of HRV (r=-.87, P=.03). Attachment security to partners as measured by the AAQ was inversely correlated with anger facial expression (r=-.43, P=.001). The confirmatory analysis showed that the composite effects index was significantly correlated to security in the AAP (r=.26, P=.05) and the AAQ (r=.30, P=.04) but not in the AMMI. Repeated measures ANOVAs conducted individually on each of the theory-consistent features revealed that only 7 of the 46 (15%) features had significantly different values among responses to three different stimuli sets.
  
  
  
  We were able to validate two of the instrument's core assumptions: its capacity to measure attachment security and the viability of using themes as placeholders for rotating stimuli. Future validation of other of its dimensions, as well as the ongoing development of its scoring and classification algorithms is discussed.
authors.affiliation: Institute for Creative Technologies, University of Southern California, Los Angeles, CA, United States.|Paragraphe Laboratory, Paris VIII University, Saint-Denis, France.
authors.forename: Federico
authors.identifier: 0000-0002-5333-8211
authors.initials: F
authors.lastname: Parra
authors.affiliation: Paragraphe Laboratory, Paris VIII University, Saint-Denis, France.
authors.forename: Raphaële
authors.identifier: 0000-0003-3140-8730
authors.initials: R
authors.lastname: Miljkovitch
authors.affiliation: University Hospital Center Sainte-Étienne, Sainte-Étienne, France.
authors.forename: Gwenaelle
authors.identifier: 0000-0003-2211-9742
authors.initials: G
authors.lastname: Persiaux
authors.affiliation: Institute for Creative Technologies, University of Southern California, Los Angeles, CA, United States.|The Graduate Center, City University of New York, New York, NY, United States.
authors.forename: Michelle
authors.identifier: 0000-0003-3238-9244
authors.initials: M
authors.lastname: Morales
authors.affiliation: Institute for Creative Technologies, University of Southern California, Los Angeles, CA, United States.
authors.forename: Stefan
authors.identifier: 0000-0002-0280-5393
authors.initials: S
authors.lastname: Scherer
mesh_terms: D000328:Adult; D003131:Combined Modality Therapy; D005149:Facial Expression; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D007802:Language; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D009769:Object Attachment; D011594:Psychometrics / Q000379:methods*
keywords: COVAREP; attachment; facial expression; heart rate; linguistics; psychometrics; psychopathology; psychophysiology