CARE Studies

CARE Studies

General Information

From 2017 on, a series of three interdisciplinary and multi-method studies (CARE, D-CARE, and M-CARE) was set up at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany. The idea behind these CARE studies is to combine several aspects of attachment research with state-of-the-art social neuroscience techniques with the aim of advancing attachment theory within the 21st century.

The CARE studies are a large collaborative effort involving researchers from the University of Essex, Max Planck Institute of Human Cognitive and Brain Sciences in Leipzig, University of Vienna, University of Erlangen-Nuremberg, University of Leipzig, and University of Virginia. 

Please see below for:
Main Study Elements
Specific Study Information
Output: Peer-Reviewed Publications
Output: Preprints
Output: Talks & Presentations


Main Study Elements

fNIRS hyperscanning in parent-child dyads (child age 5 years) using a collaborative versus independent puzzle-solving task (in addition to a free conversation or pre-school sheet completion task) to derive inter-brain coherence and bio-behavioural synchrony within the parent-child dyad. 

Video recordings during fNIRS and ratings of interaction according to several attachment-theory derived coding schemes.

Self-report questionnaires and narrative measures (adult attachment interview; story stems) of attachment and caregiving in parents and children.

(f)MRI scanning in parents to assess brain anatomy and function in relation with inter-individual differences in attachment and caregiving.

Associations between the above elements.


Specific Study Information

CARE Study

For the CARE study conducted in 2017-2018, N= 42 mother-child dyads participated in the fNIRS hyperscanning part including video-recordings of their interaction during puzzle-solving and a free conversation. Attachment and caregiving was assessed via video ratings and self-report questionnaires. Mother-child interaction quality was further rated via video ratings. 

D-CARE Study

Starting from April 2018, the D-CARE study aimed at recruiting a total of N= 50 father-child dyads with complete data. D-CARE extends the CARE study by adding (i) narrative attachment measures (adult attachment interview; story stem procedure) in both parents and children, and (ii) (f)MRI scanning in parents, as well as to for the first time look at attachment and caregiving using a multi-method social neuroscience approach in fathers. Data acquisition was completed in late 2019.

M-CARE Study

As an additional follow-up to CARE and D-CARE, the M-CARE study that started in February 2019 comprises the same elements as the D-CARE study in an anticipated N= 50 mother-child dyads with complete data. Not only does this additional study boost participant numbers – which is a crucial limitation factor in past attachment research -, but it also makes the D- and M-CARE data more directly comparable (which is not entirely possible with the CARE data). Furthermore, because a large number of participants of the M-CARE study have already been seen four years ago, a longitudinal relation to mother-child interaction assessed during infancy is possible. Such approach also represents an important step towards better attachment data, as longitudinal studies are so far very sparse. Data acquisition was ceased in March 2020 due to COVID-19, with complete data obtained from N= 41 mother-child dyads.


Output: Peer-Reviewed Publications

CARE PAPER N° 1The effects of interaction quality on neural synchrony during mother-child problem solving

Within the CARE study, we examined the effects of interaction quality on neural synchrony during a problem-solving task in N= 42 dyads of mothers and their preschool children by using dual-functional near-infrared spectroscopy (fNIRS). We found increased neural synchrony in bilateral prefrontal cortex and temporo-parietal areas during cooperative as compared to individual problem solving.

Higher neural synchrony during cooperation correlated with higher behavioural reciprocity and neural synchrony predicted the dyad’s problem-solving success beyond reciprocal behaviour between mothers and children. State-like factors, such as maternal stress and child agency during the task, played a bigger role for neural synchronisation than trait-like factors, such as child temperament.

Our results emphasise neural synchrony as a biomarker for mother-child interaction quality. These findings further highlight the role of state-like factors in interpersonal synchronisation processes linked to successful coordination with others and in the long-term might improve the understanding of others.

Nguyen, T., Kayhan, E., Schleihauf, H., Matthes, D., Vrtička, P., Hoehl, S. (2020). The effects of interaction quality on neural synchrony during mother-child problem solvingCortex, Volume 124, Pages 235-249, https://doi.org/10.1016/j.cortex.2019.11.020. OPEN ACCESS.

See also this recent blog about the main study findings.

CARE PAPER N° 2Neural synchrony in mother-child conversation: Exploring the role of communicative features

Within the CARE study, we also assessed inter-brain coherence during a 4 minute long natural verbal conversation in N= 40 dyads of mothers and their preschool children by using dual-functional near-infrared spectroscopy (fNIRS). The 4 minute natural conversation was split into eight segments of 30 seconds and inter-brain coherence was calculated separately for each segment. In addition, every conversational turn was behaviourally coded for its underlying qualities comprising: 1) turn-taking (i.e. whether dyads engaged in reciprocal utterances), 2) turn relevance (i.e. whether turns shared thematic content), 3) turn contingency (i.e. a turn provided requested information), and 4) turn intrusiveness (i.e. whether the turn allowed time to respond / interrupted the speaker).

Results revealed that neural synchrony in temporo-parietal and lateral prefrontal regions increased throughout the conversation on average. Critically, when we considered how often mothers and children took turns, higher neural synchrony was associated with higher turn-taking in later epochs of the conversation.

Our study shows that children and mothers synchronise their brain activity during natural verbal conversation and that neural synchronisation increases over time when mother and child engage in more verbal turn-taking. This observed link between conversational turn-taking and neural synchronisation opens up new possibilities to understand the potential functional role of neural synchronisation during verbal exchanges.

See also this recent blog post for a summary.

Nguyen, T., Schleihauf, H., Kayhan, E., Matthes, D., Vrtička, P., Hoehl, S. (2021). Neural synchrony in mother-child conversation: Exploring the role of communicative features. Social Cognitive Affective Neuroscience, Volume 16, Issue 1-2, Pages 93–10. https://doi.org/10.1093/scan/nsaa079. OPEN ACCESS.

D-CARE Paper N° 1Interpersonal neural synchrony during father-child problem solving: A fNIRS hyperscanning study

Building upon CARE Paper N° 1 (see above), this paper as part of the D-CARE study examined the effects of interaction quality on neural synchrony during a problem-solving task in N= 66 dyads of fathers and their preschool children (age 5) by using dual-functional near-infrared spectroscopy (fNIRS).

Similar to mother-child dyads, we also observed increased inter-brain synchrony in father-child dyads during cooperative as compared to individual problem solving (and rest) in dorsolateral prefrontal and temporo-parietal brain areas. Some other patterns, however, differed in father- as compared to mother-child dyads, and these are discussed in the paper. In addition, we for the first time report that the father’s attitude toward his role as a parent was related to inter-brain synchrony during cooperation.

These results extend our knowledge on parent-child interaction and inter-brain synchrony and for the first time highlight the importance of the father’s attitude to parenting on a bio-behavioural synchrony level.

Nguyen, T., Schleihauf, H., Kungl, M., Kayhan, E., Hoehl, S.*, & Vrtička, P.* (in press – published online 10 January 2021). Interpersonal neural synchrony during father-child problem solving: A fNIRS hyperscanning study. Child Development. *= these authors share senior authorship. https://doi.org/10.1111/cdev.13510. OPEN ACCESS.

Press releases:
University of Essex (12 January 2021)
University of Vienna (12 January 2021)

For a selection of press reports, see here.

M-CARE fNIRS Hyperscannig Methods Paper: A Guide to Parent-Child fNIRS Hyperscanning Data Analysis

In a special methods paper, we offer a guide on parent-child fNIRS hyperscanning data analysis in MATLAB and R. We provide a freely available exemplary dataset of 20 dyads (randomly sampled from the M-CARE participant pool), as well as MATLAB and R scripts to analyse the data.

With this guide, we hope to offer advice for future parent-child fNIRS hyperscanning investigations and to enhance replicability within the field.

Nguyen, T., Hoehl, S., and Vrtička, P. (2021). A Guide to Parent-Child fNIRS Hyperscanning Data Analysis. Sensors (Section Biosensors; Special issue on “Brain Signals Acquisition and Processing”), 21, 4075. https://doi.org/10.3390/s21124075. OPEN ACCESS.


Output: Preprints

D-CARE Paper N° 2Hypothalamus volume, caregiving, and attachment in adult men: similarity across men and interindividual differences among dads

A second paper as part of the D-CARE study describes an investigation of hypothalamus volume in N= 50 fathers of 5-6 year-old children and N= 45 non-fathering men. All men underwent structural magnetic resonance imaging (MRI) scanning with subsequent manual volumetric parcellation of the hypothalamus.

Most studies on mammalian caregiving and attachment have focused on the mother-child relationship, particularly in humans. Yet, changing societal roles of male caregivers have highlighted the necessity for research with fathers.

In this pre-registered study, we examined the volume of the hypothalamus, an important subcortical brain area for caregiving and attachment behavior, in a sample of N=50 fathering (child age 5-6 years) and N=45 non-fathering men using a novel technique to identify the human hypothalamus in 3T MRI. Furthermore, we employed three self-report measure to assess interindividual differences in caregiving in fathers, and attachment across all men.

Self-reported caregiving qualities, including belief in the importance of a father’s role and enjoyment of the child, were positively related to total hypothalamus volume. A follow-up analysis furthermore showed that fathers’ beliefs were related specifically to tuberal hypothalamus volume, while enjoyment of the child was not associated with volume in any specific hypothalamus sub-region. We did not observe any significant associations between hypothalamus volume and attachment orientation across all men, and no difference in hypothalamus volume between fathers and non-fathers.

Together, this suggests that there is interindividual variability in the association between brain structure and caregiving qualities in fathers, warranting further research.

Long, M., Puhlmann, L., Vrtička, P. (under review). Hypothalamus volume, caregiving, and attachment in adult men: similarity across men and interindividual differences among dadsPREPRINT [link]


Output: Talks & Presentations

Virtual Poster “On the same Wavelength: Assessing Interpersonal Neural Synchrony in Parent-Child Dyads using fNIRS Hyperscanning” presented by Dr Vrticka during BNA2021 – The British Neuroscience Association 2021 International Festival of Neuroscience (April 12, 2021).

Virtual Talk “Parent-Child Inter-Brain Coherence as a Potential New Biomarker for Relationship Quality, Attachment, and Caregiving” presented by Dr Vrticka as part of the Symposium “Understanding Dyadic Biobehavioral Synchrony: Developmental Precursors and Functions” during SRCD 2021 (April 07, 2021).


More information about the CARE, D-CARE, and M-CARE studies – particularly results and their discussion – will be posted here once it becomes available.