The Elusive Link Between Brown Fat and Social Contact

Summary: A study exploring the link between brown adipose tissue (BAT) activity and the tendency for physical contact yielded inconclusive results, challenging earlier assumptions.

Researchers attempted to replicate a 2012 study using infrared thermography to measure BAT activity, hypothesizing that lower activity might correlate with a greater need for physical contact.

Despite testing 94 participants, the method failed to reliably measure BAT activity, leaving questions about its role in social behaviors and attachment styles. This setback indicates the need for alternative methods to explore how BAT may influence human social interactions and health.

Key Facts:

  1. The study aimed to establish a non-invasive method for measuring BAT activity to understand its role in social behaviors.
  2. Infrared thermography, used to measure BAT activity, proved unreliable, contradicting previous smaller-scale studies.
  3. The research highlights the complexity of linking BAT activity with human social behaviors, suggesting further exploration is needed.

Source: Polish Association of Social Psychology

Psychologists suspect that the quantity of brown body fat, which is found in a specific area in the upper neck and can increase body temperature, is linked to the tendency of some people to seek physical contact. So, a recent study sought to evaluate whether there is an easy, low-cost and non-invasive way to determine the activity of this tissue.

If such a method existed, it would be much more achievable to understand the links between seeking physical contact, such as warming cuddles, and the activity of brown fat tissue. The main hypothesis is that a poorer activity of brown fat tissue would be associated with more behaviours of seeking physical contact (see the work of Prof. Hans IJzerman, one of the authors of this study).

The inclination to seek physical contact is intricately linked to an individual’s attachment style: be it anxious, avoidant, secure, or disorganised. Credit: Neuroscience News

The inclination to seek physical contact is intricately linked to an individual’s attachment style: be it anxious, avoidant, secure, or disorganised. In fact, an avoidant individual would typically refrain from seeking physical contact.

Whether attachment style is associated with a difference in the activity of brown adipose tissue is yet unknown. Eventually, a method to evaluate the association between thermoregulation and social behaviours would benefit social psychologists.

“In species other than humans, BAT (i.e. Brown Adipose Tissue) thermogenesis has been thought to be relevant for maternal care. But if and how BAT is involved in human interpersonal interactions or adult human attachment is equivocal,” explain Nathan Vidal (Université Grenoble Alpes, France) and his co-authors in a new research paper, published in the peer-reviewed open-access journal Social Psychological Bulletin.

“The reason for BAT and its role in adult human social interaction being so ill-understood is that the most widely-used method to measure the amount and the activity of BAT relies on very intrusive radioactive tracers,” they add.

Inspired by the findings of their fellow researchers from 2012, who reported promising results when using infrared cameras to monitor in real time how much heat the brown fat depot in the supraclavicular region would give away in cool conditions, Vidal and his team set out to find more about the link between the curious thermal activity and individual attachment traits. 

“Because of the importance of social connection and loneliness for health, BAT may well form an entry-point to better understand why social relations are good for one’s health and we regard the measurement of BAT as vital for better understanding these mechanisms,” say the authors of the recent study.

“Because of the risks associated with ionising radiation during PET-CT imaging, researchers have sought to develop alternative methods to estimate BAT activity, such as infrared thermography.”

Before that, however, the team had to replicate the earlier study to confirm infrared thermography as a reliable method, since their colleagues had only tested seven male individuals, which is a fairly small sample. So, in their study, Vidal and his team repeated the experiment with a total of 94 male and female participants. 

To their disappointment, the researchers concluded that the infrared thermography method cannot measure heat emitted from body fat, and future studies into BAT thermogenesis, social thermoregulation and attachment security should rather look into alternative methodologies and protocols. 

“At this stage, we do not know why the protocol fails,” the team says.

“Perhaps the cooling protocol does not lead to sufficient BAT activity, perhaps the measure of infrared thermography cannot assess BAT activity in the supraclavicular area, or perhaps BAT activity can only be detected through infrared thermography in a subset of the population (e.g. men).”

About this social behavior research news

Author: Dimitar Boyadzhiev
Source: Polish Association of Social Psychology
Contact: Dimitar Boyadzhiev – Polish Association of Social Psychology
Image: The image is credited to Neuroscience News

Original Research: Closed access.
Assessing the Reliability of an Infrared Thermography Protocol to Assess Cold-Induced Brown Adipose Tissue Activation in French Psychology Students” by Nathan Vidal et al. Social Psychology Bulletin


Abstract

Assessing the Reliability of an Infrared Thermography Protocol to Assess Cold-Induced Brown Adipose Tissue Activation in French Psychology Students

The authors use infrared thermography measurements of skin temperature to non-invasively assess the heat production of Brown Adipose Tissue (BAT).

In species other than humans, BAT has been linked to maternal care, and may thus be crucial for understanding differences in attachment security.

Whereas early BAT research measured its relative presence in the human body through radioactive tracers, researchers have recently used infrared thermography measurement of skin temperature in cold conditions to study BAT thermogenesis outside of medical facilities.

Infrared thermography relies on comparing skin temperature in the supraclavicular region (where a BAT depot is located) with skin temperature in the sternal region (which contains no BAT depots) in cold conditions, when the supraclavicular BAT depot produces heat.

We replicated an infrared thermography protocol, which previously reported an increase of 0.2 °C in supraclavicular (vs. sternal) skin temperature in cold (vs. control) conditions in only 7 adults, which probably led to overestimation of the effect.

With a much larger sample size (N = 94 young adults) and a similar protocol, we did not find any significant variation in relative, Cohen’s d = 0.10, 95% CI [-0.31, 0.50], or absolute supraclavicular skin temperature, Cohen’s d = 0.11, 95% CI [-0.30, 0.52]. Using conditional random forests, we also excluded a variety of alternative explanations for why the method failed to achieve an effect.

This protocol of infrared thermography cannot measure BAT thermogenesis and is thus not recommended for future studies to study individual differences in attachment.