New psychology research sheds light on the cognitive mechanisms underlying loneliness

People tend to have a harder time remembering things that are associated with their close friends compared to things that are associated with themselves, and this tendency is exacerbated among those experiencing greater levels of loneliness, according to new research published in the British Journal of Psychology. The findings provide evidence that lonely individuals exhibit a greater cognitive distance between themselves and their friends.

Loneliness is often associated with negative emotions, such as sadness and anxiety, and can lead to a range of negative health outcomes. Understanding loneliness can help researchers and mental health professionals develop effective interventions to help individuals who experience loneliness and improve their overall well-being. The authors behind the new study sought to better understand the cognitive mechanisms underlying loneliness.

“I am interested in how we represent the self and others and how this influences cognition and memory,” said study author Andrew Martin, a senior lecturer in cognitive neuropsychology at The University of Kent.

“Moreover, I am interested in how perceived social disconnection, or loneliness, is associated with differences in self-other processing and subsequent effects on cognition. Fundamentally, I am interested in how lonelier individuals may process social information in a different way from those who do not describe themselves as often feeling lonely.”

Martin and his colleagues aimed to investigate how different levels of closeness and familiarity affect memory encoding and how this is related to loneliness. They recruited 143 young adults from the University of Kent and had them make judgments about themselves, a close friend, or a celebrity while completing personality questionnaires.

Participants were presented with 60 adjectives in random order and rated each on a 9-point scale, where 1 indicated that the word was “very inaccurate” in describing the person and 9 indicated that the word was “very accurate” in describing the person. (Twenty adjectives were presented for each person.)

After completing an unrelated visual perceptual task, participants were then tested on their memory of the adjectives. During this stage, participants were presented with the previous 60 adjectives and 60 new distractor words in a random manner.

Participants were asked to indicate whether or not they remembered the word from the previous task. If participants responded “Yes,” indicating that they remembered the word, they were then asked a follow-up question: “Who was the word in reference to?” Participants had to answer with either “Yourself,” “Your Friend,” or “Boris Johnson.”

The perceived loneliness of participants was assessed using the UCLA loneliness scale, a widely used self-report questionnaire. The questions are designed to assess the individual’s perceived social isolation, feelings of loneliness, and the quality of their relationships with others. Some example questions from the scale include “How often do you feel part of a group of friends?”, “How often do you feel left out?”, and “How often do you feel close to people?”.

The researchers found that participants tended to be better at remembering words that were related to themselves, compared to when they were related to a close friend or a celebrity. They were also more confident in their memories of self-related words.

Participants who felt lonelier tended to remember things even better when they were related to themselves, but not as well when they were related to a close friend. This suggests that feeling lonely is related to a self-referential memory bias, which might make people feel like they are more distant from their friends.

“Memory can act as a social glue,” Martin told PsyPost. “If we would like to maintain strong social connections with someone, it helps if we are able to remember key aspects about that person. The results of the current study suggest that individuals who experience loneliness to a greater extent, may fail to attend to, consolidate, or recognize information about a close friend which may contribute to a feeling of social disconnection.”

Evidence from previous research indicates that people who experience loneliness tend to have a weaker connection between their own self-representation and representations of their close friends in their brain. This means that the neural activity related to processing information about themselves is different from the activity related to processing information about their close friends.

“We also may think of close friends as an extension of the self and recent neuroimaging work has shown that thinking about close others, such as friends and family, tend to recruit similar brain networks to those recruited when thinking about the self,” Martin explained. “The research also showed that lonelier individuals show a greater neural overlap between close friends and strangers.”

“We build on this research by identifying a self-referential effect in episodic memory, such that items encoded in relation to the self were recognized better than items encoded in relation to a celebrity. Close friends had an intermediate effect between the self and celebrity, suggesting that we pay more attention to items related to people closer to us.”

“Crucially, we found that lonelier individuals processed items related to the close friend in a more similar fashion to items encoded in relation to the celebrity,” Martin told PsyPost. “This provides cognitive evidence to back up the recent findings of a ‘lonely’ brain.”

Martin said he was surprised to find “how consistent and strong the self-referential and friend referential effects were across the large sample.”

But the study, like all research, includes some limitations. For example, the study was conducted with undergraduate psychology students, most of whom were females, and a more diverse sample would improve the study’s generalizability.

“Future research should look at the direction of these effects using longitudinal methods,” Martin said. “It would also be interesting to identify how loneliness may affect different stages of information processing. For example, do they pay less attention to information about close others, to they fail to consolidate, or struggle to retrieve the information.”

The study, “Loneliness is associated with a greater self-reference effect in episodic memory when compared against a close friend“, was authored by Laureta Kokici, Gratiela Chirtop, Heather J. Ferguson, and Andrew K. Martin.

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