Gender identity better than sex explains individual differences in episodic and semantic components of autobiographical memory and future thinking

Sex/Gender Differences in Brain Lateralisation and Connectivity

There is now a significant body of literature concerning sex/gender differences in the human brain. This chapter will critically review and synthesise key findings from several studies that have investigated sex/gender differences in structural and functional lateralisation and connectivity. We argue that while small, relative sex/gender differences reliably exist in lateralisation and connectivity, there is considerable overlap between the sexes. Some inconsistencies exist, however, and this is likely due to considerable variability in the methodologies, tasks, measures, and sample compositions between studies. Moreover, research to date is limited in its consideration of sex/gender-related factors, such as sex hormones and gender roles, that can explain inter-and inter-individual differences in brain and behaviour better than sex/gender alone. We conclude that conceptualising the brain as 'sexually dimorphic' is incorrect, and the terms 'male brain' and 'female brain' should be avoided in the neuroscientific literature. However, this does not necessarily mean that sex/gender differences in the brain are trivial. Future research involving sex/gender should adopt a biopsychosocial approach whenever possible, to ensure that non-binary psychological, biological, and environmental/social factors related to sex/gender, and their interactions, are routinely accounted for.

Respiratory sinus arrhythmia during biofeedback is linked to persistent improvements in attention, short-term memory, and positive self-referential episodic memory

Background

Heart rate variability (HRV) biofeedback, an intervention based on the voluntary self-regulation of autonomic parameters, has been shown to affect prefrontal brain functioning and improve executive functions. The interest in using HRV biofeedback as cognitive training is typically ascribed to parasympathetic activation and optimized physiological functioning deriving from increased cardiac vagal control. However, the persistence of cognitive effects is poorly studied and their association with biofeedback-evoked autonomic changes has not yet been explored. In addition, no study has so far investigated the influence of HRV biofeedback in adults on long-term episodic memory, which is particularly concerned with self-referential encoding processing.

Methods

In the present study, a novel training system was developed integrating HRV and respiratory biofeedback into an immersive virtual reality environment to enhance training efficacy. Twenty-two young healthy adults were subjected to a blinded randomized placebo-controlled experiment, including six self-regulation training sessions, to evaluate the effect of biofeedback on autonomic and cognitive changes. Cardiac vagal control was assessed before, during, and 5 min after each training session. Executive functions, episodic memory, and the self-referential encoding effect were evaluated 1 week before and after the training program using a set of validated tasks.

Results

Linear mixed-effects models showed that HRV biofeedback greatly stimulated respiratory sinus arrhythmia during and after training. Moreover, it improved the attentional capabilities required for the identification and discrimination of stimuli ( η p 2 = 0.17), auditory short-term memory ( η p 2 = 0.23), and self-referential episodic memory recollection of positive stimuli ( η p 2 = 0.23). Episodic memory outcomes indicated that HRV biofeedback reinforced positive self-reference encoding processing. Cognitive changes were strongly dependent on the level of respiratory sinus arrhythmia evoked during self-regulation training.

Conclusion

The present study provides evidence that biofeedback moderates respiration-related cardiac vagal control, which in turn mediates improvements in several cognitive processes crucial for everyday functioning including episodic memory, that are maintained beyond the training period. The results highlight the interest in HRV biofeedback as an innovative research tool and medication-free therapeutic approach to affect autonomic and neurocognitive functioning. Finally, a neurocognitive model of biofeedback-supported autonomic self-regulation as a scaffolding for episodic memory is proposed.

Latent profile analysis to identify subgroups of Chinese sexual minority adolescents at risk of suicidality

BACKGROUND

This study aimed to identify latent class profiles of sexual minority adolescents (Men Sexually attracted to Men, Women Sexually attracted to Women, and Bisexual) with elevated suicidal ideation.

METHODS

Data were collected from 18 secondary schools in China. Sub-group classifications were identified using variables associated with suicidal ideation in sexual minority adolescents, including parental relationship quality, electronic equipment time, school bullying, and sleep quality using the Chinese version of the Pittsburgh Sleep Quality Index to measure sleep. Anxiety was measured using the Generalized Anxiety Disorder 7 (GAD-7), depression was measured using the Patient Health Questionnaire 9 (PHQ-9), hypomania using the Hypomanic Checklist-32 (HCL-32), positive coping style was identified using the Trait Coping Style Questionnaire, and self-efficacy was measured by the General Self-Efficacy Scale.

RESULTS

Four distinctive profiles were derived from the data. Compared to "low-risk" group (Class 3), the "adolescent with mood problems" group (Class 2) had a 9.81 times higher risk of suicidal ideation; the those who classified as "severe bullied adolescent" (Class 4) had a 9.26 times higher risk of suicidal ideation. and the "adolescents with low self-efficacy" group (Class 1) had a 4.48 times higher risk of suicidal ideation.

CONCLUSIONS

Sexual minority adolescents with mood problems have the highest risk of suicidal ideation, followed by adolescents frequently being bullied at school. Interventions aimed at reducing suicide risk among sexual minority adolescents may benefit from attending to such profile factors identified in this study to develop targeted clinical care.

It's time for sex in cognitive neuroscience

In a discussion paper published in the special issue of Cognitive Neuroscience, Sex Differences in the Brain, we investigated whether certain experimental parameters contributed to findings in functional magnetic resonance imaging studies of sex differences during long-term memory. Experimental parameters included: the number of participants, stimulus type(s), whether or not performance was matched, whether or not sex differences were reported, the type of between-subject statistical test used, and the contrast(s) employed. None of these parameters determined whether or not differences were observed, as all included studies reported sex differences. We also conducted a meta-analysis to determine if there were any brain regions consistently activated to a greater degree in either sex. The meta-analysis identified sex differences (male > female) in the lateral prefrontal cortex, visual processing regions, parahippocampal cortex, and the cerebellum. We received eight commentaries in response to that paper. Commentaries called for an expanded discussion on various topics including the influence of sex hormones, the role of gender (and other social factors), the pros and cons of equating behavioral performance between the sexes, and interpreting group differences in patterns of brain activity. There were some common statistical assumptions discussed in the commentaries regarding the 'file drawer' issue (i.e., the lack of reporting of null results) and effect size. The current paper provides further discussion of the various topics brought up in the commentaries and addresses some statistical misconceptions in the field. Overall, the commentaries echoed a resounding call to include sex as a factor in cognitive neuroscience studies.

Gender identity better than sex explains individual differences in episodic and semantic components of autobiographical memory: An fMRI study

Advances in the literature of sex-related differences in autobiographical memory increasingly tend to highlight the importance of psychosocial factors such as gender identity, which may explain these differences better than sex as a biological factor. To date, however, none of these behavioral studies have investigated this hypothesis using neuroimaging. The purpose of this fMRI study is to examine for the first time sex and gender identity-related differences in episodic and semantic autobiographical memory in healthy participants (M=19, W=18). No sex-related differences were found; however, sex-related effects of masculine and feminine gender identity were identified in men and women independently. These results confirm the hypothesis that differences in episodic and semantic autobiographical memory are best explained by gender but are an interaction between biological sex and gender identity and extend these findings to the field of neuroimaging. We discuss the importance of hormonal factors to be taken into consideration in the future.

Narrative characteristics of autobiographical memory predict expectations of narrator gender

Gender differences in autobiographical memory have been documented in various domains. The current study attempts to sharpen an understanding of extant gender differences in autobiographical memory by considering listener expectations, contributing to a sociocultural model. Across three studies (a pilot and two separate data collections) a narrative database was created. Narratives were coded for variables that have been shown to differ by gender, including emotion, connectedness to others, factual and interpretive elaboration, and thematic coherence. Participants read narratives and assessed if the narrator was male or female, indicating their confidence. In the pilot study and study 1, narrative features consistently predicted participant's assessments of narrator gender in two separate methods using the same narratives. In study 2, new narratives were used, showing replicability of the method and avoiding potential confounds of naturally occurring differences in study 1 and pilot data. More emotion words predicted higher likelihood of assessing a female narrator. Results support the use of such a methodology as an innovative way to examine gender-based listener expectations in autobiographical memory. They can be used for further theorising about the source of gender differences in this domain of memory that represents a combination of cognitive and social processes.