Sex differences in mental rotation: Cortical functional connectivity using direct transfer function

Stress is associated with numerous chronic diseases, beginning in fetal development with in utero exposures (prenatal stress) impacting offspring’s risk for disorders later in life. In previous studies, we demonstrated adverse maternal in utero immune activity on sex differences in offspring neurodevelopment at age seven and adult risk for major depression and psychoses. Here, we hypothesized that in utero exposure to maternal proinflammatory cytokines has sex-dependent effects on specific brain circuitry regulating stress and immune function in the offspring that are retained across the lifespan. Using a unique prenatal cohort, we tested this hypothesis in 80 adult offspring, equally divided by sex, followed from in utero development to midlife. Functional MRI results showed that exposure to proinflammatory cytokines in utero was significantly associated with sex differences in brain activity and connectivity during response to negative stressful stimuli 45 y later. Lower maternal TNF-α levels were significantly associated with higher hypothalamic activity in both sexes and higher functional connectivity between hypothalamus and anterior cingulate only in men. Higher prenatal levels of IL-6 were significantly associated with higher hippocampal activity in women alone. When examined in relation to the anti-inflammatory effects of IL-10, the ratio TNF-α:IL-10 was associated with sex-dependent effects on hippocampal activity and functional connectivity with the hypothalamus. Collectively, results suggested that adverse levels of maternal in utero proinflammatory cytokines and the balance of pro- to anti-inflammatory cytokines impact brain development of offspring in a sexually dimorphic manner that persists across the lifespan.

Download Full-text

Sex differences in virtual navigation influenced by visual factors and individual differences

10.31234/osf.io/za4gj ◽

2019 ◽

Author(s):

Lace Padilla

Keyword(s):

Sex Differences ◽

Individual Differences ◽

Mental Rotation ◽

Morris Water Maze ◽

Water Maze ◽

Large Scale ◽

Small Scale ◽

Standard Design ◽

Males And Females ◽

Virtual Morris Water Maze

The Morris water maze is a task adapted from the animal spatial cognition literature and has been studied in the context of sex differences in humans, particularly because of the standard design, which manipulates proximal (close) and distal (far) cues. However, there are mixed findings with respect to the interaction of cues and sex differences in virtual Morris water maze tasks, which may be attributed to variations in the scale of the space and previously unmeasured individual differences. We explore the question of scale and context by presenting participants with an outdoor virtual Morris water maze that is four times the size of the mazes previously tested. We also measured lifetime mobility and mental rotation skills. Results of this study suggest that for the small-scale environment, males and females performed similarly when asked to navigate with only proximal cues. However, males outperformed females when only distal cues were visible. In the large-scale environment, males outperformed females in both cue conditions. Additionally, greater mental rotation skills predicted better navigation performance with proximal cues only. Finally, we found that highly mobile females and males perform equally well when navigating with proximal cues.

Download Full-text

Control of Three Phase to Three Phase Matrix Converter—A Direct Transfer Function Approach

Lecture Notes in Electrical Engineering - Power Electronics and Renewable Energy Systems ◽

10.1007/978-81-322-2119-7_37 ◽

2014 ◽

pp. 361-371

Author(s):

A. Jamna ◽

V. Jamuna ◽

S. Rama Reddy

Keyword(s):

Transfer Function ◽

Matrix Converter ◽

Function Approach ◽

Direct Transfer ◽

Three Phase

Download Full-text

Sex Differences in Functional Connectivity of the Salience, Default Mode, and Central Executive Networks in Youth with ASD

Cerebral Cortex ◽

10.1093/cercor/bhaa105 ◽

2020 ◽

Vol 30 (9) ◽

pp. 5107-5120 ◽

Cited By ~ 5

Author(s):

Katherine E Lawrence ◽

Leanna M Hernandez ◽

Hilary C Bowman ◽

Namita T Padgaonkar ◽

Emily Fuster ◽

...

Keyword(s):

Sex Differences ◽

Functional Connectivity ◽

Autism Spectrum ◽

Central Executive ◽

Neural Mechanisms ◽

Typical Development ◽

Typically Developing ◽

Matched Sample ◽

Biological Factors ◽

Default Mode

Abstract Autism spectrum disorder (ASD) is associated with the altered functional connectivity of 3 neurocognitive networks that are hypothesized to be central to the symptomatology of ASD: the salience network (SN), default mode network (DMN), and central executive network (CEN). Due to the considerably higher prevalence of ASD in males, however, previous studies examining these networks in ASD have used primarily male samples. It is thus unknown how these networks may be differentially impacted among females with ASD compared to males with ASD, and how such differences may compare to those observed in neurotypical individuals. Here, we investigated the functional connectivity of the SN, DMN, and CEN in a large, well-matched sample of girls and boys with and without ASD (169 youth, ages 8–17). Girls with ASD displayed greater functional connectivity between the DMN and CEN than boys with ASD, whereas typically developing girls and boys differed in SN functional connectivity only. Together, these results demonstrate that youth with ASD exhibit altered sex differences in these networks relative to what is observed in typical development, and highlight the importance of considering sex-related biological factors and participant sex when characterizing the neural mechanisms underlying ASD.

Download Full-text

Thalamic Functional Connectivity during Spatial Long-Term Memory and the Role of Sex

Brain Sciences ◽

10.3390/brainsci10120898 ◽

2020 ◽

Vol 10 (12) ◽

pp. 898

Author(s):

Dylan S. Spets ◽

Scott D. Slotnick

Keyword(s):

Sex Differences ◽

Functional Connectivity ◽

Region Of Interest ◽

Brain Regions ◽

Long Term Memory ◽

Thalamic Nuclei ◽

Term Memory ◽

Correlated Activity ◽

Abstract Shapes

The thalamus has been implicated in many cognitive processes, including long-term memory. More specifically, the anterior (AT) and mediodorsal (MD) thalamic nuclei have been associated with long-term memory. Despite extensive mapping of the anatomical connections between these nuclei and other brain regions, little is known regarding their functional connectivity during long-term memory. The current study sought to determine which brain regions are functionally connected to AT and MD during spatial long-term memory and whether sex differences exist in the patterns of connectivity. During encoding, abstract shapes were presented to the left and right of fixation. During retrieval, shapes were presented at fixation, and participants made an “old-left” or “old-right” judgment. Activations functionally connected to AT and MD existed in regions with known anatomical connections to each nucleus as well as in a broader network of long-term memory regions. Sex differences were identified in a subset of these regions. A targeted region-of-interest analysis identified anti-correlated activity between MD and the hippocampus that was specific to females, which is consistent with findings in rodents. The current results suggest that AT and MD play key roles during spatial long-term memory and suggest that these functions may be sex specific.

Download Full-text