Evidence suggests that the gut-brain axis can influence stress-related behaviour, mood and neuropsychological disorders, including anxiety. Stress exposure can increase anxiety-related symptoms such as muscle tension & worrying. Medical treatment has low success and a range of side effects on anxiety. This review aimed to see if probiotics can reduce anxiety symptoms in humans. Where relevant articles on people with anxiety disorders are lacking, the review evaluates articles addressing healthy participants in stressful situations such as exams or public speeches via anxiety questionnaires. I hypothesized that probiotics could be an effective anxiolytic treatment in combination with therapy. Most articles demonstrated reduced subjective and objective results in anxiety and stress measurements after a daily intake of probioticstrains. Findings demonstrate potential anxiolytic benefits with a daily probiotic intake. However, future research on participants with an anxiety disorder is needed to conclude the hypothesis.

Although the self is central to human beings and has been pondered on for thousands and thousands of years, its nature remains unknown to us. Many want to solve the question of self but where does one even begin? Philosophers have investigated the self for hundreds if not thousands of years, and many theories and concepts exist. In more recent years it has become possible for science to investigate the self through the use of psychoactive substances. Most notably is the use of drug-induced ego-dissolution, where individuals report a state of self devoid of many of the characteristics that would normally be considered crucial for our everyday lives. This has created new circumstances, it is no longer solely philosophy that can investigate the self, but also science. By measuring the brain activity of participants who are experiencing this ego-dissolution, information about a disrupted self can be gathered. And by using this data more can be known about the normal state of self than ever before. Even though current research is young, it has still revealed certain elements of the self, such as the importance of connectivity between multiple brain regions. These findings strongly support the materialist network approach to the self, which philosophers are taking note of. Although many of the findings are of interest, they can still be underwhelming due to the vagueness of the exact nature of ego disruption being investigated and the lack of sophistication regarding the conceptualization of self.

Det finns många studier som kollar på likheter i de neurala korrelaten i empati för smärta, medan det finns få studier som kollar på skillnaderna i hjärnresponserna. Detta arbete har som fokus att titta på skillnader i neurala korrelaten i empati för smärta inom självupplevd smärta kontra (empatiskt) observerad smärta hos andra individer. Detta arbetes sökprocess resulterade sammanlagt med tre artiklar som använder sig utav fMRI. Det man hittade var att skillnader finns genom att de somatosensoriska områdena var mer aktiverade vid självupplevd smärta medan observerad smärta involverade andra regioner så som insula och anterior cingulate cortex/anterior mid cingulate cortex. De somatosensoriska områdena var fortsatt aktiverade vid observation men i mindre utsträckning. Det som också hittades inom detta arbete som ett fynd är att de frontala delarna var mer aktiverade när man kände till någon som har ont jämfört med när man inte kände personen.

Identification of the pathways that could be targeted to alleviate ageing-related cognitive decline is of prime importance. One of the most promising target mechanisms is connected to healthy dopaminergic ageing. Extant research suggest that women may exhibit less ageing-related dopamine (DA) decline compared to men, implicating that women may suffer less from dopamine-related cognitive decline. However, to date, shortage of empirical investigations limit firm conclusions of sex differences. In the present work it is hypothesized that: (i) women as compared to men exhibit less aging-related DA losses, and (ii) less aging-related decline of episodic memory (EM), and that (iii) sex differences in episodic memory might be mediated by differences in DA integrity. To that end, sex-related differences in D1-type dopamine receptor (D1DR) integrity and episodic memory were investigated in a healthy cohort of young to old participants (age 20 – 80, n = 180, 50% women) through whole-brain voxel-wise analysis and linear regression models. Firstly, the dorsal caudate was identified as the main region of the EM-D1DR interrelation. Secondly, a significant female advantage was found for EM and D1DR in ageing. Finally, no mediation effect by D1DR on the sex-EM interaction was found. These results indicate the presence of correlational relationships between sex, cognition and D1DR, in ageing. However, D1DR was not found to be the mediating factor in the observed correlations. Future research, preferably using longitudinal design, should further investigate the underpinnings of sex differences in D1DR and EM.

Depression has increased among adolescents and adults over the last decade. Effective treatments and techniques to improve personal well being and disorders like depression are much needed. Mindfulness is a psychological technique that involves actively paying attention to one's awareness of the present moment with nonjudgmental acceptance (Kabat-Zinn, 1990). While the effectiveness of mindfulness interventions has been widely studied, relatively little research has been done on the effects of mindfulness interventions on depression using neuroimaging techniques such as functional magnetic resonance imaging (fMRI) or electroencephalography (EEG). This systematic review includes four studies that investigates the effectiveness of mindfulness interventions on depression measured by fMRI or EEG and different rating scales measuring depression. The results from this systematic review shows that mindfulness interventions may have an effect on depression. Two of the studies (Ferri et al., (2017); Yang et al., (2016), found significant differences in the rating scales for depression. The studies also suggest that mindfulness interventions can impact the brain regions involved in negative emotional processing in individuals with depression, such as the default mode network (DMN) and the dorsal anterior cingulate cortex (dACC).

Many of the skills that are considered noteworthy in our societies are either acquired through training and dedication or granted to those lucky enough to have the right genetics and environment. But one skill that is often overlooked is the ability to keep rhythm. This skill is both remarkable in temporal accuracy and common. And although rhythm-keeping is a common cognitive skill, not much is known about the neural correlates of rhythm-keeping. The aim of the current exploratory study was to investigate the electrophysiological correlates of rhythm-keeping. In this study, participants were asked to perform a task where they were introduced to a rhythm with both auditory and visual cues to correct themselves after. They were then supposed to keep the rhythm for approximately thirty seconds, even though all stimuli indicating the rhythm were removed after six seconds of performing the task. During the task, electrophysiological data were collected using electroencephalography (EEG). The electrophysiological data and task performance were then analysed using mass univariate analysis, but no significant relationship was found between the electrophysiological data and rhythm-keeping performance. Potential issues underlying these non-significant findings, as well as solutions to address these, will be addressed.

Previous findings have discovered that self-related stimuli such as one’s own face relative to a familiar or an unknown face leads to enhanced neural processing. Preferential processing of the self-face has been observed at various event-related potential (ERP) components, both when stimuli were presented on a subliminal and supraliminal level. This study extends previous research on the relationship between self-preferential processing and awareness by examining whether the visual awareness negativity (VAN) component, a proposed early signature of visual awareness, is modulated by the self-face compared to a personally familiar face. By the use of backward masking paradigm, faces were presented on the left or the right side of the screen, after which participants performed localization and identification task, and rated their perceived awareness. We found more negative amplitude for supraliminal compared to subliminal faces, indexed by the VAN (180-280ms). Further, the self-face displayed more negative amplitude than the familiar-face, supporting findings of self-referential processing. However, no interaction between face identity and awareness was found. These findings suggest that preferential processing of the self-face does not depend on the level of awareness.

In this systematic review and meta-analysis, the relationship between error awareness and the amplitude of Error-Related Negativity (ERN), a neural response to errors associated with cognitive control and error monitoring processes, was examined. Five studies published between 2010 and 2020, involving a total of 302 participants, were analyzed. Findings revealed a more pronounced negative amplitude of the ERN for aware errors compared to unaware errors, supporting the Error Detection Theory and Reinforcement Learning Theory. The results did not directly support or contradict the Conflict-Monitoring Theory. These findings underscore the critical role of conscious error detection in modulating ERN responses and adaptive behavioral modifications. However, due to the limited number of included studies and variability in their methodologies, caution is needed in interpreting the results. Future research should aim to validate these findings with larger samples and standardized study designs, while also exploring a more nuanced understanding of error awareness.

The influence of sex hormones on Attention Deficit/Hyperactivity Disorder (ADHD) symptoms in women has gained attention in recent years. This systematic review examines the impact of hormonal fluctuations, such as those occurring during the menstrual cycle, puberty, adulthood, and menopause, on ADHD symptoms in women. Sex hormones, including progesterone, estradiol, and testosterone, significantly affect the central nervous system and the neurotransmitters GABA, serotonin, dopamine, and glutamate, which are involved in mood regulation, behavior, and cognition. Hormonal imbalances can lead to neurocognitive dysfunctions and exacerbate the symptoms of neuropsychiatric disorders like ADHD. After a thorough search in two electronic databases (Web o Science and Medline Ebsco), only three original studies were selected as matching the inclusion criteria. These studies observed the effect of sex hormones in women with regular menstruation, polycystic ovary syndrome (PCOS), or primary dysmenorrhea (PD) on their ADHD symptoms. Based on the reviewed studies, it is evident that hormonal fluctuations throughout different life stages can influence the severity and expression of ADHD symptoms in women, thus affecting treatment and prognosis. Understanding the interaction between sex hormones and ADHD symptoms is essential for personalized treatment approaches and for improving the well-being of women with ADHD.

The term cognitive enhancers are substances that increase cognitive performance. The stimulant methylphenidate is commonly used as a medication for attention deficit hyperactive disorder and is highly popular as a cognitive enhancer. One of its theorized mechanisms of action is to enhance working memory. This systematic review aims to examine literature that tests the effect of methylphenidate on cognitive performance, specifically working memory, in healthy subjects. Following the PRISMA guidelines, a systematic search was conducted on Web of Science, Scopus, and Medline Ebsco on 1st March 2022. Articles were selected based on the predetermined eligibility criteria. Of the ten selected articles, three found a significant effect of methylphenidate on working memory, and one found a significant effect on spatial working memory. The studies produced varied results due to differential use of working memory tasks and methylphenidate dosage. Further studies on how methylphenidate affects working memory are needed.