Pilleriin Sikka

Pilleriin Sikka
Stanford University | SU · School of Medicine

PhD

About

67
Publications
56,114
Reads
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1,073
Citations
Introduction
I study (1) emotions and emotion regulation across the wake-sleep cycle and their relationship to health and well-being (2) the psychological and neurobiological correlates of peace of mind—an often overlooked aspect of mental well-being—and its relation to emotion regulation. I use a multidisciplinary approach by drawing on the concepts, theories, and methods from philosophy, psychology, and (affective) neuroscience.
Additional affiliations
January 2011 - present
University of Turku
Position
  • Researcher
November 2011 - present
University of Skövde
Position
  • Lecturer
Description
  • Course coordinator and lecturer for the following courses: Basic Neuroscience, Central Topics in Cognitive Neuroscience , Positive Psychology and Well-being , Mini-conference in Positive Psychology, Supervision of BSc and MSc theses.
June 2008 - December 2010
University of Turku
Position
  • Research Assistant
Education
September 2005 - September 2006
University of Oxford
Field of study
  • Neuroscience
September 2003 - June 2005
Tallinn University
Field of study
  • Psychology
September 1999 - June 2003
Tallinn University
Field of study
  • Psychology

Publications

Publications (67)
Article
Full-text available
The aim of this study was to compare the emotional content of dream reports collected at home upon morning awakenings with those collected in the laboratory upon early and late rapid eye movement (REM) sleep awakenings. Eighteen adults (11 women, seven men; mean age = 25.89 AE 4.85) wrote down their home dreams every morning immediately upon awaken...
Article
Full-text available
This study demonstrates that different methods for measuring emotional experiences in dreams – self-ratings of dreams using emotion rating scales vs external ratings in the form of content analysis of narrative dream reports – can lead to strikingly different results and contradicting conclusions regarding the emotional content of home dreams. Duri...
Article
We investigated whether inconsistencies in previous studies regarding emotional experiences in dreams derive from whether dream emotions are self-rated or externally evaluated. Seventeen subjects were monitored with polysomnography in the sleep laboratory and awakened from every rapid eye movement (REM) sleep stage 5 min after the onset of the stag...
Article
Full-text available
ASC) has been defined as a changed overall pattern of conscious experience, or as the subjective feeling and explicit recognition that one's own subjective experience has changed. We argue that these traditional definitions fail to draw a clear line between altered and normal states of consciousness (NSC). We outline a new definition of ASC and arg...
Preprint
Do the words we use reveal how we feel? While much research has explored language use in social media, little is known about how the content of spontaneous thoughts and experiences—daytime mind-wandering and nighttime dreaming—reflects well-being and ill-being. Here, we analyzed 1496 mind-wandering reports (N = 152) and 1781 dream reports (N = 172)...
Article
Full-text available
Increased psychological flexibility (PF) may underlie the lasting positive effects of psychedelic experiences on mental well-being. The associations between different components of PF, psychological inflexibility (PI), and well-being with psychedelic use are not well understood. We conducted a cross-sectional internet survey of participants (N = 62...
Preprint
Full-text available
Large language model (LLM) chatbots are susceptible to biases and hallucinations, but current evaluations of mental wellness technologies lack comprehensive case studies to evaluate their practical applications. Here, we address this gap by introducing the MHealth-EVAL framework, a new role-play based interactive evaluation method designed specific...
Article
Full-text available
Impairments in sleep and affect regulation are evident across a wide range of mental disorders. Understanding the sleep factors that relate to affect regulatory difficulties will inform mechanistic understanding and aid in treatment. Despite rising interest, some research challenges in this area include integrating across different clinical and non...
Preprint
The language people use in everyday life provides a window into the mind. Mind-wandering and dreams have been thought to reflect unique individual differences and mental health. Here we use a large dataset of mind-wandering (n=1619) and dream (n=1434) reports from 176 individuals in conjunction with graph theory applied to natural language. We find...
Article
Full-text available
Background: Alexithymia is an important transdiagnostic risk factor for emotion-based psychopathologies. However, it remains unclear whether alexithymia questionnaires actually measure alexithymia, or whether they measure emotional distress. Our aim here was to address this discriminant validity concern via exploratory factor analysis (EFA) of the...
Chapter
In this chapter, we provide an overview of alexithymia. We first outline what we believe is a useful conceptual framework for understanding alexithymia, the attention-appraisal model of alexithymia. We then review some key alexithymia assessment tools, research on the clinical relevance and treatment of alexithymia, its importance for emotion regul...
Article
Full-text available
Well-being consists of several different dimensions, such as hedonic and eudaimonic well-being. However, peace of mind (PoM)-an aspect of well-being characterized by internal peace and harmony-has only recently begun to receive attention. It has been shown that PoM predicts important outcomes, such as depression and anxiety. An open question is wha...
Article
Full-text available
Affective scientists traditionally have focused on periods of active wakefulness when people are responding to external stimuli or engaging in specific tasks. However, we live much of our lives immersed in experiences not related to the current environment or tasks at hand—mind-wandering (or daydreaming) during wakefulness and dreaming during sleep...
Article
Full-text available
Despite a surge of studies on the effects of COVID-19 on our well-being, we know little about how the pandemic is reflected in people’s spontaneous thoughts and experiences, such as mind-wandering (or daydreaming) during wakefulness and dreaming during sleep. We investigated whether and how COVID-19-related general concern, anxiety, and daily worry...
Preprint
Electroencephalography (EEG) studies of dreaming are an integral paradigm in the study of neurocognitive processes of human sleep and consciousness, but they are limited by the number of observations that can be collected per study. Dream studies also involve substantial methodological and conceptual variability which poses problems for the integra...
Article
Full-text available
Objective: Vaccines are an effective means to reduce the spread of diseases, but they are sometimes met with hesitancy that needs to be understood. Method: In this study, we analyzed data from a large, cross-country survey conducted between June and August 2021 in 43 countries (N = 15,740) to investigate the roles of trust in government and science...
Article
Full-text available
Background: Alexithymia is a trait characterized by difficulties identifying feelings, difficulties describing feelings, and externally orientated thinking. It is widely regarded as an important transdiagnostic risk factor for a range of psychopathologies, including depressive and anxiety disorders. Whilst several well-validated psychometric measur...
Method
Full-text available
The Perth Alexithymia Questionnaire-Short Form (PAQ-S) is a 6-item self-report measure of alexithymia (i.e., difficulties identifying one's own feelings, difficulties describing one's own feelings, and externally oriented thinking). It was designed to provide a brief and robust alexithymia assessment tool for quick administration in research and cl...
Article
Background: Alexithymia is a key transdiagnostic risk factor for emotion-based psychopathologies. Conceptual models specify that this is because alexithymia impairs emotion regulation. However, the extent of these putative emotion regulation impairments remains underexplored. Our aim in this study was to begin to address this gap by examining whet...
Article
Full-text available
There is increasing evidence that sleep plays an important role in affective processing. However, it is unclear whether dreaming-the subjective experiences we have during sleep-also serves an affect regulation function. Here, we investigated the within-person relationship between negative affect experienced in dreams and next-day waking affect leve...
Article
Full-text available
Learning to pronounce a foreign phoneme requires an individual to acquire a motor program that enables the reproduction of the new acoustic target sound. This process is largely based on the use of auditory feedback to detect pronunciation errors to adjust vocalization. While early auditory evoked neural activity underlies automatic detection and a...
Article
Full-text available
During the onset of the COVID-19 pandemic, the COVIDiSTRESS Consortium launched an open-access global survey to understand and improve individuals' experiences related to the crisis. a year later, we extended this line of research by launching a new survey to address the dynamic landscape of the pandemic. this survey was released with the goal of a...
Article
Full-text available
Expressive suppression refers to the inhibition of emotion-expressive behavior (e.g., facial expressions of emotion). Although it is a commonly used emotion regulation strategy with well-documented consequences for well-being, little is known about its underlying mechanisms. In this systematic review, we for the first time synthesize functional neu...
Conference Paper
Full-text available
Alexithymia is a trait characterised by difficulties in processing emotions. It is a key transdiagnostic risk factor for emotion-based psychopathologies. Conceptual models specify that this is likely because alexithymia impairs emotion regulation. However, the precise nature of emotion regulation patterns in alexithymia remains underexplored. Our a...
Preprint
Full-text available
The pronunciation of foreign phonemes is assumed to involve auditory feedback control processes that compare vocalized phonemes to target sounds. The electrophysiological correlate of this process is known as the speaking-induced suppression (SIS) of early auditory evoked activity. To gain insight into the neural processes that mediate the learning...
Preprint
Full-text available
Despite a surge of studies on the effects of COVID-19 on our well-being, we know little about how the pandemic is reflected in people’s spontaneous thoughts and experiences, such as mind-wandering (or daydreaming) during wakefulness and dreaming during sleep. We investigated whether and how COVID-19 related general concern, anxiety, and daily worry...
Preprint
Full-text available
During the onset of the COVID-19 pandemic, the COVIDiSTRESS Consortium launched an open-access global survey to understand and improve individuals’ experiences related to the crisis. A year later, we extended this line of research by launching a new survey to address the dynamic landscape of the pandemic. This survey was released with the goal of a...
Article
Full-text available
Affective experiences occur across the wake-sleep cycle-from active wakefulness to resting wakefulness (i.e., mind-wandering) to sleep (i.e., dreaming). Yet, we know little about the dynamics of affect across these states. We compared the affective ratings of waking, mind-wandering, and dream episodes. Results showed that mind-wandering was more po...
Article
Tearful crying is a ubiquitous and likely uniquely human phenomenon. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue by evoking social support intentions. Initial experimental studies supported this proposition across several methodologies, but these were conducted almost exclusively...
Preprint
Full-text available
Affective experiences occur across the wake-sleep cycle—from active wakefulness to resting wakefulness (i.e., mind-wandering or daydreaming) to sleep (i.e., dreaming). Yet, we know little about the dynamics of affective experiences across these states. Here, we investigated the within-person fluctuations in the prevalence and valence of affect expe...
Article
The COVIDiSTRESS global survey collects data on early human responses to the 2020 COVID-19 pandemic from 173 429 respondents in 48 countries. The open science study was co-designed by an international consortium of researchers to investigate how psychological responses differ across countries and cultures, and how this has impacted behaviour, copin...
Article
Full-text available
The COVIDiSTRESS global survey collects data on early human responses to the 2020 COVID-19 pandemic from 173 429 respondents in 48 countries. The open science study was co-designed by an international consortium of researchers to investigate how psychological responses differ across countries and cultures, and how this has impacted behaviour, copin...
Preprint
Full-text available
The COVIDiSTRESS global survey collects data on early human responses to the 2020 COVID-19 pandemic from 173,429 respondents in 48 countries. The open science study was co-designed by an international consortium of researchers to investigate how psychological responses differ across countries and cultures, and how this has impacted behaviour, copin...
Article
Full-text available
This N = 173,426 social science dataset was collected through the collaborative COVIDiSTRESS Global Survey-an open science effort to improve understanding of the human experiences of the 2020 COVID-19 pandemic between 30th March and 30th May, 2020. The dataset allows a cross-cultural study of psychological and behavioural responses to the Coronavir...
Preprint
Full-text available
Tearful crying is a ubiquitous and likely uniquely human phenomenon. The persistence of this behavior throughout adulthood has fascinated and puzzled many researchers. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue by triggering social support intentions. Initial experimental studie...
Article
Full-text available
The human frontal cortex is asymmetrically involved in motivational and affective processing. Several studies have shown that the left-frontal hemisphere is related to positive and approach-related affect, whereas the right-frontal hemisphere is related to negative and withdrawal-related affect. The present study aimed to investigate whether evolut...
Preprint
Full-text available
This N=173,426 social science dataset was collected through the collaborative COVIDiSTRESS Global Survey – an open science effort to improve understandings of the human experiences of the 2020 COVID-19 pandemic between 30th March and 30th May, 2020. The dataset allows a cross-cultural study of psychological and behavioural responses to the Coronavi...
Technical Report
Full-text available
This interim report presents the findings of a large international study on the psychological effects of the COVID-19 pandemic on Finnish residents
Thesis
Full-text available
We experience affect—emotions and mood—not only when we are awake but also during dreaming. Despite considerable research, existing theories and empirical findings disagree about the frequency, nature, and correlates of dream affect. In this thesis, I discuss the conceptual and methodological issues that underlie these discrepancies. I present five...
Preprint
Full-text available
Tearful crying is a ubiquitous and mainly human phenomenon. The persistence of this behavior throughout adulthood has fascinated and puzzled many researchers. Scholars have argued that emotional tears serve an attachment function: Tears are thought to act as a social glue that binds individuals together and triggers social support intentions. Initi...
Article
Full-text available
Affective experiences are central not only to our waking life but also to rapid eye movement (REM) sleep dreams. Despite our increasing understanding of the neural correlates of dreaming, we know little about the neural correlates of dream affect. Frontal alpha asymmetry (FAA) is considered a marker of affective states and traits as well as affect...
Chapter
Full-text available
In the scientific study of dreams, as in the scientific study of any other topic, it is important to first clearly define the phenomenon one is investigating. The definition determines what exactly is being studied. Then, the methods for collecting and analyzing data regarding this phenomenon need to be chosen. These methods determine what kind of...
Preprint
Affective experiences are central not only to our waking life but also to rapid eye movement (REM) sleep dreams. While the neural correlates of REM sleep are well documented, we know little about the neural correlates of dream affect. Frontal alpha asymmetry (FAA) is considered a marker of affective states and traits as well as affect regulation in...
Article
Full-text available
Waking mental well-being is assumed to be tightly linked to sleep and the affective content of dreams. However, empirical research is scant and has mostly focused on ill-being by studying the dreams of people with psychopathology. We explored the relationship between waking well-being and dream affect by measuring not only symptoms of ill-being but...
Data
Psychometric performance of TS-H in different tests measuring language, verbal abilities, visuospatial processing and learning/memory, executive functions and attention, and processing speed. (DOC)
Data
The pattern of eye-movements of TS-H in the hypnosis condition in the Saccade task. TS-H was asked to perform voluntary saccades from the centre of the screen (from the fixation circle) to target circles appearing abruptly in the visual periphery as fast and accurately as possible. Targets could appear at 24 different locations, at 5 different ecce...
Data
The pattern of eye-movements of a control subject in the hypnosis simulation condition in the Saccade task. The participant was asked to simulate how a hypnotized person performs the task the best he/she could based on detailed descriptions (including a video clip of TS-H's eye-movements in the task) given to the subject. This video clip provides a...
Data
The pattern of eye-movements of TS-H in the hypnosis condition in the Partial Field Optokinetic Nystagmus (OKN) task. TS-H was asked to maintain a stable fixation at the centre of the screen while a black-and white grating moved towards left or right at a steady pace of 4 or 6 degrees per second. This video clip provides an example of TS-H's perfor...
Data
The difference values (NC-HC) of TS-H and the control group (NC-HSC) in all measured variables in the Saccade task. (DOC)
Data
The pattern of eye-movements of a control subject in the hypnosis simulation condition in the Partial Field Optokinetic Nystagmus (OKN) task. The participant was asked to simulate how a hypnotized person performs the task the best he/she could based on detailed descriptions (including a video clip of TS-H's eye-movements in the task) given to the s...
Data
The difference values (NC-HC) of TS-H and the control group (NC-HSC) in all measured variables in the Fixation task. (DOC)
Data
Alteration of the state of consciousness in TS-H between baseline and hypnosis using posthypnotic suggestion. The green text “normal state” in the upper left corner indicates that TS-H is in her normal waking state. When the experimenter (author S.K.) utters the cue “hypno” TS-H enters the “hypnotic state”, as indicated by the red text “hypnotic st...
Data
A posthypnotic suggestion. (DOC)
Data
The difference values (NC-HC) of TS-H and the control group (NC-HSC) in all measured variables in the Partial Field Optokinetic nystagmus (OKN) task. (DOC)
Data
Neuropsychological examination of TS-H. (DOC)
Article
Full-text available
Hypnosis has had a long and controversial history in psychology, psychiatry and neurology, but the basic nature of hypnotic phenomena still remains unclear. Different theoretical approaches disagree as to whether or not hypnosis may involve an altered mental state. So far, a hypnotic state has never been convincingly demonstrated, if the criteria f...
Article
Full-text available
D-serine is an endogenous N-methyl-D-aspartate (NMDA) receptor coagonist. It is synthesized from L-serine by serine racemase (SRR), but many aspects of its metabolism remain unclear, especially in the forebrain, which lacks active D-amino acid oxidase (DAO), the major D-serine degradative enzyme. Candidate mechanisms include SRR operating in alpha,...
Article
Full-text available
Molecular Psychiatry publishes work aimed at elucidating biological mechanisms underlying psychiatric disorders and their treatment
Article
When two successive, spatially overlapping, targets (S1 and S2) are presented on a blank background, S2 typically dominates in explicit perception. We tested whether S2 dominance is also found for the conditions of presenting S1 and S2 in a stream of irrelevant objects. Successive target letters were presented within a stream of invariant stimulus...

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