Lauri Nummenmaa

Lauri Nummenmaa
University of Turku | UTU · Turku PET Centre

PhD

About

238
Publications
231,704
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Introduction
I lead the Human Emotion Systems laboratory at Turku PET Centre and Department of Psychology, University of Turku. Our group studies functional and molecular neural mechanisms of human emotions and social interaction in complex, life-like settings with magnetic resonance imaging, positron emission tomography, magneto- and electroencephalography and behavioural techniques. Currently our research is funded by the Sigrid Juselius Foundation and the Academy of Finland.

Publications

Publications (238)
Article
Full-text available
The goal of this study was to elucidate the anatomical brain basis of social cognition through two disorders with distinctively different phenotypes of social interaction. We compared structural MR images of 20 individuals with autism spectrum disorder (ASD), 19 violent offenders with high psychopathic traits, and 19 control participants using voxe...
Article
Full-text available
Neurofilament light chain (NfL) is a novel biomarker reflecting neuroaxonal damage and associates with brain atrophy, and glial fibrillary acidic protein (GFAP) is a marker of astrocytic activation, associated with several neurodegenerative diseases. Since obesity is associated with increased risk for several neurodegenerative disorders, we hypothe...
Preprint
Photoperiod drives metabolic activity of brown adipose tissue (BAT), and affects food intake and weight gain in mammals. Sympathetic innervation in BAT controls thermogenesis and facilitates physiological adaption to seasons, but the exact mechanism remains elusive. Previous studies show that the central opioid signaling tunes BAT heating and the b...
Preprint
Full-text available
Difficulties in social interactions are common to both autism and schizophrenia, and contribute to correlated autistic and schizotypal traits in the neurotypical population. It remains unresolved whether this represents a shared etiology or a superficial phenotypic overlap. Both conditions are associated with atypical neural activity in response to...
Article
Full-text available
Psychopathy and autism are both associated with aberrant social skills and empathy, yet only psychopaths are markedly antisocial and violent. Here, we compared the functional neural alterations underlying these two groups that both have aberrant empathetic abilities but distinct behavioral phenotypes. We studied 19 incarcerated male offenders with...
Preprint
Type 1 cannabinoid (CB1) receptor is expressed in cortex, hippocampus, amygdala, basal ganglia, and cerebellum. With the help of the Allen Human Brain Atlas, genomic maps visualize not only the gene expression across whole brain regions, but also the functional profile of brain structures. Therefore, it is more timely than ever to integrate genomic...
Article
Full-text available
BACKGROUND The dopamine system contributes to a multitude of functions ranging from reward and motivation to learning and movement control, making it a key component in goal-directed behavior. Altered dopaminergic function is observed in neurological and psychiatric conditions. Numerous factors have been proposed to influence dopamine function, but...
Article
Introduction: Central μ-opioid receptors (MORs) modulate affective responses to physical exercise. Individuals with higher aerobic fitness report greater exercise-induced mood improvements than those with lower fitness, but the link between cardiorespiratory fitness and the MOR system remains unresolved. Here we tested whether maximal oxygen uptak...
Article
Full-text available
Background Obesity is a pressing public health concern worldwide. Novel pharmacological means are urgently needed to combat the increase of obesity and accompanying type 2 diabetes (T2D). Although fully established obesity is associated with neuromolecular alterations and insulin resistance in the brain, potential obesity-promoting mechanisms in th...
Preprint
Full-text available
Sex differences in brain activity evoked by sexual stimuli remain elusive despite robust evidence for stronger enjoyment of and interest towards sexual stimuli in men than in women. To test whether visual sexual stimuli evoke different brain activity patterns in men and women, we measured haemodynamic brain activity induced by visual sexual stimuli...
Preprint
Full-text available
Humans can readily perceive a multitude of features from social interactions, but the phenomenological and neural basis of social perception has yet to be solved. Short film clips with rich social content were shown to 97 healthy participants while their haemodynamic brain activity was measured with fMRI. The stimulus clips were annotated for 112 s...
Article
Full-text available
Neurophysiological and psychological models posit that emotions depend on connections across wide-spread corticolimbic circuits. While previous studies using pattern recognition on neuroimaging data have shown differences between various discrete emotions in brain activity patterns, less is known about the differences in functional connectivity. Th...
Article
Full-text available
The cardiac benefits of gastrointestinal hormones have been of interest in recent years. The aim of this study was to explore the myocardial and renal effects of the gastrointestinal hormone secretin in the GUTBAT trial (NCT03290846). A placebo-controlled crossover study was conducted on 15 healthy males in fasting conditions, where subjects were b...
Article
Full-text available
The endogenous mu-opioid receptor (MOR) system modulates a multitude of social and reward-related functions, and exogenous opiates also influence sex drive in humans and animals. Sex drive shows substantial variation across humans, and it is possible that individual differences in MOR availability underlie interindividual of variation in human sex...
Preprint
The endogenous mu-opioid receptor (MOR) system modulates a multitude of social and reward-related functions, and exogenous opiates also influence sex drive in humans and animals. Sex drive shows substantial variation across humans, and it is possible that individual differences in MOR availability underlie interindividual of variation in human sex...
Preprint
Humans all around the world are drawn to creating and consuming art due to its capability to evoke emotions, but the mechanisms underlying art-evoked emotions remain poorly characterized. Here we show how embodiement contributes to emotions evoked by a large database of visual art pieces. In four experiments, we mapped the subjective feeling space...
Preprint
Laughter is a contagious prosocial signal that conveys bonding motivation; adult crying conversely communicates desire for social proximity by signalling distress. Endogenous mu-opioid receptors (MORs) modulate sociability in humans and non-human primates. In this combined PET-fMRI study (n=17) we tested whether central MOR tone is associated with...
Article
Full-text available
Eating behavior varies greatly between individuals, but the neurobiological basis of these trait-like differences in feeding remains poorly understood. Central μ-opioid receptors (MOR) and cannabinoid CB1 receptors (CB1R) regulate energy balance via multiple neural pathways, promoting food intake and reward. Because obesity and eating disorders hav...
Preprint
BACKGROUND The dopamine system contributes to a multitude of functions ranging from reward and motivation to learning and movement control, making it a key component in goal-directed behavior. Altered dopaminergic function is observed in neurological and psychiatric conditions. Numerous factors have been proposed to influence dopamine function, but...
Preprint
Full-text available
Psychopathy and autism are both associated with aberrant social interaction and communication, yet only psychopaths are markedly antisocial and violent. Here we compared the functional neural alterations underlying these two different phenotypes with distinct patterns of socioemotional difficulties. We studied 19 incarcerated male offenders with hi...
Article
Full-text available
Pleasures are tightly intertwined with the body. Enjoyment derived from sex, feeding and social touch originate from somatosensory and gustatory processing, and pleasant emotions also markedly influence bodily states tied to the reproductive, digestive, skeletomuscular, and endocrine systems. Here, we review recent research on bodily pleasures, foc...
Article
Full-text available
Pleasure and reward are central for motivation, learning, feeling and allostasis. Although reward is without any doubt an affective phenomenon, there is no consensus concerning its relationship with emotion. In this mini-review we discuss this conceptual issue both from the perspective of theories of reward and emotion as well as human systems neur...
Article
Full-text available
Humans across all societies engage in music-listening and making, which they find pleasurable, despite music does not appear to have any obvious survival value. Here we review the recent studies on the social dimensions of music that contribute to music-induced hedonia. Meta-analysis of neuroimaging studies shows that listening to both positively a...
Article
Full-text available
Brown adipose tissue (BAT) thermogenesis is activated by feeding. Recently, we revealed a secretin-mediated gut–BAT–brain axis, which stimulates satiation in mice, but the purpose of meal-induced BAT activation in humans has been unclear. In this placebo-controlled, randomized crossover study, we investigated the effects of intravenous secretin on...
Article
Full-text available
Depressed individuals exhibit an attentional bias towards mood-congruent stimuli, yet evidence for biased processing of threat-related information in human interaction remains scarce. Here, we tested whether an attentional bias towards interpersonally aggressive pictures over interpersonally neutral pictures could be observed to a greater extent in...
Article
Full-text available
Obesity is a growing burden to health and the economy worldwide. Obesity is associated with central µ-opioid receptor (MOR) downregulation and disruption of the interaction between MOR and dopamine D2 receptor (D2R) system in the ventral striatum. Weight loss recovers MOR function, but it remains unknown whether it also recovers aberrant opioid-dop...
Preprint
Full-text available
Background Structural brain lesions are the most common cause of adult-onset epilepsy. The lesion location may contribute to the risk for epileptogenesis, but whether specific lesion locations are associated with a risk for secondary seizure generalization from focal to bilateral tonic-clonic seizures, is unknown. Methods We identified patients wi...
Article
Full-text available
Bariatric surgery is the most effective method for weight loss in morbid obesity. There is significant individual variability in the weight loss outcomes, yet factors leading to postoperative weight loss or weight regain remain elusive. Alterations in the µ-opioid receptor (MOR) and dopamine D2 receptor (D2R) systems are associated with obesity and...
Article
Full-text available
Psychopathy is characterized by persistent antisocial behavior, impaired empathy, and egotistical traits. These traits vary also in normally functioning individuals. Here, we tested whether such antisocial personalities are associated with similar structural and neural alterations as those observed in criminal psychopathy. Subjects were 100 non-con...
Article
Full-text available
One-week treatment with escitalopram decreases amygdala responses to fearful facial expressions in depressed patients, but it remains unknown whether it also modulates processing of complex and freely processed emotional stimuli resembling daily life emotional situations. Inter-subject correlation (ISC) offers a means to track brain activity during...
Article
Full-text available
The melanocortin system is involved in the control of adiposity through modulation of food intake and energy expenditure. The single nucleotide polymorphism (SNP) rs17782313 near the MC4R gene has been linked to obesity, and a previous study using magnetoencephalography has shown that carriers of the mutant allele have decreased cerebrocortical res...
Article
Positron emission tomography (PET) can be used for in vivo measurement of specific neuroreceptors and transporters using radioligands, while voxel-based morphometric analysis of magnetic resonance images allows automated estimation of local grey matter densities. However, it is not known how regional neuroreceptor or transporter densities are refle...
Article
Full-text available
Background Obesity and physical inactivity are major global public health concerns, both of which increase the risk of insulin resistance and type 2 diabetes. Regulation of glucose homeostasis involves cross-talk between the central nervous system, peripheral tissues, and gut microbiota, and is affected by genetics. Systemic cross-talk between brai...
Preprint
Full-text available
Background: Bariatric surgery is the most effective method for weight loss in morbid obesity. There is significant individual variability in the weight loss outcomes, yet factors leading to postoperative weight loss or weight regain remain elusive. Alterations in the mu-opioid receptor (MOR) and dopamine D2 receptor (D2R) systems are associated wit...
Article
Objective: Whereas insulin resistance is expressed as reduced glucose uptake in peripheral tissues, the relationship between insulin resistance and brain glucose metabolism remains controversial. Our aim was to examine the association of insulin resistance and brain glucose uptake (BGU) during a euglycemic hyperinsulinemic clamp in a large sample...
Article
Music can induce strong subjective experience of emotions, but it is debated whether these responses engage the same neural circuits as emotions elicited by biologically significant events. We examined the functional neural basis of music-induced emotions in a large sample (n = 102) of subjects who listened to emotionally engaging (happy, sad, fear...
Article
Full-text available
Seasonal rhythms influence emotion and sociability. The brain μ-opioid receptor (MOR) system modulates a multitude of seasonally varying socioemotional functions, but its seasonal variation remains elusive with no previously reported in vivo evidence. Here, we first conducted a cross-sectional study with previously acquired human [11C]carfentanil P...
Preprint
Pleasure and reward are central for motivation, learning, feeling and allostasis. Although reward is without any doubt an affective phenomenon, there is no consensus concerning its relationship with emotion. In this mini-review we discuss this conceptual issue both from the perspective of theories of reward and emotion as well as human systems neur...
Preprint
Full-text available
Eating behavior varies greatly between healthy individuals, but the neurobiological basis of these trait-like differences in feeding remains unknown. Central mu-opioid receptors (MOR) and cannabinoid CB1-receptors (CB1R) regulate energy balance via multiple neural pathways, promoting food intake and reward. Because obesity and eating disorders have...
Preprint
Full-text available
Central μ-opioid receptors (MORs) modulate affective responses to physical exercise. Individuals with higher aerobic fitness report greater exercise-induced mood improvements than those with lower fitness, but the link between cardiorespiratory fitness and the MOR system remains unresolved. Here we tested whether maximal oxygen uptake (VO 2peak ) a...
Preprint
Full-text available
Background Obesity is a growing burden to health and economy worldwide. Obesity is associated with central μ-opioid receptor (MOR) downregulation, and the interaction between MOR and dopamine D 2 receptor (D 2 R) system in the ventral striatum is disrupted among obese subjects. Weight loss recovers MOR function, but it remains unknown whether it al...
Preprint
Of all the human emotions, pleasures are most tightly intertwined with the body. Pleasures including sex, feeding and social touch originate from somatosensory and gustatory processing, and pleasant emotions also markedly influence bodily states tied to the reproductive and digestive system to the skeletomuscular and endocrine systems. Here we revi...
Article
Background Secure attachment is important in maintaining individual’s health and well-being. Attachment disturbances increase the risk for developing different psychiatric disorders such as affective disorders. Yet, the neurobiological correlates of human attachment is poorly understood at the neurotransmitter level. We investigated whether adult a...
Article
Full-text available
Human neuroimaging and behavioural studies suggest that somatomotor ‘mirroring’ of seen facial expressions may support their recognition. Here we show that viewing specific facial expressions triggers the representation corresponding to that expression in the observer’s brain. Twelve healthy female volunteers underwent two separate fMRI sessions: o...
Article
Full-text available
Humans use touch to maintain their social relationships, and the emotional qualities of touch depend on who touches whom. However, it is not known how affective and social dimensions of touch are processed in the brain. We measured haemodynamic brain activity with functional magnetic resonance imaging (fMRI) from 19 subjects (10 males), while they...
Preprint
Humans across all societies engage in music-listening and making, which they find pleasurable, despite music having no obvious survival value. Here we review the neurobiology of musical pleasures and propose a “simulated sociability” hypothesis – that the social dimension of music is the key reason for musical hedonia. Neuroimaging studies show tha...
Preprint
Full-text available
The COVID-19 pandemic presents a significant challenge to wellbeing for people around the world. Here, we examine which individual and societal factors can predict the extent to which individuals suffer or thrive during the COVID-19 outbreak, with survey data collected from 26,684 participants in 51 countries from 17 April to 15 May 2020. We show t...
Article
Major depressive disorder is associated with lowered mood, anxiety, anhedonia, sleep problems, and cognitive impairments. Many of these functions are regulated by μ-opioid receptor (MOR) system. Preclinical, in vivo, and post-mortem studies have however yielded inconclusive results regarding the role of the MOR in depression and anxiety. Moreover,...
Preprint
Full-text available
Music can induce strong subjective experience of emotions, but it is debated whether these responses engage the same neural circuits as emotions elicited by biologically significant events. We examined the functional neural basis of music-induced emotions in a large sample (n = 102) of subjects who listened to emotionally engaging (happy, sad, fear...
Preprint
Full-text available
Seasonal rhythms influence mood and sociability. The mu-opioid receptor (MOR) system modulates a multitude of seasonally varying socioemotional functions, but seasonal variation in the MOR system remains elusive. We used positron emission tomography (PET) imaging with [11C]carfentanil, a high affinity MOR radioligand, to repeatedly measure in vivo...
Article
Full-text available
Alterations in the brain’s μ-opioid receptor (MOR) system have been associated with several neuropsychiatric diseases. Also healthy individuals vary considerably in MOR availability. Multiple epidemiological factors have been proposed to influence MOR system, but due to small sample sizes the magnitude of their influence remains inconclusive. We co...
Article
Full-text available
Studies of brain mechanisms supporting social interaction are demanding because real interaction only occurs when persons are in contact. Instead, most brain imaging studies scan subjects individually. Here we present a proof-of-concept demonstration of two-person blood oxygenation dependent (BOLD) imaging of brain activity from two individuals int...
Article
Full-text available
Aims Recent clinical studies have shown enhanced brain glucose uptake during clamp and brain fatty acid uptake in insulin‐resistant individuals. Preclinical studies suggest that the brain may be involved in the control of insulin secretion. The aim of this study was to investigate whether brain metabolism assessed as brain glucose and fatty acid up...
Preprint
Full-text available
Emotions modulate behavioural priorities at the central and peripheral nervous system. Understanding emotions from the perspective of specific neurotransmitter systems is critical, because the central role of affect in multiple psychopathologies, and the role of specific neuroreceptor systems as corresponding drug targets. Here we provide an integr...
Article
Full-text available
Processing of positron emission tomography (PET) data typically involves manual work, causing inter-operator variance. Here we introduce the Magia toolbox that enables processing of brain PET data with minimal user intervention. We investigated the accuracy of Magia with four tracers: [11C]carfentanil, [11C]raclopride, [11C]MADAM, and [11C]PiB. We...
Article
Full-text available
Background and aims: Preclinical studies have shown that brain FFA handling can be involved in the control of whole-body homeostasis, but data in humans are scanty. We investigated whether there are differences in brain fatty acid uptake (BFAU) between morbidly obese and lean subjects, and the effect of weight loss following bariatric surgery (BS)...
Preprint
Positron emission tomography (PET) can be used for in vivo measurement of specific neuroreceptors and transporters using radioligands, while voxel-based morphometric analysis of magnetic resonance images allows automated estimation of local grey matter densities. However, it is not known how regional neuroreceptor or transporter densities are refle...
Preprint
Full-text available
Neurophysiological and psychological models posit that emotions depend on connections across wide-spread corticolimbic circuits. While previous studies using pattern recognition on neuroimaging data have shown differences between various discrete emotions in brain activity patterns, less is known about the differences in functional connectivity. Th...
Article
Full-text available
Fear protects organisms by increasing vigilance and preparedness, and by coordinating survival responses during life-threatening encounters. The fear circuit must thus operate on multiple timescales ranging from preparatory sustained alertness to acute fight-or-flight responses. Here we studied the brain basis of sustained and acute fear using natu...
Article
Background: Successful delineation of lesions in acute ischemic strokes (AIS) is crucial for increasing the likelihood of good clinical outcome for the patient. New methods: We developed a fully automated method to localize and segment AIS lesions in variable locations for 192 multimodal 3D-magnetic resonance images (MRI) including 106 stroke an...
Preprint
Full-text available
Human neuroimaging and behavioural studies suggest that somatomotor mirroring of seen facial expressions may support their recognition. Here we show that viewing specific facial expressions triggers the representation corresponding to that expression in the observers brain. Twelve healthy female volunteers underwent two separate fMRI sessions: one...
Preprint
Studies of brain mechanisms supporting social interaction are demanding because real interaction only occurs when the persons are in contact. Instead, most brain imaging studies scan subjects individually. Here we present a proof-of-concept demonstration of a two-person blood oxygenation dependent (BOLD) imaging of brain activity from two individua...