Browsing by Subject "EEG"
Now showing items 21-40 of 51
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(2022)Language skills are an important asset in the global world, so it is important to promote language learning. Music and language learning have been shown to be interconnected. However, most of the studies have been conducted with adult language learners and in laboratories. This study is an experimental study carried out in natural learning context with intervention paradigm. The aim of the study is to explore whether using a song as a tool in learning second language vocabulary in a bilingual preschool differs from using a nursery rhyme or prose. The null hypothesis is that children in bilingual preschool learn second language vocabulary as well with song as with nursery rhyme or prose. The alternative hypothesis is that children in bilingual preschool learn second language vocabulary better with song than with nursery rhyme or prose. Seven foreign language children from the preschool took part in the study. In study paradigm children were presented in learning phase a Finnish version of a well-known nursery rhyme Simple Simon as continuous stimuli in the form of a nursery rhyme, a song and prose. In EEG test phase they were presented same stimuli with some changes in vowels and syllables and their EEG was recorded. Event-related potentials to those changes were then compared between a nursery rhyme, a song and prose situation. In behavioral testing, children were presented words from the learning material and pseudowords formed from those words. We compared how well the children recognized words in the nursery rhyme (poem), the song and the prose situation. The data were analyzed in both research methods using Wilcoxon signed rank test. The null hypothesis could not be rejected. So, it cannot be stated that second language vocabulary is learned better with song than with nursery rhyme or prose. We detected a difference between the prose and the nursery rhyme stimuli in favor of the prose option measured with EEG. However, the sample size was too small to generalize the results. In discussion the results and used research methods are primarily examined on theoretical level considering previous studies. In conclusion, based on the previous studies, it is feasible to recommend using music in education especially in language learning but also in every phase of life due to music’s positive effects on motivation and togetherness to name but a few.
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(2022)Language skills are an important asset in the global world, so it is important to promote language learning. Music and language learning have been shown to be interconnected. However, most of the studies have been conducted with adult language learners and in laboratories. This study is an experimental study carried out in natural learning context with intervention paradigm. The aim of the study is to explore whether using a song as a tool in learning second language vocabulary in a bilingual preschool differs from using a nursery rhyme or prose. The null hypothesis is that children in bilingual preschool learn second language vocabulary as well with song as with nursery rhyme or prose. The alternative hypothesis is that children in bilingual preschool learn second language vocabulary better with song than with nursery rhyme or prose. Seven foreign language children from the preschool took part in the study. In study paradigm children were presented in learning phase a Finnish version of a well-known nursery rhyme Simple Simon as continuous stimuli in the form of a nursery rhyme, a song and prose. In EEG test phase they were presented same stimuli with some changes in vowels and syllables and their EEG was recorded. Event-related potentials to those changes were then compared between a nursery rhyme, a song and prose situation. In behavioral testing, children were presented words from the learning material and pseudowords formed from those words. We compared how well the children recognized words in the nursery rhyme (poem), the song and the prose situation. The data were analyzed in both research methods using Wilcoxon signed rank test. The null hypothesis could not be rejected. So, it cannot be stated that second language vocabulary is learned better with song than with nursery rhyme or prose. We detected a difference between the prose and the nursery rhyme stimuli in favor of the prose option measured with EEG. However, the sample size was too small to generalize the results. In discussion the results and used research methods are primarily examined on theoretical level considering previous studies. In conclusion, based on the previous studies, it is feasible to recommend using music in education especially in language learning but also in every phase of life due to music’s positive effects on motivation and togetherness to name but a few.
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(2019)Aims Studies on the efficacy of NF training of ADHD patients have given ambiguous results because most randomly controlled trials (RCTs) have sought to establish its effect in the entire ADD/ADHD-population, treating it as a uniform group. This study addresses whether those who do and do not learn to self-regulate based on NF training differ in terms of ADHD related outcomes and whether the two groups could be identified in advance. Secondly, the study asks whether ’learning’ to succeed in NF training exercises is a sufficient or necessary condition for the effects of NF training on ADHD symptoms. Methods By studying existing data from 23 patients with ages between 25 and 57 and who were trained in the CENT project, the learners and non-learners were first identified by a regression model. The two groups were subsequently compared in terms of several background variables as well as behavioral and self-reported ADHD related outcomes. Moreover, the learning processes in the two groups were analysed by using continuous time structural equations modeling (CTSEM). Results One of the most important predictors of NF learning appeared to be low score in the dissociative experiences scale (DES) and high score in the behavioral inhibition scale (BIS). At the same time, NF learning was enhanced by elevated scores on the generalised anxiety disorder scale (GAD). However, the behavioral effects were mixed among the ‘learners’ and ‘non-learners’, with some positive and some negative effects visible in both groups. Conclusions The study concludes that patients’ ability to learn to self-regulate according to NF data does not appear to be a necessary nor sufficient condition for positive ADHD-related outcomes. This supports the conclusion that the effects of NF training are not solely based on operant conditioning but that the learning processes involved in NF training are more complex. The study suggests that more research should be done regarding the specific role of DES, with possible reference to different neurological mechanisms associated with different classes of symptoms (e.g. inattention and hyperactivity), and possibly explaining the mixed results of RCTs.
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Learning response inhibition is not associated with gradual changes in EEG oscillation power in rats (2022)Goal-directed behavior is reliant on the ability to choose correct actions to perform given the context of the situation while minimizing the interfering effect of goal-irrelevant stimuli. The ability to suppress inappropriate responses is called response inhibition. It can be seen as a higher order cognitive function which is one of the cornerstones for adaptive behavior in ever changing environment. Neural oscillations have been previously used to study at the neuronal processes underlying cognitive processes such as response inhibition. Neural oscillations are rhythmic fluctuation in the excitability of a neuron or a group of neurons. These temporal windows of excitability are thought to underlie efficient communication by changing the efficacy of the synaptic transmissions between neurons/group of neurons. Although, a lot has been uncovered about the different oscillations and their possible role in response inhibition, very little is known how the spectral content (power of a frequency) adapts across as the animal is learning to suppress their responses to new novel stimuli. This kind of learning associated spectral content adaptations has been observed previously in humans during motor learning for example. In the current study we aimed to look how spectral content adapts as the animals learn to suppress their responses to novel stimuli. We used head fixed rats on a treadmill that were trained to perform Go/NoGo task. Each rat performed 1-4 learning scenarios during which the “rules” for Go/NoGo task changes in an attentional set-shifting paradigm. We measured EEG from most of the rat’s cortex. EEG was measured from the point where the rat was first introduced to these novel stimuli until the rat had learned the new stimulus-response contingences. This EEG was divided into learning stages and the power spectrum was calculated for each of them. We observed power peaks centered around 1Hz, 2Hz, 4Hz, 8Hz and 11Hz across learning stages. However further analyses comparing average power across learning stages showed that these changes were not statistically significant. Thus, we did not observe gradual changes in power while rats were learning to suppress their responses to novel stimuli.
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Learning response inhibition is not associated with gradual changes in EEG oscillation power in rats (2022)Goal-directed behavior is reliant on the ability to choose correct actions to perform given the context of the situation while minimizing the interfering effect of goal-irrelevant stimuli. The ability to suppress inappropriate responses is called response inhibition. It can be seen as a higher order cognitive function which is one of the cornerstones for adaptive behavior in ever changing environment. Neural oscillations have been previously used to study at the neuronal processes underlying cognitive processes such as response inhibition. Neural oscillations are rhythmic fluctuation in the excitability of a neuron or a group of neurons. These temporal windows of excitability are thought to underlie efficient communication by changing the efficacy of the synaptic transmissions between neurons/group of neurons. Although, a lot has been uncovered about the different oscillations and their possible role in response inhibition, very little is known how the spectral content (power of a frequency) adapts across as the animal is learning to suppress their responses to new novel stimuli. This kind of learning associated spectral content adaptations has been observed previously in humans during motor learning for example. In the current study we aimed to look how spectral content adapts as the animals learn to suppress their responses to novel stimuli. We used head fixed rats on a treadmill that were trained to perform Go/NoGo task. Each rat performed 1-4 learning scenarios during which the “rules” for Go/NoGo task changes in an attentional set-shifting paradigm. We measured EEG from most of the rat’s cortex. EEG was measured from the point where the rat was first introduced to these novel stimuli until the rat had learned the new stimulus-response contingences. This EEG was divided into learning stages and the power spectrum was calculated for each of them. We observed power peaks centered around 1Hz, 2Hz, 4Hz, 8Hz and 11Hz across learning stages. However further analyses comparing average power across learning stages showed that these changes were not statistically significant. Thus, we did not observe gradual changes in power while rats were learning to suppress their responses to novel stimuli.
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(2020)Neural Oscillations at large-scale local and global neural synchrony levels can be detected at the scalp using electroencephalography. This neural activity presents itself in a varied range of frequencies referred to as ‘Brain Waves’. These frequency bands have cognitive significance and have been implicated in several neural functions due to its important role in communicating with functionally-similar but spatially-distinct brain regions. Frontal Asymmetry is the difference in activity between the right and left hemispheres in frontal areas of the brain recorded via EEG and is seen to be a strong indicator of emotional states. Specifically, approach and withdrawal motivation which have been associated with positive and negative emotions respectively. Using a combination of behavioural and physiological methods in measuring preference and responses gives us an accurate representation of the participant responses. In this study, three tests were conducted during a continuous EEG recording. Test 1: The implication of inducing a positive mood before the onset of stimulus line-up and the extent of its effect on emotions and alpha asymmetry is not extensively studied. In this test, we employed the use of an instrumental soundscape for one experimental group before beginning the stimulus presentation to test this effect against a ‘silent’ control group. Test 2: This test aims to compare the participants’ physiological measures (EEG) and behavioural self-reports to audio advertisement stimuli consisting of different categories of music: ‘Brand music’ vs. ‘Campaign’ music or ‘No music’ Controls. Test 3: There is ambiguity in research regarding how frontal alpha asymmetry as measured by EEG and self-report preferences might change with changing the format of the advertisement to: only Audio, Audiovisual and Silent videos. There has been contradictory evidence regarding the impact of music on an individual’s emotions and consequent memory and decision-making. This thesis delves into these questions through the post-study behavioural test and simple binary choice paradigm that measure the above-mentioned in relation with the stimuli presented to participants. Our results did not show a significant difference in frontal asymmetry in the stimulus presentation across the three tests conducted during EEG recording. The behavioural data however indicated significant preference in behavioural self-report ratings for Brand Music- associated stimuli in Test 2 and for Audiovisual advertisement stimuli in Test 3. Results also revealed a significant correlation between ratings given to a stimulus and post-study memorability. The final binary choice paradigm test indicated higher preference to products related to stimulus presentation (‘advertised’ brand) vs similar products not related to the presented stimulus (‘non-advertised’ brand). We anticipate that these results will further help us understand and predict general preferences that can help companies, government policy-makers and the general public be more aware and better equipped to manage their valuable resources of money, time, attention and memory.
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(2016)Models of moral judgment and decision-making are traditionally divided into rationalist and intuitionist models depending on whether moral judgments are thought to be the result of a rational reasoning process or moral intuitions. The social intuitionist model represents intuitionist models of moral judgment and suggests that moral judgments are the result of affectively based moral intuitions and that moral reasoning mainly occurs as a post-hoc rationalization. The objective of this thesis is to review recent neuroimaging studies on moral decision-making and to evaluate the validity of the social intuitionist model in that moral judgments are caused by moral intuitions and not by moral reasoning. Functional magnetic resonance imaging (fMRI) studies examining the neural correlates of moral decision-making indicate that affective processing and abstract reasoning can both result in moral judgments. Brain areas associated with emotion become more activated in moral personal dilemmas than in impersonal dilemmas, whereas impersonal dilemmas engage brain regions associated with working memory. In addition, utilitarian judgments made in difficult personal dilemmas depend more on brain areas associated with cognitive conflict monitoring and cognitive control compared with deontological judgments. Electroencephalographic (EEG) studies support the idea that moral intuitions arise early in the decision-making process. However, affective processing may begin even in the later stages of moral decision-making after moral intuitions have been initiated, thus questioning the role of emotion in moral intuitions. The social intuitionist model has both gained support and been criticized. In the light of neuroimaging studies, it appears that moral reasoning has a more significant role in moral judgments than assumed in the model. In addition, moral intuitions may not be affectively based as assumed in the social intuitionist model. It might be necessary to update the model regarding the role of reasoning in moral judgments and the relationship between emotion and moral intuition. In the future, more comparable experimental designs should be employed to make the comparison of the variety of neuroimaging studies more sensible.
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(2019)Tässä pro gradu -tutkielmassa selvitetään musiikkiharrastuksen ja erityisesti soitonopiskelun yhteyttä 13–21-vuotiaiden nuorten tarkkaavaisuus- ja toiminnanohjaustaitoihin. Musiikkiharrastus on aiemmissa tutkimuksissa liitetty tehostuneisiin kuuloerottelukykyihin, kielellisiin kykyihin ja korkeamman asteisiin kognitiivisiin prosesseihin. Tämän laajan kognitiivisten kykyjen tehostumisen takana on ehdotettu olevan tarkkaavaisuuden säätelyn ja toiminnanohjaustaitojen kehittyminen musiikki- ja erityisesti soittoharrastuksen myötä. Tarkkaavaisuudelle ja toiminnanohjaukselle tärkeä etuotsalohko kehittyy edelleen nuoruudessa ja vielä aikuisiän saavuttamisen jälkeen, joten on kiinnostavaa selvittää musiikkiharrastuksen mahdollisia hyötyjä nuorten ja nuorten aikuisten vielä kehittyviin toiminnanohjaustaitohin ja mahdollista yhteyttä niiden taustalla oleviin aivomekanismeihin. Tutkimuksessa mitattiin aivosähkökäyrämittauksella (elektroenkefalografia, EEG) nuorten ja nuorten aikuisten (N=64, joista 35 kuului musiikkiryhmään ja loput kontrolliryhmään) inhibitiota, kognitiivista joustamista ja työmuistia edellyttävän visuaalisen vaihtamistehtävän synnyttämiä P3-tyyppisiä herätevasteita. Lisäksi nuoret ja nuoret aikuiset tekivät inhibitiokykyä ja tarkkaavaisuuden sujuvaa vaihtamista sekä työmuistia ja yleistä päättelysuoriutumista mittaavia neuropsykologisia tehtäviä. Tutkimuksessa tarkasteltiin myös näissä tehtävissä suoriutumisen yhteyttä P3-tyyppisen vasteen voimakkuuteen. Musiikki- ja kontrolliryhmän välillä ei havaittu eroa toiminnan tai taitojen tasolla koeasetelman vaihtamistehtävässä eikä neuropsykologisissa tehtävissä. Ryhmien välillä ei havaittu myöskään eroa P3-tyyppisen vasteen voimakkuudessa. Vasteen jakauma erosi kuitenkin ryhmien välillä. Musiikkiryhmällä P3-tyyppinen vaste oli voimakkaampi päälaen alueella pään keskiosaan verrattuna, kun taas kontrolliryhmällä vaste oli voimakkaampi päälaen alueella vielä taaempaan takaraivon alueeseen verrattuna. Koeasetelman vaihtamistehtävässä suoriutumisella oli yhteys P3-tyyppisen vasteen voimakkuuteen: mitä suurempi vasteen voimakkuus oli, sitä lyhyemmät olivat reaktioajat tehtävässä. Sen sijaan neuropsykologisessa inhibitio- tai vaihtamistehtävässä suoriutumisella ei havaittu olevan yhteyttä P3-tyyppisen vasteen voimakkuuteen. Työmuistisuoriutuminen oli kuitenkin positiivisesti yhteydessä P3-tyyppisen vasteen voimakkuuteen. Myös iällä havaittiin yhteys vasteen päänpinnan jakaumaan. Nuorimmilla vaste oli voimakkaampi päälaen alueella taaempaan takaraivon alueeseen verrattuna, mutta vanhimmassa ikäryhmässä vasteen amplitudi oli suurempi päälaen alueella pään keskiosaan verrattuna. Toiminnanohjaustehtävissä suoriutuminen parani iän myötä molemmilla ryhmillä. Vaikka selkeitä ryhmäeroja ei tutkimuksessa havaittukaan, tulokset viittaavat siihen, että nuorilla ja nuorilla aikuisilla musiikkiharrastus on yhteydessä erilaiseen tarkkaavaisuuden säätelyyn ja toiminnanohjaukseen liittyvään hermostolliseen toimintaan musiikkia harrastamattomiin verrattuna. Tulosten mukaan tarkkaavaisuus- ja toiminnanohjaustaidot ja niihin liittyvät hermostolliset prosessit myös kehittyvät edelleen 13–21 vuoden iässä.
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(2019)Tässä pro gradu -tutkielmassa selvitetään musiikkiharrastuksen ja erityisesti soitonopiskelun yhteyttä 13–21-vuotiaiden nuorten tarkkaavaisuus- ja toiminnanohjaustaitoihin. Musiikkiharrastus on aiemmissa tutkimuksissa liitetty tehostuneisiin kuuloerottelukykyihin, kielellisiin kykyihin ja korkeamman asteisiin kognitiivisiin prosesseihin. Tämän laajan kognitiivisten kykyjen tehostumisen takana on ehdotettu olevan tarkkaavaisuuden säätelyn ja toiminnanohjaustaitojen kehittyminen musiikki- ja erityisesti soittoharrastuksen myötä. Tarkkaavaisuudelle ja toiminnanohjaukselle tärkeä etuotsalohko kehittyy edelleen nuoruudessa ja vielä aikuisiän saavuttamisen jälkeen, joten on kiinnostavaa selvittää musiikkiharrastuksen mahdollisia hyötyjä nuorten ja nuorten aikuisten vielä kehittyviin toiminnanohjaustaitohin ja mahdollista yhteyttä niiden taustalla oleviin aivomekanismeihin. Tutkimuksessa mitattiin aivosähkökäyrämittauksella (elektroenkefalografia, EEG) nuorten ja nuorten aikuisten (N=64, joista 35 kuului musiikkiryhmään ja loput kontrolliryhmään) inhibitiota, kognitiivista joustamista ja työmuistia edellyttävän visuaalisen vaihtamistehtävän synnyttämiä P3-tyyppisiä herätevasteita. Lisäksi nuoret ja nuoret aikuiset tekivät inhibitiokykyä ja tarkkaavaisuuden sujuvaa vaihtamista sekä työmuistia ja yleistä päättelysuoriutumista mittaavia neuropsykologisia tehtäviä. Tutkimuksessa tarkasteltiin myös näissä tehtävissä suoriutumisen yhteyttä P3-tyyppisen vasteen voimakkuuteen. Musiikki- ja kontrolliryhmän välillä ei havaittu eroa toiminnan tai taitojen tasolla koeasetelman vaihtamistehtävässä eikä neuropsykologisissa tehtävissä. Ryhmien välillä ei havaittu myöskään eroa P3-tyyppisen vasteen voimakkuudessa. Vasteen jakauma erosi kuitenkin ryhmien välillä. Musiikkiryhmällä P3-tyyppinen vaste oli voimakkaampi päälaen alueella pään keskiosaan verrattuna, kun taas kontrolliryhmällä vaste oli voimakkaampi päälaen alueella vielä taaempaan takaraivon alueeseen verrattuna. Koeasetelman vaihtamistehtävässä suoriutumisella oli yhteys P3-tyyppisen vasteen voimakkuuteen: mitä suurempi vasteen voimakkuus oli, sitä lyhyemmät olivat reaktioajat tehtävässä. Sen sijaan neuropsykologisessa inhibitio- tai vaihtamistehtävässä suoriutumisella ei havaittu olevan yhteyttä P3-tyyppisen vasteen voimakkuuteen. Työmuistisuoriutuminen oli kuitenkin positiivisesti yhteydessä P3-tyyppisen vasteen voimakkuuteen. Myös iällä havaittiin yhteys vasteen päänpinnan jakaumaan. Nuorimmilla vaste oli voimakkaampi päälaen alueella taaempaan takaraivon alueeseen verrattuna, mutta vanhimmassa ikäryhmässä vasteen amplitudi oli suurempi päälaen alueella pään keskiosaan verrattuna. Toiminnanohjaustehtävissä suoriutuminen parani iän myötä molemmilla ryhmillä. Vaikka selkeitä ryhmäeroja ei tutkimuksessa havaittukaan, tulokset viittaavat siihen, että nuorilla ja nuorilla aikuisilla musiikkiharrastus on yhteydessä erilaiseen tarkkaavaisuuden säätelyyn ja toiminnanohjaukseen liittyvään hermostolliseen toimintaan musiikkia harrastamattomiin verrattuna. Tulosten mukaan tarkkaavaisuus- ja toiminnanohjaustaidot ja niihin liittyvät hermostolliset prosessit myös kehittyvät edelleen 13–21 vuoden iässä.
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(2024)BACKGROUND: Perinatal asphyxia often leads to hypoxic-ischemic encephalopathy (HIE) with a high risk of neurodevelopmental consequences. While moderate and severe HIE link to high morbidity, less is known about brain effects of perinatal asphyxia with no or only mild HIE. Here, we test the hypothesis that cortical activity networks in the newborn infants show a dose-response to asphyxia. METHODS: We performed EEG recordings for infants with perinatal asphyxia/HIE of varying severity (n = 52) and controls (n = 53) and examined well-established computational metrics of cortical network activity. RESULTS: We found graded alterations in cortical activity networks according to severity of asphyxia/HIE. Furthermore, our findings correlated with early clinical recovery measured by the time to attain full oral feeding. CONCLUSION: We show that both local and large-scale correlated cortical activity are affected by increasing severity of HIE after perinatal asphyxia, suggesting that HIE and perinatal asphyxia are better represented as a continuum rather than the currently used discreet categories. These findings imply that automated computational measures of cortical function may be useful in characterizing the dose effects of adversity in the neonatal brain; such metrics hold promise for benchmarking clinical trials via patient stratification or as early outcome measures.
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(2024)BACKGROUND: Perinatal asphyxia often leads to hypoxic-ischemic encephalopathy (HIE) with a high risk of neurodevelopmental consequences. While moderate and severe HIE link to high morbidity, less is known about brain effects of perinatal asphyxia with no or only mild HIE. Here, we test the hypothesis that cortical activity networks in the newborn infants show a dose-response to asphyxia. METHODS: We performed EEG recordings for infants with perinatal asphyxia/HIE of varying severity (n = 52) and controls (n = 53) and examined well-established computational metrics of cortical network activity. RESULTS: We found graded alterations in cortical activity networks according to severity of asphyxia/HIE. Furthermore, our findings correlated with early clinical recovery measured by the time to attain full oral feeding. CONCLUSION: We show that both local and large-scale correlated cortical activity are affected by increasing severity of HIE after perinatal asphyxia, suggesting that HIE and perinatal asphyxia are better represented as a continuum rather than the currently used discreet categories. These findings imply that automated computational measures of cortical function may be useful in characterizing the dose effects of adversity in the neonatal brain; such metrics hold promise for benchmarking clinical trials via patient stratification or as early outcome measures.
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(2018)Objectives: Faces provide an ideal platform to look into the ways in which our brains process multidimensional information. In order to still recognize an individual when their expression changes, our brain must be able to separate two overlapping sources of information. Previous fMRI-studies have found several brain areas involved in face processing, especially fusiform face area (FFA), occipital face area (OFA), and superior temporal sulcus (STS). EEG- and MEG-studies have also pointed out face-specific temporal components, mainly P1, N170, and N250. However, only few studies have varied both expressions and identities at the same time, or combined spatially precise fMRI with temporally precise M/EEG. Methods: In separate experiments, EEG and fMRI were measured while participants (n=17) viewed morphed faces varying in their expression (neutral, happy, fearful and angry) and in identity. Classification accuracies were calculated using support vector machine (SVM), both from different spatial locations in fMRI and from different timepoints in EEG. In addition, the classification information in fMRI and EEG were combined using representational similarity analysis (RSA). Results: In EEG, we found support for very early processing of expressions (at 110 ms), later processing of identities (at 250 ms) than expressions, and more sustained decoding of angry faces than faces with other expressions. In fMRI, coding of expressions were found on a broad area containing early visual areas and face processing areas OFA, FFA, and STS. Results for identities, although less clear, showed FFA and middle frontal gyrus (MFG). RSA combining both EEG and fMRI showed progression of information from early visual areas at 130 ms to FFA at 150 ms, and to FFA and STS at 200 ms. Conclusions: Our results showed that with multivariate data analysis methods, temporal and spatial neural representations of faces can be studied simultaneously. Consistent with neural models of face processing, our results suggest partially separate processing of expressions and identities in spatially distributed brain network.
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(2023)Objective: The objective of this study is to investigate how parent’s dyslexia and the severity of it affect the neural speech-sound discrimination of preschool-age children. The second aim is to study whether children’s pre-reading skills combined with familial dyslexia risk are associated with neural speech-sound discrimination. The association between dyslexia and speech-sound discrimination has been found in many studies before, but there is conflicting evidence regarding dyslexia risk, especially in preschool-age children. The hypotheses are that 1) more severe dyslexia of a parent and 2) familial dyslexia risk combined with weak pre-reading skills are both associated with smaller and less left lateralized mismatch negativity (MMN) and late discriminative negativity (LDN) responses. Methods: The sample of this study was a subsample (n = 94) of the DyslexiaBaby follow-up study. The children were 4–5 years old and 19 of them were controls that did not have dyslexia in the family. The severity of parent’s dyslexia was categorized to compensated, mild or moderate/severe. The pre-reading skills of children were assessed with the Finnish Lukiva test. The experimental setup was an oddball paradigm of /tata/ standard stimulus and five deviant stimuli that was presented during an electroencephalography (EEG) recording. The deviance in the stimuli was either in the vowel duration, consonant duration, latter vowel identity, or small or big change in the frequency of the second syllable. Results: The moderate/severe dyslexia group had smaller MMN amplitudes than the controls. Also, the moderate/severe dyslexia group had smaller LDN amplitudes only on the left hemisphere compared to the controls. There were preliminary, but not significant results of very weak pre-reading skills combined with familial dyslexia risk being associated with right-lateralized MMN and LDN responses. Conclusions: Children with familial dyslexia risk have difficulties in neural speech-sound discrimination especially in the left hemisphere compared to controls. However, no evidence was found of parent’s mild or compensated dyslexia being associated with weaker speech-sound discrimination. Therefore, moderate or severe dyslexia of a parent seems to be a higher risk for a child’s difficulties in speech-sound discrimination and targeting this group with interventions seems beneficial.
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(2021)Objectives. The aim of this study was to examine with electroencephalography (EEG) the associations between speech-sound elicited mismatch negativity (MMN) and late discriminative negativity (LDN) and pre-reading skills. Exploring the neural base of pre-reading skills will benefit the development of interventions for reading difficulties. It was hypothesized that left-lateralized MMNs and LDNs are elicited by all changes and larger and left-lateralized responses are linked with better pre-reading skills. Children with dyslexia risk were assumed to have poorer pre-reading skills and their responses were assumed to be smaller and more right-lateralized than in controls. Methods. Twenty-three children (of whom 16 with dyslexia risk) participated in an assessment of language abilities and EEG recording around the age of four years seven months. MMN and LDN were recorded for vowel, phoneme duration and frequency changes occurring in the second syllable of the standard stimulus (/tata/). The Repeated-measures analyses of covariance and the correlation analyses were applied to examine the relationship between MMN and LDN amplitudes, scalp distributions and phonological awareness, rapid automatized naming (RAN), verbal short-term memory, letter knowledge and a parent’s evaluation of pre-reading skills. The effects of risk status on MMN and LDN responses and pre-reading skills were investigated with the Repeated-measures and the One-way analyses of variance. Results. MMNs in the right hemisphere for consonant duration and vowel change and LDNs for all changes were statistically significant. LDN for vowel duration change was associated with RAN, and LDN for large frequency change was associated with letter knowledge so that the responses were larger in children performing better. LDN for vowel change was larger in children with poor letter knowledge and RAN, and LDN for small frequency change was larger in children performing poorly in RAN. Children performing poorly in RAN had right-lateralized MMNs, whereas children performing better had larger amplitudes mainly in the left hemisphere. Dyslexia risk had no effect on MMNs, LDNs or pre-reading skills. Conclusions. Right-lateralized speech processing and possibly also difficulties of discriminating vowel and frequency changes are associated with poor reading skills. Strengthening the ability to discriminate and manipulate phonemes may be important when supporting reading skills, however this should be investigated with an intervention study.
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(2021)Objectives. The aim of this study was to examine with electroencephalography (EEG) the associations between speech-sound elicited mismatch negativity (MMN) and late discriminative negativity (LDN) and pre-reading skills. Exploring the neural base of pre-reading skills will benefit the development of interventions for reading difficulties. It was hypothesized that left-lateralized MMNs and LDNs are elicited by all changes and larger and left-lateralized responses are linked with better pre-reading skills. Children with dyslexia risk were assumed to have poorer pre-reading skills and their responses were assumed to be smaller and more right-lateralized than in controls. Methods. Twenty-three children (of whom 16 with dyslexia risk) participated in an assessment of language abilities and EEG recording around the age of four years seven months. MMN and LDN were recorded for vowel, phoneme duration and frequency changes occurring in the second syllable of the standard stimulus (/tata/). The Repeated-measures analyses of covariance and the correlation analyses were applied to examine the relationship between MMN and LDN amplitudes, scalp distributions and phonological awareness, rapid automatized naming (RAN), verbal short-term memory, letter knowledge and a parent’s evaluation of pre-reading skills. The effects of risk status on MMN and LDN responses and pre-reading skills were investigated with the Repeated-measures and the One-way analyses of variance. Results. MMNs in the right hemisphere for consonant duration and vowel change and LDNs for all changes were statistically significant. LDN for vowel duration change was associated with RAN, and LDN for large frequency change was associated with letter knowledge so that the responses were larger in children performing better. LDN for vowel change was larger in children with poor letter knowledge and RAN, and LDN for small frequency change was larger in children performing poorly in RAN. Children performing poorly in RAN had right-lateralized MMNs, whereas children performing better had larger amplitudes mainly in the left hemisphere. Dyslexia risk had no effect on MMNs, LDNs or pre-reading skills. Conclusions. Right-lateralized speech processing and possibly also difficulties of discriminating vowel and frequency changes are associated with poor reading skills. Strengthening the ability to discriminate and manipulate phonemes may be important when supporting reading skills, however this should be investigated with an intervention study.
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(University of HelsinkiHelsingin yliopistoHelsingfors universitet, 2003)Tainnutuksen tarkoitus on saattaa eläin välittömästi tiedottomaan tilaan, jotta teurastustapahtuman aikaiset toimenpiteet eivät olisi sille kipua tai tuskaa tuottavia. Eläimen saattaminen liikkumattomaksi on myös turvallisuustekijä. EEG- ja käyttäytymistutkimuksiin perustuen on määritelty nykyiset normit eri eläinlajien tainnutustavoille ja -ajoille, tainnutuksen ja piston väliselle ajalle sekä piston ja seuraavan toimenpiteen väliselle ajalle. Siat tainnutetaan EU-direktiivin mukaan vähintään 1,25 A ja lampaat 1,0 A 50 Hz:n sinimuotoista vaihtovirtaa käyttäen vähintään 3 s ajan tai siat myös altistamalla ne vähintään 70 %:selle CO2:lle vähintään 45 sekunnin ajaksi. Naudat, vasikat, lampaat ja hevoset suositellaan tainnutettavaksi aivot läpäisevällä pulttipyssyllä tai iskutainnuttimella. Isot ja vihaiset eläimet voidaan ampua myös luotiaseella. Tainnutuksen ja piston välinen aika saa olla enintään 60 s pulttipyssy-, luotiase- ja CO2-tainnutuksessa sekä 20 s sähkö- ja iskutainnutuksessa. Aika piston ja seuraavan toimenpiteen välillä on oltava vähintään 30 s tai niin pitkä aika, että kaikki aivorungon refleksit ovat sammuneet. Sikojen ja lampaiden tainnutuskohta sähkötainnutuksessa sijaitsee ohimoilla pääasetelmassa ja pään ja selän/rintakehän kohdalla sydänpysäytysmenetelmässä. Pulttipyssytainnutuskohta sijaitsee naudoilla vastakkaisen silmän ja sarven keskikohdan ylittävien kuviteltujen suorien risteyskohdassa, hevosilla tuon risteyskohdan yläpuolella, sarvettomilla lampailla kohtisuoraan päätä kohden, sarvellisilla lampailla sarvien keskiharjanteen takana ja sioilla 2,5-5 cm silmien tason yläpuolella kallon keskiviivassa tai keskiviivan harjanteen toisella puolella. Työni tarkoitus oli havainnoida punaisen lihan teuraseläinten tainnutusta, sen sujumista ja siihen käytettäviä välineitä. Kiersin vuosina 1991-1992 kaikki silloiset 31 teurastamoa tarkoituksenani havainnoida, mitata ja videoida tainnutusta, siihen käytettäviä välineitä ja niiden kuntoa. Mittasin tainnutusaikoja ja tainnutuksen ja piston välisiä aikoja sekä pistosta seuraavaan toimenpiteeseen käytettäviä aikoja. Kartoitin myös sikojen suihkutusta, eläinten mahtuvuutta teurastamon navetoihin, linjanopeutta sekä valaistuksen määrää tainnutuspaikalla. Suomessa eläimet viettivät teurastamossa 0-3 vrk suosituksen ollessa < 5 h. Eläimiä mahtui navettaan 50-100 % päivän teurasmäärästä suosituksen ollessa 100 %. Sikojen teurastusnopeus oli 18-240/h ja nautojen 3-70/h ollen kohtuulliset. Sikoja suihkutettiin n. 85 %:ssa teurastamoita, mikä onkin suositeltavaa. Naudat ja hevoset tainnutettiin pääasiassa Schermer- tai Cash-merkkisellä pulttipyssyllä, lampaat ja vasikat lekalla, siat sähköllä tai CO2:lla ja sairaat sähköllä tai luotiaseella. Tainnutuslaitteet toimivat pääosin moitteetta, mutta sähkötainnutuslaitteiden mittarit näyttivät 20 %:ssa teurastamoita selvästi liikaa. Tainnuttajat tainnuttivat naudat, lampaat ja hevoset pääosin oikeisiin kohtiin, mutta siat tainnutettiin sähköllä liian taakse niskaan 40 %:ssa teurastamoita. CO2-laitteet toimivat moitteettomasti. Aika tainnutuksesta pistoon vaihteli naudoilla 22,4-88,8 s (< 60 s suositus) ja sioilla 7,5-32,5 s (< 20 s sähkö- ja < 60 s CO2-tainnutuksen jälkeen suositus). Aika pistosta seuraavaan toimenpiteeseen oli naudoilla 47,4–756,5 s ja sioilla 32,4-535 s suosituksen ollessa > 30 s. Tainnutuksen jälkeen 1-40 %:lla sioista esiintyi kornearefleksi ja 1-30 % reagoi kärsän pistoon. Nautojen tainnutus tuotti jäykkiä ruhoja, gaggingin, lasittuneet eteenpäin tuijottavat silmät ja välittömän rojahduksen miltei aina, paitsi yhdessä teurastamossa, jossa oli liian heikko pulttipyssy.
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(2023)Objectives: Sleep is sensitive to mental stress. Mental stress can be triggered by everyday psychosocially stressful life events evoking feelings of fear of social evaluation, social exclusion or pressure of attaining desired goals. Deterioration of subsequent sleep is in turn widely associated with different mental health outcomes. Here we examine, whether psychosocial stress experienced before night sleep affects non-rapid eye movement (NREM) sleep architecture and sleep spindles. Furthermore, we intend to elucidate whether the effects of stress are different between two halves of the night. To our knowledge this is the first study integrating these themes and covering the entire night EEG measurement. Methods: Subjects were 20- to 34-year-old healthy adults (n=34) distributed into two experimental groups, completing different virtual reality scenarios. Subjects of stress condition performed a public speaking task in front of an attentive virtual audience whereas the subjects of control condition listened a neutral presentation in otherwise identical except empty virtual seminar room. Following both virtual reality scenarios participants’ sleep parameter data were gathered with electroencephalography (EEG) during the following night in the sleep laboratory. Results and Conclusions: We found that participants in stress condition displayed significantly lower N2 proportion during the first half of the night in contrast to control condition, accompanying slight reduction in N3 and REM sleep. Psychosocial stress had no significant effect on the entire night sleep spindle parameters, compared to non-stressful condition. However, a significant interaction between group and time on central spindle density was found, as a significant increase of central spindle density in the stress group from first to second half of sleep. Thus, we conclude that pre-sleep psychosocially stressful experience is associated with decreased N2 proportion during the first half of the sleep and increased central spindle density from the first to second half of the sleep, and the pattern is significantly different compared to sleep after neutral experience. These findings might indicate potential sleep homeostatic mechanism, whereby the stress related reduction of N2 sleep observed earlier in the night may be compensated for by a denser appearance of spindles later in the night, thus promoting sleep continuity and compensating for effects which occurred closer to the stressor.
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(2023)Objectives: Sleep is sensitive to mental stress. Mental stress can be triggered by everyday psychosocially stressful life events evoking feelings of fear of social evaluation, social exclusion or pressure of attaining desired goals. Deterioration of subsequent sleep is in turn widely associated with different mental health outcomes. Here we examine, whether psychosocial stress experienced before night sleep affects non-rapid eye movement (NREM) sleep architecture and sleep spindles. Furthermore, we intend to elucidate whether the effects of stress are different between two halves of the night. To our knowledge this is the first study integrating these themes and covering the entire night EEG measurement. Methods: Subjects were 20- to 34-year-old healthy adults (n=34) distributed into two experimental groups, completing different virtual reality scenarios. Subjects of stress condition performed a public speaking task in front of an attentive virtual audience whereas the subjects of control condition listened a neutral presentation in otherwise identical except empty virtual seminar room. Following both virtual reality scenarios participants’ sleep parameter data were gathered with electroencephalography (EEG) during the following night in the sleep laboratory. Results and Conclusions: We found that participants in stress condition displayed significantly lower N2 proportion during the first half of the night in contrast to control condition, accompanying slight reduction in N3 and REM sleep. Psychosocial stress had no significant effect on the entire night sleep spindle parameters, compared to non-stressful condition. However, a significant interaction between group and time on central spindle density was found, as a significant increase of central spindle density in the stress group from first to second half of sleep. Thus, we conclude that pre-sleep psychosocially stressful experience is associated with decreased N2 proportion during the first half of the sleep and increased central spindle density from the first to second half of the sleep, and the pattern is significantly different compared to sleep after neutral experience. These findings might indicate potential sleep homeostatic mechanism, whereby the stress related reduction of N2 sleep observed earlier in the night may be compensated for by a denser appearance of spindles later in the night, thus promoting sleep continuity and compensating for effects which occurred closer to the stressor.
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(2022)Epileptic patients experience spontaneous recurrent seizures and interictal epileptiform discharges that lead to brain injuries, triggering neuroinflammation and waste product accumulation. Due to the detrimental effect of waste products on brain homeostasis, their removal from the central nervous system is (CNS) is crucial. Meningeal lymphatic vessels (mLVs) located in dura matter contribute to CNS clearance by the drainage of metabolites, waste products, and immune cells from subarachnoid space into cervical lymph nodes. Therefore, because of its role in brain homeostasis, the study of mLVs in different neurological conditions and diseases, including TLE, has gotten increased attention in the last decade. In this study, we sought to understand mLVs role in neuroinflammation and changes in rapid eye movement (REM) sleep stage during epilepsy. For this purpose, we induced mLVs ablation followed by kainic acid (KA) epilepsy model in mice. Shortly, animals were inoculated with AAV-VEGFR3-1-4 to induce mLVs ablation and subsequently challenged with KA to induce status epilepticus. Simultaneously, a control group of animals were injected with a sham AAV and later injection of KA. Afterward, spontaneous EEG activity was registered continuously, and data analysed to compare durations of REM sleep. Also, immunohistochemistry of brain samples was performed to investigate neuroinflammatory changes between experimental groups. Ex-vivo analyses of Iba1 and GFAP expression in brain tissue did not show statistically significant changes in neuroinflammation between experimental groups. However, we observed a trend towards lower expression of inflammatory markers in mLVs ablated animals. The analysis of REM sleep duration shows a progressive reduction of this sleep stage in both groups during the first recording period with a subsequent stabilization during the second one. Our data also indicate that mLVs ablated animals present prolonged REM sleep duration compared to the control group. Although this data contradicts our initial hypothesis it is consistent with the well-established negative correlation between neuroinflammation and REM sleep duration. Future studies should consider a deeper analysis of the glial cell profile for a better understanding of the effect of mLVs dysfunction on epileptic pathology. Moreover, the impact of mLVs ablation on REM sleep duration should be characterized in healthy animals.
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(2022)Epileptic patients experience spontaneous recurrent seizures and interictal epileptiform discharges that lead to brain injuries, triggering neuroinflammation and waste product accumulation. Due to the detrimental effect of waste products on brain homeostasis, their removal from the central nervous system is (CNS) is crucial. Meningeal lymphatic vessels (mLVs) located in dura matter contribute to CNS clearance by the drainage of metabolites, waste products, and immune cells from subarachnoid space into cervical lymph nodes. Therefore, because of its role in brain homeostasis, the study of mLVs in different neurological conditions and diseases, including TLE, has gotten increased attention in the last decade. In this study, we sought to understand mLVs role in neuroinflammation and changes in rapid eye movement (REM) sleep stage during epilepsy. For this purpose, we induced mLVs ablation followed by kainic acid (KA) epilepsy model in mice. Shortly, animals were inoculated with AAV-VEGFR3-1-4 to induce mLVs ablation and subsequently challenged with KA to induce status epilepticus. Simultaneously, a control group of animals were injected with a sham AAV and later injection of KA. Afterward, spontaneous EEG activity was registered continuously, and data analysed to compare durations of REM sleep. Also, immunohistochemistry of brain samples was performed to investigate neuroinflammatory changes between experimental groups. Ex-vivo analyses of Iba1 and GFAP expression in brain tissue did not show statistically significant changes in neuroinflammation between experimental groups. However, we observed a trend towards lower expression of inflammatory markers in mLVs ablated animals. The analysis of REM sleep duration shows a progressive reduction of this sleep stage in both groups during the first recording period with a subsequent stabilization during the second one. Our data also indicate that mLVs ablated animals present prolonged REM sleep duration compared to the control group. Although this data contradicts our initial hypothesis it is consistent with the well-established negative correlation between neuroinflammation and REM sleep duration. Future studies should consider a deeper analysis of the glial cell profile for a better understanding of the effect of mLVs dysfunction on epileptic pathology. Moreover, the impact of mLVs ablation on REM sleep duration should be characterized in healthy animals.
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