The role of primary visual cortex in unconscious visual processing

Lesion in primary visual cortex (V1) causes blindness in the visual field that is processed by the damaged area. Some patients with V1 lesion can unconsciously process the stimuli presented in their blind visual field. This kind of processing can be observed, for example, using a paradigm in which a patient is required to make a guess about the visual stimulus that he or she reports not seeing. If the accuracy of the responses is better than chance, it can be interpreted as unconscious processing, which is a measurable effect on behavior without conscious perception. This phenomenon of unconscious processing without V1 is commonly referred to as blindsight. The findings of unconscious processing without V1 in blindsight patients cannot be straightforwardly generalized to neurologically healthy people. Neural plasticity changes these patients’ brains; therefore, blindsight could be explained by these neural changes. Transcranial magnetic stimulation (TMS) is a method used to study the function of a cortical area in neurologically healthy people. With TMS, it is possible to interfere with the normal functioning of the brain. TMS of V1 can suppress the conscious perception of a visual stimulus. In this thesis, I studied whether the unconscious processing of visual stimuli is possible in neurologically healthy participants when the conscious perception of the stimulus is suppressed by TMS of V1. I found that both conscious and unconscious processing of visual information depend on V1 in neurologically healthy participants. Unconscious processing was observed only with the simplest task, in which participants responded to stimulus appearance. In this task, unconscious processing was observed only when the early activation of V1 was intact. The unconscious processing of chromaticity and motion was not observed when the stimulus was suppressed by TMS of V1. Therefore, I conclude that unconscious visual processing depends on V1 in neurologically healthy participants.Aivovaurio primaarilla näköaivokuorella (V1) aiheuttaa sokeuden siihen osaan näkökenttää, jonka prosessoinnista vaurioitunut aivokuoren osa vastaa. Jotkut tällaisista primaarin näköaivokuoren vauriosta johtuvasta sokeudesta kärsivistä potilaista pystyvät kuitenkin tiedostamattomasti prosessoimaan visuaalisia ärsykkeitä, jotka on esitetty sokealle näkökentälle. Tällaista prosessointia voidaan mitata esimerkiksi pyytämällä koehenkilö esittämään paras arvaus visuaalisen ärsykkeestä, jota hän ei raportoi nähneensä. Mikäli vastaustarkkuus on arvaustodennäköisyyttä parempi, voidaan todeta, että visuaalinen ärsyke vaikutti henkilön käyttäytymiseen tiedostamattomalla tasolla. Tästä ilmiöstä käytetään yleisesti nimeä sokeanäkö. Neurologisilla potilailla tehdyistä havainnoista ei kuitenkaan voida suoraan tehdä päätelmiä, jotka yleistyisivät koskemaan kaikkia ihmisiä. Potilaiden aivoissa tapahtuu plastisiteetin vuoksi muutoksia, jotka voivat selittää näitä säästyneitä visuaalisia kykyjä. Transkraniaalisella magneettistimulaatiolla (TMS) voidaan tutkia neurologisesti terveiden koehenkilöiden aivojen osien funktioita, sillä TMS häiritsee hetkellisesti aivojen normaalia viestinvälitystä. Primaarille näköaivokuorelle kohdistetut TMS-pulssit häiritsevät tietoista näkemistä. Tässä tutkielmassa selvitin, onko tiedostamaton prosessointi mahdollista, kun ärsykkeen tietoista havaintoa on häiritty primaarin näköaivokuoren stimulaatiolla. Tutkimuksissamme havaitsimme, että sekä tietoinen että tiedostamaton näköinformaation prosessointi vaativat primaarin näköaivokuoren toimintaa neurologisesti terveillä. Tiedostamatonta näköinformaation prosessointia havaittiin ainoastaan yksinkertaisimmassa tehtävässä, jossa koehenkilö reagoi ärsykkeen ilmestymiseen. Silloinkin ainoastaan, kun aikaista prosessointia primaarilla näköaivokuorella ei häiritty. Liikkeen ja värin prosessointia mittaavissa kokeissa tiedostamatonta prosessointia V1-stimulaation aikana ei havaittu. Tiedostamaton näköinformaation prosessointi riippuu siis primaarin näköaivokuoren toiminnasta neurologisesti terveillä koehenkilöillä

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Runsain eväin maailmalle : pk-yrityksen kansainvälistymisstrategian kehittäminen

Maailmalla vallitsevan taloudellisen taantuman myötä, niin suurien kuin pientenkin yritysten vienti on romahtanut radikaalisti joka puolella. Tilanteen paikkaamiseksi Suomi tarvitsee pikaisesti uusia vakavasti kasvuhakuisia yrityksiä, jotka tavoittelevat uusia ulkomaisia markkinoita ja kasvun myötä turvaisivat suomalaisia työpaikkoja. Jotta taantuman kääntyessä markkinoille pääsy olisi helpompaa ja yleensäkin mahdollista tulee Suomen pk-yritysten ryhtyä hyvissä ajoin ajattelemaan toimintaansa kansainvälisesti ja ryhtyä kehittämään omia viennin ja kansainvälistymisen asettamia edellytyksiä. Tämän opinnäytetyön tavoitteena on kehittää suomalaisen pk-yrityksen kansainvälistymisstrategiaa kartoittamalla ja analysoimalla eri vienninedistämiskeinoja. Teoriaosuudessa käsitellään yrityksen kansainvälistymistä yleisellä tasolla, painottaen kansainvälistymisen edellytyksiä ja vaihtoehtoisia operaatiomuotoja. Empiriaosuudessa tutkitaan samoja asioita syvällisemmin ja yksityiskohtaisemmin konepajateollisuuden pk-yrityksen Stairon Oy:n näkökulmasta. Stairon Oy toimii suurten kansainvälisten teknologiateollisuusyritysten järjestelmätoimittajana ja valmistaa asiakastarpeiden mukaisia kokonaisjärjestelmiä ja komponentteja. Yritys on erikoistunut paperikoneiden ilmajärjestelmälaitteiden valmistukseen ja on voimakkaasti halukas siirtymään uusille ulkomaisille markkinoille ja eri toimialoille. Tutkimuksen empiriaosuus perustuu tutkimuksen kohdeyrityksen sisäisten dokumenttien analysointiin, avainhenkilöiden kyselylomakehaastatteluun, avoimeen haastatteluun sekä tutkijan osallistuvaan havainnointiin. Tulokset osoittavat, että yrityksillä on kansainvälistyessään useita eri operaatiomuotoja ja niiden yhdistelmiä, joista valita sopivin. Kansainvälistyminen tuo yrityksille kuitenkin lukuisia uusia edellytyksiä, joihin yritysten tulee löytää riittävästi vahvuuksia, jotta menestyminen olisi mahdollista oli operaatiomuoto mikä tahansa. Suunniteltaessa kansainvälistymistä yritysten tulee kriittisesti ja puolueettomasti arvioida omat resurssinsa ja näin kartoittaa kehitettävät alueet. Usein kaikkia tarvittavia resursseja ei löydy heti yritykseltä itseltään, jolloin erinomaisena ratkaisuna toimii tämän päivän ilmiö verkostoituminen. Verkostoituminen tuo toiminnalle resursseja, laajuutta, kokemusta ja uskottavuutta sekä auttaa erottumaan kilpailijoista kilpailukykyisesti.Due to global economic recession export of large as well as small companies has crashed radically in everywhere. In order to recover this situation Finland requires new seriously growth-oriented companies that seek new foreign markets and via growth secure Finnish workplaces. So that entering foreign markets would be easier and even possible, after turning of economic recession, Finnish SMEs should start to think their operations globally well in advance and put effort to development of export and internationalization requirements. The main objective of this thesis is to develop an internationalization strategy of a Finnish SME by surveying and analyzing different export development methods and options. This study consists of both theoretical and empirical parts. Theoretical part handles internationalization of SME on a general level with emphasis on requirements of internationalization and variant operation modes. In empirical part these same issues are studied deeper and more detailed from mechanical engineering industry SME’s Stairon Oy point of view. Stairon operates as a system supplier for large international technology industry companies by manufacturing customized systems and components. Stairon is specialized in manufacturing of paper machine air systems and now it is also strongly willing to move to new foreign markets and different business areas. The material of empirical part is based on analyzing of the documents of the target company, questionnaire interviews of company’s key persons, open interviews and student’s participant observation. The results show, that when company considers internationalization there are various operation modes and their combinations where to choose the most sophisticated one from. Internationalization brings numerous new requirements where to company must create adequate resources so that the successful performance would be possible despite the mode of operation. When planning internationalization, companies should evaluate their resources critically and impartially and this way the survey areas which need development. Usually all the required resources can not be found in the company itself. Therefore, one feasible solution for this kind of situations would be today’s phenomenon networking. Networking forms resources, extension, experience and reliability for the operation as well as enables to differentiate from the rivals more competitively

Promise and challenges for discovering transcranial magnetic stimulation induced "numbsense"-Commentary on Ro & Koenig (2021).

The notion that behavioral responses to stimuli can be mediated by separate unconscious and conscious sensory pathways remains popular, but also hotly debated. Recently, Ro and Koenig (2021) reported that when activity in somatosensory cortex was interfered with transcranial magnetic stimulation (TMS), participants could discriminate tactile stimuli they reported not consciously feeling. The study launches an interesting new area of research, helping to uncover mechanisms of unconscious perception that possibly generalize across different sensory modalities. However, we argue here that the study by Ro and Koenig also has several significant shortcomings, and it fails to provide evidence that pathways bypassing primary somatosensory cortex enable unconscious tactile discrimination. By referring to numerous studies investigating TMS-induced blindsight, we outline challenges in demonstrating unconscious sensory pathways using TMS. By facing to these challenges, research investigating TMS-induced numbsense has potential to stimulate progress in stubborn debates and reveal modality-general mechanisms of unconscious perception

Is the primary visual cortex necessary for blindsight-like behavior? Review of transcranial magnetic stimulation studies in neurologically healthy individuals

The visual pathways that bypass the primary visual cortex (V1) are often assumed to support visually guided behavior in humans in the absence of conscious vision. This conclusion is largely based on findings on patients: V1 lesions cause blindness but sometimes leave some visually guided behaviors intact-this is known as blindsight. With the aim of examining how well the findings on blindsight patients generalize to neurologically healthy individuals, we review studies which have tried to uncover transcranial magnetic stimulation (TMS) induced blindsight. In general, these studies have failed to demonstrate a completely unconscious blindsight-like capacity in neurologically healthy individuals. A possible exception to this is TMS-induced blindsight of stimulus presence or location. Because blindsight in patients is often associated with some form of introspective access to the visual stimulus, and blindsight may be associated with neural reorganization, we suggest that rather than revealing a dissociation between visually guided behavior and conscious seeing, blindsight may reflect preservation or partial recovery of conscious visual perception after the lesion

Human endogenous retroviruses of the HERV-K (HML-2) family are expressed in the brain of healthy individuals and modify the composition of the brain-infiltrating immune cells

Human endogenous retroviruses (HERVs) are remnants of ancient retroviral infections in the human genome. RNA expression of individual HERVs has frequently been observed in various pathologic conditions, but some activity can also be seen in healthy individuals, e.g. in the blood. To quantitate the basal expression levels of HERVs in the brain, we now used high-throughput sequencing-based metagenomic analysis to characterize the expression profiles of the HERV-K (HML-2) family proviruses in different brain regions of healthy brain tissue. To this end, RNA-seq data from the Genotype-Tissue Expression (GTEx) project was used. The GTEx project is a public resource to study tissue-specific gene expression and regulation, consisting of a large selection of sequenced samples from different tissues. The GTEx data used in this study consisted of 378 samples taken from 13 brain regions from 55 individuals. The data demonstrated that out of 99 intact proviruses in the family 58 were expressed, but the expression profiles were highly divergent and there were no significant differences in the expression profiles between the various anatomic regions of the brain. It is known that the brain contains a variety of infiltrating immune cells, which are probably of great importance both in the normal defense mechanisms as well as in the various pathogenic processes. Digital cytometry (CIBERSORTx) was used to quantify the proportions of the infiltrating immune cells in the same brain samples. Six most abundant (>5 % of the total population) cell types were observed to be CD4 memory resting T cells, M0 macrophages, plasma cells, CD8 T cells, CD4 memory activated T cells, and monocytes. Analysis of the correlations between the individual HERVs and infiltrating cell types indicated that a cluster of 6 HERVs had a notable correlation signature between T cell type infiltrating cell proportions and HERV RNA expression intensity. The correlations between inflammatory type infiltrating cells were negative or weak. Taken together, these data indicate that the expression of HERVs is associated with a T cell type immunity.Peer reviewe

Composition of the infiltrating immune cells in the brain of healthy individuals : effect of aging

Immune cells infiltrating the central nervous system (CNS) are involved in the defense against invading microbes as well as in the pathogenesis of neuroinflammatory diseases. In these conditions, the presence of several types of immune and inflammatory cells have been demonstrated. However, some studies have also reported low amounts of immune cells that have been detected in the CNS of healthy individuals, but the cell types present have not been systematically analyzed. To do this, we now used brain samples from The Genotype- Tissue Expression (GTEx) project to analyze the relative abundance of 22 infiltrating leukocyte types using a digital cytometry tool (CIBERSORTx). To characterize cell proportions in different parts of the CNS, samples from 13 different anatomic brain regions were used. The data obtained demonstrated that several leukocyte types were present in the CNS. Six leukocyte types (CD4 memory resting T cells, M0 macrophages, plasma cells, CD8 T cells, CD4 memory activated T cells, and monocytes) were present with a proportion higher than 0.05, i.e. 5%. These six cell types were present in most brain regions with only insignificant variation. A consistent association with age was seen with monocytes, CD8 T cells, and follicular helper T cells. Taken together, these data show that several infiltrating immune cell types are present in the non-diseased CNS tissue and that the proportions of infiltrating cells are affected by age in a manner that is consistent with literature on immunosenecence and inflammaging.publishedVersionPeer reviewe

Aging-associated increase in indoleamine 2,3-dioxygenase (IDO) activity appears to be unrelated to the transcription of the IDO1 or IDO2 genes in peripheral blood mononuclear cells

<p>Abstract</p> <p>Background</p> <p>Old age is associated with increased levels of circulating pro-inflammatory cytokines, a phenomenon termed inflamm-aging. Elevated levels of pro-inflammatory cytokines have been associated with several age-associated diseases and with a shortened lifespan. Indoleamine 2,3-dioxygenase (IDO) has immunomodulatory properties and its activity is elevated in inflammation, autoimmune disorders and malignancies. We have previously shown that IDO activity is increased in nonagenarians compared to young individuals and that high IDO activity is associated with mortality at old age.</p> <p>Findings</p> <p>In this study our aim was to assess whether this difference in IDO activity in the plasma was due to the differential expression of either the IDO1 or IDO2 gene in peripheral blood mononuclear cells. Our results show that IDO1 and IDO2 are not differently expressed in nonagenarians compared to controls and that the expression of IDO genes is not associated with the level of IDO activity in the plasma.</p> <p>Conclusion</p> <p>The level of IDO activity in the plasma is not regulated through the expression of IDO1 or IDO2 in the peripheral blood mononuclear cells.</p