Body perception and brain plasticity in blind and sighted individuals

Lack of vision is associated with large-scale brain plasticity. Vision, touch, proprioception, interoception, and other sensory modalities are thought to play a vital role in developing and maintaining bodily awareness. How do blind people perceive their bodies, and what kind of compensatory neuroplasticity processes are involved? This thesis comprises a series of experiments focused on a profoundly understudied topic – the perception of one’s body following blindness. Study I shows that blind individuals are significantly better at perceiving their heartbeats than sighted individuals. The results indicate that blind individuals experience signals from inner organs differently than sighted individuals, which has implications for further research on emotional processing and bodily awareness. Study II provides a broader insight into tactile perception following blindness by studying discriminative and affective touch plasticity in blind and sighted groups. A key novel finding is changed pleasantness sensation due to affective touch, that is, slow, gentle, caress-like stroking of the skin, especially on the palm, in blind participants compared to sighted participants. The results have implications for understanding social and physical interactions in blind individuals. Study III re-examines a classic paradigm to study multisensory bodily awareness, the somatic rubber hand illusion, in a large sample of blind participants with a well-matched sighted control group. The results present strong evidence that blind individuals are “immune” to this illusion which suggests that they rely more on unisensory processing rather than multimodal integration of sensory signals, compared to sighted individuals. Study IV investigates the effect of short-term visual deprivation by a two-hour blindfolding procedure on the bodily senses of cardiac interoception, thermosensation, and discriminative touch in sighted participants. The results show no effect on these senses, which suggests that the changes observed in blind individuals on these sensory functions relate to their long-term lack of visual experience and associated brain plasticity changes. Finally, Study V uses structural magnetic resonance imaging to analyze cortical thickness in a group of blind individuals and a matched sighted control group and relate the cortical thickness measure to the behaviorally registered changes in cardiac interoceptive accuracy. The key finding is that blind individuals with thicker occipital cortices are better at sensing their heartbeats; this finding advances our understanding of the limits of cross-modal plasticity following blindness and suggests that the visual cortex supports the awareness of inner bodily sensations in blind individuals. Overall, this thesis is the first systematic characterization of differences and similarities between blind and sighted individuals in body perception and functioning of the bodily senses, opening a line of research with important links to mental health

Opady atmosferyczne na obszarze Łodzi i województwa łódzkiego w okresie 1961-2016

Głównym celem tego opracowania jest charakterystyka opadów atmosferycznych na tle cyrkulacji atmosferycznej w województwie łódzkim oraz analiza incydentów opadowych w skali lokalnej w oparciu o sieć punktów pomiarowych na obszarze aglomeracji łódzkiej. We wszystkich sezonach, najwyższe średnie sumy dobowe opadów wystąpiły podczas typów cyklonalnych. Zima charakteryzowała się najwyższymi opadami dobowymi podczas typu cyrkulacji atmosferycznej cyklonalnej zachodniej (Wc). Latem średnie sumy dobowe opadów były dwukrotnie wyższe, niż zimą i charakteryzowały się najwyższymi wartościami podczas cyrkulacji atmosferycznej typu SEc i SWc. We wszystkich sezonach, podczas typów antycyklonalnych wystąpiły najniższe średnie sumy dobowe opadów z minimum podczas typu Na, czego powodem jest mała wilgotność mas powietrza arktycznego napływającego z północy. W województwie łódzkim najczęściej opady występują podczas adwekcji północno-zachodniej, zachodniej i południowo-zachodniej, co pokazuje duży wpływ Atlantyku w generowaniu opadów atmosferycznych w województwie łódzkim. Najmniejszą częstością charakteryzują się opady podczas adwekcji z kierunków: NE, E i SE w zależności od sezonu, przyczyną są suche masy powietrza kontynentalnego przenoszone z powyższych kierunków. Największą współzależność występowania makrotypów cyrkulacji (NAO, EA, EA/WR, SCA, POL) z opadami atmosferycznymi w województwie łódzkim odnotowano jesienią i zimą. Najsilniejszym wpływem na średnie sumy opadów atmosferycznych w województwie łódzkim cechuje się makrotyp SCA i POL, najsłabszym EA/WR. Przeważały korelacje słabe od -0,4 do 0,4. Duże zróżnicowanie korelacji może świadczyć o wpływie warunków lokalnych na opady. Na podstawie wybranych incydentów opadowych w aglomeracji łódzkiej stwierdzono, że geneza opadu jest decydującym czynnikiem, który wpływa na przebieg intensywności opadu. Pokazano, że przebieg wzrostu warstwy opadu z chmur warstwowych był jednostajny. W przypadku chmur Cumulonimbus, przebieg warstwy opadu był bardziej dynamiczny i najwyższe wzrosty warstwy opadu wystąpiły od 30 do 75% czasu jego trwania. W trakcie wybranych incydentów opadowych na obszarze Łodzi podczas wytypowanych kierunków adwekcji (NW, W i SW) w czasie 60 minut obserwuje się wyraźne zróżnicowanie rozkładu czasowo-przestrzennego średniego udziału procentowego opadu. Maksymalny średni udział procentowy opadu występuje po zawietrznej stronie miasta podczas analizowanych kierunków adwekcji

Analiza wybranych sytuacji synoptycznych związanych z ekstremalnym opadem w latach 2011-2013 nad obszarem Łodzi

The aim of the study is to analyse the maximum daily rainfall during selected synoptic situations in summer from the period 2011–2013 in Łódź. In this study, data collected from fourteen rain gauges belonging to the Łódź Infrastructure Company were used. The measurement sites were evenly distributed within the city and rainfall was recorded every 5 minutes. The study analysed five synoptic situations during which the observed day totals in the city exceeded 20 mm. The highest rainfall in Łódź occured during days featuring the passage of weather fronts, mostly cold. The maximum rainfall was observed in the southern or south-western part of the city. In four cases, south-western cyclonic circulation occurred, and in such conditions the highest rainfall was recorded in the southern part of the city and diminished towards the north. This unusual trend may be related to the terrain elevation, as the terrain in Łódź slopes north-east to southwest.614315711Badania Fizjograficzn

Limits of cross-modal plasticity? Short-term visual deprivation does not enhance cardiac interoception, thermosensation, or tactile spatial acuity

In the present study, we investigated the effect of short-term visual deprivation on discriminative touch, cardiac interoception, and thermosensation by asking 64 healthy volunteers to perform four behavioral tasks. The experimental group contained 32 subjects who were blindfolded and kept in complete darkness for 110 minutes, while the control group consisted of 32 volunteers who were not blindfolded but were otherwise kept under identical experimental conditions. Both groups performed the required tasks three times: before and directly after deprivation (or control) and after an additional washout period of 40 minutes, in which all participants were exposed to normal light conditions. Our results showed that short- term visual deprivation had no effect on any of the senses tested. This finding suggests that short-term visual deprivation does not modulate basic bodily senses and extends this principle beyond tactile processing to the interoceptive modalities of cardiac and thermal sensations.Swedish Research Council, 2017-03135Marie Skłodowska-Curie Intra-European Individual Fellowship, 891175Accepte

The perception of affective and discriminative touch in blind individuals

Enhanced tactile acuity in blindness is among the most widely reported results of neuroplasticity following prolonged visual deprivation. However, tactile submodalities other than discriminative touch are profoundly understudied in blind individuals. Here, we examined the influence of blindness on two tactile submodalities, affective and discriminative touch, the former being vital for social functioning and emotional processing. We tested 36 blind individuals and 36 age- and sex-matched sighted volunteers. In Experiment 1, we measured the perception of affective tactile signals by asking participants to rate the pleasantness of touch delivered on the palm (nonhairy skin, sparsely innervated with C tactile [CT] fibers) or the forearm (hairy skin, densely innervated with CT fibers) in a CT-optimal versus a CT-nonoptimal manner using a paradigm grounded in studies on tactile sensory neurophysiology. In Experiment 2, we implemented a classic task assessing discriminative touch abilities, the grating orientation task. We found that blind individuals rated the touch as more pleasant when delivered on the palm than on the forearm, while the opposite pattern was observed for sighted participants, who rated stimulation on the forearm as more pleasant than stimulation on the palm. We also replicated the previous findings showing enhanced discriminative tactile acuity in blind individuals. Altogether, our results suggest that blind individuals might experience affective touch differently than sighted individuals, with relatively greater pleasantness perceived on the palm. These results provide a broader insight into somatosensory perception in blind individuals, for the first time taking into consideration the socioemotional aspect of touch

Blind individuals’ enhanced ability to sense their own heartbeat is related to the thickness of their occipital cortex

Blindness is associated with heightened sensory abilities, such as improved hearing and tactile acuity. Moreover, recent evidence suggests that blind individuals are better than sighted individuals at perceiving their own heartbeat, suggesting enhanced interoceptive accuracy. Structural changes in the occipital cortex have been hypothesized as the basis of these behavioral enhancements. Indeed, several studies have shown that congenitally blind individuals have increased cortical thickness within occipital areas compared to sighted individuals, but how these structural differences relate to behavioral enhancements is unclear. This study investigated the relationship between cardiac interoceptive accuracy and cortical thickness in 23 congenitally blind individuals and 23 matched sighted controls. Our results show a significant positive correlation between performance in a heartbeat counting task and cortical thickness only in the blind group, indicating a connection between structural changes in occipital areas and blind individuals’ better ability to perceive heartbeats

Fucoidan Inhibition of Osteosarcoma Cells Is Species and Molecular Weight Dependent.

Fucoidan is a brown algae-derived polysaccharide having several biomedical applications. This study simultaneously compares the anti-cancer activities of crude fucoidans from Fucus vesiculosus and Sargassum filipendula, and effects of low (LMW, 10-50 kDa), medium (MMW, 50-100 kDa) and high (HMW, >100 kDa) molecular weight fractions of S. filipendula fucoidan against osteosarcoma cells. Glucose, fucose and acid levels were lower and sulphation was higher in F. vesiculosus crude fucoidan compared to S. filipendula crude fucoidan. MMW had the highest levels of sugars, acids and sulphation among molecular weight fractions. There was a dose-dependent drop in focal adhesion formation and proliferation of cells for all fucoidan-types, but F. vesiculosus fucoidan and HMW had the strongest effects. G1-phase arrest was induced by F. vesiculosus fucoidan, MMW and HMW, however F. vesiculosus fucoidan treatment also caused accumulation in the sub-G1-phase. Mitochondrial damage occurred for all fucoidan-types, however F. vesiculosus fucoidan led to mitochondrial fragmentation. Annexin V/PI, TUNEL and cytochrome c staining confirmed stress-induced apoptosis-like cell death for F. vesiculosus fucoidan and features of stress-induced necrosis-like cell death for S. filipendula fucoidans. There was also variation in penetrability of different fucoidans inside the cell. These differences in anti-cancer activity of fucoidans are applicable for osteosarcoma treatment

Subjective embodiment during the rubber hand illusion predicts severity of premonitory sensations and tics in Tourette Syndrome

In Tourette Syndrome, the expression of tics and commonly preceding premonitory sensations is associated with perturbed subjective feelings of self-control and agency. We compared responses to the Rubber Hand Illusion in 23 adults with TS and 22 controls. Both TS and control participants reported equivalent subjective embodiment of the artificial hand: feelings of ownership, location, and agency were greater during synchronous visuo-tactile stimulation, compared to asynchronous. However, individuals with TS did not manifest greater proprioceptive drift, an objective marker of embodiment observed in controls. An 'embodiment prediction error' index of the difference between subjective embodiment and objective proprioceptive drift correlated with severity of premonitory sensations. Feelings of ownership also correlated with premonitory sensation severity, and feelings of agency with tic severity. These findings suggest that subjective bodily ownership, as measured by the rubber hand illusion, contributes to susceptibility to the premonitory sensations that may be a precipitating factor in tics