Toward the language oscillogenome

Language has been argued to arise, both ontogenetically and phylogenetically, from specific patterns of brain wiring. We argue that it can further be shown that core features of language processing emerge from particular phasal and cross-frequency coupling properties of neural oscillations; what has been referred to as the language 'oscillome.' It is expected that basic aspects of the language oscillome result from genetic guidance, what we will here call the language 'oscillogenome,' for which we will put forward a list of candidate genes. We have considered genes for altered brain rhythmicity in conditions involving language deficits: autism spectrum disorders, schizophrenia, specific language impairment and dyslexia. These selected genes map on to aspects of brain function, particularly on to neurotransmitter function. We stress that caution should be adopted in the construction of any oscillogenome, given the range of potential roles particular localized frequency bands have in cognition. Our aim is to propose a set of genome-to-language linking hypotheses that, given testing, would grant explanatory power to brain rhythms with respect to language processing and evolution.Economic and Social Research Council scholarship 1474910Ministerio de Economía y Competitividad (España) FFI2016-78034-C2-2-

Visual cortical alpha rhythms : function and relation to other dynamic signatures in local networks

The alpha rhythm (8-12Hz) was the first EEG rhythm recorded by Hans Berger in 1929. Despite being the earliest rhythm discovered, alpha rhythms remain the most mysterious in terms of mechanism and function. In the visual system, post-stimulus alpha oscillations are observed upon closing of the eyes or removal of visual stimulus. Alpha rhythms have been implicated in functional inhibition and short term memory. This thesis presents a rat in vitro model of the cortical alpha rhythm. This was achieved by mimicking the neuromodulatory changes that occur upon the removal of visual stimulus. Beta oscillations were induced by excitation of the visual cortex slice using the glutamate agonist kainate [800nM] to mimic sensory stimulation. This excitatory drive was then reduced using the AMPA and KA receptor antagonist NBQX [5µM], followed by the blocking of neuronal Ih current with DK-AH269 [10µM] to produce alpha frequency oscillations.Alpha activity was seen throughout all cortical laminae, with alpha power predominating in layer IV of the V1. The rhythm was found to be criticallydependent upon NMDA receptor-mediated connections between neurons which required the need to be potentiated in the prior excitation phase leading to beta frequency oscillations. Alpha activity was also dependent upon gap junctional coupling and had neuromodulatory effects similar to the human profile of alpha.Alpha oscillations were generated by pyramidal neurons found in layer IV of the V1 which elicited burst discharges. The alpha rhythm was not dominated by synaptic inhibition despite the functional inhibition role it is thought to play. Instead, the alpha rhythm appeared to dynamically uncouple activity in the primary thalamorecipient neurons (layer IV regular spiking cells) from down-stream activity in both supragranular and infragranular layers. In this manner, the alpha rhythm appears to be ideally constructed to prevent ascending visual information from both passing on to higher order visual areas, and also being influenced by top-down signal from these areas

Toward the Language Oscillogenome

Language has been argued to arise, both ontogenetically and phylogenetically, from specific patterns of brain wiring. We argue that it can further be shown that core features of language processing emerge from particular phasal and cross-frequency coupling properties of neural oscillations; what has been referred to as the language ‘oscillome.’ It is expected that basic aspects of the language oscillome result from genetic guidance, what we will here call the language ‘oscillogenome,’ for which we will put forward a list of candidate genes. We have considered genes for altered brain rhythmicity in conditions involving language deficits: autism spectrum disorders, schizophrenia, specific language impairment and dyslexia. These selected genes map on to aspects of brain function, particularly on to neurotransmitter function. We stress that caution should be adopted in the construction of any oscillogenome, given the range of potential roles particular localized frequency bands have in cognition. Our aim is to propose a set of genome-to-language linking hypotheses that, given testing, would grant explanatory power to brain rhythms with respect to language processing and evolution

Sleep disconnection : EEG decoding of covert attention during different vigilance states

Sleep is a mystery for the conscious mind. Indeed, whilst being asleep, either consciousness is reduced and few memories remain upon awakening. Or consciousness is altered during dreams and memories struck us by their incongruity. What happens then when we sleep? In this thesis, we played complex sounds to study how the brain interprets information from the external world during sleep. We asked ourselves how the sleep disconnection from its sensory environment depends on cognitive processes occurring during sleep. To do so, we used EEG, a brain imaging technique. We could show that the sleeping brain keeps on monitoring sounds and can even selectively enhance or suppress certain information, as well as learn a foreign language. These capacities depend nevertheless crucially on markers of internal activity during sleep, demonstrating that sleep is a fundamentally active process and host of complex cognitive activit