Brain as Transducer: What if the brain is not a self-contained information processor? What if it is simply a transducer?

Evolution has not only produced millions of different species; it has also produced millions of different transducers. Our bodies are encased in transducers that convert distinctive properties of electromagnetic radiation, air pressure waves, airborne chemicals, liquid-borne chemicals, textures, pressure, and temperature into similarly distinctive patterns of electrical and chemical activity in the brain. What if, at some point - perhaps when humans first developed language and consciousness - the random mixing of genes produced a brain that could send signals to and receive signals from an alternate universe? Unlike string theory or theories of parallel universes, the theory that the brain is bidirectional transducer is directly testable, and empirical support for this theory has the potential to profoundly change our understanding both of ourselves and of our universe. It will help to explain, in rational and objective terms, more than 50 odd phenomena that have baffled humans for eons, among them: dreams, hallucinations, schizophrenia, and even claims about bizarre experiences such as demonic possession and communication with the dead. Neuroscience has been hamstrung for half a century by its reliance on the information processing model of the brain - a metaphor that has shed no light on how the human brain actually works. Let’s set aside the metaphors we have used for 2,000 years to "explain" human intelligence. Transduction theory is a testable theory consistent with evolutionary theory and with three core theories of modern physics - string theory, inflation theory, and quantum theory - each of which predicts the existence of alternate universes.

Uncovering new global risks from commercial chemicals in air

Commercial chemicals are used extensively across global urban centers, posing a potential exposure risk to 4.2 billion people, which accounts for 55% of the global population. Harmful chemicals are often assessed and regulated based on their environmental persistence, bioaccumulation, and toxic properties, under international and national initiatives such as the Stockholm Convention. However, current regulatory frameworks largely rely upon knowledge of the properties of the parent chemicals, with minimal consideration given to their atmospheric transformation products. This is mainly due to a significant lack of experimental data, as identifying transformation products in complex mixtures of airborne chemicals is an immense analytical challenge,hence making a comprehensive and reliable risk assessment for harmful chemicals currently unachievable. Here, we develop a novel framework, combining laboratory and field experiments, non-target analysis techniques, and in-silico modelling, to identify and assess the hazards of airborne chemicals, which takes into account atmospheric chemical reactions. By applying this framework to organophosphate flame retardants, as representative chemicals of emerging concern, we find that their transformation products are globally distributed across 18 megacities, representing a previously unrecognized exposure risk for the world’s urban populations. Furthermore, the transformation products can be up to an order of magnitude more persistent, environmentally mobile, and toxic than the parent chemicals. The results indicate that the overall human and environmental risks associated with flame retardants could be significantly underestimated, while highlighting a strong need to include atmospheric transformations in the development of regulations for all harmful chemicals moving forward.

Spatiotemporal Processing of Bimodal Odor Lateralization in the Brain Using Electroencephalography Microstates and Source Localization

The neuronal cascade related to the perception of either purely olfactory or trigeminal airborne chemicals has been investigated using electroencephalography (EEG) microstate analyses and source localization. However, most airborne chemicals are bimodal in nature, encompassing both properties. Moreover, there is an ongoing debate regarding whether there is one dominant nostril, and this could be investigated using these multichannel EEG methods. In this study, 18 right-handed, healthy participants (13 females) were monorhinally stimulated using an olfactometer with the bimodal component acetic acid during continuous EEG recording. Participants indicated the side of stimulation, the confidence in their decision, and rated the strength of the evoked perception. EEG microstate clustering determined four distinct maps and successive backfitting procedures, and source estimations revealed a network that evolved from visual-spatial processing areas to brain areas related to basic olfactory and trigeminal sensations (e.g., thalamus, cingulate cortex, insula, parahippocampal, and pre-/post-central gyri) and resulted in activation of areas involved in multisensory integration (e.g., frontal-temporal areas). Right-nostril stimulation was associated with faster microstate transition and longer involvement of the superior temporal gyrus, which was previously linked to chemical localization and provides evidence for a potential nostril dominance. The results describe for the first time the processing cascade of bimodal odor perception using microstate analyses and demonstrate its feasibility to further investigate potential nostril dominance.

The Study of Assessing the Impact on Environment by the Noxious Airborne Chemicals: a Review

In the current scenario, hazardous airborne chemicals are spreading all over the world. These can be found in the form of gases, vapors, particulate matters, or solid. Some of the airborne elements similar cadmium, lead, arsenic, zinc, mercury, fluoride, chromium, nickel, copper, manganese, etc. and approximately the hazardous airborne gases are carbon monoxide, hydrogen sulfide, nitrogen oxides, methane, ammonia, nitrogen dioxide, sulfur dioxide, etc. which are very poisonous to the environment and for human health. The major source of airborne chemicals in factories, industries, mining activities, agricultural activities, motor vehicles, burning of fossil fuels, indoor air pollution, etc. which release the very harmful gases and elements by which the air get polluted and by this intake of polluted airborne chemicals, humans are suffering from the various disease like cancer birth defects and respiratory diseases, etc., death may also occur. This review explains the detailed study of hazardous airborne gases and toxic chemicals.

Mixture coding and segmentation in the anterior piriform cortex

Coding of odorous stimuli has been mostly studied using single isolated stimuli. However, a single sniff of air in a natural environment is likely to introduce airborne chemicals emitted by multiple objects into the nose. The olfactory system is therefore faced with the task of segmenting odor mixtures to identify objects in the presence of rich and often unpredictable backgrounds. The piriform cortex is thought to be the site of object recognition and scene segmentation, yet the nature of its responses to odorant mixtures is largely unknown. In this study, we asked two related questions. 1) How are mixtures represented in the piriform cortex? And 2) Can the identity of individual mixture components be read out from mixture representations in the piriform cortex? To answer these questions, we recorded single unit activity in the piriform cortex of naïve mice while sequentially presenting single odorants and their mixtures. We find that a normalization model explains mixture responses well, both at the single neuron, and at the population level. Additionally, we show that mixture components can be identified from piriform cortical activity by pooling responses of a small population of neurons - in many cases a single neuron is sufficient. These results indicate that piriform cortical representations are well suited to perform figure-background segmentation without the need for learning.

The origin of the odorant receptor gene family in insects

The sense of smell enables the detection and discrimination of airborne chemicals via chemosensory receptors that have evolved independently multiple times throughout the tree of life. In insects, the odorant receptor (OR) gene family is the major chemosensory gene family involved in olfaction and its origin has been hypothesized to coincide with the evolution of a terrestrial lifestyle in hexapods. Missbach et al. (2014) challenged this view and suggested that ORs evolved with an ancestral OR co-receptor (Orco) after the origin of terrestriality, hypothesizing that the OR/Orco system is an adaptation to winged flight in insects instead. Building upon this work, we investigated the genomes of basal hexapod and insect lineages including Collembola, Diplura, Archaeognatha, Zygentoma, Odonata, and Ephemeroptera in an effort to identify the origin of the insect OR gene family. While absent from all non-insect hexapod lineages analyzed, ORs are present in all insect genomes. Orco is absent only in the most ancient insect lineage Archaeognatha. A fully functional OR/Orco system was present in our newly generated genome data of the Zygentoma Thermobia domestica. We suggest that ORs did evolve as adaptation to a terrestrial lifestyle outside high-humidity habitats, and not winged flight, representing a key evolutionary novelty in the ancestor of all insects. The OR family is therefore the first known molecular synapomorphy for the Class Insecta.