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It's a central dogma of creationism that humans are a special form of life created distinct from all other animals. This is one of the appeals of creationism to those who have such a high opinion of themselves that they like to believe they were created by and have a special relationship with the creator of the entire Universe, which it created specifically with them in mind.
However, when we look for evidence of this biological difference, we find instead evidence that we have the same biology as all other mammals and have much more in common than the relatively small differences that, like all other species, place us in a separate taxon. The similarities for a nested hierarchy which shows how closely (or distantly) related we are to the other mammals, particularly, in descending order, the other African great apes, the other anthropoid apes, the old-world monkeys and the other primates.
But creationists particularly like to point to our greater intelligence and aesthetic appreciation of art and music, and our ability to communicate. However, they too can be shown to be fat from unique to humans, who differ in those respects only by degree. Having special abilities with an organ of our body no more makes us a special creation than an elephant's special abilities with its trunk makes elephants a special creation, or a dolphin's special abilities with sonar makes dolphins a special creation.
Now, a team of neuroscientists from Massachusetts Institute of Technology (MIT), Cambridge, MA, USA and Vanderbilt University, Nashville, TN, USA have shown that there are six distinct layers of the mammalian brain cortex and that each of these is associated with the same distinctive pattern of electrical activity. Their results were the subject of an open access paper in Nature Neuroscience a few days ago.
So even the human brain - that favourite organ of creationists who never seem to be able to use it, is more similar to the brain of other mammals than it is different.
The scientists found that in the topmost layers, neuron activity is dominated by rapid oscillations known as gamma waves. In the deeper layers, slower oscillations called alpha and beta waves predominate. They say the universality of these patterns suggests that these oscillations are likely playing an important role across the brain. They believe these brain-waves are associated with storage, retention and recall of memory, which implies that other mammals can also learn and remember, which implies cognition and the ability to process and assimilate information. From the news release from MIT:
Layers of activity
The human brain contains billions of neurons, each of which has its own electrical firing patterns. Together, groups of neurons with similar patterns generate oscillations of electrical activity, or brain waves, which can have different frequencies. [Professor Earl] Miller’s lab has previously shown that high-frequency gamma rhythms are associated with encoding and retrieving sensory information, while low-frequency beta rhythms act as a control mechanism that determines which information is read out from working memory.
His lab has also found that in certain parts of the prefrontal cortex, different brain layers show distinctive patterns of oscillation: faster oscillation at the surface and slower oscillation in the deep layers. One study, led by [Assistant Professor André] Bastos when he was a postdoc in Miller’s lab, showed that as animals performed working memory tasks, lower-frequency rhythms generated in deeper layers regulated the higher-frequency gamma rhythms generated in the superficial layers.
In addition to working memory, the brain’s cortex also is the seat of thought, planning, and high-level processing of emotion and sensory information. Throughout the regions involved in these functions, neurons are arranged in six layers, and each layer has its own distinctive combination of cell types and connections with other brain areas.
In the new paper, the researchers wanted to explore whether the layered oscillation pattern they had seen in the prefrontal cortex is more widespread, occurring across different parts of the cortex and across species.The cortex is organized anatomically into six layers, no matter whether you look at mice or humans or any mammalian species, and this pattern is present in all cortical areas within each species. Unfortunately, a lot of studies of brain activity have been ignoring those layers because when you record the activity of neurons, it's been difficult to understand where they are in the context of those layers.
Diego Mendoza-Halliday, co-lead author, McGovern Institute for Brain Research
Massachusetts Institute of Technology, Cambridge, MA, USA
Using a combination of data acquired in Miller’s lab, Desimone’s lab, and labs from collaborators at Vanderbilt, the Netherlands Institute for Neuroscience, and the University of Western Ontario, the researchers were able to analyze 14 different areas of the cortex, from four mammalian species. This data included recordings of electrical activity from three human patients who had electrodes inserted in the brain as part of a surgical procedure they were undergoing.
[…]
Across all species, in each region studied, the researchers found the same layered activity pattern.We did a mass analysis of all the data to see if we could find the same pattern in all areas of the cortex, and voilà, it was everywhere. That was a real indication that what had previously been seen in a couple of areas was representing a fundamental mechanism across the cortex.
Diego Mendoza-Halliday
AbstractAnd another 'uniquely human characteristic that creationists love to cite because it makes them feel special, turns out to be nothing of the sort and once again we see another supposedly unique human characteristic that creationists like to claim is proof of unique creation turns out to be evidence for common descent.
The mammalian cerebral cortex is anatomically organized into a six-layer motif. It is currently unknown whether a corresponding laminar motif of neuronal activity patterns exists across the cortex. Here we report such a motif in the power of local field potentials (LFPs). Using laminar probes, we recorded LFPs from 14 cortical areas across the cortical hierarchy in five macaque monkeys. The laminar locations of recordings were histologically identified by electrolytic lesions. Across all areas, we found a ubiquitous spectrolaminar pattern characterized by an increasing deep-to-superficial layer gradient of high-frequency power peaking in layers 2/3 and an increasing superficial-to-deep gradient of alpha-beta power peaking in layers 5/6. Laminar recordings from additional species showed that the spectrolaminar pattern is highly preserved among primates—macaque, marmoset and human—but more dissimilar in mouse. Our results suggest the existence of a canonical layer-based and frequency-based mechanism for cortical computation.
Main
One of the most prominent structures of the mammalian brain is the cerebral cortex, which is thought to underlie complex cognitive functions. Despite the vast diversity of functions carried out by different areas of the cortex, almost all areas share a ubiquitous anatomical motif composed of six layers, with relatively minor variations1. This observation has led to the hypothesis that all cortical areas are composed of a common canonical microcircuit that is the fundamental unit for computation2,3,4; by understanding the principles of the canonical microcircuit, one should be able to explain how all areas of cortex accomplish their functions with variations of the ubiquitous laminar motif. This hypothesis has inspired many theoretical proposals of cortical function5,6,7.
It is reasonable to hypothesize that the anatomical differences between cortical layers in cell size, composition and projections give rise to distinct laminar activity patterns. Because the overall laminar anatomical motif8,9 is relatively preserved across cortical areas and across individual subjects, the corresponding laminar activity patterns should also be preserved across cortical areas and subjects. Moreover, in all areas and subjects, the activity patterns should consistently map onto the same anatomical landmarks of the laminar architecture.
Numerous studies have observed laminar activity patterns10,11,12,13,14,15,16,17,18. However, these patterns have been observed in a given cortical area and in the context of a given function, not as a common phenomenon across cortex. It has been proposed that there is a canonical laminar activation pattern that reflects the ubiquitous anatomical laminar motif of the cortex: an initial excitation in layer 4, followed by subsequent excitation in layers 2/3 and then layers 5/6 (refs. 4,19). Using current source density (CSD) analysis of local field potentials (LFPs)20, this activation pattern has been observed in visual cortex and is currently the established method for estimating the relative location of cortical layers in electrophysiological recordings21,22. However, the generality of this circuitry has been questioned by the observation that deep layers can be activated independently of superficial layers23. Furthermore, the CSD pattern is driven by sensory input and, thus, may be less common in non-sensory areas.
It has also been proposed that cortex generates a canonical laminar activity pattern composed of gamma rhythms (50–150 Hz) in superficial layers and alpha-beta rhythms (10–30 Hz) in deep layers5,10,12,15,18,24,25,26,27,28,29. However, other reports have stressed distinct laminar activity patterns in the inferotemporal (IT) cortex11 and the supplementary eye field (SEF)28 compared to early visual cortex in macaque cortex. If such a canonical pattern of superficial-layer gamma and deep-layer alpha-beta exists, it could provide a scaffold for these rhythms to functionally segregate feedforward and feedback inter-areal communication, respectively18,30,31,32,33.
Whether the cortex contains a canonical laminar oscillatory activity pattern, and whether this pattern is preserved across all of cortex, remains unknown. To investigate this, we recorded LFP signals across all cortical layers using multicontact laminar probes. We combined data collected in multiple laboratories from five macaque monkeys and 14 cortical areas spanning a variety of hierarchical processing stages and functions (Fig. 1a): V1 (primary visual cortex), V3, V4, middle temporal (MT) (early visual areas), medial superior temporal (MST) (a visual association and multimodal area), medial intraparietal (MIP) (a visual/somatosensory/motor area), area 5 (somatosensory cortex), area 6 (premotor cortex), dorsal prelunate (DP), Tpt (temporo-parietal-auditory cortex), TPO (temporo-parieto-occipital junction; a polysensory area), 7A, lateral intraparietal (LIP) (higher-order parietal association areas) and lateral prefrontal cortex (LPFC) (a higher-order executive area). Across all areas, we observed a common laminar pattern, which we termed the spectrolaminar motif: LFP power in the gamma frequency band (50–150 Hz) was strongest in superficial layers, and the alpha-beta band (10–30 Hz) was strongest in deep layers.
To test whether the spectrolaminar motif consistently aligns with specific anatomical layers in macaques, we performed electrolytic lesions. Histological analyses revealed that key landmarks of the spectrolaminar motif consistently mapped onto the same anatomical layers: peak gamma power was located in layers 2/3; peak alpha-beta power was located in layers 5/6; and the crossover between relative gamma and alpha-beta power corresponded to layer 4.Fig. 1: Laminar recording methods and laminar differences in LFP oscillatory power. 
a, Inflated cortical surface of the macaque brain showing cortical areas recorded depicted using Caret software60 on the F99 template brain and using Lewis and van Essen61 area parcellation scheme. b, Structural MRI nearly-coronal section of one monkey from study 2 showing recording chamber grid (top) and location of areas MT, MST, 7A, 5, MIP and LIP on the right hemisphere. Yellow lines show the locations of example probes in all areas. c, Nissl section from the same monkey corresponding to a ×10 magnification of the black rectangular region in b with an example probe diagram showing the locations of recording channels (black dots) with respect to the cortical layers in area LIP. WM, white matter. d,g, Relative power as a function of frequency in a superficial-layer channel and a deep-layer channel from two example probes in areas LIP (d) and MT (g). e,h, Relative power maps for the two example probes. f,i, Relative power averaged in the alpha-beta (blue) and gamma (red) frequency bands as a function of laminar depth for the two example probes. Laminar depths are measured with respect to the alpha-beta/gamma crossover.
Finally, we tested whether the spectrolaminar motif generalizes across other species by analyzing laminar recordings from marmoset, human and mouse cortex. The spectrolaminar pattern was highly similar among the macaque, marmoset and human but was qualitatively and quantitatively more dissimilar between these primates and mice.
It is becoming more and more apparent why creationists are encouraged by their cult to attack and try to disparage science when it is unremittingly falsifying all their sacred dogmas like this.
This book explains why faith is a fallacy and serves no useful purpose other than providing an excuse for pretending to know things that are unknown. It also explains how losing faith liberates former sufferers from fear, delusion and the control of others, freeing them to see the world in a different light, to recognise the injustices that religions cause and to accept people for who they are, not which group they happened to be born in. A society based on atheist, Humanist principles would be a less divided, more inclusive, more peaceful society and one more appreciative of the one opportunity that life gives us to enjoy and wonder at the world we live in.
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How did you come to be here, now? This books takes you from the Big Bang to the evolution of modern humans and the history of human cultures, showing that science is an adventure of discovery and a source of limitless wonder, giving us richer and more rewarding appreciation of the phenomenal privilege of merely being alive and able to begin to understand it all.
Available in Hardcover, Paperback or ebook for Kindle
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