Phenomenal consciousness in insects? A possible way forward

Klein & Barron (2016) propose that subjective experience in humans arises in the midbrain and then argue that insects have the capacity for subjective experience because their nervous system can perform neural processing similar to that of the midbrain. This approach ultimately fails because it is built on the false premise that the midbrain is the source of the awareness of sensory stimuli. I instead propose that the capacity for subjective experience must be based on fundamental neural computations that generate the “what it feels like” experience. Two such computations associated with metarepresentations and high level representations entering working memory are discussed as possible measures of the capacity for subjective experience

Going beyond just-so stories

Colloquial arguments for fish feeling pain are deeply rooted in anthropometric tendencies that confuse escape responses to noxious stimuli with evidence for consciousness. More developed arguments often rely on just-so stories of fish displaying complex behaviours as proof of consciousness. In response to commentaries on the idea that fish do not feel pain, I raise the need to go beyond just-so stories and to rigorously analyse the neural circuitry responsible for specific behaviours using new and emerging technologies in neuroscience. By deciphering the causal relationship between neural information processing and conscious behaviour, it should be possible to assess cogently the likelihood of whether a vertebrate species has the neural hardware necessary to — at least — support the feeling of pain

Appeals for “One Million Belgian Children”: Understanding the Success of the Commission for Relief in Belgium through the Mudd Family Papers

In response to the German occupation of Belgium in World War I, future U.S. president Herbert Hoover and a handful of his colleagues in the mining engineer industry founded the Commission for Relief in Belgium (CRB). The CRB engineered one of the greatest relief movements in history partly on account of its successful public appeals; nevertheless, the success of these appeals has never been fully explained due to a remarkable dearth of scholarship on the topic. This paper seeks to fill in the gap by analyzing salient documents in the Mudd Family Papers, located in Honnold/Mudd Library’s Special Collections section. The artifacts ultimately evince that the CRB tailored its appeals to the American upper and middle classes, appropriating their respective motifs and lexicons to successfully mobilize both groups; that rumors of wartime atrocities against Belgian children augmented its appeals to the middle class; and that it issued targeted messages to its American supporters after the United States’ entry into World War I, maintaining vital public support. The findings of this paper promise to add invaluable knowledge to an exceedingly understudied historical subject

Minds, morality and midgies

Mikhalevich & Powell argue that the exclusion of the vast majority of arthropods from moral standing is unwarranted, particularly given the purported evidence for cognition and sentience in these organisms. The implied association between consciousness and moral standing is questionable and their assumption that rich forms of cognition and flexible behavior are dependent on phenomenal consciousness needs to be reconsidered in light of current neuroscientific evidence. We conclude by proposing a neural algorithmic approach for deciphering whether organisms are capable of subjective experience

Lack of imagination can bias our view of animal sentience

How an animal reacts to a sensory stimulus is often used to assess whether that animal can experience feelings such as pain and pleasure. This behavioural path is typically complemented with reference to how a human would normally respond to and experience an analogous stimulus. Together, these approaches can lead to a “hard to imagine otherwise” argument for feelings. It is time to go beyond these qualitative assessments and to now determine whether a nervous system can execute the neural functions necessary for sentience

The extracellular matrix modulates olfactory neurite outgrowth on ensheathing cells

Primary olfactory axons grow along a stereotypical pathway from the nasal cavity to the olfactory bulb through an extracellular matrix rich in laminin and heparan sulfate proteoglycans (HSPGs) and bounded by the expression of chondroitin sulfate proteoglycans (CSPGs). This pathway is pioneered by olfactory ensheathing cells, which provide a substrate conducive for axon growth during early development. In the present study, we examined the effect of several extracellular matrix constituents on the spreading and migration, as well as the neurite outgrowth-promoting properties, of olfactory ensheathing cells. Laminin and Matrigel enhanced the spreading and migration of olfactory ensheathing cells and increased their neurite outgrowth-promoting activity. In contrast, HSPG and CSPG had little effect on the spreading and migration of olfactory ensheathing cells and hence did not promote olfactory neurite outgrowth. In vitro olfactory axons grew preferentially on the surface of olfactory ensheathing cells rather than the underlying extracellular matrix. We propose that olfactory ensheathing cells secrete laminin and HSPGs, which together with other cofactors, stimulate these cells to migrate and adopt a neurite outgrowth-promoting phenotype. Expression of CSPGs in the surrounding mesenchyme confines the growth of ensheathing cells, as well as the axons, which grow on the surface of these cells, to a specific pathway. Thus, the ECM indirectly modulates the growth and guidance of olfactory axons during development

Development of P2 olfactory glomeruli in P2-internal ribosome entry site-tau-lacZ transgenic mice

Primary olfactory neurons project their axons to the olfactory bulb, where they terminate in discrete loci called glomeruli. All neurons expressing the same odorant receptor appear to terminate in a few glomeruli in each olfactory bulb. In the P2-IRES-tau-LacZ line of transgenic mice, LacZ is expressed in the perikarya and axons of primary olfactory neurons that express the P2 odorant receptor. In the present study, we examined the developmental appearance of P2 neurons, the topographical targeting of P2 axons, as well as the formation of P2 glomeruli in the olfactory bulb. P2 axons were first detected in the olfactory nerve fiber layer at embryonic day 14.5 (E14.5), and by E15.5 these axons terminated in a broad locus in the presumptive glomerular layer. During the next 5 embryonic days, the elongated cluster of axons developed into discrete glomerulus-like structures. In many cases, glomeruli appeared as pairs, which were initially connected by a fascicle of P2 axons. This connection was lost by postnatal day 7.5, and double glomeruli at the same locus were observed in 85% of adult animals. During the early postnatal period, there was considerable mistargeting of P2 axons. In some cases P2 axons entered inappropriate glomeruli or continued to grow past the glomerular layer into the deeper layers of the olfactory bulb. These aberrant axons were not observed in adult animals. These results indicate that olfactory axons exhibit errors while converging onto a specific glomerulus and suggest that guidance cues may be diffusely distributed at target sites in the olfactory bulb