Invested effort and our open-ended sense of ownership.

Pascal Boyer achieves a felicitous integration of what is known about human ownership psychology by deriving ownership intuitions from the interaction of resource acquisition and our cooperative sociality. By exploring the sense of ownership already present in the domain of resource acquisition, I sketch an evolutionary path to the open-ended nature of the specifically human version of that sense.

Coordinated rhythms in animal species, including humans: Entrainment from bushcricket chorusing to the philharmonic orchestra.

Coordinated group displays featuring precise entrainment of rhythmic behavior between neighbors occur not only in human music, dance and drill, but in the acoustic or optical signaling of a number of species of arthropods and anurans. In this review we describe the mechanisms of phase resetting and phase and tempo adjustments that allow the periodic output of signaling individuals to be aligned in synchronized rhythmic group displays. These mechanisms are well described in some of the synchronizing arthropod species, in which conspecific signals reset an individual's endogenous output oscillators in such a way that the joint rhythmic signals are locked in phase. Some of these species are capable of mutually adjusting both the phase and tempo of their rhythmic signaling, thereby achieving what is called perfect synchrony, a capacity which otherwise is found only in humans. We discuss this disjoint phylogenetic distribution of inter-individual rhythmic entrainment in the context of the functions such entrainment might perform in the various species concerned, and the adaptive circumstances in which it might evolve.

The integrated information theory of consciousness: Unmasked and identified.

In our response to a truly diverse set of commentaries, we first summarize the principal topical themes around which they cluster, then address two "outlier" positions (the problem of consciousness has been solved vs. is intractable). Next, we address ways in which commentaries by non-integrated information theory (IIT) authors engage with the specifics of our IIT critique, turning finally to the four commentaries by IIT authors.

Music, bonding, and human evolution: A critique.

Savage et al. propose that music filled a hypothetical "bonding gap" in human sociality by Baldwinian gene-culture coevolution (or protracted cognitive niche construction). Both these stepping stones to an evolutionary account of the function and origin of music are problematic. They are scrutinized in this commentary, and an alternative is proposed.

The integrated information theory of consciousness: A case of mistaken identity.

Giulio Tononi's integrated information theory (IIT) proposes explaining consciousness by directly identifying it with integrated information. We examine the construct validity of IIT's measure of consciousness, phi (Φ), by analyzing its formal properties, its relation to key aspects of consciousness, and its co-variation with relevant empirical circumstances. Our analysis shows that IIT's identification of consciousness with the causal efficacy with which differentiated networks accomplish global information transfer (which is what Φ in fact measures) is mistaken. This misidentification has the consequence of requiring the attribution of consciousness to a range of natural systems and artifacts that include, but are not limited to, large-scale electrical power grids, gene-regulation networks, some electronic circuit boards, and social networks. Instead of treating this consequence of the theory as a disconfirmation, IIT embraces it. By regarding these systems as bearers of consciousness ex hypothesi, IIT is led toward the orbit of panpsychist ideation. This departure from science as we know it can be avoided by recognizing the functional misattribution at the heart of IIT's identity claim. We show, for example, what function is actually performed, at least in the human case, by the cortical combination of differentiation with integration that IIT identifies with consciousness. Finally, we examine what lessons may be drawn from IIT's failure to provide a credible account of consciousness for progress in the very active field of research concerned with exploring the phenomenon from formal and neural points of view.

Codes are for messages, not for neurons.

My commentary draws on extensive arguments against "coding in the brain" developed by my neuroscience mentor, the late Eugene Sachs, who summarized them as follows: "[T]he energy in the signal is the only code there is for information…. The code is the same for each cell, but each cell's location is different, and location is the only basis for significance" (p. 13).

Conscious olfaction: Content, function, and localization.

The target article's emphasis on olfaction is a welcome reminder of the multimodal nature of conscious experience. Here, I explore the distinctive and even unique attributes of our sense of smell from the point of view of their bearing on and fit with a subcortical locus of sensory experience.

Brain Network Reconfiguration and Perceptual Decoupling During an Absorptive State of Consciousness.

Trance is an absorptive state of consciousness characterized by narrowed awareness of external surroundings and has long been used-for example, by shamans-to gain insight. Shamans across cultures often induce trance by listening to rhythmic drumming. Using functional magnetic resonance imaging (fMRI), we examined the brain-network configuration associated with trance. Experienced shamanic practitioners (n = 15) listened to rhythmic drumming, and either entered a trance state or remained in a nontrance state during 8-min scans. We analyzed changes in network connectivity. Trance was associated with higher eigenvector centrality (i.e., stronger hubs) in 3 regions: posterior cingulate cortex (PCC), dorsal anterior cingulate cortex (dACC), and left insula/operculum. Seed-based analysis revealed increased coactivation of the PCC (a default network hub involved in internally oriented cognitive states) with the dACC and insula (control-network regions involved in maintaining relevant neural streams). This coactivation suggests that an internally oriented neural stream was amplified by the modulatory control network. Additionally, during trance, seeds within the auditory pathway were less connected, possibly indicating perceptual decoupling and suppression of the repetitive auditory stimuli. In sum, trance involved coactive default and control networks, and decoupled sensory processing. This network reconfiguration may promote an extended internal train of thought wherein integration and insight can occur.

Five fundamental constraints on theories of the origins of music.

The diverse forms and functions of human music place obstacles in the way of an evolutionary reconstruction of its origins. In the absence of any obvious homologues of human music among our closest primate relatives, theorizing about its origins, in order to make progress, needs constraints from the nature of music, the capacities it engages, and the contexts in which it occurs. Here we propose and examine five fundamental constraints that bear on theories of how music and some of its features may have originated. First, cultural transmission, bringing the formal powers of cultural as contrasted with Darwinian evolution to bear on its contents. Second, generativity, i.e. the fact that music generates infinite pattern diversity by finite means. Third, vocal production learning, without which there can be no human singing. Fourth, entrainment with perfect synchrony, without which there is neither rhythmic ensemble music nor rhythmic dancing to music. And fifth, the universal propensity of humans to gather occasionally to sing and dance together in a group, which suggests a motivational basis endemic to our biology. We end by considering the evolutionary context within which these constraints had to be met in the genesis of human musicality.

Speech, vocal production learning, and the comparative method.

The faith that "comparative analysis of the behaviour of modern primates, in conjunction with an accurate phylogenetic tree of relatedness, has the power to chart the early history of human cognitive evolution" (Byrne 2000 p. 543) runs afoul of the fact that no other primate besides humans is capable of vocal production learning. This basic enabling adaptation for articulate speech bears crucially on the reconstruction of language origins.

Consciousness without cortex: a hydranencephaly family survey.

AIM: Hydranencephaly is commonly taken to exemplify the developmental vegetative state, based largely on the assumption that radical loss of cortical tissue is incompatible with consciousness. The aim of the study reported here was to survey primary caregivers of children born with hydranencephaly for behavioural evidence indirectly informative about the conscious status of these children. METHODS: The survey recruited 108 primary caregivers through a parent support group and was conducted online via a commercial survey hosting facility. As part of a more extensive questionnaire, participants answered 106 questions bearing on the environmental responsiveness, emotional reactivity, mood and agency of the child in their care. RESULTS: The survey elicited a many-facetted and detailed set of caregiver answers and written observations regarding the child's behaviour. A conservative measure of agreement among respondents' answers yielded a generic portrait of the responsiveness and expressive behaviour of a hydranencephaly child. CONCLUSION: The generic behavioural characteristics of hydranencephaly thus assessed are incompatible on multiple counts with the unconsciousness characteristic of the vegetative state. This bears on what is included under the concept of quality of life for children with hydranencephaly, and hence on appropriate forms of treatment and care in their case.

Genes, hosts, goals: disentangling causal dependencies.

The special sense in which the concept of "selfishness" is defined in Dawkins's popularization of basic evolutionary theory is analyzed with regard to its applicability to the relation between goals and those who entertain and pursue them. It is concluded that grounds analogous to those on which independent self-interest vis-á-vis their hosts is attributed to genes in Dawkins's sense are lacking in the case of goals in their relation to those who entertain and pursue them.

The efference cascade, consciousness, and its self: naturalizing the first person pivot of action control.

The 20 billion neurons of the neocortex have a mere hundred thousand motor neurons by which to express cortical contents in overt behavior. Implemented through a staggered cortical "efference cascade" originating in the descending axons of layer five pyramidal cells throughout the neocortical expanse, this steep convergence accomplishes final integration for action of cortical information through a system of interconnected subcortical way stations. Coherent and effective action control requires the inclusion of a continually updated joint "global best estimate" of current sensory, motivational, and motor circumstances in this process. I have previously proposed that this running best estimate is extracted from cortical probabilistic preliminaries by a subcortical neural "reality model" implementing our conscious sensory phenomenology. As such it must exhibit first person perspectival organization, suggested to derive from formating requirements of the brain's subsystem for gaze control, with the superior colliculus at its base. Gaze movements provide the leading edge of behavior by capturing targets of engagement prior to contact. The rotation-based geometry of directional gaze movements places their implicit origin inside the head, a location recoverable by cortical probabilistic source reconstruction from the rampant primary sensory variance generated by the incessant play of collicularly triggered gaze movements. At the interface between cortex and colliculus lies the dorsal pulvinar. Its unique long-range inhibitory circuitry may precipitate the brain's global best estimate of its momentary circumstances through multiple constraint satisfaction across its afferents from numerous cortical areas and colliculus. As phenomenal content of our sensory awareness, such a global best estimate would exhibit perspectival organization centered on a purely implicit first person origin, inherently incapable of appearing as a phenomenal content of the sensory space it serves.

Cortical gamma oscillations: the functional key is activation, not cognition.

Cortical oscillatory synchrony in the gamma range has been attracting increasing attention in cognitive neuroscience ever since being proposed as a solution to the so-called binding problem. This growing literature is critically reviewed in both its basic neuroscience and cognitive aspects. A physiological "default assumption" regarding these oscillations is introduced, according to which they signal a state of physiological activation of cortical tissue, and the associated need to balance excitation with inhibition in particular. As such these oscillations would belong among a variety of generic neural control operations that enable neural tissue to perform its systems level functions, without implementing those functions themselves. Regional control of cerebral blood flow provides an analogy in this regard, and gamma oscillations are tightly correlated with this even more elementary control operation. As correlates of neural activation they will also covary with cognitive activity, and this typically suffices to account for the covariation between gamma activity and cognitive task variables. A number of specific cases of gamma synchrony are examined in this light, including the original impetus for attributing cognitive significance to gamma activity, namely the experiments interpreted as evidence for "binding by synchrony". This examination finds no compelling reasons to assign functional roles to oscillatory synchrony in the gamma range beyond its generic functions at the level of infrastructural neural control.

On the role and origin of isochrony in human rhythmic entrainment.

Wherever human beings live, and however they may organise their affairs, they gather from time to time to sing and dance together, often in a ritual setting. In doing so they synchronise their voices and bodily movements to a shared, repeating interval of time, the musical pulse, beat or tactus. We take this capacity to "entrain" to an evenly paced stimulus (isochrony) so much for granted that it may come as a surprise to learn that from a biological point of view such behaviour is exceptional. But it is not altogether unique. There are a number of other species, none of them closely related to humans, that also engage in group synchrony of behaviour through entrainment to an isochronous pulse. Despite their evolutionary distance from us their life circumstances throw an interesting light on the possible origin and nature of our own entrainment capacity. Here we consider this capacity in terms of its possible origin, functional mechanisms, and ontogenetic development.

Consciousness without a cerebral cortex: a challenge for neuroscience and medicine.

A broad range of evidence regarding the functional organization of the vertebrate brain - spanning from comparative neurology to experimental psychology and neurophysiology to clinical data - is reviewed for its bearing on conceptions of the neural organization of consciousness. A novel principle relating target selection, action selection, and motivation to one another, as a means to optimize integration for action in real time, is introduced. With its help, the principal macrosystems of the vertebrate brain can be seen to form a centralized functional design in which an upper brain stem system organized for conscious function performs a penultimate step in action control. This upper brain stem system retained a key role throughout the evolutionary process by which an expanding forebrain - culminating in the cerebral cortex of mammals - came to serve as a medium for the elaboration of conscious contents. This highly conserved upper brainstem system, which extends from the roof of the midbrain to the basal diencephalon, integrates the massively parallel and distributed information capacity of the cerebral hemispheres into the limited-capacity, sequential mode of operation required for coherent behavior. It maintains special connective relations with cortical territories implicated in attentional and conscious functions, but is not rendered nonfunctional in the absence of cortical input. This helps explain the purposive, goal-directed behavior exhibited by mammals after experimental decortication, as well as the evidence that children born without a cortex are conscious. Taken together these circumstances suggest that brainstem mechanisms are integral to the constitution of the conscious state, and that an adequate account of neural mechanisms of conscious function cannot be confined to the thalamocortical complex alone.

The liabilities of mobility: a selection pressure for the transition to consciousness in animal evolution.

The issue of the biological origin of consciousness is linked to that of its function. One source of evidence in this regard is the contrast between the types of information that are and are not included within its compass. Consciousness presents us with a stable arena for our actions-the world-but excludes awareness of the multiple sensory and sensorimotor transformations through which the image of that world is extracted from the confounding influence of self-produced motion of multiple receptor arrays mounted on multijointed and swivelling body parts. Likewise excluded are the complex orchestrations of thousands of muscle movements routinely involved in the pursuit of our goals. This suggests that consciousness arose as a solution to problems in the logistics of decision making in mobile animals with centralized brains, and has correspondingly ancient roots.