Amazing stuff! Was prior research too much focused too much on analyzing specific brain regions (like missing the forest for the trees)?
"What is the evolutionary advantage of our consciousness? And what can we learn about this from observing birds? ...
Although scientific research about consciousness has enjoyed a boom in the past two decades, one central question remains unanswered: What is the function of consciousness? Why did it evolve at all? ...
Furthermore, observing the brains of birds shows that evolution can achieve similar functional solutions to realize consciousness despite different structures. ...
Humans and some animals then develop a reflexive (self-)consciousness. In its complex form, it means that we are able to reflect on ourselves as well as our past and future. We can form an image of ourselves and incorporate it into our actions and plans. “Reflexive consciousness, in its simple forms, developed parallel to the two basic forms of consciousness,” explains Newen. “IN such cases conscious experience focuses not on perceiving the environment, but rather on the conscious registration of aspects of oneself.” This includes the state of one’s own body, as well as one’s perception, sensations, thoughts, and actions. To use one simple example, recognizing oneself in the mirror is a form of reflexive consciousness. Children develop this skill at 18 months, and some animals have been shown to do this as well, such as chimpanzees, dolphins, and magpies. Reflexive conscious experiences – as its core function – makes it possible for us to better integrate into society and coordinate with others. ...
The researchers highlight three central areas in which birds show remarkable parallels to conscious experience in mammals: sensory consciousness, neurobiological foundations, and accounts of self-consciousness. ...
Firstly, studies of sensory consciousness indicate that birds not only automatically process stimuli, but subjectively experience them. When pigeons are presented with ambiguous visual stimuli, they shift between various interpretations, similar to humans. Crows have also been shown to possess nerve signals that do not reflect the physical presence of a stimulus, but rather the animal’s subjective perception. ...
Secondly, birds’ brains contain functional structures that meet the theoretical requirements of conscious processing, despite their different brain structure. “The avian equivalent to the prefrontal cortex, the NCL, is immensely connected and allows the brain to integrate and flexibly process information,” says Güntürkün. “The connectome of the avian forebrain, which presents the entirety of the flows of information between the regions of the brain, shares many similarities with mammals. Birds thus meet many criteria of established theories of consciousness, such as the Global Neuronal Workspace theory.”
Thirdly, more recent experiments show that birds may have different types of self-perception. Even though some species of corvids pass the traditional mirror test, other ecologically significant versions of the tests have shown further types of self-consciousness in other bird species. “Experiments indicate that pigeons and chickens differentiate between their reflection in a mirror and a real fellow member of their species, and react to these according to context. This is a sign of situational, basic self-consciousness,” ...
The findings suggest that consciousness is an older and more widespread evolutionary phenomenon than had previously been assumed. Birds demonstrate that conscious processing is also possible without a cerebral cortex and that different brain structures can achieve similar functional solutions. ..."
From the abstract (1):
"The evolution of consciousness is a neglected topic that plays a surprisingly insignificant role in all major theories of consciousness. Furthermore, substantial disagreements can be observed in the dominant views on the neural correlates of consciousness (NCCs), which focus too much on cortical brain regions.
In order to dissolve some of the contradictions among these views and to constrain the rival theories, we propose to distinguish three core phenomena of phenomenal consciousness: basic arousal, general alertness and reflexive (self-)consciousness.
The central aim is to show that we can fruitfully distinguish specific functions for each of the three phenomena.
Basic arousal has the function to alarm the body and secure survival by intervening in the slow updating of homeostatic processes.
General alertness fosters advanced learning and decision-making processes, enabling various new behavioural strategies to deal with challenges, and
reflexive (self-)consciousness enables future-directed long-term planning, accounting for the mindset of oneself and other agents.
Constraining our contemporary theories of consciousness with this evolutionary and functional approach will enable the science of consciousness to make progress by accounting for three specific functions of consciousness, thereby informing the search for distinct an NCC."
From the abstract (2):
"In this article, we start from the assumption that consciousness is not the ultimate triumph of human evolution but rather represents a more basic cognitive process, possibly shared with other animal phyla.
In this article, we show that there is growing evidence that
(i) birds have sensory and self-awareness, and
(ii) they also have the neural architecture that may be necessary for this.
We present behavioural studies and recent neurobiological data and discuss them in relation to three major theories of consciousness: the Global Neural Workspace Theory (GNWT), the Recurrent Processing Theory (RPT) and the Integrated Information Theory.
Although the findings so far do not allow for a strong conclusion, the neurophysiological and anatomical features of the avian brain seem to align with the prerequisites of the GNWT and RPT to host consciousness."
We Have a Consciousness? (original news release)
Three types of phenomenal consciousness and their functional roles: unfolding the ALARM theory of consciousness (open access, 1)
Conscious birds (open access, 2)
Fig. 1 Global Neuronal Workspace Theory (GNWT) and the avian connectome.
(A) The GNWT requires local and specialized neuronal modules (small circles grouped by function in the external networks) linked to a central, highly interconnected global workspace. ...
(B) The telencephalic connectome of the pigeon forebrain as analysed with graph theoretical approaches, showing exclusively the connections to and from the hub nodes. ... are densely interconnected to each other as well as to the localized modules (small circles). This represents a potential substrate for a global workspace ...
No comments:
Post a Comment