Image taken from Wikipedia, see in: https://en.wikipedia.org/wiki/Wikipedia:WikiProject_Altered_States_of_Consciousness)
This is a very debated topic, which expresses the search for a utility value of the phenomenon of consciousness, in terms of adaptation or usefulness for humans. We could also ask this question in the case of non-human animals, if it happens to be that they also have consciousness. Finding ourselves asking this questions tells us a lot about the still mysterious nature of consciousness, we wouldn’t equally ask “what’s digestion for?” since we know about this. So we still have not solved the question of how conscious awareness arises from brain function, which is one of the biggest challenges of current research in neuroscience. Even though we could argue that it is not necessary to solve that problem first before we can talk about the function of consciousness, the two questions are connected, and we might gain insights about one aspect or the other in either direction, but the existence of these problems show how little we now about this phenomenon. In addition, there is the issue of defining consciousness. According to Wilkes (1984), the term “consciousness” is like the word “thing”, which is useful to designate many elements because it lacks specific content. For Lycan (2006), “consciousness” has been used with a great variety of meanings, and even the so-called “theories of consciousness” have a very diverse intellectual structure. Still, I think we can address our question without getting too deep on how we ought to define the term. Although most academics agree that there is an adaptive value of consciousness, there appears to be a minority who considers it not an important phenomenon in terms of biological adaptation, but a secondary by-product of other processes (Earl, 2008) and this needs to be discussed.
In Cameron (1998), Baars explains in simple terms that consciousness functions as a theatre, which suggests a host of functions. One use might be to distribute information from a source in the “spotlight” to many target tissues simultaneously, executive functions of prefrontal cortex could be involved in this and use such a publicity medium for controlling voluntary actions. On the other hand, it could also be useful for the co-ordination of separate unconscious habits or memories. Another function could be the contextualization of events, like learning to use a word in an entirely new meaningful context. Also, consciousness would support a running narrative about current and long-term concerns, and about significant others. As Baars indicate, overall, consciousness is apparently needed for novel kinds of access, coordination and control. This would be supported by biofeedback learning, which shows that any neuron or population of neurons can come under rapid, pinpoint voluntary control when immediate conscious sensory feedback is provided (Cameron, 1998). In the same sense, Baumeister, Masicampo and Vohs (2011) indicate that one function of consciousness would refer to overriding automatic responses, for example, when people are aware of emotions, they can adaptively prevent themselves from acting on them.
According to Edelman et al. (2011), the adaptive advantage of consciousness lies in the capacity that it gives to human beings to plan and prepare for future circumstances. This is a very common claim. In general terms, it is said that consciousness enhances processes of rational thought and planning, intentional action and executive function (Rosenthal, 2008). Regarding this last aspect, Crick and Koch (1992) have stated that there might be particular neurons associated to qualia (the subjective sensations or experiences of things, i.e. the redness of red, (Blackmore, 2005)), and these neurons would be those that project to the frontal lobes. Moreover, Naci, Cusack, Owen and Anello (2014) have identified what appears to be a common neural code that underpins similar conscious experiences, consisting of synchronized brain activity across frontal and parietal cortices in regions known to support executive function.
Consciousness has been linked to working memory as well. According to Baars and Franklin (2003), it can be observed that all active components of classical working memory are conscious, these refer to things such as input, rehearsal, visuospatial operations, recall and report. This could be supported by the fact that working memory and conscious perception share common neuronal substrates (Soto & Silvanto, 2014), particularly the prefrontal cortex and the connections to parietal areas has been associated to conscious states forming a global neural workspace for conscious accessibility of information, which in turn has been linked with working memory operations and cognitive control. When Baars (1997) talks about the “global workspace” for example, this implies a subjectively experienced event that is part of the working memory. Also, it has been suggested that conscious awareness could be one of the functions of the central executive component of working memory (Hassin, Bargh, Engell & McCulloch, 2009). This tells us about the possible functions of consciousness, which links memory and prefrontal cortex function, if we think that it serves action control, planning and reasoning.
Ramachandran and Hirstein (1997) seem to link the concepts of memory, executive function and consciousness in their idea of the laws of qualia, laws that must be present in order to have conscious awareness. They indicate that in order to have qualia, representations must have the possibility to be used for other processes, and that the subjective experience must remain for a certain amount of time (memory), so that the executive processes can work with that content. This idea comes from evidence obtained by phenomena such as blindsight. This condition occurs when subjects are capable of discriminating certain visual information without being conscious of it (Weiskrantz, 1986). According to Milner and Goodale (1995), patients with blindsight can correctly rotate an envelope and place it on a box, which is either in a vertical or horizontal position, for example, even though they cannot consciously perceive the box’s orientation. It is argued that the dorsal visual stream which process information related to the orientation of objects in space and affects the movement of the arm works like a reflex, based on ongoing information that it is not retained, and once the information is gone it cannot be used for other processes, failing to fulfil the laws of qualia previously mentioned (Ramachandran & Hirstein, 1997). It is not clear, however, weather this tells us that consciousness is important for executive function, and memory serves as a way to maintain representations for that use, or in fact because of the existence of memory and executive function something such as consciousness arises. If consciousness is a by-product of those processes, consciousness itself would not have the function to serve executive planning and action, but the link seems to exist. This association is very strong when we consider in addition that working memory has neuronal correlates in frontal lobe activity (Todd, Han, Harrison & Marois, 2011), which are also implicated in executive function. (Gazzaniga, Ivry & Mangun, 2013). At the same time, it has been shown that widespread bilateral fronto-parietal network activation is observed during various working memory tasks (Rottschy et al. 2012).
However, according to Ramachandran and Hirstein (1997), qualia would be based on the structures linked to the temporal lobes, as the subjective experience appears not to be associated either to the first stages of sensory processing, where there are not many outputs possible, or to the final steps of perceptual processing and behavioural planning. Instead they are linked to the middle stages of processing, with the temporal lobes acting as a sort of interface between perception and action. We must take into account that these authors consider that there is a limbic executive structure, which is associated to decision making and long tern behavioural planning, that it is the one most likely linked to consciousness as opposed to frontal lobe structures. For them, lesions that are more likely to produce deficits or alterations of consciousness or awareness are those that affect the temporal lobes.
But it appears that the laws of qualia are sometimes present without conscious awareness, which would indicate that memory and executive function are not necessary linked to consciousness. According to Soto and Silvanto (2014), it appears that we are not necessary aware of engaging in working memory operations, as shown by an experiment where no evidence of awareness was present when participants engaged in a task that used spatial sequence information to guide behaviour, which requires maintenance and updating of memory representations. Also, observers can maintain unseen, masked, visual cues, filled with similar distracters and still perform significantly above chance level, during a delayed discrimination test. High level cognitive functions, such as arithmetic computations and reading, can be carried out over non-conscious information. These would fall within the repertoire of working memory functions, and depend on the availability of the executive component of it (Soto & Silvanto, 2014). We could argue therefore that something else must be key for consciousness to happen. This is a problem if we are trying to determine the function of consciousness, would consciousness then be serving reasoning and planning?
Consciousness is also implicated in social cognition, in the case, for example, of mentally simulating others’ perspectives, which could be one of the main functions of consciousness. According to these authors, however, consciousness can also have counterproductive, maladaptive effects, but we could say that the beneficial effects would have been enough for consciousness to have been favoured by evolution (Baumeister et al. 2011).
Regarding consciousness and complex behaviour, Xiang, Wang and Zhang (2013) ask whether consciousness is necessary for conflict detection and conflict resolution. They used high temporal resolution event-related potentials (ERPs) to separate conflict detection from conflict resolution in a masked prime Stroop task. They conclude that consciousness of conflict information may not be necessary for detecting conflict, but that it may modulate conflict detection and that consciousness of conflict information may be a necessary boundary condition for the subsequent initiation of control operations in the more extended PFC–parietal control network.
According to Palmer and Ramsey (2012), consciousness has an important role in multisensory integration. This refers to the process by which information from different sensory modalities is combined to form a consistent and integrated representation of an object or event. Although cross-modal effects can occur in the absence of consciousness, it appears that consciousness is necessary for the information of representations in certain modality to cross other modalities. In accordance to this, Baddeley (2000) states that the episodic buffer (a concept that relates to working memory), provides temporary storage of information held in a multimodal code that has the capacity of integrating other information from the subsidiary systems, and also from long-term memory, to form a unitary episodic representation, where conscious awareness would be the main mode of retrieval from this buffer. Here multisensory integration and memory are linked. This idea of an episodic buffer that stores information in a multimodal code, binding it from the subsidiary systems, also makes sense in terms of our sense of a unified and integrated conscious experience.
Rosenthal (2008) concludes, however, that the consciousness of cognitive and desiderative states is unlikely to be useful for these purposes. For him, conscious states are a result of other highly useful psychological developments, some of which are related to language. Rosenthal exemplifies the consideration of consciousness as a by-product of other processes. The argument derives in part, due to the following: if we think about the High Order Thoughts theory of consciousness (HOT) for example, it is argued that distinct, occurring HOTs, would be very costly in cognitive and neuronal terms, that a disposition for such HOTs to occur based on other processes is more likely. Here we start to see the other picture of the problem, ¿is consciousness something secondary to other functions?
Earl (2008) states that a few number of people considers that a qualitative experience, like the experience of a certain colour when one sees one, is caused by a neuronal event, which affects other neuronal events that have an impact in behaviour, but the qualitative experience itself is not the cause of that behaviour, but an outcome of the other neuronal events that determine behaviour. However, the author indicates that this argument is very simplistic and that it lacks sufficient evidence. For example, Edelman et al. (2011) indicate that consciousness is not causal in a phenomenological sense, that it is the neuronal structures underlying conscious experience that imply causality. But in that case, the conscious subjective experiences are not entities separated from the neuronal structures, tied to their own principles, in fact they would correspond to the internal discriminations that correlate with the activity of the “dynamic core”, a concept developed in part by this author. Still, consciousness seems to be a result of something but the barrier proposed by the hard problem (Chalmers, 1996) of finding a scientific explanation for consciousness in term of the subjective experience (the qualia), is only apparent for these authors, and we should not think of brain causes and phenomenological causes, so if we find an adaptive role of the neuronal correlates of consciousness, then we could think that there is an adaptive value of consciousness.
If we think about the complex properties of organisms, we can all conclude that they have evolved by natural selection, and so it is argued that consciousness has evolved by this mechanism as well, which would suggest that there is and advantage of it for the organism, and an important function that it is fulfilling for the organism’s survival (Earl, 2008). However, at this point we found ourselves with another problem that our question represents: not every aspect of an organism is “for something” in particular (it does not necessary represent an evolutionary adaptation) (Not an adaptation. n.d – see a link in “References”). A property of an organism could be a chance result of history, like with the base sequence GGC, which codes for the amino acid glycine in a protein, there is no particular reason for that, and it represents a historical accident. Additionally, there is genetic drift, which happens when a variation present in populations does not affect fitness one way or another, like an “A” vs “G” base at a particular point in the genome that has no effect in survival or reproduction one way or the other. Additionally, some quality could be a by-product of another characteristic, like the redness of blood, which is a result of its chemistry, which causes it to reflect red light waves (Not an adaptation. n.d). This last case would be the one that is mainly argued by those who do not see an advantage of consciousness in itself, but think of it as a by-product (Earl, 2008). And this is not all, for example, a property of an organism can be an outdated adaptation, that is, a trait that was an adaptation for past environments but not for the current one. Similarly, an exaptation is a characteristic that serves a function that was not produced by natural selection for its current use, this could be the case of feathers that might have originally arisen for insulation, and only later were used for flight (Not an adaptation. n.d).
So the link between evolution – natural selection – and function or purpose of organism’s properties is not so direct or naturally given. All this represents a challenge when we think about what consciousness is for, we should not precipitate ourselves to consider that consciousness is serving a function, it might not, or even remotely, it could have served a function but no longer or could have taken a new function which was not the original one it evolved to perform.
According to Baumeister et al. (2011) however, the evidence for conscious causation of behaviour is strong and extensive, but this kind of causation is often indirect and delayed, interplaying with unconscious processes, still, consciousness would play a key role in many processes. They indicate, for example, that conscious simulation contributes to later behaviour and it functions as a kind of mental rehearsal. Also, repetitive conscious thoughts that were focused on planning tended to improve later performance and outcomes, indicating an anticipating and planning function of consciousness. In that sense, it has been found that thoughts about concrete steps to solve problems led to better coping in case of misfortunes. In addition, thinking about past events, or to think about them in certain ways, can alter future behaviour and other outcomes. In this case, consciousness would play a role in replaying, interpreting and reflecting on past events that ultimately affects behaviour (Baumeister et al. 2011).
Additionally, there is still a controversial issue, if consciousness does not have a significant function for human beings, one could consider the possibility of mental zombies, as Chalmers (1996) proposes, the idea that the same functions that a human being exhibits, in terms of reasoning, feeling or displaying certain behaviours, could be possible without any phenomenological consciousness. Although it is argued that logical reasoning depends on mental systems that use conscious thought, it has been asserted that unconscious processes imply a superior capacity and generate better, more logical choices and decisions. However, the evidence for this is provided by cases like the experiments in Dijksterhuis et al. (2006), in which, according to Baumeister et al. (2011), reasoning is not really required, but the task simply implies an addition of features, and so it is possible that people might choose the option in the task based on one heavily weighted feature. In relation to all this, an interesting question that we could ask is how the brain “thinks or reflects” about the subjective experience if the phenomenological experience is detached from or not linked in any way to biology or neuronal activity. This would makes us think that the two are related, or perhaps are the same thing, but I do not think we can make that assertion so easily, in my opinion, more debate is needed.
Bargh and Morsella (2008) argue that unconscious processes are not less flexible, complex, controlling, deliberative, or action-oriented that conscious ones. There appears to be independent perceptual, evaluative, and motivational unconscious behavioural guidance systems. These evolved as a source of adaptive and appropriate action impulses. These unconsciously activated preferences should be found to be directly connected to behavioural mechanisms. Several studies appear to show this connection, for example: immediate and unintended evaluation processes are directly linked to approach and avoidance behavioural predispositions (Bargh & Morsella, 2008). Also, as these authors mention, findings would support that complex judgmental and behavioural phenomena operate outside of awareness. According to them, some studies have now shown that unconscious goal pursuit produces the same outcomes that conscious goal pursuit. So if complex mental processes and behaviour can occur without consciousness, then finding a function of consciousness seems to be even harder. According to Baumeister et al. (2011), consciousness seems especially useful for enabling behaviour to be shaped by non-present factors and by social and cultural information, and also for dealing with multiple competing options or impulses. But, as they state, it is plausible that almost every human behaviour comes from a mixture of conscious and unconscious processing.
I think this is an important idea to reflect upon. I believe we should not exclude the possibility that consciousness is a by-product of other processes, and when we say consciousness is useful, then it would be the usefulness of the underlying factors that we are talking about. As shown, this is a much-debated issue, but advances have been made, although it may take a long time before we get definite answers.
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