The neuroscience of vision and pain: evolution of two disciplines. Barbara L. Finlay. Proceedings of the Royal Society B, Volume 374, Issue 1785, September 23 2019. https://doi.org/10.1098/rstb.2019.0292
Abstract: Research in the neuroscience of pain perception and visual perception has taken contrasting paths. The contextual and the social aspects of pain judgements predisposed pain researchers to develop computational and functional accounts early, while vision researchers tended to simple localizationist or descriptive approaches first. Evolutionary thought was applied to distinct domains, such as game-theoretic approaches to cheater detection in pain research, versus vision scientists' studies of comparative visual ecologies. Both fields now contemplate current motor or decision-based accounts of perception, particularly predictive coding. Vision researchers do so without the benefit of earlier attention to social and motivational aspects of vision, while pain researchers lack a comparative behavioural ecology of pain, the normal incidence and utility of responses to tissue damage. Hybrid hypotheses arising from predictive coding as used in both domains are applied to some perplexing phenomena in pain perception to suggest future directions. The contingent and predictive interpretation of complex sensations, in such domains as ‘runner's high’, multiple cosmetic procedures, self-harm and circadian rhythms in pain sensitivity is one example. The second, in an evolutionary time frame, considers enhancement of primary perception and expression of pain in social species, when expressions of pain might reliably elicit useful help.
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My comments: Could it be that those who experienced no pain died much more frequently (hemorrhages, internal damage, etc) than those who experienced pain and asked for support?
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From 2015... The unique pain of being human. Barbara Finlay. New Scientist, Volume 226, Issue 3020, May 9 2015, Pages 28-29. https://doi.org/10.1016/S0262-4079(15)30311-0
We seem to experience pain differently to other animals. Why, wonders neuroscientist Barbara Finlay
FOR years I worked in Brazil on the evolution of vision in primates and was often stationed near monkeys who had undergone caesarean sections. Their recovery was impressive – in stark contrast with my own after two
C-sections. Within hours, the monkeys would be sitting, climbing and annoying each other.
Looking at these unbothered monkeys, I began to think that some causes of the sensation of pain in humans might be fundamentally different to those in other animals.
The basic function of pain is the same for all vertebrates: it alerts an animal to potential damage and reduces activity after trauma. It is often argued that pain must be different in humans because of our ability to anticipate it or imagine its effects on us. But independent of whether cognition and culture can modify
pain, I am suggesting a more basic difference in humans compared with animals: that some varieties, such as labour pain, appear only in humans, and others such as posttrauma pain are magnified.
These forms of pain appear in tandem with the ability to recruit help, to elicit an altruistic response in others. By “help” I mean the simple protection and provisioning that parents supply to children, not medical intervention – although our medical interventions probably first grew from this basis. This view arises from work carried out nearly 50 years ago by pain researcher Patrick Wall. He was the first person to suggest a functional view of pain – that it should be understood as a mixture of sensation and the motivation to make it stop, not sensation alone. His starting point was the now wellresearched placebo effect. His account explained how rituals or procedures offered by a doctor or shaman, regardless of the efficacy or even existence of an actual treatment, could reduce pain.
But even with this early advocate for a functional view of it, studies of pain have mainly concentrated on receptors and specific clinical manifestations, while neglecting its purpose. Pain is a motivational signal to get an animal to do something – escape from a source of damage, protect a wound or devote energy to recovery. Wall argued that one of its roles in humans is as a motivation to seek help from some trusted source. When that goal is satisfied, pain is relieved.
I want to extend this view. I think that, over evolutionary time, several stimuli and situations that are not painful in other animals have come to be experienced as painful for humans. This is because our obvious distress elicits help from others and hence offers a survival advantage. This is distinct from the numerous demonstrations that context and culture can alter our sensation of pain. I argue that the primary circuitry of pain and malaise has been changed in human evolution in cases where getting help from others would be useful.
The pain of altruism
There is much indirect evidence in support of this “pain of altruism”. Take, for instance, the fact that certain types of pain are not associated with any physiological damage, and studies that show the presence of others can affect reported sensations of pain. Labour pain is another good example.
Across all human cultures, there are nearly always helpers, from relatives to medical professionals, who attend births. Giving birth is risky and help at any level improves survival. The cliché scenario of a mother from some exotic tribe going off to give birth alone is not unheard of, but is exceedingly rare. By contrast, among our primate relatives, solitary birth is the norm.
Human childbirth appears to be uniquely painful among members of the animal kingdom. Typically, scientists have accounted for this in terms of the size mismatch between the infant’s head and the mother’s pelvis, and not in terms of differences in social structure.
Human birth is dangerous, but we are not the only primates at risk – the smallest-bodied, large-brained monkeys, like marmosets, have similar head to pelvis disproportionality and birth-related mortality. Yet compared with humans, primates appear to give birth with little pain. Ungulates such as horses and cattle produce large, long-limbed offspring with a substantial chance of complications, but with little evidence of distress. Any such evidence, in fact, could prove fatal by alerting predators. So why is childbirth so painful for women? The source of labour pain is the contraction of the uterus and dilation of the cervix, but these are not damaging or pathological in themselves. Rather they predict a risky and potentially lethal event: the actual birth, to occur hours later. I suggest that protracted labour pains make us show distress and recruit help from others well in advance of the birth – a strategy that offers a survival advantage, as the offspring of those who seek help are more likely to survive.
But if the pain of labour is not linked to tissue damage and is primarily a call to enlist help, why does it have to be so excruciating? Helping someone in pain comes at a cost to the helper, and societies can’t afford to tolerate “cheating” in the form of excessive malingering or fake pain. I think that the pain of altruism may be connected to the concept of honest signalling in behavioural biology, whereby producing a signal has to be sufficiently costly to deter cheaters and freeloaders. Pain could be the obligatory cost of an honest signal, in the same way that a peacock’s tail or stag’s antlers are hard-to-fake signs of their owner’s underlying fitness.
However, since pain has no concrete physical manifestation that others can verify, cheating is difficult to eliminate – there is probably not one person reading this article who has never exaggerated pain or illness for their own benefit. If feeling pain to recruit the help of others is an evolutionarily assembled neural construct, this could be triggered in error. Perhaps this is what happens in the case of mysterious but distressing illnesses for which a direct physical cause cannot be found.
The pain of altruism also explains why malaise after trauma and infection are long and exaggerated for humans compared with laboratory mice. Mice, like most non-human animals, cannot provide the high level of social support needed to nurse an individual with an illness or a broken leg. Such injured animals must confine their energetically expensive immune response to the minimum time needed to survive without help.
It is also possible that this pain of altruism has been extended to domesticated livestock and pets, as they too can enlist human help. In contrast, most adult animals in the wild try to avoid showing disability or distress, which might attract rivals or predators.
Periods of extended illness might only be feasible in species where individuals protect and provide for others for such lengths of time. If help from others is the root cause of some types of pain, then this needs to be factored into our understanding of pain and disease. An evolutionary calculation that we cannot be aware of, rather than a specific physical cause, could be the source of much real agony.
Other Unexplained Agony
Pain exists to get an animal to change its behaviour. This functional account of pain may explain some ongoing mysteries, such as the cause of the muscle soreness that follows a day of intense exercise, which has eluded physiological explanation. The popular idea that it is due to the build-up of lactic acid has been discounted, as have other proposed theories. Bodybuilders have found that the optimal way to build muscle is to take a rest day after a strenuous workout. Perhaps nature has converged on the same idea, and muscle soreness is simply a signal to rest, to enable optimal muscle building.
International
law enforcement agencies report an apparent relationship between autism
and cyber-dependent crime, although any such link remains unproven
(Ledingham and Mills 2015; NCA 2017).
This was the first study to empirically explore whether autism,
autistic-like traits, explicit social cognition, interpersonal support
and digital skills were predictors of cyber-dependent criminality.
Whilst higher levels of autistic-like traits were associated with a
greater risk of committing cyber-dependent crime, a self-reported
diagnosis of autism was associated with a decreased risk of committing
cyber-dependent crime. Around 40% of the association between
autistic-like traits and cyber-dependent crime was attributable to
greater levels of advanced digital skills. Basic digital skills were
also found to be a mediator between autistic-like traits and
cyber-dependent crime, although they accounted for a smaller proportion
of the association than advanced digital skills.
These
findings are consistent with the proposal that the apparent association
between autism and cyber-dependent crime identified by law enforcement
agencies may be reflecting higher levels of autistic-like traits amongst
cybercriminals but that this does not necessarily equate to autism
being a risk factor for cybercrime. This confusion may well arise
because typically, autistic people do report higher levels of
autistic-like traits than the general population (Ruzich et al. 2015a).
Cyber-dependent crime may therefore represent an area that
distinguishes high autistic-trait non-autistic groups from autistic
groups, consistent with proposal that people with autism differ
qualitatively from non-autistic people who are nevertheless high in
autistic-like traits (see Ashwood et al. 2016; Frith 2014).
The finding that autistic respondents were less likely to commit
cyber-dependent crime is also consistent with literature suggesting that
autistic people are generally as law abiding, if not more so, than the
general population. Lower levels of criminality are shown, at least for
certain types of crime (Blackmore et al. 2017; Cheely et al. 2012; Ghaziuddin et al. 1991; Heeramun et al. 2017; Howlin 2007; King and Murphy 2013; Murrie et al. 2002; Wing 1981; Woodbury-Smith et al. 2005a, 2006; but see, Rava et al. 2017; Tint et al. 2017).
Thus,
there is evidence that higher AQ scores are associated with higher
levels of cyber-dependent crime regardless of an autism diagnosis. As
this association was independent from the autism diagnosis, there may be
something about autistic-like traits beyond the diagnostic criteria for
autism that relates to cyber-dependent criminal activity. The mediation
analysis suggests that an association between autistic-like traits and
advanced digital skills may represent a key factor. We cautiously state
above that those reporting an autism diagnosis were less likely to
report cyber-dependent crime. Cautiously, as this could be for various
reasons beyond high AQ and autism being different things, including a
diagnosis of autism leading to some protection (e.g., more support
leading to less potential criminal behaviour; see Heeramun et al. 2017).
Importantly, however, there are potential selection issues in relation
to individuals who respond to an invitation to complete an online survey
on this topic, thus the possibility of selection bias cannot be ruled
out. We do not know how many did not respond to the invitations (and
therefore could not identify a response rate, for example) and the
apparent protective effect could be a chance finding due to small
numbers. Future research using larger samples can address such concerns
and until that time the suggestion that autism may be protective should
be considered speculative, especially as the data is self-reported and
diagnostic status could not be independently verified in the present
study.
Previous research has identified
higher levels of autistic-like traits being present within scientific
disciplines in which computer science students and employees are
included (Baron-Cohen et al. 2001; Billington et al. 2007; Ruzich et al. 2015b).
This study is the first to specify a direct relationship between higher
levels of autistic-like traits and advanced digital skills. In addition
to being a pre-requisite for committing cyber-dependent crimes, these
skills are essential for the cyber security industry which will have an
estimated 3.5 million unfulfilled jobs by 2021 (Morgan 2018).
This study suggests that targeting groups high in autistic-like traits
would be a beneficial strategy to meet this employment need. Given the
employment difficulties that can be faced by members of the autistic
community (Buescher et al. 2014; Knapp et al. 2009; see also Gotham et al. 2015; Hendricks 2010; Howlin 2013; Levy and Perry 2011; National Autistic Society 2016; Taylor et al. 2015; Shattuck et al. 2012)
and that around 46% of autistic adults who are employed are either
over-educated or exceed the skill level needed for the roles they are in
Baldwin et al. (2014), targeting the autistic community for cyber security employment may be particularly beneficial.
Notwithstanding
the limitations described above, this may be particularly pertinent as
this study found that a diagnosis of autism was associated with reduced
cyber-dependent criminality. This would be consistent with perceptions
of autistic strengths of honesty and loyalty (de Schipper et al. 2016)—ideal
attributes within employment settings. Importantly, this is not to
suggest that all autistic people are good with technology, or that all
autistic people should seek employment within cyber security industries
(see Milton 2018).
Rather, this study highlights that in a particularly challenging
employment context, some members of the autistic community may be
ideally suited to such employment opportunities and emphasises the need
for employers to ensure that their recruitment methods and working
environments are autism-friendly and inclusive (see Hedley et al. 2017 for review).
The
direct link between autistic-like traits and cyber-dependent crime is
also consistent with previous research (Seigfried-Spellar et al. 2015) and may extend to a relationship with cyber-enabled crime (such as online fraud). Seigfried-Spellar et al. (2015)
explored relationships between autistic-like traits and cyber-deviancy
more broadly defined than cyber-dependent crime. Future research could
explore whether the level of autistic-like traits, mediated by advanced
digital skills, also relates to cyber-enabled crime, and whether there
are any direct effects that are specific to cyber-dependent crime.
Seigfried-Spellar et al. (2015)
and the present study were both cross-sectional studies. The mediation
of advanced digital skills between autistic-like traits and
cyber-dependent crime has been assumed in the present study, but this
could be best established in longitudinal research. Exploring prison
populations to identify if ‘traditional’ crime was related to
autistic-like traits found no differences between prisoners and the
general population (Underwood et al. 2016),
which may suggest that autistic-like traits are associated with
cybercrime specifically (that is, cyber-dependent crime and potentially
cyber-enabled crime).
Sex, age, non-verbal
IQ, explicit social cognition and perceived interpersonal support did
not significantly relate to cyber-dependent criminal activity, which
serves to highlight the salience of autistic-like traits. A potential
limitation is that explicit social cognition was assessed, but not
implicit social cognition. Based on the autism literature (Callenmark et
al. 2014; Dewey 1991; Frith and Happé 1999),
we would not necessarily expect difficulties with explicit social
cognition in groups with high autistic-like traits. Implicit social
cognition was also assessed by Callenmark et al. using interviews after
the IToSK. Such interviews, however, do not readily extend to the online
context and future research could explore any role of implicit social
cognition in cyber-dependent crime. However, recent accounts of implicit
social cognition have questioned whether such a system exists and
findings from such measures can better be attributed to general
attentional processes (Conway et al. 2017; Heyes 2014; Santiesteban et al. 2014, 2015, 2017).
Future
research should also focus on autistic communities as well as those
convicted of cyber-dependent and cyber-enabled crimes to further develop
our understanding of this area, an important aspect of which is the
potential strengths some members of the autistic community can bring to
cyber security employment.