ORIGINAL PAPER
Cognitive Enhancement: Methods, Ethics, Regulatory
Challenges
Nick Bostrom Æ Anders Sandberg
Received: 12 August 2006 / Accepted: 25 March 2009 / Published online: 19 June 2009
Springer Science+Business Media B.V. 2009
Abstract Cognitive enhancement takes many and diverse forms. Various methods
of cognitive enhancement have implications for the near future. At the same time,
these technologies raise a range of ethical issues. For example, they interact with
notions of authenticity, the good life, and the role of medicine in our lives. Present
and anticipated methods for cognitive enhancement also create challenges for public
policy and regulation.
Keywords Cognitive enhancement Ethics Human enhancement IQ
Intelligence Policy
Introduction
Cognitive enhancement may be defined as the amplification or extension of core
capacities of the mind through improvement or augmentation of internal or external
information processing systems. As cognitive neuroscience has advanced, the list of
prospective internal, biological enhancements has steadily expanded (Farah et al.
2004). Yet to date, it is progress in computing and information technology that has
produced the most dramatic advances in the ability to process information.
1
N. Bostrom (&) A. Sandberg
Future of Humanity Institute, Faculty of Philosophy & James Martin 21st Century School,
Oxford University, Littlegate House, 16/17 St Ebbes Street, Oxford OX1 1PT, UK
e-mail: nick.bostrom@philosophy.ox.ac.uk
A. Sandberg
e-mail: anders.sandberg@philosophy.ox.ac.uk
1
Advances in social organization have also enabled individual minds—through interactions with other
people’s minds—to become vastly more effective. Improvements in social organization that are not
directly mediated by technology lie outside the scope of this review.
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Sci Eng Ethics (2009) 15:311–341
DOI 10.1007/s11948-009-9142-5
www.nickbostrom.com
External hardware and software supports now routinely give human beings effective
cognitive abilities that in many respects far outstrip those of biological brains.
Cognition can be defined as the processes an organism uses to organize
information. This includes acquiring information (perception), selecting (attention),
representing (understanding) and retaining (memory) information, and using it to
guide behavior (reasoning and coordination of motor outputs). Interventions to
improve cognitive function may be directed at any one of these core faculties.
An intervention that is aimed at correcting a specific pathology or defect of a
cognitive subsystem may be characterized as therapeutic.Anenhancement is an
intervention that improves a subsystem in some way other than repairing something
that is broken or remedying a specific dysfunction. In practice, the distinction
between therapy and enhancement is often difficult to discern, and it could be
argued that it lacks practical significance. For example, cognitive enhancement of
somebody whose natural memory is poor could leave that person with a memory
that is still worse than that of another person who has retained a fairly good memory
despite suffering from an identifiable pathology, such as early-stage Alzheimer’s
disease. A cognitively enhanced person, therefore, is not necessarily somebody with
particularly high (let alone super-human) cognitive capacities. A cognitively
enhanced person, rather, is somebody who has benefited from an intervention that
improves the performance of some cognitive subsystem without correcting some
specific, identifiable pathology or dysfunction of that subsystem.
The spectrum of cognitive enhancements includes not only medical interven-
tions, but also psychological interventions (such as learned ‘‘tricks’’ or mental
strategies), as well as improvements of external technological and institutional
structures that support cognition. A distinguishing feature of cognitive enhance-
ments, however, is that they improve core cognitive capacities rather than merely
particular narrowly defined skills or domain-specific knowledge.
Most efforts to enhance cognition are of a rather mundane nature, and some have
been practiced for thousands of years. The prime example is education and training,
where the goal is often not only to impart specific skills or information, but also to
improve general mental faculties such as concentration, memory, and critical
thinking. Other forms of mental training, such as yoga, martial arts, meditation, and
creativity courses are also in common use. Caffeine is widely used to improve
alertness. Herbal extracts reputed to improve memory are popular, with sales of Ginko
biloba alone in the order of several hundred million dollars annually in the U.S. (van
Beek 2002). In an ordinary supermarket there are a staggering number of energy
drinks on display, vying for consumers who are hoping to turbo-charge their brains.
Education and training, as well as the use of external information processing
devices, may be labeled as ‘‘conventional’’ means of enhancing cognition. They are
often well established and culturally accepted. By contrast, methods of enhancing
cognition through ‘‘unconventional’’ means, such as ones involving deliberately
created nootropic drugs, gene therapy, or neural implants, are nearly all to be
regarded as experimental at the present time. Nevertheless, these unconventional
forms of enhancements deserve serious consideration for several reasons:
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• They are relatively new, and consequently there does not exist a large body of
‘‘received wisdom’’ about their potential uses, safety, efficacy, or social
consequences;
• They could potentially have enormous leverage (consider the cost-benefit ratio
of a cheap pill that safely enhances cognition compared to years of extra
education);
• They are sometimes controversial;
• They currently face specific regulatory problems, which may impede advances;
and
• They may eventually come to have important consequences for society and
even, in the longer run, for the future of humankind.
In examining the challenges for public policy with regard to cognitive enhancement,
it is important to consider the full range of different possibilities that are becoming
available, and their different individual characteristics. From such a comprehensive
viewpoint, the inadequacies of some aspects of the current regulatory and policy
framework become apparent, as it treats different modes of enhancement differently
even though, arguably, there is no good justification for doing so.
One general caveat must be noted about the survey that follows. Many of the
cognitive enhancement methods being studied today remain highly experimental or
have small effect sizes. This makes the present scientific literature a weak guide to
their eventual usefulness (Ioannidis 2005). Findings need to be repeated in multiple
studies and larger clinical trials before they can be fully trusted. It is likely that many
enhancement techniques will in the long run prove less efficacious than their current
promoters claim. At the same time, the sheer range of enhancement methods suggests
that it would be very unlikely that all current methods are ineffective or that future
advances will fail to produce an increasingly potent toolbox for enhancing cognition.
Methods of Cognitive Enhancement
Education, Enriched Environments and General Health
Education has many benefits beyond higher job status and salary. Longer education
reduces the risks of substance abuse, crime and many illnesses while improving
quality of life, social connectedness, and political participation (Johnston 2004).
There is also positive feedback between performance on cognitive tests such as IQ
tests and scholastic achievement (Winship and Korenman 1997).
Much of what is learned in school is ‘‘mental software’’ for managing various
cognitive domains: mathematics, categories of concepts, language, and problem
solving in particular subjects. This kind of mental software reduces one’s mental
load through clever encoding, organization, or processing. Instead of memorizing
multiplication tables, the pattern of arithmetic relationships is compressed into
simpler rules of multiplication, which in turn (among very ambitious students) can
be organized into efficient mental calculation methods like the Trachtenberg system
(Trachtenberg 2000). Such specific methods have a narrower range of applicability
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but can dramatically improve performance within a particular domain. They
represent a form of crystallized intelligence, distinct from the fluid intelligence of
general cognitive abilities and problem solving capacity (Cattell 1987). The relative
ease and utility of improving crystallized intelligence and specific abilities have
made them popular targets of internal and external software development.
Enhancement of fluid intelligence is more difficult.
Pharmacological cognitive enhancements (nootropics) have physiological effects
on the brain. So, too, do education and other conventional interventions. In fact,
conventional interventions often produce more permanent neurological changes
than do drugs. Learning to read alters the way language is processed in the brain
(Petersson 2000). Enriched rearing environments have been found to increase
dendritic arborisation and to produce synaptic changes, neurogenesis, and improved
cognition in animals (Walsh et al. 1969; Greenoug and Volkmar 1973; Diamond
et al. 1975; Nilsson et al. 1999). While analogous controlled experiments cannot
easily be done for human children, it is very likely that similar effects would be
observed. Stimulation-seeking children, who might be seeking out and creating
enriched environments for themselves, score higher on IQ tests and do better at
school than less stimulation-seeking children (Raine et al. 2002). This also suggests
that interventions, whether environmental or pharmaceutical, that make exploring
and learning more appealing to children might improve cognition.
Enriched environments also make brains more resilient to stress and neurotoxins
(Schneider et al. 2001). Reducing neurotoxins and preventing bad prenatal
environments are simple and widely accepted methods of improving cognitive
functioning. These kinds of intervention might be classified as preventative or
therapeutic rather than enhancing, but the distinction is blurry. For instance, an
optimized intrauterine environment will not only help avoid specific pathology and
deficits but is also likely to promote the growth of the developing nervous system in
ways that enhance its core capacities.
In brains that have already been damaged, e.g. by lead exposure, nootropics may
alleviate some of the cognitive deficits (Zhou and Suszkiw 2004). It is not always
clear whether they do so by curing the damage or by amplifying (enhancing)
capacities that compensate for the loss, or whether the distinction is even always
meaningful. Comparing chronic exposure to cognition-enhancing drugs with an
enriched rearing environment, one study in rats found that both conditions improved
memory performance and produced similar changes in the neural matter (Murphy
et al. 2006). The improvements in the drug-treated group persisted even after
cessation of treatment. The combination of drugs and enriched environment did not
improve the rats’ abilities beyond the improvement provided by one of the
interventions alone. This suggests that both interventions produced a more robust
and plastic neural structure capable of learning more efficiently.
Improving general health has cognition-enhancing effects. Many health problems
act as distracters or directly impair cognition (Schillerstrom et al. 2005). Improving
sleep, immune function, and general conditioning promotes cognitive functioning.
Bouts of exercise have been shown to improve temporarily various cognitive
capacities, the size of the effect depending on the type and intensity of the exercise
(Tomporowski 2003). Long-term exercise also improves cognition, possibly
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through a combination of increased blood supply to the brain and the release of
nerve growth factors (Vaynman and Gomez-Pinilla 2005).
Mental Training
Mental training and visualization techniques are widely practiced in elite sport
(Feltz and Landers 1983) and rehabilitation (Jackson et al. 2004), with apparently
good effects on performance. Users vividly imagine themselves performing a task
(running a race, going to a store), repeatedly imagining every movement and how it
would feel. A likely explanation for the efficacy of such exercises is that they
activate the neural networks involved in executing a skill at the same time as the
performance criteria for the task is held in close attention, optimizing neural
plasticity and appropriate neural reorganization.
General mental activity—‘‘working the brain muscle’’—can improve perfor-
mance (Nyberg et al. 2003) and long-term health (Barnes et al. 2004), while
relaxation techniques can help regulate the activation of the brain (Nava et al. 2004).
It has been suggested that the Flynn-effect (Flynn 1987), a secular increase in raw
intelligence test scores by 2.5 IQ points per decade in most western countries, is
attributable to increased demands of certain forms of abstract and visuospatial
cognition in modern society and schooling, although improved nutrition and health
status may also play a part (Neisser 1997; Blair et al. 2005). On the whole, however,
the Flynn effect seems to reflect a change in which specific forms of intelligence are
developed, rather than an increase in general fluid intelligence.
The classic form of cognitive enhancement software consists of learned strategies
to memorize information. Such methods have been used since antiquity with much
success (Yates 1966; Patten 1990). One such classic strategy is ‘‘the method of loci’’.
The user visualizes a building, either real or imaginary, and in her imagination she
walks from room to room, depositing imaginary objects that evoke natural
associations to the subject matter that she is memorizing. During retrieval, the user
retraces her imaginary steps, and the sequence of memorized information is recalled
when she ‘‘sees’’ the objects she placed along the route. This technique harnesses the
brain’s spatial navigation system to remember objects or propositional contents.
Other memory techniques make use of rhyming or the fact that one more easily recalls
dramatic, colorful, or emotional scenes, which can serve as proxies for items that are
more difficult to retain, such as numbers or letters. The early memory arts were often
used as a substitute for written text or to memorize speeches. Today, memory
techniques tend to be used in service of everyday needs such as remembering door
codes, passwords, shopping lists, and by students who need to memorize names, dates,
and terms when preparing for exams (Minninger 1997; Lorrayne 1996).
One study which compared exceptional memorizers (participants in the World
Memory Championships) with normal subjects found no systematic differences in
brain anatomy (Maguire et al. 2003). However, it found differences in activity
patterns during memorization, likely reflecting the use of a deliberate encoding
strategy. Areas of the brain involved in spatial representation and navigation were
disproportionately activated in the skilled memorizers, regardless of whether the
items to be memorized were numbers, faces, or the shapes of snowflakes. Asked
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