How close are we to uploading our minds Michael S.A. Graziano

Imagine a future where nobody dies—

instead, our minds are uploaded
to a digital world.

They might live on in a realistic,
simulated environment with avatar bodies,

and could still call in and contribute
to the biological world.

Mind uploading has powerful appeal—

but what would it actually take to scan a
person’s brain and upload their mind?

The main challenges are scanning a brain
in enough detail to capture the mind

and perfectly recreating
that detail artificially.

But first, we have to know what to scan.

The human brain contains
about 86 billion neurons,

connected by at least a
hundred trillion synapses.

The pattern of connectivity
among the brain’s neurons,

that is, all of the neurons and
all their connections to each other,

is called the connectome.

We haven’t yet mapped
the connectome,

and there’s also a lot more
to neural signaling.

There are hundreds, possibly thousands
of different kinds of connections,

or synapses.

Each functions in a slightly
different way.

Some work faster, some slower.

Some grow or shrink rapidly in
the process of learning;

some are more stable over time.

And beyond the trillions of precise,
1-to-1 connections between neurons,

some neurons also spray out
neurotransmitters

that affect many other neurons at once.

All of these different kinds of
interactions

would need to be mapped in order to
copy a person’s mind.

There are also a lot of influences on
neural signaling

that are poorly understood
or undiscovered.

To name just one example,

patterns of activity between neurons

are likely influenced by a type
of cell called glia.

Glia surround neurons and,
according to some scientists,

may even outnumber them
by as many as ten to one.

Glia were once thought to be purely
for structural support,

and their functions are still
poorly understood,

but at least some of them can generate
their own signals

that influence information processing.

Our understanding of the brain isn’t good
enough to determine

what we’d need to scan in order
to replicate the mind,

but assuming our knowledge does
advance to that point,

how would we scan it?

Currently, we can accurately scan a living
human brain

with resolutions of about half a
millimeter

using our best non-invasive
scanning method, MRI.

To detect a synapse, we’ll need to scan
at a resolution of about a micron—

a thousandth of a millimeter.

To distinguish the kind of synapse and
precisely how strong each synapse is,

we’ll need even better resolution.

MRI depends on powerful magnetic fields.

Scanning at the resolution required

to determine the details of
individual synapses

would requires a field strength high
enough to cook a person’s tissues.

So this kind of leap in resolution

would require fundamentally
new scanning technology.

It would be more feasible to scan a dead
brain using an electron microscope,

but even that technology is nowhere
near good enough–

and requires killing the subject first.

Assuming we eventually understand the
brain well enough to know what to scan

and develop the technology to safely
scan at that resolution,

the next challenge would be to recreate
that information digitally.

The main obstacles to doing so are
computing power and storage space,

both of which are improving every year.

We’re actually much closer to attaining
this technological capacity

than we are to understanding or scanning
our own minds.

Artificial neural networks already run
our internet search engines,

digital assistants, self-driving cars,
Wall Street trading algorithms,

and smart phones.

Nobody has yet built an artificial network
with 86 billion neurons,

but as computing technology improves,

it may be possible to keep track
of such massive data sets.

At every step in the scanning and
uploading process,

we’d have to be certain we were capturing
all the necessary information accurately—

or there’s no telling what ruined
version of a mind might emerge.

While mind uploading is
theoretically possible,

we’re likely hundreds of years away

from the technology
and scientific understanding

that would make it a reality.

And that reality would come with ethical
and philosophical considerations:

who would have access to mind uploading?

What rights would be accorded to
uploaded minds?

How could this technology be abused?

Even if we can eventually upload
our minds,

whether we should remains
an open question.

想象一个没有人死亡的未来——

相反,我们的思想被上传
到一个数字世界。

他们可能生活在具有化身身体的逼真的
模拟环境中,

并且仍然可以呼唤
生物世界并为生物世界做出贡献。

思想上传具有强大的吸引力——

但扫描一个
人的大脑并上传他们的思想实际上需要什么?

主要挑战是对大脑
进行足够详细的扫描以捕捉大脑

并完美
地人工重建该细节。

但首先,我们必须知道要扫描什么。

人脑包含
大约 860 亿个神经元,

由至少
一百万亿个突触连接。

大脑神经元之间的连接模式,

即所有神经元
及其彼此之间的所有连接

,称为连接组。

我们还没有
绘制连接组图,

神经信号还有很多。

有成百上千
种不同类型的连接

或突触。

每个功能都略有
不同。

有些工作更快,有些工作更慢。

有的在学习过程中迅速成长或缩小

有些随着时间的推移更加稳定。

除了神经元之间数万亿个精确的、一对一的
连接之外,

一些神经元还会喷射

出同时影响许多其他神经元的神经递质。 为了复制一个人的思想,

所有这些不同类型的
交互

都需要被映射

还有很多对
神经信号传导

的影响知之甚少
或未被发现。

仅举一个例子,

神经元之间的活动模式

很可能受到
一种称为神经胶质细胞的影响。

神经胶质细胞围绕着神经元,
据一些科学家称,

它们的数量甚至可能比
它们多十比一。

Glia 曾被认为纯粹是
为了结构支持

,它们的功能仍然
知之甚少,

但至少它们中的一些可以产生
自己的信号

,影响信息处理。

我们对大脑的理解还
不足以确定

我们需要扫描什么
来复制大脑,

但假设我们的知识确实
发展到了这一点,

我们将如何扫描它?

目前,我们可以

使用我们最好的非侵入性
扫描方法 MRI 以大约半毫米的分辨率准确扫描活的人脑。

为了检测突触,我们需要以
大约一微米(

千分之一毫米)的分辨率进行扫描。

为了区分突触的种类以及
每个突触的强度,

我们需要更好的分辨率。

MRI依赖于强大的磁场。 以确定单个突触细节

所需的分辨率进行扫描

需要足够高的场强
来烹饪人的组织。

因此,这种分辨率的飞跃

需要
全新的扫描技术。

使用电子显微镜扫描死脑会更可行

但即使是这种技术也
远远不够好——

并且需要先杀死对象。

假设我们最终对
大脑有足够的了解,知道要扫描什么,

并开发出
以该分辨率安全扫描的技术,

那么下一个挑战就是以数字方式重新创建
该信息。

这样做的主要障碍是
计算能力和存储空间,

这两者每年都在提高。

我们实际上更接近于获得
这种技术能力,而

不是我们理解或扫描
我们自己的思想。

人工神经网络已经在
我们的互联网搜索引擎、

数字助理、自动驾驶汽车、
华尔街交易算法

和智能手机上运行。

目前还没有人建立一个
拥有 860 亿个神经元的人工网络,

但随着计算技术的进步

,可能有可能
跟踪如此庞大的数据集。

在扫描和
上传过程的每一步,

我们都必须确保我们准确地捕捉到了
所有必要的信息——

否则不知道会出现什么样的毁坏
版本的大脑。

虽然思想上传在
理论上是可能的,

但我们可能

距离使其成为现实的技术
和科学

理解还有数百年的时间。

而这一现实将伴随着伦理
和哲学考虑:

谁可以访问思想上传? 上传的思想

将被赋予什么权利

这种技术怎么会被滥用?

即使我们最终可以上传
我们的想法,

我们是否应该仍然是
一个悬而未决的问题。