McCulloch-Pitts Neuron — Mankind’s First Mathematical Model Of A Biological Neuron


Source: McCulloch-Pitts Neuron — Mankind’s First Mathematical Model Of A Biological Neuron


McCulloch-Pitts Neuron — Mankind’s First Mathematical Model Of A Biological Neuron

It is very well known that the most fundamental unit of deep neural networks is called an artificial neuron/perceptron. But the very first step towards the perceptron we use today was taken in 1943 by McCulloch and Pitts, by mimicking the functionality of a biological neuron.

Note: The concept, the content, and the structure of this article were largely based on the awesome lectures and the material offered by Prof. Mitesh M. Khapra on NPTEL’s Deep Learning course. Check it out!

Biological Neurons: An Overly Simplified Illustration

A Biological Neuron — Wikipedia

Dendrite: Receives signals from other neurons

Soma: Processes the information

Axon: Transmits the output of this neuron

Synapse: Point of connection to other neurons

Basically, a neuron takes an input signal (dendrite), processes it like the CPU (soma), passes the output through a cable like structure to other connected neurons (axon to synapse to other neuron’s dendrite). Now, this might be biologically inaccurate as there is a lot more going on out there but on a higher level, this is what is going on with a neuron in our brain — takes an input, processes it, throws out an output.

Our sense organs interact with the outer world and send the visual and sound information to the neurons. Let’s say you are watching Friends. Now the information your brain receives is taken in by the “laugh or not” set of neurons that will help you make a decision on whether to laugh or not. Each neuron gets fired/activated only when its respective criteria (more on this later) is met like shown below.

Not real.

Of course, this is not entirely true. In reality, it is not just a couple of neurons which would do the decision making. There is a massively parallel interconnected network of 10¹¹ neurons (100 billion) in our brain and their connections are not as simple as I showed you above. It might look something like this:

Still not real but closer.

Now the sense organs pass the information to the first/lowest layer of neurons to process it. And the output of the processes is passed on to the next layers in a hierarchical manner, some of the neurons will fire and some won’t and this process goes on until it results in a final response — in this case, laughter.

This massively parallel network also ensures that there is a division of work. Each neuron only fires when its intended criteria is met i.e., a neuron may perform a certain role to a certain stimulus, as shown below.

Division of work

It is believed that neurons are arranged in a hierarchical fashion (however, many credible alternatives with experimental support are proposed by the scientists) and each layer has its own role and responsibility. To detect a face, the brain could be relying on the entire network and not on a single layer.

Sample illustration of hierarchical processing. Credits: Mitesh M. Khapra’s lecture slides

Now that we have established how a biological neuron works, lets look at what McCulloch and Pitts had to offer.

Note: My understanding of how the brain works is very very very limited. The above illustrations are overly simplified.

McCulloch-Pitts Neuron

The first computational model of a neuron was proposed by Warren MuCulloch (neuroscientist) and Walter Pitts (logician) in 1943.

This is where it all began..

It may be divided into 2 parts. The first part, takes an input (ahem dendrite ahem), performs an aggregation and based on the aggregated value the second part, f makes a decision.

Continues in source: McCulloch-Pitts Neuron — Mankind’s First Mathematical Model Of A Biological Neuron

Wellbeing in a Changing World – free ‘warm data lab’ like event for the climate strike – Tue, Sep 24, 2019 at 4:30pm, London UK


Source: Wellbeing in a Changing World Tickets, Tue, Sep 24, 2019 at 4:30 PM | Eventbrite

SEP 24 Wellbeing in a Changing World

What is wellbeing in a changing world?

The Global Strike from 20-27 September 2019 is to mark the urgency of the climate crisis and to demonstrate that people are no longer willing to continue with business as usual.

In support of this week of strikes, there will be a large group conversation on wellbeing: a topic that is at the heart of the climate change agenda. The strike will bring together many of us to show world leaders that people are demanding significant changes in our societal systems to ensure wellbeing for ourselves and all species on the planet.

You are invited to come and to bring your perspectives, ideas, hopes and stories. Nobody needs to be an expert as wellbeing impacts us all.

Please also invite others: the greater the diversity in the group, the more stories and experiences shape our experience of what wellbeing is for people. Where this conversation will lead cannot be predicted, but the time to be having these conversations is now.

Do Join us by registering for a free place:

We are a group of facilitators experienced in running large group conversations that have come together to support the global Climate Strike week as best we can. We are also a group of people who care deeply about people, nature and the planet. Our intention is to host a number of large group conversations on a range of topics. If you would like to be kept informed of our next events, please email:

Tue, September 24, 2019 4:30 PM – 7:00 PM BST

The Archbishop Amigo Jubilee Hall, Lambeth Road London SE1 7HY

Source: Wellbeing in a Changing World Tickets, Tue, Sep 24, 2019 at 4:30 PM | Eventbrite


The Future of Operational Research is Past – Ackoff, 1979


Source: The Future of Operational Research is Past | SpringerLink



Journal of the Operational Research Society

Volume 30, Issue 2pp 93–104Cite as

The Future of Operational Research is Past

Russell L. Ackoff

General Paper


After a brief discussion of the diagnoses of others of OR’s ailments, a detailed examination is made of the impacts of academic OR on its practice. These impacts include the dispersion of OR in organizations, the displacement of OR workers, and the dissolution of its interdisciplinarity. Then the changes in OR’s environment which should have evoked adaptive responses from it, but didn’t, are considered. The increasing inappropriateness of OR’s methodology is discussed by focusing on the deficiencies of its concept and practice of optimization, and its pursuit of objectivity. These deficiencies, it is argued, can only be overcome by a comprehensive reconceptualization of the field, its methodology, the way it is practised, and the way students are educated to practise it.


‘spontaneous’ synchronisation

A System Leader’s Fieldbook


Source: A System Leader’s Fieldbook

A System Leader’s Fieldbook

Gaining traction on today’s ever-more complex challenges requires collective leadership. That means practicing new ways of operating at the levels of Self, Team, Organization, and System. This online Fieldbook provides tools and resources for system leaders to use in supporting people and groups as they develop the skills to accelerate progress on intractable problems together.

To make real and lasting change, we need to:

Recognize that we are part of the systems we seek to change: Self
Interact productively with—and learn from—others: Team
Collaborate across internal stakeholder groups: Organization
Work across boundaries to co-create the future: System

Questions for Getting Started

Hover over the different segments of the circle, to the left, to identify the modules that will help you build your capacity to become a system leader.

Engaging Stakeholders Around Complex Problems

“Tools for transformation and learning will have little impact if not embraced and practiced by the community. Outside helpers like NOS cannot restore the Ensenada; the only ones who can do that are the community members themselves….Many felt that the real aim of environmentalist NGOs was simply to force the fisherman to stop fishing. In turn, it took time for NOS [Noroeste Sustentable] to appreciate that there were strong restoration leaders within the community.”

– Hubert Méndez, leaders of the fishing cooperative OPR

Web Prototype 1.0
Created by the Academy for Systems Change


Source: A System Leader’s Fieldbook

systems play


Source: About – systems play

We support systems innovators,

share systems resources in multiple languages, and build a community of praxis. Here’s how:


Systems knowledge and resources

  • Translating core resources
  • Documenting case studies and telling stories
  • Making resources accessible through curation, plain language writing, and analysis

Learning through

  • Research
  • Experiments
  • Projects


  • For capacity building and community building
  • In-person and on-line


How systems play came to be

Systems play evolved out of The Rockefeller Foundation Global Fellowship Program on Social Innovation. With learning from that three-year pilot and further research, we identified practical needs of system innovators that aren’t easily met through other platforms. From this, we developed our systems play approach for supporting systems innovators.

The Bertha Centre for Social Innovation and Entrepreneurship at the University of Cape Town is our institutional home.

Over the next three years, three regional hubs and this on-line hub are being established in a connected, global network of practitioners. Click here to learn more.

Bertha Centre for Social Innovation and Entrepreneurship

…is the first academic centre in Africa dedicated to advancing social innovation and entrepreneurship. It was established at the UCT Graduate School of Business in 2011, in partnership with the Bertha Foundation, which works with leaders who are catalysts for social and economic change and for human rights. The centre pursues social impact towards social justice through teaching, knowledge-building, convening, and projects with a systems lens on social innovation.

Founding supporters

Source: About – systems play

Complexity and Collaboration – implications for leadership and practice

Complexity and Management Conference 5-7th June 2020

Complexity & Management Centre

Complexity and Management Conference 5-7th June 2020

If collaboration was that straightforward, wouldn’t we all already be doing it? Collaboration is another one of those motherhood-and-apple-pie words which are hard to argue against – is there anyone not in favour of collaboration? At its most simplistic, the invitation to collaborate can be an idealisation which encourages the belief that if we only put aside our differences and work constructively and positively, then everything will turn to the good – as if that were an easy thing to do. But to what extent does the taken-for-granted idea of collaboration encourage setting aside the very differences and conflicts which promote movement and novelty?skydiving Is the naïve discourse on collaboration really rather unhelpful? 

The Complexity and Management Conference 5-7th June 2020 will explore in greater depth what it means to collaborate together, with the intention of developing a more complex…

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