PDP: a precursor to modern neural networks?

Parallel Distributed Processing: Explorations in the Microstructure of Cognition, a multi-volume publication by David Rumelhart, James McClelland and the PDP Research Group, was released in 1968 and is recognised as one of the most important works relating to neural networks.

They lay out eight features necessary to perform what they called 'parallel distributed processing' (which I suppose you can think of as a sort of precursor to modern-day deep learning):

• processing units
• a state of activation
• an output function for each processing unit
• a pattern of connectivity among units
• a propagation rule (for propagating what is learned through the network)
• an activation rule
• a learning rule (where 'patterns of connectivity are modified by experience')
• an environment in which the system operates

I haven't read the book, and I don't fully understand all these different pieces, but it isn't particularly hard to see the pattern of what would later come to be handled by modern-day neural networks in these features. The vocabulary used to describe it is slightly different, but you have the connectivity between neurons, and you have a process through which you update the layers…

This feels like a book that would reward returning to for a proper in-depth read later on in my studies.

The book you need to read on bin Laden's life post-2001

There is no shortage of books on the September 11 attacks and their aftermath. Some stand back to analyse it in terms of trends and networks, seeking to explain the 'why' through abstractions. Others have written participant accounts or their histories from the sidelines. The Exile offers a fulsome corrective to this trend towards abstraction. Curious what life was like for bin Laden, his commanders and their families? Cathy Scott-Clark and Adrian Levy deliver in spades.

The beating heart of this book are the stories of bin Laden's wives, their children and their life in 'exile'. The authors seem to have managed to achieve as yet unparalleled access to the wives and some other family members of Osama bin Laden, and their tale is both gripping and believable. The second important contribution that the book makes is to reveal Iran's role in hosting the bin Laden families (and commanders) post-2001. The rich detail goes a long way to giving the reader a sense of the day-to-day frustrations of their lives in Tehran (and other places) as well as their interactions with Iranian military and government officials. The book would be worth its price just for these sections alone.

Chapter Eleven tells the story of the night bin Laden died, to a large extent from the perspective of his wives and family members. They also weave in accounts from US soldiers participating in the raid, but this is a perspective we have been denied till now and I think it is an important one. Indeed, the trauma faced by the children on that night (and throughout the years prior, for the most part unable to leave their home) is one of the understated but crucial themes that stand out from 'The Exile'.

Every account of bin Laden's time post-2001 has to grapple with the question of Pakistan's role. The authors take a smart position throughout the book, which is to abstain from abstraction and a strong analytic voice. There are some claims of Pakistani ISI involvement and meetings here and there, but they step back a little before charging the government or senior officials with a state-level conspiracy. Whatever happened, this account holds, was much more an affair of bit players.

The book had the feeling of being rushed to press. It must have cost a lot to research the book, so perhaps the authors simply ran out of funds, but it seemed like there were so many other lines of enquiry that could have been started. The hardcover copy I read still had a fairly large number of typos, and it's a shame that the authors use the word "Afghanis" to refer to Afghans.

The book is extremely readable -- it kept me up until two in the morning as I finished it -- and this is in large part because of the use of dialogue and building up narrative tension through conversations. Unfortunately, the handling of some of these conversations -- reported through interviews with participants -- strains credulity. Study of memory and oral history has shown how these kinds of memories degrade or get reshaped with each telling, and I wish there were more caveats throughout the book that what we're reading is an approximation of what happened in order to better imaginatively enter the situation.

All in all, though, The Exile is an important book, an engrossing read and hopefully the beginning of more enquiries as others follow up on leads and side-stories raised in the telling. I took copious notes and will be digesting its various contents for a while, I think. It seems that scholars of September 11 and its aftermath are doomed to eternally reading and retelling the same events in slightly different contortions as new facts and witnesses emerge. If all the books were as good as this one, I wouldn't mind so so much.

The ways memory skills augment your life

I released a new episode of Sources and Methods today. This week I spoke with Lynne Kelly, author of ‘The Memory Code: The Secrets of Stonehenge, Easter Island and Other Ancient Monuments', a fascinating exploration of the intersection between history, archaeological sleuthing and memory techniques. We delved into the contents of her book as well as the practical applications she found for these ancient skills.

I’ve been fascinated with the work that Lynne has been doing on the history of memory and her own personal memory ‘experiments’. If you need some inspiration as to things you might learn (or ways you might learn them), head over to her blog and the page entitled ‘My 33 Memory Experiments’. She generously includes photos and explanations of how the various systems work. Her latest groups places them in even further context. As someone who’s been following her memory experiments for a while, I found the book really useful to understand why she was picking a certain technique over another.

She’s about to start a new project involving memory skills, education and schools (she discusses that in the podcast around the 34-minute mark) and I look forward to reading about the outcome.

Syria’s Revolution: The First Draft

I haven’t been following events in Syria that closely. ‘Burning Country: Syrians in Revolution and War’ (by Robin Yassin-Kassab, Leila Al-Shami) is only one among several books that have been written in the midst of the ongoing conflict, but I’d heard consistently good things about it since its release at the beginning of 2016. It doesn’t disappoint. I started it yesterday, lulled by the conclusion of a large project and a thousand pictures of Christmas dinner preparations on twitter. I woke up this morning and finished the rest.

Burning Country is compellingly written, not only on a structural level but also on account of its interspersed interview and other oral history-type testimony. This is the book’s primary strength, I felt. It’s hard enough to write accurate and compelling history after the fact. Doing so while events are still unfolding makes the job even harder. Thankfully, Burning Country delivers the goods.

After introducing Syria and Syrians as if to set the stage, Yassin-Kassab and al-Shami launch into an account of the Syrian uprising’s early days, told through a diversity of sources from a variety of backgrounds. They make a strong case for the initial moments of the revolution as being less co-opted by one group or another, even as later chapters show how a variety of forces pushed and pulled that initial impulse in unintended directions. I learnt a lot from the accounts of initial organisational strategies, the way different groups responded to similar kinds of threats from the state and how the logic of violent escalation started to take on more prominence. The chapter on cultural shifts (or expressions) brought about by the revolution (chapter eight) was also excellent. The end of the book falls a little short, if only because the conflict is ongoing and you had the sense that it is an unfinished project.

As a one-stop shop introduction and opening-out to some important parts of Syrian society, history and current affairs, Burning Country is well worth your time. The book ends with a note on thinking about and understanding Syria:

“In order to truly think globally – rather than to hide from thought behind clumsy globalising paradigms – it is necessary to act locally. We ask the reader, rather than applying the usual grand narratives, to attend to voices from the ground.”

I hope we get to read other histories of Syria (and other countries) that employ the same logic.