Friday, December 10, 2010

Thesis finally published

I am pleased to say that my thesis has now finally been published and submitted, with my graduation ceremony next week. After that, I will have truly finished the long and arduous road that was my PhD. Since I've stayed in academia (so far at least...) I'm going to engage in a little self-promotion (what's a blog for otherwise?), and give the thesis abstract for those (very few) of you who may be interested.

Foundations of a Constructivist Memory-Based approach to Cognitive Robotics:

Synthesis of a Theoretical Framework and Application Case Studies

Cognitive robotics are applicable to many aspects of modern society. These artificial agents may also be used as platforms to investigate of the nature and function of cognition itself through the creation and manipulation of biologically-inspired cognitive architectures. However, the flexibility and robustness of current systems are limited by the restricted use of previous experience.

Memory thus has a clear role in cognitive architectures, as a means of linking past experience to present and future behaviour. Current cognitive robotics architectures typically implement a version of Working Memory - a functionally separable system that forms the link between long-term memory (information storage) and cognition (information processing). However, this division of function gives rise to practical and theoretical problems, particularly regarding the nature, origin and use of the information held in memory and used in the service of ongoing behaviour.

The aim of this work is to address these problems by synthesising a new approach to cognitive robotics, based on the perspective that cognition is fundamentally concerned with the manipulation and utilisation of memory. A novel theoretical framework is proposed that unifies memory and control into a single structure: the Memory-Based Cognitive Framework (MBCF). It is shown that this account of cognitive functionality requires the mechanism of constructivist knowledge formation through ongoing environmental interaction, the explicit integration of agent embodiment, and a value system to drive the development of coherent behaviours.

A novel robotic implementation - the Embodied MBCF Agent (EMA) - is introduced to illustrate and explore the central features of the MBCF. By encompassing aspects of both network structures and explicit representation schemes, neural and non-neural inspired processes are integrated to an extent not possible in current approaches.

This research validates the memory-based approach to cognitive robotics, providing the foundation for the application of these principles to higher-level cognitive competencies.

This work was conducted at the University of Reading (U.K.) under the supervision of Dr. Will Browne. While I enjoyed my time there, it was a fairly lonely research process, and I am very much appreciating the opportunity for frequent and open discussions that I now have in Plymouth.

Monday, December 06, 2010

What's the point of having evidence..

... if it's not going to be used, or ignored because it doesn't match the current state of public opinion.

Sometimes it's frankly just embarrassing...

The removal of a few lines from a piece of paper (admittedly legislation) is going to remove the requirement for formal scientific advice in the determination of drug policy in the U.K. (noted though that it doesn't necessarily mean that no scientists will form part of the relevant committee - but it's surely not a good sign: these are politicians we're talking about.) I would have hoped that the change in government might have meant that 'squabbles' of the past may have been left there - but then the idea that government policy could be challenged by people who know more than politicians would be worrying for anyone in power, whatever their political persuasion. Besides, the manipulation of evidence (and statistics) to serve political ends is hardly new is it - except that now it can technically be done without the evidence in the first place.

Oh well, only another 4 years until the next opportunity to register displeasure at the ballot box...

Thursday, October 14, 2010

On Memory, from St. Augustine

I've been sitting on this quote for a while. I somehow came across it a few years ago (though I can no longer remember how I first found it), and used part of it as the opening quote of my thesis (in that quest to find a really old, obscure, but relevant way of opening the first chapter - I guess as a means of 'showing off' your supposed breadth of research...):
"There are all things preserved distinctly and under general heads, each having enetered by its own avenue, as light, and all colors and forms of bodies, by the eyes; by the ears all sorts of sounds; all smells by the avenue of the nostrils; all tastes by the mouth; and by the sensation of the whole body, what is hard or soft, hot or cold, smooth or rugged, heavy or light, either outwardly or inwardly to the body. All these doth that great harbor of the memory receive in her numberless secret and inexpressible windings, to be forthcoming, and brought out at need; each entering in by his own gate, and there laid up. Nor yet do the things themselves enter in; only the images of the things perceived, are there in readiness, for thought to recall. Which images, how they are formed, who can tell, though it doth plainly appear by which each hath been brought in and stored up? For even while I dwell in darkness and silence, in my memory I can produce colors, if I will, and discern betwixt black and white, and what others I will. Nor yet do sounds break in and disturb the image drawn in by my eyes which I am reviewing, though they also are there, lying dormant, and laid up, as it were, apart. For these too I call for, and forthwith they appear."
From the 1976 Translation version of "The Confessions of St. Augustine" (398 A.D.), Book 10, by Edward B. Pusey.

I've not found a more poetic description of the introspective function of memory, which is of course as relevant now as it was when written in the 4th century A.D.

Tuesday, September 21, 2010

Robotic companions in the news

There was a minor flurry of media activity a week or so ago concerning the ALIZ-E project, just after the university put out a press release:

-> And a bit closer to home, is "Robots developed in Plymouth to befriend sick children" on the BBC Devon News website.

In a somewhat surreal event, we were also invited for a radio interview, in which our Nao robot was a speaking guest!

There seems to be a common picture with all of these stories (probably because it appears on the ALIZ-E project homepage) - at least it's a good one :-)

Wednesday, August 18, 2010

ALIZ-E videos and dancing robot

With my work on the ALIZ-E project, I get to play around (by play, I mean work...) with the Nao humanoid robot (it's a cute little thing). One of things I've been getting it to do recently is dance. Actually, a summer project student did most of the low-level implementation (the time consuming definition of angle joints etc), so I've just been dealing with how to use these behaviours. This video is the first and really simplistic example:

The video is actually pretty poor quality, and I've somehow managed to squash the picture (my first awful attempt at a youtube video...), but it shows the Nao moving around (even if calling it 'dancing' is a bit of a stretch at the moment). I've set up a You-tube channel on which I will put more (and better quality) videos in the future of our Nao robots engaging in interesting behaviours related to the ALIZ-E project.

Monday, August 16, 2010

What is a PhD?

I like this pictorial description of what a PhD is supposed to be. Not a perfect metaphor (the increasingly important training aspect, for U.K. institutions at least, isn't really incorporated), but it's nice nonetheless. Whilst it could be interpreted as a bit bleak, I would say it puts things into a little perspective :-)

Tuesday, August 10, 2010

Coming to the end of a chapter

I had my PhD viva last week. Happily, it went quite well, and I passed, with minor corrections to complete. Looking back on the viva, it passed relatively quickly (for the four hours it lasted) considering the building anxiety I felt for the couple of weeks or so beforehand. While I've not finished the PhD yet (the aforementioned corrections), and I've been fortunate enough to find a postdoc before this final milestone, I thought this would be a good opportunity to mention a couple of things that helped me through the process. I would of course appreciate any additions or other feedback on this - these are just some very brief notes :-)

The writing-up process was the most tortuous and least enjoyable academic task I have ever had to undertake. Even though I was nominally writing-up for about 9 months, most of the words got written in the final month and a bit. It was a truly horrible process: procrastination well and truly took hold - in fact, there were multiple occasions when my research on procrastination itself seemed so much more important than my thesis. Since my PhD research was essentially an individual effort (I had a supervisor of course, luckily a particularly good one, but he moved to another university while I was writing-up), I didn't have project colleagues working on similar things who I could discuss things with, or bounce ideas off of. I believe that the process would have been less daunting and painful if I had been able to do this. In my last month, there was another PhD student writing his thesis too, but on a completely different topic. This was a great help - for motivation and company: seeing someone else go through the same thing at the same time helped to put it all into perspective.

The second thing that really drove me to complete the writing process was the presence of a hard deadline. Well, actually two hard deadlines. The first was my registration period as a PhD student drawing to a close. I know extensions can usually be acquired, but it's a fairly good deadline to work to :-) More importantly for me though was the promise of a waiting postdoc position. I started the week after I submitted my thesis, and still had to move across the country - so the sooner I submitted the better. It's quite a motivator.

These two things made me finish on time, but the way it turned out probably wasn't the best way of doing it. I didn't leave myself a huge amount of time for proof-reading, even though the thesis said what I wanted it to say. But then hindsight is a wonderful thing... I'm just happy to have gotten this far :-)

Tuesday, June 29, 2010

Error bars

Error bars are a necessary part of science reporting, but (as so eloquently described here) they are often misunderstood and frequently misused (including of course by myself). Whilst there has been much written about it (not to mention the descriptions in actual statistics books...), I came across a short paper on the use of error bars in the field of experimental biology. Eight rules are proposed to help with the use and interpretation of error bars, but they aren't specific to biology, so I thought I'd summarise them:

Rule 1:
When showing error bars, always describe in the figure legends what they are.

Rule 2:
The sample size/number of independently performed experiments (i.e. n) must be stated in the figure legend.

Rule 3:
Error bars and statistics should only be shown for independently repeated experiments, and never for replicates.

Rule 4:
For very small values of n (e.g. 3), it is better to simply plot the individual data points rather than showing error bars and statistics.

Rule 5:
95% confidence intervals capture the true mean on 95% of occasions, so you can be 95% confident that your interval includes the true mean.

Rule 6:
How standard error bars relate to 95% confidence intervals; when n=3, and doublethe SE bars don't overlap, P <>

Rule 7:
With 95% CIs and n = 3, overlap of one full arm indicates P approx 0.05, and overlap of half an arm indicates P approx 0.01.

Rule 8:
In the case of repeated measurements on the same group (animals, individuals, cultures, or reactions, for example) CIs or SE bars are irrelevant to comparisons within the same group.

They really are quite basic, but it's useful to be reminded of rules 1-5 occasionally. Another part of the paper I quite liked was the single sentence summary of P values (as the result of t-tests for example), but more particularly how to interpret them.

If you carry out a statistical significance test, the result is a P value, where P is the probability that, if there really is no difference, you would get, by chance, a difference as large as the one you observed, or even larger.

Cumming G, Fidler F, & Vaux DL (2007). Error bars in experimental biology. The Journal of cell biology, 177 (1), 7-11 PMID: 17420288

Wednesday, June 23, 2010

A slow shift to cloud computing...

This is my first post in a while, I realise. I can't promise that this is the start of more frequent posting, but can say that I still like the idea of blogging (in preference to all these twitter-like update methods, including facebook updates, which I see as ultimately pointless and a little annoying, except for in very limited contexts), and don't want this little blog to die completely...

...and now moving on.

Cloud computing approaches and applications have been around for a while, and are becoming ever more prevalent. It's quite involved, but they are essentially those programmes that run on a remote networked server, and which are accessed on client machines connected to the network. This often includes the storage of content generated by these applications too - for example, word processing using googledocs. In the past, I've been very resistant and a bit mistrusting of these applications. Partly I think because I like to have everything to hand on my local machine, without having to be dependant on an internet connection - an obvious prerequisite for cloud computing applications - partly because of space limitations on online storage, and partly because of security of data. However, in recent months, I've been using more and more applications that have a cloud-like aspect to them, particularly regarding the storage of data. So for example, I've become particularly addicted to using Tomboy Notes as a note-taking program, especially the cross-platform support, and integration with UbuntuOne (where you can access, view, edit and create notes). Also, I was recently introduced to Mendeley, described as a research management tool (incorporating academic networking tools, and literature statistics, etc), but for me most usefully can be used as a reference management system (using a desktop component). The reference library in this case is held in the cloud, linked to a personal account, and synced with local machines where desired. I'm not completely familiar with it yet, but I'm getting to like it. Finally, I'm now an avid user and admirer of Dropbox, which is a great document sync tool. Anybody with further experiences of either of these tools, or indeed with similar tools I haven't mentioned, then please let me know.

Back to my point. It is that the ability to access personal data, often in a proprietory format, from any computer regardless of operating system and installed programs is a very useful tool. However, the additional functionality afforded by locally running programs (such as the integration between a word processor and a reference manager) means that I'm not going to go completely into the cloud just yet.

Friday, January 15, 2010

Reinforcement Learning illustrated...

Friends always seems to be on television here, several times a day, every day of the week. Once they reach the end, the whole thing is shown again from the beginning. I was watching an episode this evening, and this little gem of a quote came up:

Ross: I'm really impressed that you were able to memorize all this so quickly.
Joey: I'm an actor. I can memorize anything. Last week I had to say "Frontal Temporal Zygomatic Craniotomy."
Ross: Wow, what does that mean?
Joey: No idea. But the guy I said it to dies in the next scene, so I guess it means, you're going to get eaten by a bear.

From the episode "The one with the fertility test", you can see the clip here (at about 7mins).

Saturday, January 02, 2010

Happy New Year!

Happy New Year to all :-)

PS I didn't take the photo - I just found it...