Friday, November 28, 2008


Because I'm a complete slacker, I have only just had a proper look at TED, despite many previous recommendations.

If anyone's reading this, if you know of any talk/presentation that is particularly good and/or interesting, I'd really like to know about it :-)

Tuesday, November 25, 2008

Encephalon #59 @ Ionian Enchantment

Recently put up is the latest edition of Encephalon, at Ionian Enchantment. I'll get around to posting something other than links to the Encephalon editions sooner or later, but I'm afraid my blog is less of a priority than getting work done for my PhD... :-) Anyways, my three posts of particular interest in this fortnight's compilation:

- From Mind Hacks is a short piece on the Ganzfeld procedure: a method often used to induce hallucinations. Is it just me, or is the last hallucination that Vaughan mentions slightly disturbing...

- Physical exercise and 'brain health' from Sharp Brains

- Something that I found of particular interest is a review of a paper by Clark and Wheeler on Embodied cognition and cultural evolution, at Neuroanthropology. It's a long (but very good) review of the paper and the concepts involved, but helpfully some of the more important points are highlighted. Essentially, the problem is as follows (copied from article):
Whereas embodied cognition models the brain as a product of dynamic
interplay among processes at different time-scales — evolutionary,
developmental, and immediate –, evolutionary psychologists tend to assume the
existence of underlying, enduring structures in the brain, shaped by natural
selection and encoded (even where we cannot find evidence) in genetic

As far as I'm concerned a fascinating review of a paper which I will now endeavor to get my grubby little hands on...

Tuesday, November 11, 2008

Encephalon #58 at Highlight Health

Didn't get around to it yesterday, but the latest Encephalon has been put up at Highlight Health. With the special theme of Decision Making, I particularly like the organisation of this one, with submissions put into one of four categories: needs, preferences, values and emotions. The contributions aren't half bad either! :-)

- A look at peoples ability to perform multiple tasks at once - or rather a lack of it... from SharpBrains

- On confabulation, brain damage and the lack of a role for memory? From the BPS Research Digest blog

- Something I've sort of mentioned before: a brief review of definitions of intelligence from Brain Blogger

Monday, November 10, 2008

Robotics walking aid

This looks interesting, even if a tad uncomfortable...

I did a (very) quick google search on it - why is it so difficult to any information on things that haven't been digested through multiple news corporations? The Honda website provides a few more details though.

Monday, November 03, 2008

Fetal Pain?
The issue of abortion is obviously a contentious one, from a moral, medical and emotional point of view. Of central importance to this debate is the question of whether a fetus can feel pain during surgery or during other operative procedures. Necessary for this is an objective assessment of when a fetus can feel pain, or rather, when during development do the mechanisms underlying pain reception and processing emerge to form a functioning system.

In this paper by Vanhatalo and Niewenhuizen (2000), a review of the development of the pain systems of the fetus is given, followed by the discussion of a particularly pertinent and scientific (i.e. not emotionally laden) question: what is the effect of noxious (read: painful) stimuli on the subsequent development of the fetus?

Given that a formal definition of pain (as stated by the aptly named International Association for the Study of Pain) is given as "a unpleasant sensory and emotional experience associated with actual or potential tissue damage", it may be seen that pain is an inherently subjective phenomenon. Indeed, all of the standard measures of pain rely on subjective scales and the verbal reports of the patients - which are clearly not suitable for neonate use. Indirect measures such as behavioural reactions and autonomic responses to noxious stimuli must therefore be used.

In addition to these indirect indicators of pain, an understanding of the development of the development of the pain mechanisms themselves. Three levels are described in the following paragraphs: the somatosensory functions, the physiological reflexes and the pain behaviours.
The somatosensory pain system involves the pain receptors and associated neural pathways. The development of these takes place relatively early on in development: by the 7th week receptors appear around the mouth, and by the20th week they are present all over the body. This is followed by synapse connection to the spinal cord. These lower levels have been relatively well characterised. At higher levels (sub-cortical and cortical regions), the picture is less clear. Thalamo-cortical connections occur at approximately week 25, but it is not until week 29 that evoked potentials can be measured from the cortex, indicating the formation of meaningful functional pathways at this time. Despite this, there are likely to be other connections formed between the sensory periphery and "deeper brain areas" when the spine and thalamic connections are formed at week 20, allowing the potential for sub-cortical processing of pain at this time. There are naturally many other relevant developmental milestones, but it is important to note that the initial pain related pathways which form in the fetus may be very different from those in the mature individual - giving an indication of the importance of individual development both pre- and post-natally.

The second element of fetal pain characterisation is the behavioural reflexes displayed, including withdrawal reflexes, other body movements and even vocalisations. These reflexes are, however, known to be mediated entirely by the spinal cord, and therefore do not involve "higher perception of pain". Additionally, there is no clear correlation between intensity of the stimulus, and strength of the reflex - meaning that the reflex cannot be used as a reliable indicator of 'painfulness'. However, there is some evidence that facial expressions, for fetus's as young as 26 weeks, may more accurately give an indication of pain level.

The third level in characterising pain is the development of the autonomic and endocrine systems. In mature humans for example, changes in autonomic responses (e.g. increased heart rates, and production of various hormones such as cortisol) may be used as indicators for pain - similar mechanisms may also apply to the developing fetus. However, as yet (or at least at the time of the paper), there appears to be no reliable correlation upon which to base a measurement scale.

Finally, the question of how prenatal pain affects the subsequent development of the fetus is examined. It is noted that subcortical pain processing may occur a number of weeks prior to any noxious stimuli processing in the cortex. Also noted is the plasticity of the nervous system throughout this period, meaning that development is strongly shaped by external input - a number of studies have provided evidence for ...correlations of the early pain experiences to later behavioural variables or to later developmental outcomes..." - particularly the effects on stress responses. In summary: the presence of pain during development can have profound long-term effects on both neurological and psychological development.

In conclusion, the authors note that while the fist sensory experiences (read: conscious experience?) of pain are theoretically possible around the 26th week of gestation (corresponding to the growth of the thalamocortical connections), noxious stimuli could have a damaging effect on fetal development irrespective of processing in the brain. This is because pain also results in activation of stress responses which do not rely on cortical processing. Hence, the authors point to week 10 (development of spinal cord afferents) as being of significance in terms of effect of pain on development – and finish with the question: “which sensory experiences are potentially harmful for the development of a fetus?”.

Note: this paper is from 2000 - those mentions of mechanisms as not being well characterised may now be well understood. If anyone knows of any such advancements, I'd be happy to hear about them – I'm by no means an expert on this topic :-)

Sampsa Vanhatalo, Onno van Niewenhuizen (2000). Fetal Pain? Brain and Development, 22, 145-150

Friday, October 31, 2008

Encephalon #57 at Mind Hacks

Internet problems at home have prevented me from posting, so after a 5-day delay, I can finally say that Encephalon #57 is up at Mind Hacks. It's an excellent compilation as usual, with posts on infantile amnesia, long-term potentiation and memory erasing particularly catching my eye.

I've not been posting much recently (have spent my days recently sitting in front of a screen attempting to programme an embodied developmental-like cognitive architecture, so sitting in front of a screen any more to write and post on the blog hasn't really been in the forefront of my mind), but in the coming week, watch out for posts on pain (and its developmental role), and perhaps also one on the mirror neuron debate.

Monday, October 13, 2008

Encephalon #56

Welcome to the 56th edition of Encephalon, here at Combining Cognits. After the emerald anniversary a fortnight ago, I felt I had to find some significance for this issue number – and so I turned to the infinite wisdom of Wikipedia and found the answer (wait for it...):

56 (fifty-six) is the natural number following 55 and preceding 57.

So there we have it. Who said Wikipedia was useless* :-) Anyways, moving swiftly on, we have in this edition we have a nice range of submissions, though dual themes seemed to emerge: Anti-social behaviour, and the somewhat predictable Brains (code for 'I can't quite find a category to cover the rest, even though they're each interesting')**.


Anti-Social Behaviour

With anti-social behaviour being of growing concern in the U.K. at least, with multiple thousands of complaints to the authorities every day, a recently published paper in Biological Psychiatry on cortisol and aggressive behaviour has received a lot of media attention. This paper has been taken up by two of our submitting authors. The Neurocritic provides us with an overview of the paper, highlighting the differing levels of cortisol in subjects with a “Conduct Disorder” with control subjects when performing a frustrating game. Daniel at Neuroanthropology also looks at this paper, but he takes a much more critical line, and broadens his discussion to much wider issues: from criticising the methodology of the study itself, to the media hyping almost beyond recognition (a pet hate for most people methinks), and a commentary on general societal attitudes towards misbehaving youths. A nice discussion piece I feel.

One factor which has pointed to as being a major contributor to anti-social behaviour is alcohol. Besides the social effects, the personal and physiological effects are very pronounced. Jared at Brain Blogger takes us through some of these effects – what it does to cells and tissues, and the potential effects (albeit on a longer time-scale) on the bodily organs and brain, specifically mentioning Korsakoffs syndrome (which has in past been the subject of my personal interest).

One property of alcohol which can make its effects far worse (and which is in common with narcotic substances) is that it can be very addictive, which may lead to the personal and social problems previously mentioned. Dr. Shock brings us an overview of addiction, and raises the possible use of deep-brain stimulation methods to counteract it. (In a pertinent post, Vaughan at Mind Hacks recently posted a list of DBS-related applications)

Going back to our theme of anti-social behaviour: let's say the police pick you up and charge you for some transgression of the law. However, the media (here at least) seems to delight in telling the occasional story of how some obviously guilty (and non mentally impaired) crook has got off free (or lightly at least) with a tale of mental problems. Now clearly, each case must be taken on its individual merits (and I wish to make no general statement regarding the validity of any such claims of mental impairment), but Joshua at Science Blog takes us through a problem with such a legal defence. Given that cognitive science holds that all human behaviour comes from the 'brain' (or more generally the CNS), to say that your brain 'made you do the deed' is a perfectly accurate statement in all cases. In Joshua's words: “...most people prefer that the legal system only punish those who are responsible for wrongdoing. If we exclude from responsibility everybody whose actions are caused by their brains, we must exclude everybody.” There's a bit more to it than that though: what if someone has a genuine problem which has not yet been characterised?


Brains, and everything else...

Jared of Brain Blogger brings us a summary of a paper on the impairments in empathy that many people suffer after undergoing a traumatic brain injury. However, it is not as simple as it may first appear: there didn't appear to be a relationship between severity of the brain trauma and the empathy deficiency, nor could the low empathy scores be predicted by measures of emotion.

Next comes a subject very close to my own interests: Chris Hallquist of Biology of Mind discusses consciousness and qualia, though particularly pointing out the shortcomings of introspection.

Dan of “Sports are 80% Mental” brings us a review of a paper on the six elements of a momentum chain: elements of a sporting event which, when they occur, have an effect on the performance of the athletes, and the outcome of the game, and which typically result from a “precipitating event”. An interesting perspective on the effect of affect and cognition on sport, and things can change very quickly.

Walter of Highlight Health reviews a study of the molecular characterisation of brain tumours, which is based on the Cancer Genome Atlas (TCGA). In the words of Walter, the TCGA “ an integrated network of clinical sites, core resources and specialized genome characterization and genome sequencing centers that work together to accelerate our understanding of the molecular basis of cancer”. This study in particular identified a number of pathways central to brain tumours, and importantly used a “...statistically robust number of samples...”. The post provides the details, so best not to rely on my paraphrasing.

With two late entries, we have a review of a book by James Zull on teaching methods based on the neurobiology of learning, and a review of recent developments in cognitive health and brain fitness, both from SharpBrains.


And finally, if you're short of reading, we have from Neuroanthropology a compilation of links on various subjects – particularly the section on “The Brain”.

That's it from me and this edition, I hope it has approached the level of interest and quality I have come to expect from Encephalon. In a fortnight's time, the 57th edition will be brought to us by the ever stimulating Mind Hacks. Submissions in the usual fashion: send a title, URL and summary to ~at~ gmail ~dot~ com.


* Incidentally, I don't – I'm just being facetious. As a first stop (followed by many other more academically reputable stops), it can be a very useful resource for general indicative definitions and pointers to more information.
** Although I have to admit, I have performed some very unsubtle shoe-horning to fit the entries to these themes – for which I apologise.

Tuesday, October 07, 2008

Encephalon Reminder

Just a quick reminder that the next edition of Encephalon will be hosted here at Combining Cognits next Monday (13th October), so make sure you get your best neuroscience related posts in by the weekend.

Normal submission applies - send links to your post(s) to encephalon {dot} host {at} gmail {dot} com. I look forward to reading them all, and hope that the compilation will up to scratch.

Incidently, the AISB Turing Test Symposium is being hosted at the University of Reading this coming Sunday (12th October) for anyone interested. Not sure what the registration procedure is though (whether you can pay-on-the-door for e.g.). The website should have more info.

Monday, September 29, 2008

Encephalon #55

The 55th edition of Encephalon (the 'emerald aniversary' edition) is now up at Neuroscientifically Challenged. My three picks as usual:

- Five points on why, even though absolutely important and fascinating, neuroplasticity has been overstated (or mis-stated at least), from Neuroanthropology. I particularly agree with point four, which states that "...much of the story of neuroplasticity is in developmental settings, in the normal interactions and activities that occur during childhood..." - an aspect very much understated, though I'd say implicitly assumed.

- From the ever thorough Mo at Neurophilosophy comes a review of Developmental topographagnosia - a disorder that essentially leads to a difficulty in producing cognitive maps, as Mo says: "It therefore seems plausible that a reluctance to form cognitive maps, starting from an early age and continuing throughout life, could result in a reduced capacity for the hippocampus to perform this particular function." For me, this seems to lead on nicely from the neuroplasticity post - development of the individual as being of central importance.

- Finally, from Neuronism comes a nice little article on computational neuroscience - building general models and theories in order to make predictions.

The next edition of Encephalon will be held here at Combining Cognits on October the 13th, so get your posts written and readied, and send them to encephalon {dot} host {at} gmail {dot} com as usual. Until then!

Wednesday, September 17, 2008

Special Issue on Arousal, Alertness and Attention

I recently came across a special issue of the Annals of the New York Academy of Sciences on Molecular and Biophysical Mechanisms of Arousal, Alertness, and Attention. It is May's issue, but for some reason, my alerting mechanism only told me about it on Monday. It's split into four main sections: (1) Elementary Central Nervous System Arousal; (2) The Emotion-Cognition Interface (which I think look particularly interesting); (3) Alertness and Attention; and (4) Circadian Rhythms in the Activation of Behavior (with a main emphasis on sleep). Anyways, some details in case of interest:

Issue 1129 - Table of Contents
Molecular and Biophysical Mechanisms of Arousal, Alertness, and Attention
DOI: 10.1196/annals.1417.034

Excerpt from preface:
"The volume starts with the most primitive function, generalized arousal, and then considers disorders of this function that cause comatose or vegetative states. After a series of chapters on emotion, alertness and attention, we finish with chapters on one of the most dynamic areas in neuroscience: sleep and circadian rhythms. "

Tuesday, September 16, 2008

Encephalon #54

I'm a day late, but the 54th installation of Encephalon yesterday returned home to Neurophilosophy. A few of my picks from this edition:

- Also the 'editor's pick' (something we'll no doubt see in future edition), from neurobiotaxis comes a nicely written post on the development of modularity in the brain, covering developmental processes and evolution.

- From Neuronism comes a piece on the Blue Brain project, specifically the recently observed persistent oscillatory activity in the gamma range in the simulated cortical columns.

- Dan Peterson reviews a paper on embodied cognition: particularly the link between motor skills and the language comprehension of those skills.

- Finally, from Neurophilosophy is a review of a paper on the reactivation of hippocampal cells during recall tasks.

Monday, September 01, 2008

Encephalon #53

Encephalon comes from Africa in the latest (53rd) edition. Excellent as usual or course! Just a few quick picks from me this time - I'm at TAROS (and it's just about to start)...

- The first of a three parter on Grid Cells at Neuronism.

- An explanation of Orthogonal Coding (basically, an extension of ensemble coding) over at Pure Pedantry.

- A few links to various articles, interviews, etc, on brains and plasticity at SharpBrains.

Tuesday, August 26, 2008

On cognition

A while ago now, Andy at Figural Effect posted a concise summary (by way of quotations) of four definitions of 'Cognition' from researchers in different disciplines: Williamson, LeDoux, Clark & Grush, and Neisser. Because I see the Clark & Grush definition as more clearly defining a computationally implementable framework (as I've discussed previously), I find this one the more appealing, however, as noted by Andy, the views from different disciplines is interesting to note.

Related to this, and as mentioned in the comments of the Figural Effect post, is an interesting compilation of definitions of intelligence as viewed from psychology, AI, and others. Personally though, the view of intelligence given by H.G. Wells in 'The Time Machine' is possibly the most elegant I have seen.

Friday, August 22, 2008

I'm afraid I can't post properly at the moment, as am having problems with blogger...

Tuesday, August 19, 2008

Encephalon #52

The 52nd issue of Encephalon has now been put up at Ouroboros. With a nice Q&A layout, it covers the usual wide range of subjects, from neurogenesis to grannies, and from perception to culture. A couple of, in my view, the most interesting:

- From Neurophilosophy, a review of a paper on brain plasticity, particularly the visual cortex: visual experience can modulate the production of proteins which can influence plasticity along the visual pathway.

- From Neuroscientifically Challenged comes a look at the reason for sleep, and how the humble fruit fly has helped to shed some light on the problem.

- Finally, from Neuroanthropology is a lengthy review of a paper which lays the foundation of "cultural neuroscience": the influence of cultural and social factors on neural mechanisms, and how this may be taken into account in neuroimaging studies. My first thought though when reading this was that it would then be of more immediate concern to somehow account for individual differences in bodily morphology and individual personal histories - these, I would suggest, would have a more direct influence on development, and hence present neural mechanisms, than cultural influences - even though these are, as evidenced by this paper, obviously present. But then again, I'm not a neuroscientist, and have not studied the paper in great detail yet, so may have missed something.

Friday, August 15, 2008

The Inseparability of Emotion and Cognition

A paper on how emotion and cognition should not really be considered as separate entities, but as integrated - a move away from functional specialisations in the brain, and towards widespread interaction and integration for the production of behaviour. Abstract:
The current view of brain organisation supports the notion that there is a considerable degree of functional specialisation and that many regions can be conceptualised as either 'affective' or 'cognitive'. Popular examples are the amygdala in the domain of emotion and the lateral prefrontal cortex in the case of cognition. This prevalent view is problematic for a number of reasons. Here, I will argue that complex cognitive-emotional behaviours have their basis in dynamic coalitions of networks of brain areas, none of which should be conceptualised as specifically affective or cognitive. Central to cognitive-emotional interactions are brain areas with a high degree of connectivity, called hubs, which are critical for regulating the flow and integration of information between regions.

Reference: Pessoa L (2008) On the relationship between emotion and cognition. Nat Rev Neurosci 9:148-158 - full text (may require subscription)

Thursday, August 14, 2008

The Animat project at Reading University

As reported on the BBC news website (and now many other news channels), and as subsequently nicely summarised by Mo at Neurophilosophy, the Animat project at the University of Reading aims to use a biological neuron culture to not just control a mobile robot, but also to receive sensory signals (in this case from 4 sonar sensors) from the robot - thus a closed loop system. The work is being done by CIRG (of which I am a part), in collaboration with the Pharmacy department, and hopes to allow the the biological neuronal culture to learn control of the mobile robot through the feedback mechanism in order to produce meaningful real-world behaviours - such as obstacle avoidance for example.

The official press release is here, and further information can be found here.

Wednesday, August 13, 2008

The Loebner Prize and Turing Test Symposium

On Sunday October the 12th, this year's Loebner Prize will be held here at the University of Reading. The Loebner Prize is essentially an implementation of the Turing Test which started in 1991, and which uses a text-based interface between the tester and the subjects (a human and a 'chat-bot'). This year, there are six finalists who will take part in proceedings on the day.

In conjunction with this event, AISB have decided to run a symposium on the Turing Test in parallel with the Loebner Prize. There are some fantastic speakers due to present, and I anticipate some lively discussions. I'm looking forward to it :-)

Thursday, August 07, 2008

Sense about Science

Something I blogged about over a year ago, I've just noticed that the Sense about Science campaign (which is a charitable trust "promoting good science and evidence in public debates") has a leaflet " help people to query the status of science and research reported in the media". As well as this, they've produced a button which links to it:

Hopefully, it will help prevent this sort of thing (from Jan 2007)...

Hemispherical 'electronic eye' - and some implications...

The BBC News website yesterday reported on the development of a camera with a hemispheric detection surface, rather than the traditional 2D array. The paper on which this article is based (in Nature - link) proposes that this new technology will enable devices with "...a wide field of view and low aberrations with simple, few-component imaging optics", including bio-inspired devices for prosthetics purposes, and biological systems monitoring. This figure from the paper gives a very nice overview of the construction and structural properties of the system. Note that the individual sensory detectors are the same shape throughout - it is the interconnections between them which are modified. Abstract:
The human eye is a remarkable imaging device, with many attractive design features. Prominent among these is a hemispherical detector geometry, similar to that found in many other biological systems, that enables a wide field of view and low aberrations with simple, few-component imaging optics. This type of configuration is extremely difficult to achieve using established optoelectronics technologies, owing to the intrinsically planar nature of the patterning, deposition, etching, materials growth and doping methods that exist for fabricating such systems. Here we report strategies that avoid these limitations, and implement them to yield high-performance, hemispherical electronic eye cameras based on single-crystalline silicon. The approach uses wafer-scale optoelectronics formed in unusual, two-dimensionally compressible configurations and elastomeric transfer elements capable of transforming the planar layouts in which the systems are initially fabricated into hemispherical geometries for their final implementation. In a general sense, these methods, taken together with our theoretical analyses of their associated mechanics, provide practical routes for integrating well-developed planar device technologies onto the surfaces of complex curvilinear objects, suitable for diverse applications that cannot be addressed by conventional means.
From the cognitive/developmental robotics point of view, this sort of sensory capability has (to my mind) some pretty useful implications. Given that the morphology of the robots concerned, and that would include the morphology of the sensory systems, take central importance in the development (or learning) that the robot may perform, then these more 'biologically plausible' shapes may allow better comparisons to be made between robotic agent models and animals. Furthermore, from the morphological computation point of view (e.g. here, and here), this sort of sensory morphology may remove the need for a layer of image pre-processing - motion parallax for example. As seen in flighted insects, the shape of the eye and arrangements of the individual visual detectors upon it remove the need for complex transformations when the insect is flying through an environment - an example of how morphology reduces 'computational load'. If effects similar to these can be taken advantage of in cognitive and developmental robotics research, then a greater understanding and functionality may be gained. The development of this type of camera may be an additional step in this direction.

Wednesday, August 06, 2008

The necessity for Intelligence

From "The Time Machine" - H.G. Wells, 1895:
"It is a law of nature we overlook, that intellectual versatility is the compensation for change, danger, and trouble. An animal perfectly in harmony with its environment is a perfect mechanism. Nature never appeals to intelligence until habit and instinct are useless. There is no intelligence where there is no change and no need of change. Only those animals partake of intelligence that have to meet a huge variety of needs and dangers."
In case you don't know the story, a synopsis is here. As far as I'm concerned though, well worth reading in full.

Tuesday, August 05, 2008

On Grandmother Cells Grandmother cells were proposed as single neurons which encoded for a single concept - in this case one's Grandmother. The concept was used as a straw-man to criticise sensory hierarchy-based brain organisation theories, but the ideas underlying it are becoming increasingly accepted (not the single neuron per concept I hasten to add). In a paper by Charles Gross (2002 - full ref below), a history of the term is given, with origins and influences.

These cells were originally proposed at the opposite end of the spectrum to ensemble or population coding - where it is the pattern of activity across a group of neurons which codes for a sensory percept. Although the term was coined by Jerry Lettvin in the late 1960's, after which its use quickly proliferated, it was actually proposed as a scientific theory a number of years earlier by the Polish neurophysiologist Jerzy Konorski.

Proposed in his work "Integrative Activity of the Brain" (1967), Konorski predicted the existence of individual neurons sensitive to sensory stimuli such as faces, hands, emotional expressions, etc - and named them "Gnostic" neurons. These were proposed to be located in specific areas of the cortex (in "gnostic fields"), such as the ventral temporal cortex (for the face field), and the posterior parietal cortex (for space fields). These predictions have proven reasonably similar to current proposals for the extra-striate visual cortex in monkeys.

Naturally however, Konorski's work was influenced by that of others. Firstly, in the early 1960's, Hubel and Wiesel demonstrated the hierarchical processing of sensory information in the geniculo-striate system: from simple receptive fields up to the ability to selectively generalise across the retina. Secondly was research on what was then known as the Association Cortex by Pribram and Mishkin: lesions of the inferior temporal cortex produced specific visual cognition impairments in monkeys.

These two bodies of evidence, along with his own familiarity with various agnosias which follow human cortical lesions, led to Konorski's proposal of gnostic cells as a means of accounting for these cognitive impairment effects. Despite the publication of these ideas, and the subsequent coining of the term 'grandmother cells', for at least a decade afterwards, gnostic cells were only taken up in the learning literature, not the perception literature. The term has now, however, had greater use in general textbooks and the pattern recognition literature.

Two features of the gnostic cells have long histories in neuroscience research. Firstly, they are examples of labeled line coding. Labeled line coding refers to a neuron property that allows it to code a particular stimulus property, such as line orientation in the visual field. Secondly, gnostic cells were held to be at the top of a 'hierarchy of increasing convergence'. This concept of convergence hierarchies had, for example, been proposed by William James (the pontifical cell), C.S. Sherrington (in "Man on His Nature", 1940), and Barlow (with the slightly modified concept of cardinal cells, 1972).

In conclusion, the paper notes that the idea of convergence of neural input onto one cell seems to have arisen independently a number of times - and that contemporary human brain imaging have revealed cortical regions (e.g. inferior temporal cortex) which resemble the gnostic fields proposed by Konorski.

As an example of more recent research efforts in exploring this converging hierarchy proposal, Quiroga et al ("Sparse but not 'grandmother-cell' coding in the medial temporal lobe", TICS, 12(3), 2008) - which also involved the somewhat infamous experiments which identified the 'Jennifer Aniston cells' - identified very sparse coding of visual percepts in the medial temporal lobe. In this paper though, a number of arguments were presented for why these cannot be considered to be grandmother cells - a view which I think may be widespread: sparse encoding but not convergence onto a single cell.

Gross, C. (2002). Genealogy of the "Grandmother Cell". The Neuroscientist, 8(5), 512-518.

Encephalon #51

The 51st issue of Encephalon is now up at The Mouse Trap - an ode to the brain, which nicely intertwines the submitted subjects. Two which I found particularly interesting:

- From Effortless Incitement, a summary of a paper on the encoding of concepts in the mouse brain.

- On the exaggerated claims surrounding mirror neurons, from Neuroscientifically Challenged, particularly concerning an essay by Damasio and Meyer in Nature on Convergence/Divergence Zones.

Monday, August 04, 2008

A new name and a new look...

After a 4-month blogging gap, I've decided to overhaul this blog's appearance, and change the name as 'Memoirs of a Postgrad' seemed far too long and clunky. So, the new name is simply 'Combining Cognits' - much shorter I think you'll agree. The term 'cognit' is taken from the Network Memory theory, where it is used to describe a basic memory/perception associative unit in the human cognitive system.

A couple of other cosmetic changes: the colour scheme (much lighter), text (I hope a bit clearer), a couple of extra widgets (post ratings, recent comments lists, and a basic search function - all from widgets for free), and a pretty basic banner (the result of a 10-min playaround in I'm certainly no artist!). I don't expect much else to change, other than the occasional minor detail in the coming days. I do however expect to post some more useful/interesting posts on cognition-related issues and studies in the next few days.

Please let me know what you think!

EDIT 04/08/08: changed the blog name again - to "combining cognits"

Friday, April 04, 2008

Science and Engineering as Art

From the BBC news website (again...) is a short opinion piece by Mark Miodownik, head of the Materials Research Group at King's College London, who (as seems to be all too common these days) bemoans the lack of development of young scientists/researchers/engineers in present day Britain. Pointing as many others do towards flaws in the education system, and a lack of willing among commercial enterprises to put money into keeping people in science (rather than letting them be tempted by the larger salaries available in other lines of work), he makes a comparison between science and art, which is new to me, but which I rather like:
"Science is like poetry in this respect: it is an expression of something sublime. Engineering likewise is an expression of human emotions and passions - cars, hip replacements and even washing machines are as much expressions of our soul as paintings, literature and music."

Saturday, March 29, 2008

On Synaesthesia, by a synaesthete

I just found a short piece on the BBC news website on living, and growing up, with Synaesthesia, written by James Wannerton, president of the UK Synaesthesia Association, and himself a synaesthete (with taste associations). I personally am fascinated by synaesthesia, for all sorts of reasons, and this piece only enhances that by providing a personal view on how it affects ones life (for better and worse) rather than a discussion from the impersonal perspective of a neuroscience paper. An extract or two:
"...I found my word/taste associations having an increasing effect in my
everyday life, subtly dictating the nature and course of my friendships,
personal relationships, my education, my career, where I live, what I wear, what
I read, the make and colour of car that I drive. The list is endless.
What is beyond doubt is that I would never consider the option of being
cured, if ever such a thing were offered, although it would interest me to find
out how my perceptions would be altered if I "lost" it for a day. "

Link to the story

Thursday, March 20, 2008

Encephalon #41

The 41st issue of Encephalon is now up at Pure Pedantry (ok, so I'm a few days late...). An excellent round-up as usual, with the following posts being particularly interesting to me:

- From Neuroanthropology comes a piece on dissociation strategies, particularly in regard to sporting activities. Dissociation in this context refers to the ability to (or rather the effect of) perform some conscious task completely independantly of the actions you are making, the actions themselves thus no longer being consciously considered: for example, focussing on repeatedly counting to 100 whilst running. Indeed, attempting to concentrate on the physical activity, rather than dissociating from it, may actually impair performance.

- From Providentia comes the story of Solomon Shereshevsky, a man with an extraordinary memory - although he is better known as 'S' in Alexander Luria's writings. After much testing, Luria concluded that Solomon had an extreme case of synesthesia, where all stimuli were converted to (or rather strongly associated with) visual images. A nice reminder that many of the subjects of the classic (and most well-known) psychology case studies were just people trying to on with their lives in spite of their 'impairments'.

- Finally, from The Neurocritic, comes a review of an earth-shattering neuroimaging study press release which shows that hungry people are more attracted to pictures of food (specifically donuts in this case) than full people are :-) Despite the ridicule, there is also a review of the actual published paper, which revealed activation in the locus coeruleus during the hungry state, a hitherto generally overlooked region.

Tuesday, March 11, 2008

Extended Hiatus

I'm afraid that over the past few weeks, I've not been able to post much (or at all...) as I've been rather busy (just submitted my first conference paper - here's hoping it gets accepted...). I hope to post again in the next week or two through. A couple of links until then:

- The latest Encephalon, up at Mind Hacks
- A short piece on the widely reported thermally powered submarine robot
- The start of a series on introduction to neuron types: The Grid cell, at The Phineas Gage fan club
- A definition of "Emergence" at Brain Hammer

Tuesday, February 19, 2008

Encephalon returns

I haven't posted for a while now due to other commitments, but for now a link to the new incarnation of Encephalon, the first issue of which is now up at Sharp Brains. It has more posts than usual (24 in all), with a wide range of subjects: from God to stress, and free will to depression, via a healthy sprinkling of other neuroscience-related matters...

I guess it could be the 39th edition of Encephalon? (Unless I've missed one somewhere...)

Link to new Encephalon Home

Thursday, February 07, 2008

Simulation versus reality, and the reliance of cognition on embodiment

Cognitive robotics work makes extensive use of both real world robots and environments, and their simulation equivalents. Simulations are useful in that development time is shorter (or at least has the potential to be), so proof-of-concept experiemnts are readily implemented, and all of the variables are under the control of the designer, allowing better testing and debugging for example. However, from a practical point of view, there are a number of reasons why the use of a physical robotic agent is necessary. Brooks suggested through the “physical grounding hypothesis” [1, 2] that since simulations are by their very nature simplifications of the real world, they miss out details which may be important in terms of complexity of the problem faced by the virtual agent. However, by attempting to implement a high fidelity simulation model, one may use more resources (both human and computational) than by using a real robot – hence defeating the object of using a simulation at all. Related to this, it is also suggested that the designers of the simulation make assumptions as to what is required, thereby unintentionally introducing biases into the model, which would have an effect on the validity of the simulation. An effect of this may be unrealistic behaviours (or ones which would not map to real world behaviour). However, it is acknowledged that when a simulator designed to be independent of any particular theory is used, this last point is effectively rendered void [3].

In addition to the practical problems outlined in the previous paragraph, there are more philosophical concerns when considering embodiment which will now be briefly stated. The assertion that embodiment is necessary for cognition is now generally accepted, as evidenced by [4] for example. However the definition of the notion of embodiment is far from clear. Numerous definitions have been used, eight of the most frequently used concepts of which are reviewed by [5]. Among these are general definitions such as embodiment as structural coupling to the environment or as physical instantiation as opposed to software agents (as argued for in the previous paragraph). More restrictive definitions also exist, such as embodiment in an organism-like bodies (which have life-like, but not necessarily alive, bodies), or organismoid embodiment which states that only living bodies allow true embodiment. However, even if the most restrictive definition becomes generally accepted (strong embodiment: that a living body is required), it has been argued that studying 'weakly' embodied systems as if they were strongly embodied would still be a worthwhile research path [6].

One particularly persuasive argument regarding the essential elements of embodied cognition states that “...the sharing of neural mechanisms between sensorimotor processes and higher-level cognitive processes” is of central importance [7]. This view, which is supported by a wide range of empirical evidence, highlights the necessity of 'low-level' sensory motor contingencies for 'high-level' cognitive processes. In this way, cognition is fundamentally grounded in the sensory and motor capacities of the body in which it is instantiated; cognition can not exist without embodiment – a point emphasized in [8].

[1] Brooks, R.A., Elephants don't play chess. Robotics and Autonomous Systems, 1990. 6: p. 3-15.
[2] Brooks, R.A., Intelligence without Representation. Artificial Intelligence, 1991. 47: p. 139-159.
[3] Bryson, J., W. Lowe, and L.A. Stein. Hypothesis Testing for Complex Agents. in Proceedings of the NIST Workshop on Performance metrics for intelligent systems. 2000.
[4] Pfeifer, R. and C. Scheier, Understanding Intelligence. 2001, Cambridge, Massachusetts: MIT Press.
[5] Ziemke, T. What's that thing called Embodiment? in 25th Annual Meeting of the Cognitive Science Society. 2002. (review)
[6] Sharkey, N.E. and T. Ziemke, Mechanistic versus Phenomenal embodiment: can robot embodiment lead to strong AI? Journal of Cognitive Systems Research, 2001. 2: p. 251-262. (review)
[7] Svensson, H. and T. Ziemke. Making sense of Embodiment: simulation theories and the sharing of neural circuitry between sensorimotor and cognitive processes. in 26th Annual Cognitive Science Society Conference. 2004. Chicago, IL.
[8] Clark, A. and R. Grush, Towards a cognitive robotics. Adaptive Behavior, 1999. 7(1): p. 5-16. (review)

Wednesday, February 06, 2008

A short note on Artificial Ethology

In attempting to understand the workings of a complex system such as the human brain, psychology has analysed the behaviour of individuals when performing certain tasks to infer the internal processes at work as those tasks are completed. The study of behaviour is thus an important aspect of brain research. In zoology, the term ‘ethology’ describes the study of animal behaviour. ‘Artificial ethology’ thus describes the study of behaviour of artificial agents [1], and has been described as being an important aspect of research in the development of autonomous [2] or developmental robotics [3].

Robotics have been used extensively in the past for exploring biological issues by using the observed behaviour of the artificial agents as a means of identifying functional requirements. ‘Grey’ Walter’s tortoises were created as a means of investigating goal seeking behaviour, with numerous parallels made to simple animal behaviour (as reviewed in [4]) and the use of biological inspiration in the same way as is currently used. Similarly, Braitenberg vehicles [5], particularly the simpler vehicles, have a strong biological influence (Valentino Braitenberg is himself a brain researcher, who proposed the vehicles as a thought experiment), and provide a strong example of how the environment, as coupled through the physical agent, plays just as important a role in the behaviour (and ‘autonomy’) of an agent as the control mechanism (as discussed in chapter six of “Understanding Intelligence” [6]). These two examples (many others are described and discussed in [6] and [1]) demonstrate that the use of robotic agents, and particularly the behaviour of those agents, to examine theoretical problems from the animal sciences is an established success. Indeed, it has been suggested that the ultimate aim of artificial agent research is to contribute to the understanding of human cognition [7].

[1] Holland, O. and D. McFarland, Artificial Ethology. 2001, Oxford: Oxford University Press (summary)
[2] Sharkey, N.E. and T. Ziemke, Mechanistic versus Phenomenal embodiment: can robot embodiment lead to strong AI? Journal of Cognitive Systems Research, 2001. 2: p. 251-262 (review)
[3] Meeden, L.A. and D.S. Blank, Introduction to Developmental Robotics. Connection Science, 2006. 18(2): p. 93-96
[4] Holland, O., Exploration and high adventure: the legacy of Grey Walter. Philosophical Transactions Of the Royal Society of London A, 2003. 361: p. 2085-2121
[5] Braitenberg, V., Vehicles, experiments in synthetic psychology. 1984, Cambridge, Mass.: MIT Press (review)
[6] Pfeifer, R. and C. Scheier, Understanding Intelligence. 2001, Cambridge, Massachusetts: MIT Press
[7] Guillot, A. and J.-A. Meyer, The Animat contribution to Cognitive Systems Research. Journal of Cognitive Systems Research, 2001. 2: p. 157-165 (review)

Tuesday, February 05, 2008

What is autonomy?

ResearchBlogging.orgIn yesterdays post, I reviewed a paper which discussed the role of emotion in autonomy. The concept of autonomy itself was found to be quite fuzzy, with definitions being dependant on the field of research in which the term is used. In an attempt to elucidate the concept, the editorial of the special issue of BioSystems on autonomy (of which the previously reviewed paper was a part) explores some of the issues involved.

Starting from the broad definition of autonomy as being self-determination (or the ability to act independantly of outside influence), it can be seen that this description applies to many levels of a system (be it biological, or artificial). However, the role of external (environmental) influences cannot be discounted: the reactive nature of autonomous systems is an essential part of proceedings - to the extent that some theorists have argued that there is no distinction between the two - even in the theory of autopoiesis is this the case. So, even from a theoretical standpoint autonomy is not isolated from the environment, but emphasises the independence.

Eve here though is the term independence problematic. There are three aspects which are pointed out as being of importance to the present discussion: (1) the reactive extent of interactions with the environment, (2) the extent to which the control mechanisms are self-generated, and (3) the extent to which these inner processes can be reflected upon. From these three properties of independence, it can be seen that autonomy is on a sliding scale, rather than a binary property.

The final notion of relevance to the present discussion of autonomy is self-organisation, due to it being a central element in life, and in those properties which we desire artificial systems to have. While some have shied away from the use of this term because of the connotations of something doing the organising, the concept of self-organisation is generally used to refer to the spontaneous emergence of organisation, and/or the maintenance of the systems' organisation once in this state. An interesting aspect to the term self-organising is this: a self-organising system cannot be broken down into constituent parts for analysis since these parts are interdependent (an aspect likely to be emphasised by autopoietic approaches).

An additional aspect to the discussion of autonomy which is covered in this editorial paper is the theoretical tension between ALife (artificial life) and GOFAI (good old-fashioned AI) techniques. Where the latter has been often pilloried, the author points out a number of theoretical successes it has had in terms of describing autonomy and agency which has not been achieved by ALife due to its emphasis on lower level processes - an approach which in its own way has proven enormously successful in accounting for a number of mechanisms involved.

While this discussion of the term autonomy has not resulted in a hard and fast definition, the consideration of two closely related concepts (independence and self-organisation) has placed the term into a context applicable to a wide range of research fields. Indeed, this lack of a definite definition may prove to be more productive than counter-productive.

BODEN, M. (2008). Autonomy: What is it? Biosystems, 91(2), 305-308. DOI: 10.1016/j.biosystems.2007.07.003

Monday, February 04, 2008

On the role of emotion in biological and robotic autonomy

ResearchBlogging.orgAutonomy is a concept often used, but not always clearly defined. Indeed, there are a number of definitions which are used, often dependant on the context in which it is used. For example, "autonomy" may be used to refer to a mobile robot in the sense that it can move around on its own (whetever the control system used), but the same term may also be applied to a biological agent capable of defining its own goals and surviving in the real world. In the debate of autonomy, and as indicated from these examples, the concepts of embodiment and emotion are also important in being able to explain the mechanisms involved. In recent times, emotio has become a hot topic in a wide range of disciplines, from neuroscience and psychology, to cognitive robotics. In order to elucidate the role of emotion in autonomy, Tom Ziemke reviews the concepts concerned and outlines a promising course of future research.

First comes a discussion of the difference between robotic and biological autonomy. This discussion is especially pertinent given the problem mentioned in the first paragraph: the widely differing definitions of autonomy used in robotics work. Important for biological autonomy is the concept of autopoiesis. Broadly speaking, an autopoietic agent is one which is capable of maintaining its own organisation: it has the ability to produce the components which define it. For example, a multicellular organism has the ability to create individual cells, which in turn form the organism itself. Despite a range of slightly different versions of the term, they all emphasise this self-constitutive property - and thereby exclude all current technology robots. Concerning robotics, autonomy generally refers to independance from human control. The aim is thus that the robot determines its own goals in the environment. This use of the term autonomy has some problems, particularly with regard to the biological definition, but is in widespread use. An important point raised though is that robotic autonomy is used to refer to systems which are embodied in mobile robots which act in the real world, as opposed to the mostly disembodied decision making systems of more traditional AI methods.

With embodiment comes the issue of grounding. Following Harnad's formulation of the symbol grounding problem, and Searle's Chinese room argument, the grounding of meaning for artificial agents is an important issue. A large amount of work has been carried out in this area throughout the 90's as a means of improving the behaviour improved. However, merely the imposition of a physical body does not necessarily result in intelligent behaviour, since this embodiment emphasises sensorimotor interaction, and not the other aspects (of which there are many) which are highly relevant for biological agents. The question then is: what is missing from robotic setups?

The argument is that robotic models, in addition to implementing the sensorimotor interactions which have been previously emphasised, must also link this to an equivalent of homeostatic processes: i.e. linking the body to the cognition, not just the bodies' sensors and motors. An example of this may be a need to keep a system variable (perhaps battery level) in a certain range - in this way, behaviour must be affected in order to achieve this. A number of theorists have likened this connection to a hierarchical organisation, with homeostatic processes (or metabolism) providing a base for the more 'cognitive' sensorimotor processes, thus supposedly resulting in a more complex, and meaningful, emergent behaviour. Homeostatic processes are often implemented in robotic systems as emotion or value systems, which are often ill-defined, and not usually grounded in homeostatic processes, but arbitrarily added as externally defined (or observer-defined) variables. The widely differing dfinition used for emotions are problematic when it comes to comparisons between architectures. One definition, provided by Damasio, breaks down the broad notion of emotion as that displayed by humans into "different levels of automated homeostatic regulation" - basically, the term "emotion" can be applied to a range of behaviours, ranging from metabolic regulation, through drives and motivations, to feelings (e.g. anger, happiness). In this way, these somewhat arbitrarily defined implementations of emotion may be seen to be higher levels of the emotion hierarchy, which may ultimately be tied to bodily processes (e.g. somatic theories of emotion).

Bringing this discussion of autonomy and emotion in artificial (robotic) systems together, it is clear that current technologies are neither autonomous in the narrow biological sense, nor implement grounded emotions (due to their supposed basis in biological homeostatic processes). However, it has been argued that the narrow biological definitions do not provide sufficient conditions for cognition, and that higher level cognitive processes are not necessarily emergent from these constitutive processes alone, but that interactive processes are also necessary. Similarly, the necessity of such autopoietic properties for self and consciousness are not established. Robotic models may then be used as models of autonomy without having to rely on such philosophical concerns. The emergent conclusion is though that embodied cognition of the form favoured in cognitive robotics work commits itself to a central role for the body, not just in sensorimotor terms, but also in homeostatic terms. The interplay between the two is then of central importance, and this investigation is proposed as a promising avenue for future research.

Ziemke, T. (2008). On the role of emotion in biological and robotic auonomy. BioSystems, 91(2), 401-408.

Sunday, February 03, 2008

The Week of Science

As most probably know, the Week of Science is due to start tomorrow, and last five days instead of last years seven. As last year, I'll update this post as an index to my posts over the five day period.

Day 1: On the role emotion in biological and robotic autonomy

Day 2: What is Autonomy?

Day 3: A short note on Artificial Ethology

Day 4: Simulation versus reality, and the reliance of cognition on embodiment

Day 5: Due to other commitments, I wasn't able to produce a post of adequate quality for the final day of Just Science week. Bring on next year!

The RSS feed for the Just Science aggregator can be found here.

Thursday, January 31, 2008

Links, and Technorati search...

A couple of links which I've found quite interesting:

- A blog called "Reality Apologetics": written by Jon Lawhead (a recent philosophy graduate), it covers a wide wide of subjects, though focusing primarily on philosophy of mind. I've only just found it, but there appears to be some interesting stuff.
- A post entitled "Robot thoughts" at Saint Gasoline: a quick review of limitations in artificial consciousness, although the concepts of consciousness and thought seem to be confused, followed by a link to the widely reported story on Floreano's evolving robotic colonies (and the emergence of liars and altruists) - actually, I found the resulting comments more interesting than the post itself...
- A post called "Nature inspires creepy robot swarms" at Environmental Graffiti which seems to indicate that most robotics work is aimed at producing agents capable of world domination. While I feel it was over-the-top (although maybe I missed the well hidden sarcasm), it does raise some interesting issues over the public perception of the research field in which I find myself - 'intelligent' robotics. Having said that, the post was a good read :-)

And now for a short rant... As some may have noticed, I have a Technorati search chart on the right hand side of my blog. When I first put it in, it provided me with a quick and easy way to keep track of some very interesting blog posts. I even had the pleasure of watching the number of "cognitive robotics" posts linking here increase after my posts on the definition of cognitive robotics. However, in recent months (since last November), the system has let me down. It no longer updates the graph (an annoyance since I quite like the visual aspect), and most importantly, the search seems to be flooded with posts from dud/porn blogs. I suppose that's not Technorati's fault - no, wait, it is: my search term is "cognitive robotics", and I'd expect a search engine to work moderately well at finding relevant posts (the occasional dud may slip through the net, but this is just silly). So, I'm about to remove the once mighty keyword chart. Apologies, rant over...

UPDATE 01/02/08: I've tried to remove the keyword chart, but Blogger won't let me. Grr...

Sunday, January 27, 2008

New low-power MRI machine

As reported in January's issue of the IEEE Spectrum, what is essentially a very low power MRI (magnetic resonance imaging) machine has produced its first images of a human brain. Whereas a standard MRI machine produces magnetic fields of around 1.5 tesla, this new version produces only around 46 microtesla - an over thirty thousand-fold reduction, and a field apparently comparable in strength to the earths' magnetic field. This reduction in power results in a slightly different method for producing the images.

In a standard MRI machine, a strong magnetic field is used to align the proton in each of the hydrogen atoms before using an RF pulse to knock them out of alignment. As they snap back into alignment with the magnetic field, they emit a signal which can be detected and used to create a 3D image. In the new version, the very small magnetic field isn't enough to align the protons, so a short duration (1 second) magnetic pulse of slightly higher magnitude (30 millitesla). The resulting signals are very small, so an array of highly sensitive magnetometers are used (so-called superconducting quantum interference devices, or SQUIDS). A hugely important additional advantage of using these SQUIDS is that they are also used in the MEG (magnetoencephalography) imaging technique. This potential for MRI and MEG using the same machine raises the intriguing possibility of producing simultaneous structural images (using the MRI) and brain activation maps (using the MEG).

One other major advantage of using this low-power MRI technique is its potential to image tumors. Due to the subtle differences between cancerous and non-cancerous tissue, the differences are not readily captured by standard MRI pictures - whereas the low-power version can. Furthermore, the possibility arises of using this type of imaging during operations themselves, as the very low magnetic fields used would not interfere with the use of metal surgical implements. As with any newly developed technology though, it will be a fair few years before it will be in full use - although this situation will be helped due to comparatively low cost of the new device: due to the absent need for high magnetic fields, the new machines may cost as little as one tenth of its high-powered counterpart.

UPDATE 29/01: Vaughan at MindHacks has pointed out the downsides of using SQUIDs, which I didn't mention.

Thursday, January 10, 2008

Internal Representations: a metaphor

What follows is a brief note on why I don't believe that internal representations necessarily mean complex modelling capabilities, through the use of a (slightly suspect) metaphor. This isn't based on any peer reviewed work, just some thoughts I jotted down in a rare moment of effective cerebral activity :-)

Consider the following scenario: I have a large flat piece of plasticine. I also have a small rock. Let us assume that for some incredibly important reason (which has somehow slipped my mind at this moment in time), I wish to create a representation of the rock using the plasticine, to fulfill some vital task. The two main options are:

(1) I use my hands and my eyes, and I create a model of the rock using the plasticine which is visually accurate. This would be difficult (my skills as an artist are non-existant) and time consuming. The result would be a reasonably accurate (though not perfect) representation of the rock - the advantage of this method is that anybody else would be able to look at my model and be able to say without very much effort that I have a model of a rock.

(2) I let the rock fall onto my piece of plasticine, such that it leaves an impression (assuming the rock is heavy enough and/or the plasticine is soft enough). The resulting representation of the rock would be far more accurate, though incomplete, and dependant on exactly how the rock made contact (how deep it was pushed, the angle, etc). Furthermore, whilst I may know exactly what it is (with limitations due to my very limited knowledge of the conditions), somebody else would take longer to recognise what is being represented. However, it so much easier to do this than to create a sculpture.

Of course, there are variations on the above two methods. The most interesting/important being:

(3) I take the piece of plasticine in my hand and I push it onto the surface of the rock. In this way, I control (to a certain extent at least) what imprint is left as I vary the force and the angle. I'm still just left with an impression in a piece of plasticine, but the benefit is that I have more information on that impression. The effort expended is almost as little as in case two though. Of course another observer would have just as difficulty in recognising what this impression was a representation of.

What we have here is a very coarse, and not very subtle, metaphor for how I see the three main views of so called 'internal representations'. Basically, despite the adverse connotations that the term 'representation' (with regard to cognition and intelligence) may conjure for some, I don't believe that it necessarily implies highly complex internal modelling facilities. I wouldn't want to take the metaphor much further than I've elaborated above for fear of it failing utterly, but the three options may be seen to roughly correspond to the following.

In point one, you have the GOFAI (good old fashioned artificial intelligence) point of view, which, supported by personal introspection, uses complex internal modelling processes to create a high-fidelity internal representation upon which various mathematical planning processes may be performed. In the second point you have reactive or behavioural robotics, where the environment pushes itself onto the agent, and shapes its behaviour directly. The metaphor is failing already - there shouldn't be any representation in this case (not an explicit one anyway - though I would argue that it is implicit in the resulting behaviour - plenty of room for argument on that one!) - but the point is that the information gleaned from the environment isn't of much use in itself, only in terms of the effect it has. It's far easier to do this though, in terms of computational load etc.

If you view these two approaches as extremes, then point three may be seen as a 'middle road' - a vastly reduced amount of computational effort through taking advantage of what is there (both in terms of the environment and the agent itself), but with the presence of more information due to the additional knowledge of how that representation was acquired. So, perhaps the analogue for this point would be active perception, or perhaps more generally, embodied cognition. As with most things, I feel this 'middle road' to have more potential than the two extremes - although that is of course not to say that they are devoid of merit, for they both have produced many interesting and useful results.

But why do I think that the concept of internal representations is important? Because I think that internal simulation (as Germund Hesslow called it, otherwise generally referred to as imagination, simulation, etc) is central to many, if not all, cognitive tasks, which in turn is dependant on previous experience and internal knowledge: i.e. internal representations.

Finally, I would very much like to hear anybody's views on this topic - and my use of this suspect metaphor. I'm not aware of anyone else having used a similar metaphor (as undoubtedly they have, but then I haven't looked), so would appreciate it if someone could tell me if they have heard of one. I think I could do with reading the work of someone who's formulated this properly :-)

Tuesday, January 08, 2008

Getting published and dealing with rejection...

Just came across a post from SCLin's neuroscience blog listing a few links to resources giving hints and tips on how to write a cover letter to a journal for with a paper submission, how to review papers, and my two favorites: how to deal with rejection of a paper (part 1 and part 2).

Link to post

Monday, January 07, 2008

The simple brain?

There's a nice post up at Thinking as a Hobby on the possibility that the brain (actually more the neocortex than brain as a whole) just isn't as complex as it may appear. Basically, the idea is that while the evolutionarily older parts of the brain are specialised, the newer neocortex is more uniform and generally generic. The question then arises as to how this generic structure gives rise to functions such as language, which only appears in the species with the most developed neocortex (i.e. us humans). The solutions are either that the assumption of uniformity is wrong, or that emergence plays a huge role (where simple rules give rise to complex behviour). A very nice thought-provoking post.

I was thinking though, from the complex behaviour as being emergent standpoint above, that this wouldn't be enough to explain something like language. The environment would have to play an overly large role on proceedings (compared to simply being a matter of brain complexity): specifically inter-human interaction, or more broadly, societies, would have to be taken into account. Essentially, the complexity of behaviour that undoubtedly exists comes from the external world rather than the internal 'rules'. The consequence of this would be that to study the emergence of language (for example), inter-agent interaction would be just as, if not more, important than the internal complexity of an individual agent. So instead of the relatively simple neocortex making things easier in terms of describing complex behaviour such as language, it would actually become more difficult, since there would be multiple concurrent levels of analysis.

Just a thought, mind, I could be missing the point :-)

Back to the beginning though, this post by Derek James is very interesting.

Thursday, January 03, 2008

The Week of Science returns!

Happy New Year to all, may it bring good fortune and happiness to all :-)

After a resounding success last year, Just Science Week is returning at the beginning of February this year (4th - 8th). It's two days shorter this year, covering Monday to Friday, to ensure that there isn't a drop-off in posts over the weekend as before. I will be participating again, and hope to post some decent material. The aim for the participants is to post at least one post a day on scientific topics only - and not to post on non-science issues for that week. All of the posts will be aggregated, so a single feed will let you keep up with everything. What's the difference between science and non-science?

What counts as science and non-science? A post which discusses the political implications of science is not science; a post which discusses the cognitive psychology or neuroscience of individual political orientation is science. A post which uses a reference to Creationism before elucidating a biological topic is science; a post which discusses the social and religious dynamics of Creationism is not.

Taken from Just Science 2008 website - visit to sign up!