Archive for February, 2014

Choice Reaction Time – are we really that simple?


Recently I received a link to a post regarding Reality Based Self Defence (“RBSD”).  The post covered areas that are usually used by this specific area of martial arts to support the techniques that they use, it also covered areas of science and how it relates to human movement and behaviour stating Ockham’s Razor, Hicks Law and Power Law of Practice (“PLP”) to support underlying technique.   Having recently introduced a RBSD method myself I feel it appropriate to write something.  This has been an intention of mine for some time. The book that I am currently writing delves into this topic in a great deal of depth. I would first like to clarify my approach to my own combative training vehicle, Volitional Attention Training (“V.A.Training”), as it is important that the reader can place the information into context.

V.A.Training is not a self-defence method, period.   It was not conceived to be and does not in any way teach a defence form of tactics, quite the opposite, if asked to define it I would say, “it teaches a method of Self Preservation”. Although it has limited scenario based techniques it’s main aim is to develop stimulus-based responses. This method has been pitched at a very specific category of violence, that of A Social level and not the every day social violence that we encounter 98% of the time. I use this high percentage to get across my point that this is not for your every day classes that teach self defence, and therein lies one huge psychological problem, because the majority of RBSD methods believe that what they teach will allow an individual to manage and cope with A Social violence, using different situations in different environments to convince individuals that what they teach is the real thing!   The “real thing”? according to whom?


Ockham was a 14th century English philosopher who first proposed the principle that “plurality should not be posited without necessity” and its from this very unobtrusive start that we later arrive at Hick’s Law and then subsequently we find RBSD instructors advocating that human movement, within a combat situation, should be trained only to a very limited amount of moves.   According to Jeffery’s and Berger (1999) it’s unclear as to what was meant by this statement, as it can be interpreted in many ways.  However, later versions were clear and here is an example given by Jeffery’s and Berger:  “entities should not be multiplied without necessity” or “it is vain to do with more what can be done with less” and finally, a more up to date rendering, “an explanation of the facts should be no more complicated than necessary”.  Over the years, many noted individuals have used this theory to reduce complicated ideas to a simple more logical theory and this is all well and good when it relates to simple ideas and is used as a rule of thumb. However, humans have made great leaps forward since the 14th century, in our understanding of DNA for example, not a subject where corners could be cut to aid understanding and it’s therefore easy to see how those with a limited arsenal would want to use such terms to build a self defence system upon.   This theory was then backed up years later by Hick and then followed by PLP.

In fighting and in sports, we all know action beats reaction.   If you are reacting to an attack, as the good guys generally are, you are already behind the action curve. Just how behind scientists have labored intensely to discover over the last 60 years, and like splitting the atom, they have split the single second into one thousand parts to do it.   So what did Hick prove and what was the benefit to human movement?   Basically Hick experimented with reaction time and the decisions that occur during this process.    To be very accurate his research centered on Choice Reaction Time (“CRT”) and it’s the “choice” which has been conveniently dropped from most of the writing surrounding this law, which according to Hick slows down as the decision variables increase.   In other words, there is an increase in choice reaction time with the logarithm of set size, or put another way, the more choices you have the longer it takes to choose. There are some statistics around that state that it takes 58% more time to choose between two choices.  That’s a staggering amount of time when real time life and death decisions are needed, right?  Hick’s Law explores the interference that occurs during retrieval from declarative memory, it also goes on to state that there are occasional savings in response time due to stimulus response repetitions, this is covered in detail within my new book.    Just looking at the words being used here will give a clue as to what is going on, ‘choose’ and ‘stimulus response’ are two examples that are key to understanding the implications of this Law when applied to behavioural based method s of self defence. The message that is relatively clear here is that there is a significant change in data, with practice and stimulus response repetition.

Here is an extract from my next book concerning memory, which will help spread some light on the confusion that has occurred;

A stimulus that brings forth an episodic memory will also bring with it the ability for the mind to pay more detailed attention to that particular thought. Episodic memories are those that are encoded into the mind through an emotional experience.   These experiences are capable of coding in the time, place, feelings and details of the event, they are far more real to the mind than attempting to memorise an event to which you are just a passive observer. Semantic memory is generally concerned with knowledge of the world that we live in, there is a difference between knowledge that is factual and personal experiences that have encoded knowledge and understanding with a greater grounding and meaning.   Both semantic and episodic memory deals with long term, rather than short-term memory.  A key difference is that episodic memories encode the actual acquisition experience and the context in which the memory occurred.   For any combative or martial art technique to become efficient and effective, the coding process will need to support the intended action.  Techniques will have to become linked to procedural memory. Declarative memory deals with facts and data gained from learning. “declarative memory serves to “chunk” or “bind” together the converging processing outcomes reflecting the learning event, providing a solution to the “binding problem” for memory, Cohen, N. Poldrack, R. Eichenbaum (1975).   The sea is wet and the sun is hot are example of long-term declarative memories. Procedural memory is concerned with long-term memory including complex motor skills. These skills are first coded into the brain and over time become second nature; you do not have to use a cognitive thought process to access the skills. Playing a musical instrument, driving a car, or combative/martial art techniques, are all examples of procedural memory.

Its important to understand the context in which the original research was conducted and to also get a grips on what is happening when the human brain is being programmed by the type of reactions that it will default to in times of stress. I know that some of the research and the terms used are a little complicated, but bare with me, in order to support the information here, it is vital that I validate the theories, so apologies in advance for some of the writing….

There has been plenty of research into the area of reaction time; one particular piece was done by Schneider and Anderson (2012).  Their research explored past research on Hick’s Law and its interpretation in terms of information theory, which they based on the Adaptive Control of Thought-Rational. Their model produced a set-size (number of stimulus response alternatives) that closely resembles Hick’s Law.  They also account for changes in the set-size effect with practice and they explain the stimulus response repetition effects, which together challenges the information theoretic view of Hick’s law. The original research conducted by Hick was carried out in 1952, he used a computer test, to measure the time it took to decide between options and came up with the equation RT=a+blog2 (n). In basic terms his research confirmed that when faced with choices it takes longer to choose and the more choices that you have the longer it takes and it is from this very simple thought process the up to date reality based methods of teaching were born.     Are we humans so very simple?   Is the way the human brain works so simple?   Does it take a long, slow, encumbering amount of time to make decisions that could, put life at risk, for example?  For some, the answer is a resounding YES and as a consequence they misinterpret this information or worse, still do not have the knowledge that allows for an intelligent exploration of human behaviour.

Research by Schneider and Anderson (2012) found that when practice was allowed the slope of Hick’s Law tends to decease as the number of trials increase.   There have also been mathematical calculations done that estimate that after about one million trials the CRT will be independent of any set size.  So there it is, one million repetitions and your reaction time will be down to zero!    Lets remind ourselves what Hick found.   Using CRT   experiments, response was proportional to log (N), where N is the number of different possible stimuli.   In other words, reaction time rises with N, but once N gets large, reaction time no longer increases so much as when N was small, as the number of stimuli rise so the RT decreases.

Kosinski (2010) created a literature review on reaction time.   Within the review he discussed practice and errors and what he found would at first seem to support Hick’s Law in that, when participants were new to a choice reaction test, they were predictably slower.   Once they had time to practice, the reaction times increased.  Again very predictable, and too most a logical progression.   The results also found that when errors were made, RT slowed, they also noticed that practice time stabilized the reaction time for up to three weeks.   If a system was teaching a limited amount of moves, it would certainly see results based on these facts as the practice that was repeated would have embedded itself for a reasonable amount of time and if further practice was undertaken then the results would bounce themselves on for another period of time.   There is no distinction here with complicated routines, if volitional practice occurred, reactions and movements would soon start to get faster with less mistakes.

Now here is the real important part Stimulus Response and Hick’s Law!   What Schneider and Anderson (2012) also found is that the slope of Hick’s Law can be close to zero for highly compatible stimulus-response combinations.   The type of responses that were researched covered vocal and manual responses to manipulated stimulus types.  Without going into the detail, the explanation given for the close to zero stimulus-responses combinations were highly compatible and that much more pre-experimental practice had occurred prior to test as a control less compatible combinations were also tested (Brainard et al., (1962); Davis et al., (1961); Fits and Posner, (1967); Longstreth et al., (1985); Teichner and Krebs, (1974); see Morin, Konick, Troxell, and McPherson, (1965) cited by Schneider and Anderson (2012).    This evidence supports the age old adage of practice makes perfect or a more up to date term might be, perfect practice done slow and accurately programs the brain to respond fast! In the above tests the stimulus responses were chosen for their compatibility with natural behavior.   However, the real point is that it’s not a good idea to take what seems to be a logical statement, warp it out of all context and then sell it as the answer to all the problems.   It takes long enough to get to grips with any movement, let alone maladaptive ones.




Jefferys, W H. and Berger, j O. (1992) Ockham’s razor and Bayisean analysis. American Scientist. Vol. 80. No 1 (January-February 1992), pp. 64-72. Published by Sigma Xi, The Scientific Research Society.


Cohen, N. Poldrack, R. Eichenbaum (1997) Memory for items and Memory for relations in the Procedural/Declarative memory framework. Psychology press, an imprint of Erlbaum (UK) Taylor & Francis Ltd.


Darryl W. Schneider, John R. Anderson Cogn Psychol. Author manuscript; available in PMC 2012 May 1. Published in final edited form as: Cogn Psychol. 2011 May 1; 62(3): 193–222. doi: 10.1016/j.cogpsych.2010.11.001


Newell, Allen and Rosenbloom, Paul S., “Mechanisms of skill acquisition and the law of practice” (1980). Computer Science

Department. Paper 2387.


Kosinski, R, J. (2010) A Literature review on Reaction Time. Updated September 2013,. Accessed on 17-02-2014 @

Silva, C. Cid, L. Ferreira, D. and Marques, A. (2011) Attention and Reaction time in Shotokan Athletes. Published Revista de Artes Marciales Asiaticas (2011), vol, 6 issue 1, p141 16p. accessed on 17-02-2014 @

, , , , , , ,

1 Comment

%d bloggers like this: