Challenging the Ageing Mind
A multidisciplinary, neuroscientific perspective of an older drummer

1. I began by playing a pattern of 5 beats with one hand (I'll call this the "Leading Hand" rather than referring to left or right as drummers are not all the same) while the other hand played 4 regular beats in the same space. In other words: 5 over 4 in drummer parlance.
2. Next, I added a 4 over 3 pattern in the same manner.
3. Finally, a 3 over 2 pattern was added.
   
   NOTE: Coincidentally and very interestingly, but unrelated, these ratios correspond and conform to ratios in Pythagorean Tuning Theory, which uses lengths of string:
   
         5:4 corresponds to a Major Third
         4:3 corresponds to a Perfect Fourth
         3:2 corresponds to a Perfect Fifth
   
   
4. Once these three patterns were flowing well individually I played them one after the other, repeating the three-bar sequence until I was satisfied with the "flow".
5. Now came the question "what to do with the feet"? I wrote out separate foot patterns for each of the three bars starting with easy patterns and creating more challenging ones as I became more adept at playing them. The thinking behind this was that the foot patterns should not be "obvious" in that bass drum or hi-hat beats should fall in unusual parts of the bar, thus not coinciding with what the hands are doing. I have added an image below of what this came out looking like: 

1. After working on these patterns over some time I was able to play them with a good musical flow. Again, the question came: "what can I do to move forward"?
2. At this point I started switching the Leading Hand from one to the other at every bar change.
   To clarify what that entails: 
• Bar 1 (5|4) Right hand leads
• Bar 2 (4|3) Left hand leads
• Bar 3 (3|2) Right hand leads
• Bar 4 (5|4) Left hand leads
• Bar 5 (4|3) Right hand leads
• Bar 6 (3|2) Left hand leads
  
  Brain functions: I look at these exercises from the perspective of what is happening in my brain while playing. Each of the above exercises relies on sets (networks) of neurons firing together, what Donald Hebb* has referred to as "cell assemblies" (Hebb, 2002). Switching the leading hand each bar means that the network coordinating the movements for the hands also switch for each bar. 
  
  * Hebb wrote that “When an axon of cell A is near enough to excite cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A’s efficiency as one of the cells firing B is increased.” (Hebb 2002).
  From this the principle "Cells that fire together, wire together" was construed (however not directly by Hebb), meaning that by potentiation of specific neurons during repeated practice, the connections between them strengthen. This is where myelination and Long-Term Potentiation (LTP) occurs, leading to consolidation of the learned pattern(s).
  
  Counter to the above, when the practice is no longer repeated and time passes, the established connections between neurons weakens. Professor Sam Wang PhD Associate Professor of Molecular Biology and Neuroscience at Princeton University refers to this as "Out of sync, lose your link" (Wang, 2010). 
  
  
3. The next step was to take a piece of music in 6/4 time and play these patterns, counting the music as 6 beats per bar. Thinking about it mathematically, a bar of 5 beats, followed by 4 and then by 3 produce 12 beats. If you play two sets of each bar ( as shown above) you have 24 beats, corresponding to 4 bars of 6/4 and are back at the beginning of the musical phrase.
   NOTE: This is not something I or anyone else would do in a real performance setting, it is purely an academic, mental challenge. However, my aim throughout has been to make it sound as "musical" as possible.
4. After mastering these exercises I once again asked myself "now what"?
5. The next step was to use a set of dice and come up with random progressions of the three different time signatures, as long as there were always two 5's, two 4's and two 3's present. As before, these progressions were played with the music in 6/4.
   
   Sidebar: One day, as I was playing a set of combinations (an example could be: 5,3,3,4,5,4) I played a 4 where I should have played something else. What surprised me at this moment was that my brain told me to adjust and make the necessary replacement pattern so that everything would work out evenly. All while focusing on playing the complex patterns. This led me to ask "where did that come from?"
   
   Brain functions: Asking the above questions has led me to the brain's so-called 'performance monitoring and error detection executive function' which is located in the anterior cingulate cortex and dorsolateral prefrontal cortex areas of the fronto-temporal area of the brain. These areas can be summarised under the heading executive attention, which helps us, through analysis of the incoming information to execute actions, pay attention, prioritize behavior, and adapt to change in a controlled manner. These are closely related to willpower and self-control. As it is anticipated that executive function deteriorates through shrinking of dendritic branching, beginning in one's 70's or 80's, I am personally invested in studying the longitudinal effects of regular practice of exercises as described in this blog.
      
   Motor skills, such as those used in playing a musical instrument, however, changes areas of our somatosensory system and makes use of structures in our extrapyramidal motor system located in the striatum, premotor and motor cortices, and the cerebellum. The latter plays a critically important role in the coordination of learned, skilled movement, such as drumming  and is commonly referred to as "muscle memory". Muscles, however, have no memory neurons of their own but receive synapses from motor neurons located in the brain. Essentially, with continued practice, the firing of so-called Purkinje neurons in the cerebellum becomes more and more synchronized and solidified over time, continuously improving the learned skill. In other words, continued practice makes perfect. The good news is that procedural and professional skills such as these are typically retained as one gets older and that the plasticity of the brain allows for new learning throughout life.
   
   

A research team at the Ruhr-University Bochum, Germany, led by Lara Schlaffke, PhD, found in 2019 that the "enhanced motor performance in professional drummers was accompanied by structural differences in the neuroanatomy of the corpus callosum", which connects the two halves of the brain. The team's data shows that "the corpus callosum is relevant for the ability to perform two different motor trajectories with the two hands. Specifically, our data show that the anterior corpus callosum connecting the frontal lobes is relevant for motor decoupling in professional drummers. Subsegments 1 and 2 of the corpus callosum in our study connect the orbitofrontal and prefrontal left and right cortices and are part of an area of the corpus callosum referred to as genu." (Schlaffke et al, 2019)

The more I learn about the interconnectivity between the brain's auditory cortex, visual cortex, and motor cortex when working on complex drumming exercises, as described here, and the incredible speed at which these neural connections (synapses) occur, and new ones are generated and/or altered, the more in awe I become of our brains' capabilities, plasticity, and potential for expansion. 

Analogy: I have created a different explanation for non-musicians at the end of this blog of what my brain is having to manage during the exercises described in this blog. 

Back to the polyrhythmic exercises:

1. After some time I no longer required the dice to throw random patterns out for me but developed the ability to do it in my head while playing.
2. Knowing that this was not the end I again asked myself "now what do I do"?
3. You guessed it, the next step was to take the notes played by the non-leading hand and shift them by a 16th or triplet 4th as appropriate while still maintaining the regular beat within the bar. This led to between 5 and 7 iterations for each pattern.
   Repeat these new patterns as above with randomised sequences (still with two 5's, two 4's and two 3's)
4. I now find myself at a point where I can play these patterns quite effortlessly so, naturally, I have asked myself "where do I go from here"? The answer has been to go through the above set of steps but using one bar of 7 over 4, followed by a bar of 5 over 3. Also included are 7 over 3 and 7 over 5. The foot patterns used for these are more advanced than the earlier ones and now feature somewhat unexpected double bass patterns played by both feet and occasional beats played by the left foot on a woodblock pedal. The left foot, in other words, needs to travel between two separate pedals. The music accompaniment remains in 6/4.
5. What do I see as the next step? The possibilities are endless, I could come up with other time signature combinations, work on speed, play along to something other than 6/4 , etc., etc.
   All that's needed is a pinch of creativity in making up new challenges to stretch the mind such as what is described here.

New Breed version 2:

Development of exercises on pp 64 (5/8 exercises) , 68 (7/8 exercises), and 72 (6/8 exercises) 

 

Month 1: Play one bar of each 3-limb combination and then change to a different combo.  

                  Alternate leading hand every bar. 

 

Month 2:  

Play all exercises below with alternating leading hands every bar. 

 

Week 1   
Play 4 bars w/ 1 limb reading the text 
Play 4 bars with only 3 limbs 
Repeat above 
 
Week 2  
Play 2 bars w/ 1 limb reading the text 
Play 2 bars with only 3 limbs 
Repeat above 
 
Week 3 
Play 1 bars w/ 1 limb reading the text 
Play 1 bars with only 3 limbs 
Repeat above 
 
Week 4  
Try playing with changing the reading limb every bar 

The below image, showing the first few lines of the 5/8 reading exercise, may prove helpful when reading the following description.

Playing the exercises now involves deciding at the beginning of the exercise which limb is going to start the 'reading part' and then changing the reading limb in a predetermined order, e.g. Hand -> Right Foot -> Left Foot.  It then involves immediately switching the mental focus after having a played a bar with one limb 'reading' to the three limbs which will be playing the ostinato in the next bar, followed by adding the reading limb in the next bar and so on. This is facilitated by having developed mental representations for the three limbs that are playing the ostinato pattern, allowing me to dedicate more focus to the lone limb reading the 'melody' part (see below example of the first few lines of the 5/8 melody). 

New Breed version 3:

A third approach to playing these exercises came to me in early November 2022. This is similar to the first approach, outlined in New Breed II by the authors but instead of 'reading' the prescribed  'melody', the independent limb improvises patterns/melodies while the other three limbs play the accompanying ostinato pattern.

Brain functions: During one of the 'improvisational' sessions I came to realize the immense power and capabilities our brains possess. It occurred to me that, while improvising or switching focus, in version 2 several coordinated brain activities in different areas must occur simultaneously. Initially, the auditory cortex may (if playing with accompaniment or other musicians) receives input from the outside world. Simultaneously, a motor-neuron action has to be planned in the motor cortex, known as 'readiness potential' (Libet et al, 1993), then initiated (by the cerebellum) as an action potential which stimulates an anterior horn cell in an appropriate muscle, while the pyramidal and extrapyramidal systems counterbalance each other and manage the movement of the muscle, and the prefrontal cortex executive function at the same time manages all these events. Interestingly, the neural activity precedes the actual movement of the limb before a conscious commitment to move it is made.

All this takes place in fractions of seconds while the improvisation or switching of focus occurs. Compare this to speaking "off-the-cuff" when conversing with others. We invent both language and music creatively in the moment. Very impressive!

Tachibana et al (2024) "investigated, with the use of improvised guitar tasks, the role of Broca's area during spontaneous creativity, regardless of individual skills, experience, or subjective feelings. Twenty guitarists performed improvised and formulaic blues rock sequences while hemodynamic responses were recorded using functional near-infrared spectroscopy. We identified a new significant response in Broca's area (Brodmann area [BA] 45L) and its right hemisphere homologue during improvised playing but not during formulaic playing. Our results indicate that bilateral BA45 activity is common during creative processes that involve improvisation across all participants, regardless of subjective feelings, skill, age, difficulty, history, or amount of practice. While our previous results demonstrated that the modulation of the neural network according to the subjectively experienced level of creativity relied on the degree of deactivation in BA46L, our current results independently show a common concurrent activity in BA45 in all participants. We suggest that this is related to the sustained execution of improvisation in "motor control," analogous to motor planning in speech control."

New Breed version 4:

As indicated above in version 2, I wanted to work on changing the reading limb every bar but wasn't able to get to that level at the time. A year later, in September 2023, I decided to create a structure for working on this very challenging version. The structure was as follows:

Week 1: Play only ostinatos with three limbs but change the limb combination in each bar. Additionally, change leading hand every bar. This becomes a six-bar repeated patter and can be represented thus:

Week 2:  The plan was to play very simple patterns with the 'Melody' limb. I was pleasantly surprised to discover that, having ground the changing ostinatos into my subconscious the previous week, I was able to play more advanced 'melody' patterns than expected. I did actually find myself improvising patterns with the 'melody' limb. Stress indices (more about this in the next section) were surprisingly low.

After identifying the [object], the idea for a movement or act must be translated into the selection of muscles needed to perform the task. This process must involve, at some places in the nervous system, a plan for action–a motor plan. Before a motor plan can be executed, the visual system must first inspect the scene to determine what kind of movement might be appropriate for obtaining the [object]. The visual information enters the retina

and is passed through the lateral geniculate nucleus (LGN) to the primary visual cortex (V1), where information about the shape and location of the object can be assessed. 

Information about the object is then relayed from V1 to the cortical regions that will plan and initiate the movement. The information is passed to areas V2 and V4 on its way to the prefrontal cortex via the inferior temporal lobe. This pathway is involved in object recognition. 

An important function of the prefrontal cortex is to plan the sequence of movements necessary to perform a task. This information is then forwarded to the premotor cortex, which organizes the planned movement, but does not specify the details of how the movement is to be carried out. 

The premotor cortex projects to the primary motor cortex, which acts as the executive control mechanism for voluntary movements. The primary motor cortex encodes the serial order, or temporal sequence, of the behavior. 

This information is sent via the corticospinal tract to the spinal cord, where the motorneurons act as the final common pathway for the behavior. 

Two additional brain regions are also important in the control of voluntary movement.

These are the basal ganglia (caudate, putamen, and globus pallidus) and the cerebellum. These two brain regions serve to modulate movements by affecting the strength of the response (basal ganglia) as well as the timing and accuracy of the movement (cerebellum). 

The entire sequence, from visual perception to the initiation of muscle movement, is remarkably fast. In humans, the time required from visual input to the initiation of the motor response is on the order of 250 to 300 milliseconds.  (Oxford University Press, 2024)