Stress and Jazz Improvisation

PRESSING’S MODEL OF IMPROVISATION

Pressing’s model of improvisation seems to be one of the most accurate in the literature so far. In fact, most of the research done to this date tends to acknowledge it. In 2015, Beaty wrote the review The neuroscience of musical improvisation and summarized it in his introduction.

Improvisation is an acquired skill that requires a lot of practice to be mastered  (about 10000 hours over a 10-year period, also known as the 10-year rule).  It is stated that it involves an interplay between cognitive, perceptual and emotional referent processes (a series of well-rehearsed retrieval cues that are deployed during performance, minimizing processing demands and guiding idea generation) and procedural and declarative information stored in a domain-specific knowledge base (hierarchical knowledge structures stored in long-term memory). Also, Pressing includes the perceptual feedback, short-term (ongoing motor movement) and long term (decision making and response selection), and error correction, that allows the improviser to minimize the distance between intended and actual performance. (Beaty, 2015)

In fact, the close-loop model Pressing proposes includes the feedback in the creative process, as the improviser is comparing the actual output with the intended output, and then adjusting the future performance.  He conceptualized improvisation as a series of generative and evaluative processes. Although these processes involve some level of cognitive control and conscious monitoring, Pressing emphasizes the role of automatized motor processes and routines (e.g., well-rehearsed action sequences) and argues that improvisational fluency relies on automatized processes that require minimal conscious attention. (Beaty, 2015)

“Domain-specific expertise seems especially relevant to musical improvisation. In addition to the physical and psychological constraints common to other domains of skilled performance, jazz musicians must perform under extraordinary temporal constraints. Improvising requires the simultaneous execution of several processes in real-time, including sensory and perceptual encoding, motor control, performance monitoring, and memory retrieval, among others.”  (Beaty, 2015)

“Stress refers to an organism’s physiological and psychological reaction triggered by an external or internal stressor, such as an environmental condition or a psychological stimulus. It is a state of mental or emotional strain or tension resulting from adverse or demanding circumstances and can last for just a few minutes to hours (acute stress) up to months or even years (chronic stress).” (Ness & Calabrese, 2016)

So, what makes us stressed out? What characteristics make a situation stressful?

THE N.U.T.S THEORY OF STRESS

According to the N.U.T.S. theory, a stress response in human can be triggered if one or more of the following characteristics are present in any given situation.  The more elements present, the more chances there is for an individual to experience stress. They are: Novelty, Unexpectability, Threat to the ego and the lost of Sense of control over a situation.

OK, a situation is perceived as stressful by the brain…  Then, what happens in the body??

 As pointed out by Ness and Calabrese (2016), when a situation is perceived as stressful, neurons located in the periventricular nucleus of the hypothalamus synthesize and release corticotrophin-releasing hormone (CRH) which in turn triggers the release of adrenocorticotropic hormone (ACTH) from the pituitary gland into the bloodstream. ACTH acts on the adrenal glands and thus induces the release of glucocorticoids from the adrenal cortices. Glucocorticoids alter the function of multiple body tissues in order to mobilize or store energy to meet the demands of a stress challenge.

This stress system is called Hypothalamus-Pituitary-Adrenal Axis (also called HPA axis)

There are two main classes of stress hormones: the glucocorticoids, also called cortisol in human, and catecholamines, also known as epinephrine and norepinephrine. Once those hormones are released, they bind to two types of receptors at different location in the body. First, the low-affinity mineralocorticoid receptors, situated almost exclusively in the hippocampal formation, and secondly, the high-affinity glucocorticoid receptors which are present in high concentrations in the hippocampus, the amygdala, and the prefrontal cortex. (Ness & Calabrese, 2016)

“In a resting state, the mineralocorticoid receptors are usually occupied, while the glucocorticoid levels are too low to bind to the low-affinity glucocorticoid receptor.  When a stressful event occurs, glucocorticoid level gets high enough to activate both low-affinity and high-affinity receptors” (Ness & Calabrese, 2016). It is then that stress symptoms may be experienced.

Here’s a short explanatory video on the topic:

So, what symptoms does stress create on the human body?

They can be categorized as follows (Kenny, 2011):

1. SOMATIC (Physiological): Symptoms including muscle tension, diarrhea, constipation, nausea, cold hands, tremors, dry mouth, cold sweat…
2. AFFECTIVE (Emotional): Symptoms like feeling of confusion, panic, insecurity, fear, worries, guilt…
3. COGNITIVE: Can include memory slips, inability to focus, decrease concentration, narrowing of attention …
4. BEHAVIORAL (That other people can assess too): impaired coordination, trembling, fidgeting, social avoidance…

Attention is something really difficult to define. During the course of history, a lot of different definitions have been given to it. Here’s one of them: “Attention is conceptualized as the capacity to focus on particular stimuli over time and to manipulate flexibly the information.” (Sohlberg & Mateer 1986)

A clinical model of attention

• Focused attention: The ability to respond discretely to specific visual, auditory or tactile stimuli.
• Sustained attention: The ability to maintain a consistent behavioral response during continuous and repetitive activity
• Selective attention: The ability to maintain a cognitive set in which requires activation and inhibition of responses dependent upon discrimination of stimuli.
• Alternating attention: Capacity for mental flexibility which allows for moving between tasks having different cognitive requirements.
• Divided attention: The ability to respond simultaneously to multiple tasks.

Here are three explanatory videos on attention models and theories:

Different attention types:

• Internal Attention (endogenous): selecting information that is already represented in the mind, recalled from long-term memory or being maintained in working memory.

“Internal attention includes cognitive control processes and operates over representations in working memory, long-term memory, task rules, decisions, and responses. It is the set of operations that are focused on such cognitive representations.” (Chung, Golomb & Turk-Browne, 2011)

• External Attention (exogenous): Observation of stimulus through the senses (outside of the self).

“Attention can be directed to one or several modalities (e.g. the five senses), separable from each other during initial neural processing. Independent of modality, attention is deployed over space and over time, with separate issues to consider for spatial versus temporal attention. In addition, attention can be allocated over space, time, and modality according to stimulus features or how they are organized into objects”(Chung, Golomb & Turk-Browne, 2011).

Different attentional styles (Williamon, 2004):

• Broad/external: Observation of a wide range of stimuli outside of the self.
• Broad/internal: Observation of a wide range of sensations, feelings, thoughts within the self.
• Narrow/internal: Focusing attention on specific sensations, feelings and thoughts within the self.
• Narrow/external: Focusing on specific events and stimuli outside of the self.

The Oxford dictionary defines memory as being the faculty by which the mind stores and remembers information.

According to Baddeley, memory is an informational processing system in three parts: the sensory processor, the working memory and the long-term memory.

• Sensory processor allows information from the outside world to be sensed in the form of chemical and physical stimuli and attended to with various levels of focus and intent.
• Working memory serves as an encoding and retrieval processor. Information in the form of stimuli is encoded in accordance with explicit or implicit functions by the working memory processor. The working memory also retrieves information from previously stored material. It has a pretty limited capacity: maximum storage is 7 +/- 2 items at a time. Baddeley’s model of working memory includes three components: The visuospatial sketchpad, the central executive and the phonological loop.
• Long-term memory stores data through various categorical models or systems.

Different memory systems within the long-term memory and where their processing occurs in the brain:

Declarative memory allows for encoding the relationships between multiple items and events, it is considered to be representational, hence providing an internal model of the external world which is either true or false. It is divided in two systems: semantic (facts) and episodic (events) memory.  “Both of these declarative memory systems critically rely on brain structures in the medial temporal lobe (e.g., hippocampus) and the diencephalon. Additionally, other brain structures, such as the prefrontal lobe, also participate in episodic memory processes.” (Ness & Calabrese, 2016)

Non-declarative memory contents are not subject to conscious recollection, are not representational, and are thus neither true nor false. It is further divided into four subsystems, which are responsible for functionally distinct processes (Ness & Calabrese, 2016):

• procedural/habit memory: Refers to skill based and largely automatic processes and is dependent on the striatum.
• priming/perceptual learning: The phenomenon of an increased likelihood of re identifying a previously subconsciously perceived stimulus/item, which is regulated by the neocortex.
• conditioning: involves the amygdala and the cerebellum.
• non-associative learning: operates over reflex pathways.

Here’s an explanatory video on the topic.

Other symptoms can interfere with the quality of the improvised performance.  The cognitive aspect was our general focus here, but the somatic, affective and behavioural symptoms can definitely interfere with an optimal performance.  For example, a trombone player, or any other instrumentalist, needs to be in perfect control of his instrument in order to improvise freely.  To achieve this, he will need to (1) control the air stream that make his lips vibrate to produce the desired sound, (2) have fine motor control over the muscles implied in his embouchure, (3) control the fine movements of the tongue for subtleties in the articulation, (4) to control the movement of his right arm in order to move smoothly from position to position and (5) coordinate all those elements together to be able to play the musical fragment that he hears in is mind, without any score or visual support. So symptoms that are not necessarily in the cognitive category like, dry mouth, muscular tension, tremor, respiratory problems, lack of fine motor control or lost of muscular coordination for example, may have an impact on the quality of the performance.

At the end of our introductory story, the answer of our stressed musician to the piano player’s question could have been different.  One hypothesis could be that seeing this intimidating musician coming in the venue triggered a stress response, probably due to the T part of the N.U.T.S stress theory, the threat to the ego, as he was fearing negative judgement. The H-P-A axis went on and glucocorticoids were released by the adrenal glands.  The different effects of stress hormones on tissues made him suffer from somatic, behavioral, affective and cognitive symptoms of stress.  As he lost track of the form, sustained and focused attention were impaired.  Memory retrieval was also impaired, as he forgot parts of the melody and the chord changes, leaving him helpless in the middle of, what HE felt was, sound chaos. Feelings of worry, shame and guilt haunted him after the performance, as he got back home.

First, stress management strategies can be adopted to minimize the stress response.  Studies show that the practice of mindfulness meditation (Kenny, 2011), pranayama breathing techniques (Pal, Velkumary, & Madanmohan, 2004) or progressive muscular relaxation (Williamon, 2004) exercises can have a positive impact on reducing stress.  Common sense suggests that a healthy way of living, good and balanced nutrition with regular and sufficient water intake, regular moderate exercising and good sleeping habits have, in general, a positive impact on stress management.

Attention too can be practiced.  Attention style exercises, meditation and breath counting for example are proven to increase the capacity of switching types and styles over time. (Williamon, 2004)

Knowing that, in stressful situations, the habit memory is taking over the cognitive memory can orient practice sessions toward the transfer of the information into the non-declarative memory system.  The use of the different attentional types to enhance encoding and consolidation could be a good avenue for further exploration.

Finally, changing our attitude toward stress and seeing it as a positive feeling (to some extent) can help.  As seen above, in the right amount, emotional arousal can enhance information encoding and can put the performer in the optimal performance zone.  It can be perceived as excitement and can bring joy and happiness to the person experiencing it.