Tag Archives: dopamine

Introversion and Extraversion Starts with Your Genes and Shows in Your Brain

Susan Cain

Susan Cain

Introverts seem to be experiencing an increasingly “level playing field” in work and social environments after Susan Cain’s best-selling book celebrating “the power of introverts in a world that can’t stop talking.”

Hans Eysenck

Hans Eysenck

University of London’s Hans Eysenck provided one of the first physiological explanations of this duality after Carl Jung’s introduction to “psychological types.”

The subjective experience of introversion and extraversion is measured by the Big Five personality dimensions, developed by Robert McRae and Paul Costa, then of the National Institutes of Health, in addition to the widely-used yet psychometrically-criticized Myers-Briggs Type Indicator. 

Eysenck's Three-Factor Theory of Personality

Eysenck’s Three-Factor Theory of Personality

Observable behaviors associated with extraversion include positive emotions, assertiveness, sociability and talkativeness with energetic engagement in work and social contexts.

In contrast, external manifestations of introversion are lower social engagement and energy, and less need for external social stimulation than extraverts, with a quieter, more deliberate style.

Robert McCrae

Robert McCrae

These behaviors are at least partially based on individuals’ genetic profiles, leading to differing brain activity associated with introverted and extraverted thinking and behavior.

Paul Costa

Paul Costa

Eysenck posited that extraverts and introverts differ in their levels of cortical arousal:  Introverts, he suggested, have a higher baseline level of arousal than extraverts, so need less external stimulation.

In contrast, he hypothesized that extraverts seek external stimulation because they have a lower baseline level of cortical arousal.

Yasuyuki Taki

Yasuyuki Taki

Differences in brain structure and function among introverts and extraverts was analyzed by Yasuyuki Taki’s team at Tohoku University, including collaborators  Benjamin Thyreau, Shigeo Kinomura, Kazunori Sato, Ryoi Goto, Kai Wu, Ryuta Kawashima, and Hiroshi Fukuda. 

The evaluated whether personality traits measured on a revised Big Five inventory (Revised NEO Personality Inventory – NEO-PI-R) were related cortical gray matter volume, measured by brain magnetic resonance images (MRI) for more than 270 healthy volunteers over 6 years.

Colin DeYoung

Colin DeYoung

Likewise, University of Minnesota’s Colin DeYoung, Jacob Hirsh of University of Toronto, The Mind Research Institute’s Matthew Shane, and Yale’s Xenophon Papademetris, Nallakkandi  Rajeevan, and Jeremy Gray used a similar method to conclude that behavioral and subjective extraversion was positively correlated with orbitofrontal cortex metabolism and increased cerebral volume of the medial orbitofrontal cortex in 116 adults. 

Michael X. Cohen

Michael X. Cohen

Extraversion has been correlated with sensitivity to rewards and to the brain’s dopamine system, so University of Amsterdam’s Michael X. Cohen and team investigated the brain’s dopamine-based reward system.

He collaborated with Jennifer Young, Jong-Min Baek, Christopher Kessler, and Charan Ranganath of University of California, Davis to demonstrate the connection among trait extraversion, the A1 allele on the dopamine D2 receptor gene, and “extraverted” activity in the brain’s reward system during a gambling task.

Charan Ranganath

Charan Ranganath

Participants received rewards either immediately following a behavioral response or after a 7.5 second “anticipation” interval.
The research team monitored differing fMRI brain activity in the amygdala, which processes emotional stimuli and triggers excitement, and in the nucleus accumbens, which pushes people to seek rewards, novelty and risks.

Brain activation patterns were related to individual differences in extraversion and presence of the A1 allele on the dopamine D2 receptor gene.
Neural pathways differed for extraverts and introverts, validating anecdotal observations that these personality styles are distinctly different, even deep inside the brain and genes.

Many introverts adopt extraverted behaviors in work and social situations, and a remaining question is how fMRI patterns differ for introverts displaying uncharacteristic extraverted behaviors in contrast to people with trait extraversion.

-*How easily can you adopt your non-dominant personality style when you need to display introversion or extraversion behaviors?

-*What tactics enable you to adopt your less-preferred personality style?

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Evidence-Based Stress Management – Music – Part 4 of 5

Many people intuitively turn to music when they want to regulate energy and mood.

Valorie Salimpoor

Valorie Salimpoor

Listening to music evokes sympathetic nervous system activity, a sign of emotional arousal measured by changes in heart rate, respiration, electrodermal activity, body temperature, and blood volume pulse, according to Rotman Research Institute’s Valorie Salimpoor, McGill’s Mitchel Benovoy, Gregory Longo, Jeremy Cooperstock, and Robert Zatorre.

Mitchel Benovoy

Mitchel Benovoy

The researchers asked twenty-six participants to select and listen to “pleasurable” music and researchers selected “neutral” music for participants based.
Pleasure ratings and emotional arousal measures were strongly related, and those who did not experience pleasure also showed no significant increases in emotional arousal.

Gregory Longo

Gregory Longo

This finding suggests that listening to preferred music can be used as a mood-enhancement and stress management approach.

Lori Gooding

Lori Gooding

Kentucky University’s Lori Gooding and Olivia Yinger validated music’s stress management benefits for surgical patients.
They found that listening to music can reduce anxiety, subjective pain, and requests sedative medication following surgery.

Olivia Yinger

Olivia Yinger

Slow music expedited relaxation and reduced pain, suggesting that music tempo, rhythm and volume can contribute to reduced anxiety, improved treatment experiences, with lower medical costs in medical intensive care units.

Nick Perham

Nick Perham

Besides managing stress, listening to background music before task performance can increase attention and memory by evoking arousal and positive mood, according to Nick Perham and Joanne Vizard, then of University of Wales Institute Cardiff.

Joann Vizard

Joann Vizard

However, listening to music during a task decreased serial recall among adult volunteers, again pointing to the value of listening to music before but not during tasks that require acute concentration.

Kristie Young

Kristie Young

Beyond passively listening to music, performing music by singing during a complex task can decrease performance.
Monash University’s Genevieve Hughes and Kristie Young with Christina Rudin-Brown of Transport Canada found that singing while performing complex, attention-requiring task increases mental workload and distraction.

Christina Rudin-Brown

Christina Rudin-Brown

They asked participants to learn the lyrics two popular songs, then sing them while operating a simulated car during a 6.6 km urban trip with four speed zones and encountering expected and unexpected traffic events.

Volunteers who sang while “driving” scanned their visual field less often, focused on the area directly ahead (“cognitive tunnelling”), and were less aware of potential hazards during a peripheral detection task (PDT).
However, singing reduced “driving” speed and enabled volunteers to maintain position in their “lanes.”

Efforts to compensate for the increased mental workload associated with singing and listening to music appeared ineffective, suggesting that listening to music during complex tasks impairs performance.

Jim Blascovich

Jim Blascovich

In contrast to performance-disrupting impact  of listening to music while performing complex tasks, SUNY Buffalo’s Karen Allen with Jim Blascovich of University of California, Santa Barbara reported that surgeons worked more quickly and accurately when they listened to preferred music, and physical stress was reduced, indicated by cardiac and electrodermal autonomic responses, hemodynamic measures.
Those who listened to no music did not perform as quickly and accurately as those who listened to their preferred music.

Stress-reducing and performance impacts of music appear related to both personal musical preferences, and musical temp and genre.

Leigh Riby

Leigh Riby

Northumbria University’s Leigh Riby found that “uplifting” music can boost mental alertness, attention and memory.

Volunteers pressed a keyboard space bar when a green square appeared on screen but not when they saw different-colored circles and squares under two conditions: in silence and while listening “uplifting” concertos (Vivaldi’s Four Seasons).

Riby measured brain activity with an EEG and found that participants responded accurately more quickly when listening to the ”uplifting” Spring concerto in contrast to performing with no music or the slower, more somber Autumn concerto.
The Spring concert “seemed to give rise to particular imagery in the brain and evoke positive, contented feelings which translated into higher levels of cognitive functioning,” according to Riby.

The underlying mechanism of music’s effects on attention, concentration, and performance is dopamine release in response to music that elicited “chills” or ‘‘musical frisson” — changes in skin conductance, heart rate, breathing, and temperature that were correlated with pleasurability ratings of the music.

Alain Dagher

Alain Dagher

Salimpoor and her McGill team, including Kevin Larcher and Alain Dagher, used PET and fMRI brain imaging techniques to measure anticipation and consumption of music as a reward, and demonstrated that volunteers who listen to preferred, “pleasurable” music experience greater release of dopamine, which is associated with emotional arousal and pleasurability ratings.

This is one of the first demonstrations that an abstract, cognitive, non-tangible reward can lead to dopamine release, and that different brain circuits are involved in anticipating (caudate) and experiencing (nucleus accumbens) musical tension and resolution.

Teresa Lesiuk

Teresa Lesiuk

University of Miami’s Teresa Lesiuk reported improved task speed, performance, and new ideas with information technology specialists who listened to preferred music.

She attributed these positive effects to reduced stress and improved mood, and found that people who were moderately skilled at their jobs benefited most, but experts experience no benefit.
Consistent with findings that music can be a distraction in cognitively-demanding tasks, novices found that music undermined performance.

Amit Sood

Amit Sood

When people’s minds wander, music can help focus on the present moment, according to Amit Sood of Mayo Clinic, who advocates music’s value in developing and reinforcing Mindful Attention – another approach to managing stress.

 -*When does music in the workplace reduce stress? Increase performance?

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RELATED POSTS

Motivation to Manage Stress

Mindful Attention (Part 2)

Social Support (Part 3)

Music (Part 4)

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Look for related posts on:

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  • Mindful Attention (Part 2)
  • Social Support (Part 3)
  • Physical Exercise (Part 5)

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