Autonomic Mechanism of Emotional Reactivity and Regulation

Catherine Uy, Psychology 2013 Samuel James

Introduction

The parasympathetic and sympathetic nervous systems are two divisions of the autonomic nervous system.  The parasympathetic nervous system is connected with the fight or flight response. (Jansen, 1995) It helps to activate the body from a state of rest. The parasympathetic system is also associated with emotions such as sadness and sexual arousal (there are many more emotions associated with the parasympathetic nervous system).(Kreibig, 2010)

The sympathetic nervous system is connected with bringing someone back to a state of rest. It is always at play in order to maintain homeostasis. (Maickel, 1967)   The sympathetic and parasympathetic nervous system do not counter each other, instead they act to regulate each other. The parasympathetic and sympathetic nervous systems connected to various neural pathways that allow them to stimulate muscle movement, such as increasing/decreasing heart rate. (Pomeranz, 1985)

Purpose“The goal of this study is to elucidate the autonomic mechanism of emotional reactivity and regulation in response to ecological valid affective stimuli”

Methods

Seven healthy subjects were used for this study. • Four were woman and three were men • They were all between the ages of 23 to 40• They had no history of any mental illness• None of them had severe medical issues

The subjects had •Three electrocardiograph electrodes •Placed on collar bones and on their left lower rib cage •Electrodes were also used to take respiratory signals •Subject was then placed in a room facing a computer screen •Electrocardiograph data was then taken  Module I: •Patients watched eight movie clips in different sets •Movie clips lasted from 1.5 to 5 minutes •Movies clips were used to elicit different emotions

Module II: •The subjects also viewed three clips that elicited disgust •The subject watched the first clips normally •They watched the second one but suppressed their reactions •In the last clip the subjects amplified their reactions •Subjects were also given post clip questionnaires

•Time frequency analysis was done •It determined Respiratory Frequency Area (RFA). RFA indicates parasympathetic activity •The Low Frequency Area (LFA) was also looked at because it indicates sympathetic activity •Data was taken during the interval of interest (IOI) or the 30 seconds where the most emotion was evoked

  Results

Discussion• The LFA/RFA ratio was close to 1 during the Interval Of Interest • RFA and LFA indicate parasympathetic and sympathetic activity • They are meant to regulate each other • For a balance to occur their activity must be equal. • In terms of LFA/RFA this would translate to a ratio of 1:1  • In the questionnaires that there was a strong positive correlation

between cvRFA and embarrassment

• Indicating that higher embarrassment has to do with higher fluctuation within the higher frequency component of HRV

 • LFA/RFA ratio for subjects who tried to suppress their emotions

while watching disgust evoking clips was similar to the LFA/RFA when the subject was watching a neutral clip

• This is good indication, for it means that healthy people can thoroughly suppress their disgust, a skill which is useful in everyday life.

 

Conclusion“ Emotional reactivity is reflected in mean level activity in the Low Frequency Area…whereas emotional regulation is reflected in fluctuation of the Respiratory Frequency Area”  Expressive behavior (this includes behaviors such as crying and laughing) is correlated with high mean LFA. This was shown with amusement and backed by sexual amusement (low LFA with this may be due to the lack of expressive behavior).  Complications: The result of this study is challenged by many prior studies. For example, some studies have shown that LFA should have not increased with amusement. Furthermore negatively valence stimuli such as fear should have had higher activity of LFA. All these problems may stem from the low number of subjects and that the subjects had seen some of the clips.  

BibliographyCy, Catherine. "Autonomic Mechanisms of Emotional Reactivity and Regulation." Psychology (2013): n. pag. Web. Jansen, A. S. P., X. V. Nguyen, V. Karpitskiy, T. C. Mettenleiter, and A. D. Loewy. "Central Command Neurons of the Sympathetic Nervous System: Basis of the Fight-or-Flight Response." Science 270.5236 (1995): 644-46. Print. Kreibig, Sylvia D. "Autonomic Nervous System Activity in Emotion: A Review." Biological Psychology 84.3 (2010): 394-421. Print. Maickel, R. P. "THE SYMPATHETIC NERVOUS SYSTEM AS A HOMEOSTATIC MECHANISM. I. ABSOLUTE NEED FOR SYMPATHETIC NERVOUS FUNCTION IN BODY TEMPERATURE MAINTENANCE OF COLD-EXPOSED RATS." The Journal of Pharmacology (1967): n. pag. Print. Pomeranz, B. "Assessment of Autonomic Function in Humans by Heart Rate Spectral Analysis." Heart and Circulatory Phsyiology (1985): n. pag. Print. Pottenger, P. M. "Sympathetic and Parasympathetic System Benefits." The Journal of Nervous and Mental Disease 56.5 (1922): 519. Print.

Module II

Module IHeart Rate Variability (HRV) is looked at in the subject. It is quite simply the interval between each beat.

Results

LFA increased during amusement

LFA was also higher than the RFA in non-sexual amusement

LFA /RFA ratio - close to one

But, positive emotions had a higher ratio than the negative emotions and neutral

LFA /RFA ratio - close to one

But, positive emotions had a higher ratio than the negative emotions and neutral

cvLFA and cvRFA were relatively constant cvLFA - increase with amusement Significant difference in cvLFA and cvRFA for amusement and fear

LFA/RFA - highest during unregulated disgust

LFA/RFA for disgust suppression similar to neutral clips