Ordinary bad dreams may be the brain's way of helping us regulate our negative emotions, while nightmares may reflect a glitch in that process, according to researchers.
Scientists and non-scientists alike have long puzzled over the exact function of dreams. In recent years, research into the psychology and brain activity associated with dreaming has given more clues as to why our sleep is filled with often bizarre, and sometimes frightening, images.
Writing in the journal Current Directions in Psychological Science, Drs Ross Levin and Tore Nielsen suggest that run-of-the-mill bad dreams are part of the brain's method of processing emotions. In fact, they say, emotional regulation may be the primary function of REM sleep, the sleep stage during which most dreams occur.
In contrast to your standard dream, nightmares - technically, a bad dream that startles you out of sleep - may arise when that emotion-regulating process goes wrong.
Bad dreams are nothing out of the ordinary. Studies show that most of our dreams are not happy ones.
"The 'default' dream is basically the bad dream," explained Levin, a psychologist at Yeshiva University in New York who specialises in treating sleep disorders. We seem to be hardwired to attend to negative emotions - which, in the context of evolution, is not surprising, according to Levin, since vigilance offers a survival advantage.
"If you missed a threat, you were lunch," the researcher noted.
Process fear memories
Dreams - or, more broadly, REM sleep - may serve to process fear memories so that the system does not become overwhelmed. Bits of our memories "get thrown into a room together and jumbled around," Levin explained, which puts them in a new context and diffuses the fear attached to them.
Studies show that during REM sleep, activity in certain brain regions - including the limbic system, which is involved in emotional regulation, as well as memory - spikes considerably.
With nightmares, though, the dreamer wakes up, disrupting normal emotion processing, according to Levin and Nielsen. Waking up is a relief in the moment, Levin noted, but it may ultimately serve to "reinforce" the feeling that the threat was real.
Nightmares are common
Most people have the occasional nightmare, particularly during times of high stress. Research suggests that 85% of adults have at least one per year.
Nightmares only become a problem when they distress people during the day as well, according to Levin.
People who are generally prone to anxiety in response to stress are at greater risk of problem nightmares. Their nightmares may lead to more distress in waking life, which may in turn spur more nightmares, Levin and Nielsen point out.
The good news is that the greater understanding of the origins of nightmares has allowed more effective therapies, according to Levin.
For example, he said, so-called imagery-rehearsal therapy - where a person imagines, then changes, the stuff of their nightmares while awake - has proven highly effective. - (Amy Norton/Reuters Health)
SOURCE: Current Directions in Psychological Science, April 2009.
January 2021 December 2020 November 2020 October 2020 September 2020 August 2020 July 2020 June 2020 May 2020 April 2020 March 2020 February 2020 January 2020 December 2019 November 2019 October 2019 September 2019 August 2019 July 2019 June 2019 May 2019 April 2019 March 2019 February 2019 January 2019 December 2018 November 2018 October 2018 September 2018 August 2018 July 2018 June 2018 May 2018 April 2018 March 2018 February 2018 January 2018 December 2017 November 2017 October 2017 September 2017 August 2017 July 2017 June 2017 May 2017 April 2017 March 2017 February 2017 January 2017 December 2016 November 2016 October 2016 September 2016 August 2016 July 2016 June 2016 May 2016 April 2016 March 2016 February 2016 January 2016 December 2015 November 2015 October 2015 September 2015 August 2015 July 2015 June 2015 May 2015 April 2015 March 2015 February 2015 January 2015 December 2014 November 2014 October 2014 September 2014 August 2014 July 2014 June 2014 May 2014 April 2014 March 2014 February 2014 January 2014 December 2013 November 2013 October 2013 September 2013 August 2013 July 2013 June 2013 May 2013 April 2013 March 2013 February 2013 January 2013 December 2012 November 2012 October 2012 September 2012 August 2012 July 2012 June 2012 May 2012 April 2012 March 2012 February 2012 January 2012 December 2011 November 2011 October 2011 September 2011 August 2011 July 2011 June 2011 May 2011 April 2011 March 2011 February 2011 January 2011 December 2010 November 2010 October 2010 September 2010 August 2010 July 2010 June 2010 May 2010 April 2010 March 2010 February 2010 January 2010 December 2009 November 2009 October 2009 September 2009 August 2009 July 2009 June 2009 May 2009 April 2009 March 2009 February 2009 January 2009 December 2008