Featured Research

from universities, journals, and other organizations

Our pupils adjust as we imagine bright and dark scenes

Date:
December 3, 2013
Source:
Association for Psychological Science
Summary:
Conjuring up a visual image in the mind -- like a sunny day or a night sky -- has a corresponding effect on the size of our pupils, as if we were actually seeing the image.

Conjuring up a visual image in the mind -- like a sunny day or a night sky -- has a corresponding effect on the size of our pupils, as if we were actually seeing the image, according to new research.
Credit: Serg Zastavkin / Fotolia

Conjuring up a visual image in the mind -- like a sunny day or a night sky -- has a corresponding effect on the size of our pupils, as if we were actually seeing the image, according to new research.

These findings, published in Psychological Science, a journal of the Association for Psychological Science, suggest that the size of our pupils is not simply a mechanistic response, but one that also adjusts to a subjective sense of brightness.

"Visual imagery is a private and subjective experience which is not accompanied by strongly felt or visible physiological changes," explains psychological scientist and lead researcher Bruno Laeng of the University of Oslo. "It is a particularly difficult topic to research, as years of controversy about the nature of mental imagery testifies."

Along with co-author Unni Sulutvedt, also from the University of Oslo, Laeng conducted a series of experiments to see whether they could tap into subjective mental imagery by monitoring pupillary size with an eye-tracking device.

Initially, participants were asked to look at a screen while triangles of different levels of brightness appeared. When they were later asked to actively imagine those triangles, the participants' pupils varied in size according to the triangle's original brightness. When imagining brighter triangles, their pupils were smaller. But when imagining darker triangles, their pupils were larger.

In a series of additional experiments, the researchers found that participants' pupils also changed in diameter when imagining a sunny sky, a dark room, or a face in the sun compared with a face in the shade, as if in preparation for experiencing the various scenes.

The experiments further showed that these results aren't due to voluntary changes in pupil size or differences in the mental effort required to imagine scenes.

"Because humans cannot voluntarily constrict the eyes' pupils, the presence of pupillary adjustments to imaginary light presents a strong case for mental imagery as a process based on brain states similar to those which arise during actual perception," says Laeng.

The researchers suggest that this work may have further applications, potentially allowing us to probe the mental experiences of animals, babies, and even patients with severe neurological disorders.


Story Source:

The above story is based on materials provided by Association for Psychological Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. B. Laeng, U. Sulutvedt. The Eye Pupil Adjusts to Imaginary Light. Psychological Science, 2013; DOI: 10.1177/0956797613503556

Cite This Page:

Association for Psychological Science. "Our pupils adjust as we imagine bright and dark scenes." ScienceDaily. ScienceDaily, 3 December 2013. <www.sciencedaily.com/releases/2013/12/131203091618.htm>.
Association for Psychological Science. (2013, December 3). Our pupils adjust as we imagine bright and dark scenes. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/12/131203091618.htm
Association for Psychological Science. "Our pupils adjust as we imagine bright and dark scenes." ScienceDaily. www.sciencedaily.com/releases/2013/12/131203091618.htm (accessed October 1, 2014).

Share This



More Mind & Brain News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pregnancy Spacing Could Have Big Impact On Autism Risks

Pregnancy Spacing Could Have Big Impact On Autism Risks

Newsy (Oct. 1, 2014) A new study says children born less than one year and more than five years after a sibling can have an increased risk for autism. Video provided by Newsy
Powered by NewsLook.com
Stopping School Violence

Stopping School Violence

Ivanhoe (Oct. 1, 2014) A trauma doctor steps out of the hospital and into the classroom to teach kids how to calmly solve conflicts, avoiding a trip to the ER. Video provided by Ivanhoe
Powered by NewsLook.com
Pineal Cysts: Debilitating Pain

Pineal Cysts: Debilitating Pain

Ivanhoe (Oct. 1, 2014) A tiny cyst in the brain that can cause debilitating symptoms like chronic headaches and insomnia, and the doctor who performs the delicate surgery to remove them. Video provided by Ivanhoe
Powered by NewsLook.com
Burning Away Brain Tumors

Burning Away Brain Tumors

Ivanhoe (Oct. 1, 2014) Doctors are 'cooking' brain tumors. Hear how this new laser-heat procedure cuts down on recovery time. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins