A study by the University of Sussex found that multitasking (specifically, consuming multiple media sources at the same time) is _associated_ with reduced density in the grey matter of the part of the brain associated with empathy, cognitive control and control over emotions.

The study doesn't say whether one thing causes the other.

http://sro.sussex.ac.uk/50361/

>The questionnaire consisted of two main sections: The first section listed 12 common media types and participants reported the total number of hours per week they spent using each medium. In the modified version used in the present study, 10 media types were retained from [2]: Print media, television, computer-based video, music, voice calls using mobile or telephone, instant messaging, Short Messaging Service (SMS) messaging, Email, web surfing and other computer-based applications. The item ‘‘video or computer games’’ was modified to include games on mobile phones. The item ‘‘non-music audio’’ was replaced with ‘‘using social networking sites’’. The changes were made to better reflect current trends in media consumption. The second section consisted of a matrix that involved participants indicating how much they concurrently used all the other types of medium as they used a primary medium. Amount of concurrent use was indicated on a scale of 1 to 4 (1 = ‘‘Never’’, 2 = ‘‘A little of the time’’, 3 = ‘‘Some of the time’’ and 4 = ‘‘Most of the time’’). The participants’ responses were first recoded as follows: ‘‘Never’’ = 0, ‘‘A little of the time’’ = 0.33, ‘‘Some of the time’’ = 0.67 and ‘‘Most of the time’’ = 1.

This seems like a bit of a silly study to me. It would be incredibly difficult for anyone in the software sector to say they aren't multitasking considering what they consider to be multitasking. I would be willing to bet most people use some forms of that concurrently, whether it's dealing with emails while in a web meeting or listening to music while coding.

FWIW I don’t do any of what you describe as a matter of normal practice.

Sometimes I will listen to a podcast while doing a routine task.

Otherwise I don’t multitask at all, for at least 90% of my working hours.

You never have a browser open with documentation/stackoverflow etc while coding?

Or checking and responding to emails while in the middle of fixing a bug?

Or managing texts from family members while doing whatever else on your PC?

Sometimes I stop coding and go look something up because I am stuck. At that point I’m doing a different activity: I’m research/learning/generally frustrated and not really coding.

For the others you bring up, I truly do not. I don’t text or email while I’m trying to do something productive.

This is what I can gather from skimming some articles in a lazy research attempt:

* Almost all evidence shows multitasking is not actually possible

* Some evidence shows attempting to do so anyway results in IQ reduction and loss of ability to focus

* Some evidence shows this reduction lasts even after you are done

* Some evidence shows this reduction is due to permanent physiological changes in the brain

'Brain damage' might be going to far.

I can have a conversation with someone while driving a car. Is that not multitasking?

To anticipate an objection, I would agree that the competence of both tasks diminishes somewhat. However the overall competence of both is sufficient.

My brain also seems capable of detecting when more attention is required, and automatically stopping the lower priority task. For example, if I had to quickly merge across many lanes on a busy freeway, then I would likely cease conversation during that maneuver. I don’t have to think too much about this consciously. The brain understands that driving is paramount and it will automatically preempt anything lower priority when more cognitive attention is required.

I would be interested to know what the research says about phenomena like that. There must be research like this supporting aviation, space flight, and nautical activities.

It seems easiest to multitask across different modes, e.g., I can work with my hands or drive a car while listening to an audiobook. I can have a social conversation with friends over voice chat while playing a video game.

Maybe the degree to which you can multitask depends upon the type of task and to what extent your brain can perform it automatically. The rote tasks involved in driving for example require very little attention to perform safely and correctly.

Yes, I had a lot of similar questions. Maybe 'task' is a misnomer? Maybe it's context switching that is the issue. Like talking and driving and having music playing in the background all exist in the same context of operating a vehicle. Just like using a calculator, reading a textbook and writing in a notebook are all different tasks you switch between to study, but are all in the same context of studying.

Side note, Wikipedia claims you can multitask between tasks you are already highly proficient at.

I think the idea is that the neocortex doesn't multitask. So you can talk and drive a car but not talk and learn abstract algebra.

>Some Evidence

Obviously the studies aren't definitive, but if they were and multitasking caused me to be less intelligent and less able to focus due to "permanent physiological changes in the brain", I would consider my brain to be damaged regardless of whether it meets the literal medical definition of brain damage.

If one is free to ignore or alter the definition of anything, then one could consider anything to be anything one wants.

But I get what you mean. We can only hope that permanent means permanent if you don't do anything to reverse it like being overweight.

There's a phrase for that. "not permanent."

There's a word for that!

Impermanent.

This article sites Stanford:

https://www.forbes.com/sites/travisbradberry/2014/10/08/mult...