How can the blind see? A look into blindsight.

Today I am super excited to host a guest blog post by my amazing friend Jahn Kidd. Jahn has a background in psychology and is currently working towards an engineering degree (Go Jahn!). He wanted to share some of his knowledge on the inner workings of the human brain. Get excited to learn!


First, watch this video:

Now, you may be thinking “So what? It’s a man navigating a pretty simple obstacle course. Anybody could do that.” And you would be correct. Except for one thing (if somehow you haven’t noticed the video title): the man in front is blind, but reacting to the obstacles in his path the way you or I would react. And the man behind him is a researcher, shadowing the participant in case he should stumble over one of the obstacles. This is a demonstration of a visual phenomenon known as blindsight.

To begin with, let’s get into a quick and dirty explanation of the human visual system. The visual system consists of the eyes (obviously), some nerve tracts, and the all-important visual cortex (otherwise known as the occipital lobes, located at the rear of the brain, seen in Figure 1).

Figure 1

 As you can see from Figure 2, the nerves from the eyes project subcortically (where the green arrow in Figure 3 is pointing, an area near the center of brain and below the cortex; Remember this- it’s important later), before continuing on to the visual cortex. It is in the occipital lobes that much of the information is processed and responsible for the conscious experience of sight.

Figure 2
Figure 3









If it helps, imagine the nerves as roadways and the visual information as cars that move along those roadways. These cars enter the roadway at an on-ramp (the eyes), and eventually arrive at a large intersection (the subcortical area of the brain). Most of the cars will continue further along the main road to their destination (the visual cortex), while some cars will take side roads to other areas (other parts of the brain that aren’t the visual cortex).

The next important thing to consider: Blindness. The definition is pretty simple, we all know it: blindness means you can’t see. But what may not necessarily be known is that there are a few ways that blindness can occur. Blindness can be caused by injury to the eyes, or by congenital defect (i.e. the nerve tracts develop abnormally in the brain), or by damaging the visual cortex (specifically an area known as the striate cortex, or V1). This last cause is important for blindsight: being cortically blind means that the other organs and nerves important to sight are still functional.

Blindsight is a phenomenon that has been actively studied for several decades, first being noticed in animals and then later in humans. Commonly, patients are only blind in part of their visual field (the striate cortex in the occipital lobes isn’t completely destroyed, only damaged). As you can see from the video, and from other studies, people who are cortically blind are able to respond to various stimuli that are presented in the blind areas of their visual field. Importantly, they do this at levels significantly above chance. This can include being able to navigate an obstacle, to detecting when lights are flashing, when objects are moving, and even the size of objects in some cases.

Remember that I said it was important that the optic nerves projected to subcortical areas? This is thought to be the mechanism through which blindsight may occur. Visual information is projected to several other areas in the brain, which can then possibly pass that information further along to other areas. This means that even when the V1 is damaged/destroyed, there is still visual information making it to other areas of the brain to be processed on some level. Continuing our earlier car and roadway analogy, this means that the main roads are completely or mostly blocked, which prevents those cars from reaching their destination (the visual cortex). But the cars that are taking the side roads are still able to reach their destinations (the other areas of the brain).

It’s important to note that this is an ongoing field of investigation: this phenomenon has implications about the way in which we are affected by things in our visual field (evidently, conscious awareness of a stimuli is not always necessary). There are also questions about the physical mechanisms that some blindsight capacities may depend upon in certain instances, about how to predict if blindsight will occur in a region of blindness, about rehabilitation of visual sensitivity and discrimination, and about brain activity during blindsight.

These are important questions about a fascinating (and as one researcher put it, rare) discovery in the field of psychology, and science in general. My goal here was to briefly expose you, the reader, to an interesting and perhaps little known phenomenon. It’s beyond my abilities to give a thorough enough explanation in a blog post, so I encourage you to read to further on the subject, even if it’s just the Wikipedia article. For those interested in further reading, I’ll provide the information on a relatively easy to read article about blindsight below.

Weiskrantz, L. (2010). Looking Back: Blindsight in Hindsight. Psychologist, 23, 356-359
Figure sources:
Figure 1:
Figure 2:
Figure 3:

Make it thematic: Best practices 4/5

My past best practices posts have focused on getting to know your audience and using questions to help create a conversation. But, what the heck should you talk about to people? I have yet to address creating a message. (Hey, I never said the posts would be in a logical order…)

Best practice number 3: Make it thematic.

One of the scariest questions to get asked is often “So what do you study?”. Ugh. Really? Where do I start?

The best way to get yourself going is find the big picture! You may be in the depths of analyzing DNA from bird blood, but is that the point of your research? Probably not. The big picture may often be the same as the first or last paragraphs of your journal article. Thinking about it that way can make it easier to address a new audience.

Theme vs Topic: A theme and a topic are very different. Your research topic might be: hybridization of plants along the Rocky Mountains. Your research theme is often more broad and sometimes includes the answer to your research. A theme could be: Pollination by hummingbirds facilitates hybridization of plants in the Rocky Mountains. Notice also how the theme includes a VERB and is a more complete thought than a topic. Your theme can be even more broad like: Plant-animal interactions influence the evolution of new species. This theme can apply to topics outside of your research project.

Why be thematic? When you walk away from an interaction with a member of the public, whether it is a chat on the street or a public talk, you should aim for at least one big take away. Of course they may come away with a variety of ideas and thoughts, but if you can at least get them to leave with your theme, that’s great! By using a theme (with a verb!) they can come away with a complete idea. So instead of coming away with, “Joe studies plants in the Rocky Mountains” they’ll hopefully come away with “The hummingbirds interact with the flowers to create new species”. That theme provides a new viewpoint for future scientific stories they hear.

Be flexibleAs a museum educator, I’ve learned that flexibility is crucial! I’ll often start an interaction with the hope of connecting the visitor to a certain theme, but instead they want to ask about something totally different. The same thing happens when researchers discuss their work. First step is to not panic! You’re going to create a more meaningful interaction if you connect with people based on their inherent interests. It may even help to use some questions to open up your conversation so that you can guide the conversation to their interests from the start. For example, my graduate school research was not necessarily focused on climate change, but people often asked me about the role it may play in the tropics. So I would then switch to talking about shifts in animal and plant ranges across elevation with climate change. Always good to have a back-up plan.

This best practice may seem very straightforward to you, but is often more complex in practice than it seems. I really think that finding a theme yet remaining flexible to other interests will make your science communication the best!

Try it out: Write down at least 3 themes that relate to your past or present research. Remember, include a verb to make it thematic!

Good luck!DSCN6815

Know Your Audience: Best Practices (2/n)

(This post is part of my Best Practices in Science Communication series. Check the original post for more information)

Know your audience: Tips and Techniques for different groups.

Use these ideas in your next classroom visit, public talk, or conversation on the sidewalk!

Young children: Kids say and do the darndest things, but they can also be the hardest audience to keep engaged. Let them use all their senses including looking, touching, and (sometimes) smelling to really get your point across. Got some samples from the field still in your lab? Bring them with you to facilitate observations with the kids! Young kids love the interaction and wow factor of your science activities and information. Always make it fun and hook them in.  

If you plan to do an activity remember that young children need clear instructions. I often make the mistake of thinking that the the kids can figure it out on their own, but often they need to be told exactly what to do. (Bonus: following directions is often part of Pre-K and Kindergarten curriculum, so if you are in a classroom, the teacher will be happy to see that this is met).

Teens: Ah yes, the dreaded teenage years. I am still working on the best ways to reach aloof teens so please let me know YOUR suggestions. I like to treat teens like adults and make conversation with them. Teens love the “cool” factor and interesting stories. Teens today are so connected with the world that they often have ample stories about what they saw on the internet to guide your conversation. As the “spider-woman” (a non-self imposed title), I hear comments like “Did you hear about that story where the spider burrowed into the guy’s belly?” Those cool (although bizarre) stories are just what teens love! Don’t be worried about the sidetracking because you can always wrap it up with your message in the end.

In contrast to young children who need clear instructions, teens like a good physical or mental challenge. In a recent museum activity, we challenged people to perform better than nature’s superstars, like the brilliant crow seen here. The teens loved to show-off their skills especially when told how tough the challenge was. We also took a group of 50+ teenagers and had volunteers battle it out in the physical challenges (jumping, throwing, etc). A little healthy competition and showmanship goes over well with teens. Present your research as a challenge and let teens come up with their own solutions to stretch their brains.

Adults: Hey, that’s us! Most adults like to be treated as equals in a conversation. Open up for them to add experiences, insights, and personal connections. When I asked my parents (very non-sciencey people…sorry Mom and Dad!) about what makes them interested in a science story they said when it has a human connection (global warming, agriculture, habitat changes) and when it has the “wow” factor. Using one of those two hooks can help you get talking with adults and can help you lead the conversation towards your research.

Try it out!

Pick a friend and have them act as either a 5-year old, 16-year old, or adult. Practice telling them about what you do and what you research. Use the tips from above to keep them engaged for 1-2 minutes. (Bonus points for the friend that sits on the floor acting like a true 5-year old or plays on their phone the whole time as that typical teen.)


Who is the public?


When a scientist decides to enter the world of communicating their science outside of academia, she often starts with some phrase like, “I want the public to understand what I do.” This statement summarizes how most scientists feel, myself included. I’ve come to realize, however, that there is a problem with a statement like that serving as your goal: there is this nebulous term “the public” that has no good definition. Often people assume the public is anyone outside of academia. Others would consider it anyone outside your speciality field. For example, I may be considered part of the public to someone that works on physics. Therefore the public can include schoolchildren, parents, adults, teachers, policymakers, friends, neighbours etc. This list is long. If we want to have effective science communication, the first step is to define your public. 

Chances are that whatever your outreach method is whether it is writing a blog, visiting a classroom, facilitating citizen science, giving a talk, or filming a video, you cannot reach all of “the public” in one fell swoop. Just as you would do for your experiments, set a reasonable and attainable goal so you can measure your success (more on measurement in a future post). Define your audience for that particular outreach project. As an overarching goal, many of us want to reach all those parts of the public, but in reality we’ll need to take small steps, focusing our attention on “the public” with which we connect.

Others argue that by having our goal be “the public” it forces scientists to get out of their comfort zones and learn about a new audience. I certainly agree with forcing yourself to reach a new audience, but this should be a gradual process after starting with a more comfortable audience.

I am also not the first person to question the vagueness of “the public”.  The Center for Advancement of Informal Science Education summarizes the term “Public Engagement” noting its tendency as a “buzzword that succeeds because it allows multiple stakeholders to rally together despite sometimes conflicting goals”. Take a look at their post to learn more about different forms of engagement.

What do you think? Should we use the catch-all term “the public” or focus our attention on sectors of that group? Let me know in the comments or tweet me. (@crhoffman99)


6 science people to follow on Twitter.

I will be honest: I totally love Twitter. I started my Twitter (@crhoffman99) over 5 years ago for personal use and over the past two years transitioned to using it professionally and for communication. I follow a lot of science folks, but also some celebs & lifestyle bloggers (diversity is good!). Here are some great science related people and places that I think YOU should follow to get started.


1. Specimen FMNH PR2081 (@SUEtheTrex): Okay, so this is not a person, but a SPECIMEN from the Field Museum in Chicago that tweets pretty hilarious scientific jokes. Always good for a laugh.

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2. California Academy of Science (@calacademy): An outstanding museum in San Francisco tweeting about its exhibits and education efforts. Lots of stunning visuals come through their feed.

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3. Ed Yong (@edyong209): Science journalist who shares a multitude of interesting stories. Ed always seems to be ahead of curve on popular science trends. Follow him to get the latest and greatest of science journalism.

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4. Emily Graslie (@ehmee): With a job title like “Chief Curiosity Correspondent”, you can guess you’ll get some great tweets from Emily. She hosts “The Brain Scoop” on YouTube and is generally making great strides for science communication and women in science.

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5. Alex Wild (@Myrmecos): A prominent wildlife and insect photographer, his feed will bombard you with out of this world, up-close shots of insects. Be prepared for lots of ants and spiders!

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6. Real Scientists (@realscientists): As the name implies, this Twitter account contains real scientists who alternate weekly to bring you various content. Check the info box and picture to identify the weekly scientist. Great account for getting answers to questions!

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What other account do you suggest for getting started? Let me know in the comments below or tweet me!