This really gets me freaked out! Martin says I’m just a grumpy old (?) man. So let me lie along the Neurocritic approach just for a minute, and just air my frustration:
HOW CAN YOU GET A SCIENCE PUBLICATION WITH A HUMONGOUS ERROR?
Take a look at this image. It’s from a 2007 article in Science by Depue et al.
It’s supposed to show activation in the hippocampus and amygdala. Looks innocent, right? Let’s take a closer look.
Slice number 3 really provides the best errors:
I spent quite a while figuring the figues out. Did the yellow names indicate the blobs or where the structures actually are? For one thing, the blue blobs don’t fit into amygdala or hippocampus, but rather the entorhinal cortex. But let me comment on two big errors related to this slice.
First, the hippocampus is not present on this slice, so why put the name there? And why put it that lateral? This is really bothering. Do the researchers (and reviewers) really think that the hippocampus has anything to do here?
Second, the rightmost activation blob is centered in white matter. Hmm.. would that not give you the opportunity to speculate whether your coregistration was correct? I would. Related to this, let me just comment briefly on the two leftmost slices:
If you look at the blob, it really looks as if it fits better into the hippocampus. The entorhinal cortex is a thin slice with a whole different orientation. My guess: the hippocampus.
Next slide:
As before, I’m really curisous whether this is only a sign of poorly coregistered (and checked) fMRI images to the structural template brain. Or can it be just another example of why standard spatial normalization in this region is too problematic.
Guys, let’s face it: this is probably one of the bigger, non-spotted errors one can find in visualization of fMRI data. Does it help validate fMRI as a method? NO. How can this error be allowed? I have no idea. But would I trust ANY of the other spatial localizations in this article? NO WAY!
Get a grip, guys! Check your images, and get your medial temporal lobe your anatomy right!
-Thomas
I think you’re getting all worked up over very little. The slices shown range from y=-22 to y=5, so the clusters of activation probably extends beyond the hippocampus to include some other regions. It is rather weird that they would choose to label something clearly outside of hippocampus as such. Entorhinal cortex is part of the hippocampal system, so there’s nothing wrong with the “hippocampus” label. It’s not as if fMRI is going to be credible at distinguishing the various parts, at least not with their design.
Anyway, I’d like the last 15min of my life back. And please, enough with the sensationalist headline.
Hi Anon,
I disagree. IMO, too many people make fMRI localization in a much too loosely or unconstrained way. What do they do with these kind of activations? Use the SPM Anatomy toolbox… which definitely is wrong in this region. Or just the use of spatial normalization is known to induce errors. You don’t only see this in the medial temporal lobe region. You see it in the occipital lobe, the orbitofrontal cortex etc. So no, this is not an isolated problem.
Or how about doing a test of “guess the structure” in researchers? I’m amazed about how wrong people can be in just identifying basic brain regions such as the hippocampus and amygdala.
So you get the anatomy wrong. What you call the hippocampus may be the entorhinal or perirhinal, what you call the amygdala may the the temporopolar cortex. So what, right? Isn’t this just one big system? Just as Squire, Zola and the others have claimed a long time ago? Well, if you look at the literature, there is a big discussion (just as ardent as that of the fusiform face area) that is vigorously debating the role of different medial temporal lobe structures. That is why this is important. It DOES matter what you label your blobs as, and in particular whether you check your images properly. People are way too sloppy about this (still).
My own musing into this region has shown me that:
1) there is great individual and intra-individual difference in the regions
2) spatial normalization really does everything worse in terms of spatial localization (and, thus, structural conclusions)
3) a region of interest approach, and native-space analysis is one way to work around this.
And to bring your 15 minutes even more back, why should *anybody* allow big and very significant white-matter blobs to occur? How about finding some big blobs outside the skull, then? This happens when your images are poorly co-registered. At our lab we call this “aura-activation”, since it’s just as freaky to accept this as it is to accept auras to exist (and you better check your images). Same story with big white matter activations.
But yes, I’m a tad nerdy about this region (by all means, I spent my PhD probing into it). Is it really that important. Well, if you’re work is relating to structure-function discussions, this is important.
Want to have your 15 minutes back? How about me getting 3 years back for spending time on learning this region in detail, just to learn that it might not be necessary to get a good publication?
And remember, I did actually warn you: read the first paragraph again, and see what I mean.
Anyway, thanks for your comment 😀
-Thomas
As a foster/adoptive parent-trainer in Oregon, I am fascinated by many of the articles on your blog. I work for a company which helps bring the latest scientific research to the world of parenting children with trauma histories. I was drawn to your site by some of the brain scans you have posted in regards to the amygdala and hippocampus. I really appreciated your critique of these images.
My question is this: If those images are unfounded, then where would you point me to find scans that are worthy of using in my classes? I am desperate for more images that show the development of the brain and it’s ability (or lack thereof) to handle trauma and stress, especially in this format that incorporates the age comparisons.
Thank you for the dedication you put forth to offer the latest research on so many topics. I am a fan of your blog all the way!
Bethany Griffin-Porter
Facilitator for the Consciously Parenting Project