人物专栏｜Saloni Krishnan博士访谈

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《理论语言学五道口站》（2023年第15期，总第279期）人物专栏与大家分享Stephen Wilson副教授对Saloni Krishnan博士的访谈。Stephen Wilson，美国范德堡大学医学中心副教授。Saloni Krishnan博士，英国伦敦大学皇家霍洛威学院高级讲师，发展认知神经学家。

本期访谈节选自Stephen Wilson副教授于2021年4月与 Saloni Krishnan博士所做的一期播客。在访谈中，Saloni Krishnan博士就“Functional organisation for verb generation in children with developmental language disorder”一文回答了与语言障碍相关的问题。访谈内容转自网站：https://langneurosci.org/podcast/，由本站成员董泽扬、何姝颖翻译。本次访谈共分为上下两期，后续内容将在下一次人物专栏中继续与大家分享，敬请期待。

采访人物简介

Saloni Krishnan博士 

Saloni Krishnan博士，英国伦敦大学皇家霍洛威学院高级讲师，发展认知神经学家。研究方向为沟通障碍（如发育性语言障碍和阅读障碍）患儿的大脑差异。一作论文“Functional organisation for verb generation in children with developmental language disorder”已于2021年1月在《神经影像》（NeuroImage）期刊上发表。

Brief Introduction of Interviewee

Saloni Krishnan is Reader at Royal Holloway, the University of London and a developmental cognitive neuroscientist. Her research focuses on brain differences in childhood communication disorders, such as DLD (developmental language disorder) and dyslexia. Her first-authored paper “Functional organisation for verb generation in children with developmental language disorder” was published in Neuroimage in January 2021.

采访者简介

Stephen Wilson

Stephen Wilson，美国范德堡大学医学中心副教授。他的研究兴趣主要为语言的神经基础，侧重于大脑的语言处理机制（尤其是不同类型的失语症患者）。

Brief Introduction of Interviewer

Stephen Wilson is an Associate Professor at Vanderbilt University Medical Center, USA. His primary research interests are in the neural basis of language, focusing on language processing mechanisms in the brain (especially in patients with different kinds of aphasia).

访谈内容

01.

Stephen Wilson教授：首先，祝贺您获得由英国心理学会发展心理学分会（the developmental section of the British Psychological Society）颁发的尼尔·奥康纳奖（the Neil O'Connor award）。读了您的论文，我发现了很多感兴趣的内容。您能谈谈患有发育性语言障碍（developmental language disorder，DLD）的儿童吗？按我的理解，发展心理学界已经对DLD这个新术语达成了某种程度上的共识，那么它能否取代特殊型语言障碍（specific language impairment，SLI）这一术语呢？还是说DLD是一个不同于SLI的概念呢？在DLD这一术语与其他概念的区别性方面，你们有什么新的见解吗？

Saloni Krishnan博士：以前我在印度的诊所实习的时候，印度还没有什么人会用SLI这个术语。我认为，SLI是研究领域中的热门术语，但在临床中却并没有那么高的使用率。实际上，即使在如今，临床应用中所使用的术语也是千差万别，有些人可能会用“语言迟缓（language delays）”，而另一些人则会用“语言障碍（language disorder）”。在研究中也会有“发育性言语困难症（developmental dysphasia）”之类的不同术语。2016年的时候，Dorothy（编者注：论文合著者之一）发起了一项名为CATALISE的学术活动。CATALISE旨在推动学界就两个问题达成一致：第一，构成语言障碍的标准是什么；第二，应该使用什么术语。我觉得我们已经意识到了问题的关键，术语本身的概念固然重要，但人们在术语使用上的共识更加重要。而这则是因为，要想使一种疾病的诊断法得到普及，必须先让人们了解它到底是什么。自闭症、多动症、阅读障碍等疾病的术语统一得很好，但我们对于SLI和DLD这样的术语却缺乏共识。起初，SLI规定患者的语言能力和智商之间必须存在差异，但是临床上却基本不会出现这种情况。所以我们的做法是，不仅考虑到研究意义，还照顾到少部分语言障碍患者。因此，我们会使用DLD作为通用术语以涵盖更多人群。我认为，即使是非语言智商超过70的人群也可以被诊断为DLD。我们不要求患者的非语言能力和语言能力之间存在差异，这是与SLI不一样的规定。

02.

Stephen Wilson教授：这一点很有意思。我认为SLI这个术语是由那些意识形态上坚信语言模块化的人所推广的。但从您的论文中可以很明显看出，语言的模块化是例外而不是规则。那么在研究中，您是如何定义DLD的呢？

Saloni Krishnan博士：人们在这一点上确实存在分歧。我觉得你可以这样理解DLD：想象语言能力是一种特征，可以和类似身体质量指数（body mass index，BMI）这种数据一样进行测算。这种观点认为人的语言能力是连续变化的，但低于某个点的话，我们就会认为它超出了正常范围，并判断这样的人群是需要支持和帮助的。BMI已经在连续统上划分了类别，我们认为DLD也需要进行类似的划分。对于分界线的位置，不同的研究人员的划定会略有不同。例如，在对DLD患病率进行估算的大型研究中，人们通常会进行两次或更多的语言测试，并以低于平均值1.5个标准差处为界。考虑到被试招募的困难程度，我们的研究采取了更宽松的标准。我认为在两次或多次语言测试中，以低于平均值1个标准差处为界，对于实验来说是可以接受的。进行两次或多次语言测试，这一点非常重要，因为这样才能证明结果不是在正常变化范围内的。而如果是通过随机选取两个或更多的任务来测试语言的不同方面，就不能沿用相同的类别划分。

03.

Stephen Wilson教授：确实如此。您研究中的儿童们也需要进行临床诊断，对吗？

Saloni Krishnan博士：不尽然。DLD是一个有争议的术语，临床上使用并不普遍，这一点我也已经提到过。研究初期，我们对此有过很多争论，因为现在DLD的接受度和采用率相对之前高了一些。但是推特上还是偶尔会有言语-语言治疗（SLT）人士跳出来说我们在临床实践中不会给出诊断结果云云。实际上，我们觉得应当针对儿童的表现提出改善功能性的对策。这种诊断也是最近才有的，所以那些大一点的儿童可能没有接受过这种诊断。有时由于各种原因，人们并不想要诊断结果，所以我们并没有对诊断做硬性要求，但语言测试还是进行了的。

04.

Stephen Wilson教授：他们必须要有语言康复治疗的经历吗？

Saloni Krishnan博士：他们必须有言语障碍史，但我认为这个问题只需要询问家长即可。

05.

Stephen Wilson教授：您研究的理论依据似乎是探求语言处理中是否有功能性上的异常可以解释这些儿童的语言缺陷。先前有些研究涉及这一群体语言的功能和结构差异，也许能够解释语言障碍问题。但您和您的同事显然不满足于这种认知。您能谈谈这个问题吗？

Saloni Krishnan博士：当然。我会试着把这些放到重要位置，以此来提醒自己人们完成的各项研究。但正如我所说，功能方面的研究数量非常之少。关于这些可以查看我和Harriet Smith合作过的文献综述。在这篇和他合作的文章里共有七组数据。所以当我们开始做BOLD的时候，大约已有七次功能性的研究了。基本上所有的研究都有一个共性，那就是它们涉及的人数都不多。而且，每项研究都采用了完全不同的任务。举个例子，其中一项研究采用了执行功能任务的切换，另一项研究则采取一种内隐语言学习任务。Kate和Dorothy做过一项研究，文章的第一作者是Nick Babcock，该研究运用到了一种隐性听觉命名任务。在这个任务里，你会听到一个定义，随后需要想出与这个定义对应的单词。这方面的研究不仅数量稀少，而且研究内容存在些许差异，对DLD定义的看法也稍有不同。所以对于DLD儿童左脑额下回（IFG）的活动量比常人少，我们还没有清晰的认识，也就不那么奇怪了。学者们在一些主题上观点接近，比如他们尤其在功能任务里倾向于关注颞上区或者额区下部。但这并不连贯，由于我所提到的某些原因，也无法抽取出一个清晰的图景。这确实很符合当时时代背景。我所提到的这些研究都属于21世纪早期。回看以前的研究，参与者数目不多的实验设计是相当常见的。

06.

Stephen Wilson教授：为了超越以往的研究，您做了一些决定，我们来聊聊这些。首先，你们都希望招收大量儿童被试，是吗？显然，越多儿童越好，但您是怎么决定具体需要多少儿童被试的呢？

Saloni Krishnan博士：这是一个说来话长但很有意思的故事。我们是在某个节点开始计划这个项目的，在某一次的项目会议上，Dorothy提议让我们对项目进行事前预防式演练。我不确定你是否听说过这个概念，当时我并没有听说过。这个概念大意是你坐下来，宣布项目彻底失败了。随后大家会坐在一起，花几个小时讨论导致BOLD失败的可能原因是什么。其中有一些原因显而易见，比如我们招收不到被试；而有一些原因则比较隐蔽。打个比方，我很担心我们会说自己要对语言和认知能力的特征进行全面的描述。如果是这样的话，我们一定会遇到一名审稿人，指出我们遗漏了至关重要的问题或者关键的事物，而通常只有在出现差错的时候我们才会意识到这个关键问题或事物，并且即使意识到也为时已晚。显然，那个时候，开放科学运动（open science movement）正开始兴起，会议日期已经非常临近，我们看到通知说《神经影像》将会接受注册报告以及神经影像数据。我们觉得这个挺有意思，或许可以把一个任务当作某种实验方案或者基础内容来提交。这可以帮助我们决定将要招收参与者的数量，或者是需要招收的最低数量。对于Kate来说，我帮了个倒忙，因为实际上她拥有分析所需的具体信息，直接指向了我们所需的数量，但我们也希望能把具体的数量以及在这个文章中提及的决策正式确定下来。当我们填写数量的时候，总体目标是160个儿童。我们计划，或者说希望其中有一半是患有DLD的儿童，因为正如我所说，在他们到来之前我们并不能确定具体情况。而另一半就会成为对照组。

English Version

01.

Assoc. Prof. Stephen Wilson: So, first of all, congratulations on getting the Neil O'Connor award, which I think is from the developmental section of the British Psychological Society. I looked at your paper and I was like, oh, this has heaps of things in it that are really interesting to me. Can you talk a bit about the DLD kids? So I understand that the field has kind of converged on this new terminology, is it replacing SLI? Or is it just a different concept than SLI? Are you guys thinking about it differently now, in terms of how it is distinguished from other things?

Dr. Saloni Krishnan: When I was in clinics, even the term SLI in India wasn't used. I think SLI has tended to be a term that was quite popular in research and I think didn't quite make it to clinics in quite the same degree. And even today, a lot of clinical practices will actually use very different labels. So they might have things like language delays, sometimes language disorder. In research, you'll find terms like developmental dysphasia, and things like that. And so back in 2016, Dorothy led this kind of consortium exercise called CATALISE. And the purpose of CATALISE was to try to agree on two things. One is specifically like, what are the criteria which we think constitute the language disorder. And then the second part of this was, what is the label we should use? And I think we realized that it was important, not just, you know, it was obviously important what that label was, but actually what that label was, was somewhat less important than people converging on using it. Because in order for a diagnosis to gain popularity, actually, you have to have people know what it is. And with autism, or ADHD, we seem to do this very well. Or dyslexia, for example, we just don't have that same recognition for terms like SLI and DLD. And of course, with SLI, the idea was that you had to show this discrepancy between language skills and IQ. And I think, in practice, it was recognized that that doesn't happen, or that happens very, very rarely. And so we were kind of focusing not just research but also services on a very small subset of people who had language problems. And so kind of DLD as a label is a little bit more inclusive. So I thinkwith a nonverbal IQ of greater than 70, you can get a kind of diagnosis of DLD. You don't have to show that discrepancy between nonverbal and verbal skills as you would have had to do for SLI.

02.

Assoc. Prof. Stephen Wilson: That's really interesting. I think that the term SLI was promoted a lot by people that had a lot of ideological commitment to the modularity of language. And, yeah, it's pretty clear from your paper that that's the exception rather than the rule. So how do you define DLD in your study and in general?

Dr. Saloni Krishnan: So yeah, people disagree on this a little bit. And I think the idea is that, you know, you can imagine thatlanguage ability is some kind of trait, right, and it's a trait in a similar way to how we might calculate like, BMI for instance, which is body mass index. And the idea there is it lies on a continuum, but at some point, you're gonna say like, this is a bit excessive. I think these people need support, that these people need help. And with BMI, we have established categories to do that along the continuum. And then we argue that you would do a similar kind of thing for DLD as well. So I mean, different researchers differ a little bit in where they draw about specific cut. For example, in the kind of larger studies that have tried to estimate the prevalence of DLD, what people tend to do is use a criterion of one and a half standard deviations below the mean, on two or more language tests. We've gone slightly gentler, because recruitment was obviously a slightly more challenging and in research settings, I think it tends to be accepted that you use about one standard deviation below the mean, on two or more tests of language. And that kind of two or more tests of language is actually really important, because that's where you're saying it's not just some kind of normal variation. But say, if you're testing different aspects of language, you shouldn't be following kind of in that category, by chance on two or more of those tasks.

03.

Assoc. Prof. Stephen Wilson: Yeah, it does. Don't the kids in your study also have to have a clinical diagnosis?

Dr. Saloni Krishnan: No. So actually, you know, because DLD is such a contentious term. It's not used comprehensively by clinical practices, as I said. There was quite a lot of debate around the time we started, because it's a bit more accepting and adopted now. But you'll still find on Twitter, the occasional SLT will pop up and say, like, you know, for example, our clinical practice doesn't do diagnoses. We think that, you know, we should respond functionally to the child's profile. It's also quite a new diagnosis. So you might expect that older children haven't really received it. For a variety of reasons, and sometimes people don't want the diagnosis. So we didn't mandate that people have to have a diagnosis. But we tested them on language tests.

04.

Assoc. Prof. Stephen Wilson: Didn't they have to have a history of treatment for speech language issues?

Dr. Saloni Krishnan: They had to have a history of speech and language problems, but I think we just asked parents.

05.

Assoc. Prof. Stephen Wilson: Right. So it seems like the rationale for your study is essentially to see if there's any functional abnormalities in language processing that might explain the language deficits that these kids have. Can you tell us about prior studies of functional and structural differences in this population that might explain that language disorder? And evidently, you guys weren't satisfied with the state of knowledge. So maybe talk about that a bit?

Dr. Saloni Krishnan: Yeah, sure, I'll try and pull this up to remind myself about what different people had done. But as I said, especially functionally, there had just been a really, really small number of studies. So I think I'm looking at a literature review that we kind of carried out. On my lovely excel sheet that Harriet Smith, who is one of the co authors on this might remember, I think we have seven rows of data. So there were about seven functional studies when we started doing BOLD. And basically one of the issues with all of these studies were that the numbers of people they had used have been quite small. And then each of them have used a completely different task. To give you an example, one of the studies did a kind of task switching executive function task, another did a kind of implicit language learning task. And then the study that Kate and Dorothy did, which was first authored by Nick Babcock, had a kind of covert auditory response naming tasks. You'd kind of hear like, a little definition, and you had to kind of come up with the word for it in your own head. So really, very, very few studies. And every study did something slightly different, and then had a slightly different definition for what they consider DLD to be. So perhaps it was kind of unsurprising that we didn't have this clear picture of like, okay, well, kids with DLD show less activity over the left IFG. There were kind of converging themes, perhaps, that people tended to focus on kind of superior temporal regions, or inferior frontal regions, particularly in the functional tasks. But it wasn't cohesive, and you couldn't really extract a clear pattern for some of the reasons that I've mentioned. I mean, also, it was fairly typical of the times, right. The studies I'm talking about are sort of, like, early 2000s. And, you know, looking back at studies that it was fairly typical to just have a few participants in those designs.

06.

Assoc. Prof. Stephen Wilson: Right. So let's talk about some of the decisions that you made to kind of go beyond these past studies. So first of all, you all wanted to recruit a large number of kids, right? So it's obvious that more kids is good, the more kids the better. But how did you decide how many kids you are going to need?

Dr. Saloni Krishnan: This is kind of a long but pretty interesting story, I think. So at some point, we had started planning this project and in one of our project meetings, Dorothy suggested this idea of like, why don't we do a pre-mortem of the project. I don't know if you've ever heard of this before, I certainly hadn't. But it's this idea that you sit around, and you kind of say, the project has completely failed. Now, here are the reasons I think it's completely failed. And so we kind of sat around for a couple of hours coming up with a whole bunch of different reasons that we thought BOLD could fail. And some of them are really obvious, like, we just wouldn't be able to recruit people. Some of them were kind of less obvious. So for example, I was really concerned that we were going to say that we were going to fully characterize language and cognitive abilities. And I'd be like, well, I'm sure we'll go to a reviewer and they're going to point out that we missed this really important question or, you know, this really key thing and we're just not going to think about it till it's too late. And obviously, at the time, the open science movement was kind of kicking out and kind of just very close to this meeting, we saw an announcement saying that NeuroImage was going to accept registered reports and kind of neuroimaging data. And we thought this could be kind of cool. Maybe we can submit one task as a kind of protocol or a basis. This would kind of help us decide how many participants we're going to kind of collect, or at least minimums that we need to collect. I'm also doing Kate a disservice here, because actually, in the grind, she does have a really detailed section on power analyses. But I think, which obviously led to kind of the numbers we propose for the grant. But I think we wanted to formalize it a bit more and formalize some of the decisions we were taking in this paper. But yeah, the overall grant, I think, when we wrote it, the objective was to scan 160 children. We said that half of those would be kids with DLD or what we hoped would be kids with DLD, because as I said, we didn't necessarily know before they came to us. Then the other half would be kind of matched controls.

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编辑：雷晨 赵欣宇 何姝颖 董泽扬 

排版：雷晨 赵欣宇 何姝颖 董泽扬 

审校：时仲 田英慧

英文编审责任人：董泽扬