Does language shape our perception of the world? This classic question has long provoked fierce debate in cognitive science. In recent years, new insights have been brought to bear on the debate, drawing on the functional organization of the brain. The nature of this organization predicts that language should influence perception more in the right visual field (RVF) than the left visual field (LVF), because stimuli in the RVF are initially processed by the left hemisphere, the side of the brain dominant for language. A number of studies have supported this prediction, showing that people are better able to discriminate items in the RVF when they come from different categories (e.g., a dog and a cat) than from the same category (e.g., two different cats), an effect of categorical perception (CP). In contrast, it appears that perception in the LVF is much less affected, if at all, by the categories of the items. This hemispheric asymmetry, known as left-lateralized CP, has been regarded by many researchers as strong evidence for the influence of language on perception. The Fellow's previous research has challenged this interpretation, however, by demonstrating that categories without names can also produce left-lateralized CP. At the same time, several other recent studies have contested the very existence of left-lateralized CP in failing to replicate it. The Fellow's postdoctoral research seeks to reconcile this conflicting body of evidence by probing the nature of the categories that give rise to the phenomenon. Four studies examine the extent to which various kinds of categories--linguistic vs. non-linguistic, overtly learned vs. implicitly represented, coarse- vs. fine-grained, lay vs. expert--elicit left-lateralized CP. Broadly, this research clarifies the circumstances under which various means of highlighting conceptual distinctions, including but not limited to language, shape our representations of the visual world.
Intellectual Merit. The idea that language influences perception, but only in half of the visual world, is an important but currently contested proposal. The findings from the Fellow's research will shed light on the nature and specificity of this influence. It may be that the simple act of forming a category, whether linguistic or otherwise, is sufficient to change how members of the category are perceived. Such a finding would suggest that knowledge need not be represented linguistically in order to exert a powerful influence on perception. Alternatively, linguistic categories may exert a stronger or more reliable influence than other kinds of conceptual distinctions, consistent with the possibility that language is privileged in the conceptual system. The findings from this research will thus provide a useful contribution to the ongoing debate on whether and to what extent language shapes thinking, with the potential to inform theories of knowledge representation and acquisition more generally.
Broader Impacts. As a first-generation college student and a person of mixed race, the Fellow holds a deep personal commitment to broadening the participation of underrepresented minority groups in STEM fields. To this end, the Fellow has been a leader in outreach efforts to inspire talented undergraduates at minority-serving institutions to recognize the value of scientific research and the rewards of a career in science. Through his postdoctoral training, the Fellow is extending these efforts by mentoring undergraduate researchers from diverse backgrounds, initiating targeted outreach events within the UC Berkeley community and beyond, presenting the research findings to a wide range of academic and non-academic audiences, and promoting scientific discourse on the Internet. In addition, part of the research examines perception in people with expertise in highly specialized domains, engaging groups rarely considered in the research process and providing an intriguing window on perceptual diversity. Such insights may ultimately help address barriers in intergroup communication, demonstrating that when people from different groups talk past each other, it may be in part because they--quite literally--see the world differently.
Does language shape our perception of the world? This classic question has long provoked fierce debate in cognitive science. In recent years, new insights have been brought to bear on the debate, drawing on the functional organization of the brain. The nature of this organization predicts that language should influence perception more in the right visual field (RVF) than the left visual field (LVF), because stimuli in the RVF are initially processed by the left hemisphere, the side of the brain dominant for language. Several studies have supported this prediction, showing that people are better able to discriminate items in the RVF when they come from different categories (e.g., a dog and a cat) than from the same category (e.g., two different cats). In contrast, such categorical perception (CP) appears to be weaker or even non-existent in the LVF. This hemispheric asymmetry, referred to as lateralized CP, has been regarded by many researchers as strong evidence for the influence of language on perception. However, the Fellow’s previous research challenged this interpretation by showing that unlabeled categories learned in the lab (e.g., arbitrary groupings of objects without names) also produce lateralized CP. The Fellow's postdoctoral research extended this line of work by investigating whether unlabeled categories yield lateralized CP in real-world domains like color and space. The findings from this project indicate that native English speakers show lateralized CP for color categories attested in languages with only two basic color terms (corresponding to the non-basic, non-color-specific terms "warm" and "cool" in English), and that native Korean speakers show lateralized CP for spatial categories marked by basic-level spatial terms in other languages (e.g., English: "on" vs. "above"), but not in Korean. These findings demonstrate that lateralized CP is not limited to the basic-level categories of one's native language, but extends to at least some non-native (i.e., unlabeled) categories as well. Intellectual Merit. The idea that language influences perception, but only in half of the visual world, is an important but controversial proposal. The findings from the Fellow’s postdoctoral research shed light on the nature and specificity of this influence.The findings suggest that the simple act of forming a category is sufficient to change how members of the category are perceived (at least when processed by the left hemisphere of the brain), regardless of whether the category has an explicit linguistic label. Such a conclusion implies that knowledge need not be represented in a linguistic format to exert a measurable effect on perception.The Fellow's research suggests that although language may shape perception in some cases, other ways of mentally organizing information may also have a powerful impact on how we view and represent the visual world. Broader Impacts. As a first-generation college student and a person of mixed race, the Fellow holds a deep personal commitment to broadening the participation of underrepresented minority groups in STEM fields. To this end, the Fellow has been a leader in outreach efforts to inspire talented undergraduates at minority-serving institutions to recognize the value of scientific research and the rewards of a career in science. Through his postdoctoral training, the Fellow extended these efforts by mentoring undergraduate researchers from diverse backgrounds. During the Fellow's tenure as a postdoctoral researcher at UC Berkeley, two undergraduates completed honors theses on lateralized CP under the Fellow's supervision. One of them earned the Robert J. Glushko Prize for Distinguished Undergraduate Research in Cognitive Science at UC Berkeley for her work, and the other presented her findings at the annual meeting of the Cognitive Science Society and is conducting follow-up research to build on her thesis work. Findings from the project were also presented in invited talks by the Fellow at four undergraduate-serving institutions, and to a variety of other audiences, including philosophy, linguistics, and cognitive science colloquia and undergraduate classes.
