Browsing by Author "Geng, Jingyi"

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    Role of Features and Categories in Representing Object Knowledge
    (2015-04-21) Geng, Jingyi; Schnur, Tatiana T.; Martin, Randi C; Fischer-Baum, Simon; Cox, Steven; Hernandez, Arturo
    Understanding how our knowledge about the world is organized can help us understand how we are able to access that knowledge to easily identify objects and communicate with others. One general view of object knowledge organization assumes that object knowledge is represented by how we perceive and interact with objects (for example features like the color or shape we see and touch) (i.e., feature view; e.g., Allport, 1985; Barsalou, 1999, 2008; Gallese & Lakoff, 2005; Tyler & Moss, 2001). In contrast, an alternative view hypothesizes that in addition to features from different modalities (e.g., visual, motor, and tactile), taxonomic (e.g., dog and rabbit are animal) and thematic category information (e.g., eating theme: a dog is chewing a bone) is also critical for representing object knowledge (i.e., feature-plus-category view; e.g., Crutch & Warrington, 2005, 2010; Patterson et al., 2007; Schwartz et al., 2011; Mirman & Graziano, 2012). In order to examine these two general views of object knowledge organization, I investigated whether feature and category information is activated when people access the meaning of words using both behavioral (i.e., response times and errors; Experiments 1 and 2) and functional magnetic resonance neuroimaging measures (Experiment 3). Consistent with the feature-plus-category view, Experiments 1 and 2 showed that when people access the meaning of words, this access was affected (slower/faster) by manipulating visual features (e.g., shape), taxonomic and thematic category information associated with objects. In support of the feature-plus-category view, Experiment 3 revealed that action features (e.g., cutting) associated with objects (e.g., saw) activated the motor brain region (i.e., primary motor cortex) and the taxonomic and thematic categories recruited the bilateral anterior temporal lobes and left temporo-parietal junction respectively. Taken together, my dissertation provides converging evidence from both behavioral and neuroimaging perspectives showing that both feature and category information play a key role in representing object concepts.
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    Role of features and categories in the organization of object knowledge: Evidence from adaptation fMRI
    (Elsevier, 2016) Geng, Jingyi; Schnur, Tatiana T.
    There are two general views regarding the organization of object knowledge. The feature-based view assumes that object knowledge is grounded in a widely distributed neural network in terms of sensory/function features (e.g., Warrington & Shallice, 1984), while the category-based view assumes in addition that object knowledge is organized by taxonomic and thematic categories (e.g., Schwartz etﾠal., 2011). Using a functional magnetic resonance imaging (fMRI) adaptation paradigm, we compared predictions from the feature- and category-based views by examining the neural substrates recruited as subjects read word pairs that were identical, taxonomically related, thematically related or unrelated while controlling for the function features involved across the two categories. We improved upon previous study designs and employed an fMRI adaptation task, obtaining results overall consistent with both the category-based and feature-based views. Consistent with the category-based view, we observed for both hypothesized regions of interest (ROI) and exploratory (whole-brain analyses) reduced activity in the left anterior temporal lobe (ATL) for taxonomically related versus unrelated word pairs, and for the exploratory analysis only, reduced activity in the right ATL. In addition, the exploratory analyses revealed reduced activity in the left temporo-parietal junction (TPJ) for thematically related versus unrelated word pairs. Consistent with the feature-based view, we found in the exploratory analyses that activity reduced in the bilateral precentral gyri (i.e., function regions) including part of premotor cortex as the function relatedness ratings increased. However, we did not find a relationship between adaptation effects in the bilateral ATLs and left TPJ and corresponding ratings of taxonomic/thematic relationships suggesting that the adaptation effects may potentially not reflect aspects of taxonomy that have been traditionally assumed. Together, our findings indicate that both feature and category information are important for the organization of object knowledge although the exact nature of those organization principles is an important question for future research.
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    The distractor frequency effect in Stroop and picture-word interference paradigms
    (2010) Geng, Jingyi; Schnur, Tatiana T.
    The color naming (Stroop) and picture-word interference (PWI) paradigms play a pivotal role in theorizing about cognitive processes in general, and language production in particular. Despite their assumed similarities, there exist discrepancies. In this study, I compared the effect of distractor word frequency between Stroop and PWI paradigms (in PWI picture naming is faster for high frequency than low frequency word distractors; Miozzo & Caramazza, 2003). In five experiments, I confirm the presence of DFE in both Stroop and PWI paradigms when the naming latencies are longer but the absence of DFE in both paradigms when the naming latencies are shorter and found that when naming latencies are fast, the distractor words are most likely processed to the phonological level by the time targets are named in both paradigms in the last experiment. Thus, my results are consistent with the assumption that the two paradigms operate in the same manner.
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    The Representation of Concrete and Abstract Concepts: Categorical Versus Associative Relationships
    (American Psychological Association, 2014) Geng, Jingyi; Schnur, Tatiana T.
    In 4 word-translation experiments, we examined the different representational frameworks theory (Crutch & Warrington, 2005; 2010) that concrete words are represented primarily by category, whereas abstract words are represented by association. In our experiments, Chinese-English bilingual speakers were presented with an auditory Chinese word and 3 or 4 written English words simultaneously and asked to select the English word that corresponded to the auditory word. For both abstract and concrete words, higher error rates and longer response times were observed when the English words were categorically or associatively related compared to the unrelated conditions and the magnitude of the categorical effect was bigger than the associative effect. These results challenge the different representational frameworks theory and suggest that although category and association are important for representing abstract and concrete concepts, category plays a greater role for both types of words.