Cognitive Science Program

Learning to decode cognitive states from brain images.(2004)
Tom M Mitchell, Rebecca Hutchinson, Radu S Niculescu, Francisco Pereira, Xuerui Wang, Marcel Just ...
Machine learning, 57 (1-2), 145-175

Abstract

Over the past decade, functional Magnetic Resonance Imaging (fMRI) has emerged as a powerful new instrument to collect vast quantities of data about activity in the human brain. A typical fMRI experiment can produce a three-dimensional image related to the human subject's brain activity every half second, at a spatial resolution of a few millimeters. As in other modern empirical sciences, this new instrumentation has led to a flood of new data, and a corresponding need for new data analysis methods. We describe recent research applying machine learning methods to the problem of classifying the cognitive state of a human subject based on fRMI data observed over a single time interval. In particular, we present case studies in which we have successfully trained classifiers to distinguish cognitive states such as (1) whether the human subject is looking at a picture or a sentence, (2) whether the subject is …

Frontal and parietal participation in problem solving in the Tower of London: fMRI and computational modeling of planning and high-level perception.(2003)
Sharlene D Newman, Patricia A Carpenter, Sashank Varma and Marcel Adam Just
Neuropsychologia, 41 (12), 1668-1682

Abstract

This study triangulates executive planning and visuo-spatial reasoning in the context of the Tower of London (TOL) task by using a variety of methodological approaches. These approaches include functional magnetic resonance imaging (fMRI), functional connectivity analysis, individual difference analysis, and computational modeling. A graded fMRI paradigm compared the brain activation during the solution of problems with varying path lengths: easy (1 and 2 moves), moderate (3 and 4 moves) and difficult (5 and 6 moves). There were three central findings regarding the prefrontal cortex: (1) while both the left and right prefrontal cortices were equally involved during the solution of moderate and difficult problems, the activation on the right was differentially attenuated during the solution of the easy problems; (2) the activation observed in the right prefrontal cortex was highly correlated with individual differences in …

Differential effects of syntactic and semantic processing on the subregions of Broca’s area.(2003)
Sharlene D Newman, Marcel Adam Just, Timothy A Keller, Jennifer Roth and Patricia A Carpenter
Cognitive Brain Research, 16 (2), 297-307

Abstract

This study attempts to specify the contribution of two subregions of Broca’s area during syntactic and semantic processing of sentences by examining brain activation in a grammaticality judgment task. The processing of two types of ungrammatical sentences was examined. One type leaves the thematic interpretation generally unaffected, by violating the noun–verb agreement in number, while the other type introduces an extraneous verb, which cannot be incorporated into the developing thematic structure. Pars triangularis was more sensitive to the extra verb violation, whereas pars opercularis was more sensitive to the noun–verb agreement violation. The current study adds to the growing literature that suggests there are separable functional subregions of Broca’s area, with pars triangularis more involved in thematic processing and pars opercularis more involved in syntactic processing. The posterior left …

Imagery in sentence comprehension: an fMRI study.(2004)
Marcel Adam Just, Sharlene D Newman, Timothy A Keller, Alice McEleney and Patricia A Carpenter
Neuroimage, 21 (1), 112-124

Abstract

This study examined brain activation while participants read or listened to high-imagery sentences like The number eight when rotated 90 degrees looks like a pair of spectacles or low-imagery sentences, and judged them as true or false. The sentence imagery manipulation affected the activation in regions (particularly, the intraparietal sulcus) that activate in other mental imagery tasks, such as mental rotation. Both the auditory and visual presentation experiments indicated activation of the intraparietal sulcus area in the high-imagery condition, suggesting a common neural substrate for language-evoked imagery that is independent of the input modality. In addition to exhibiting greater activation levels during the processing of high-imagery sentences, the left intraparietal sulcus also showed greater functional connectivity in this condition with other cortical regions, particularly language processing regions …

Differences in auditory processing of words and pseudowords: An fMRI study.(2001)
Sharlene D Newman and Donald Twieg
Human brain mapping, 14 (1), 39-47

Abstract

Although there has been great interest in the neuroanatomical basis of reading, little attention has been focused on auditory language processing. The purpose of this study was to examine the differential neuroanatomical response to the auditory processing of real words and pseudowords. Eight healthy right‐handed participants performed two phoneme monitoring tasks (one with real word stimuli and one with pseudowords) during a functional magnetic resonance imaging (fMRI) scan with a 4.1 T system. Both tasks activated the inferior frontal gyrus (IFG), the posterior superior temporal gyrus (pSTG) and the inferior parietal lobe (IPL). Pseudoword processing elicited significantly more activation within the posterior cortical regions compared with real word processing. Previous reading studies have suggested that this increase is due to an increased demand on the lexical access system. The left inferior frontal …

Imagining material versus geometric properties of objects: an fMRI study.(2005)
Sharlene D Newman, Roberta L Klatzky, Susan J Lederman and Marcel Adam Just
Cognitive Brain Research, 23 (3-Feb), 235-246

Abstract

Two experiments are reported that used fMRI to compare the brain activation during the imagery of material and geometric object features. In the first experiment, participants were to mentally evaluate objects along either a material dimension (roughness, hardness and temperature; e.g., Which is harder, a potato or a mushroom?) or a geometric dimension (size and shape; e.g., Which is larger, a pumpkin or a cucumber?). In the second experiment, when given the name of an object and either a material (roughness and hardness) or geometric (size and shape) property participants rated the object on a scale from 1 to 4. Both experiments were designed to examine the underlying neural substrate that supports the processing of material object properties with respect to geometric properties. Considering the relative amount of activation across the two types of object properties, we found that (1) the interrogation of …

Baseline conditions and subtractive logic in neuroimaging.(2001)
Sharlene D Newman, Donald B Twieg and Patricia A Carpenter
Human Brain Mapping, 14 (4), 228-235

Abstract

Discrepancies in the patterns of cortical activation across studies may be attributable, in part, to differences in baseline tasks, and hence, reflect the limits of the subtractive logic underlying much of neuroimaging. To assess the extent of these effects, three of the most commonly used baseline conditions (rest, tone monitoring, and passive listening) were compared using phoneme discrimination as the experimental task. Eight participants were studied in a fMRI study with a 4.1 T system. The three baseline conditions systematically affected the amount of activation observed in the identical phoneme task with major affects in Broca's area, the left posterior superior temporal gyrus, and the left and right inferior parietal regions. Two central findings were: 1) a differential effect of baseline within each region, with the rest baseline condition producing the greatest amount of activation and the passive listening condition …

The synchronization of the human cortical working memory network.(2002)
Sharlene D Newman, Marcel Adam Just and Patricia A Carpenter
Neuroimage, 15 (4), 810-822

Abstract

A verbal reasoning problem at the intersection of verbal working memory, problem-solving, and language comprehension was examined using event-related fMRI to distinguish differences in the differential timing of the response of the various cortical regions that compose the working memory network. Problems were developed such that the process demand as well as the timing of the manipulation of the contents of working memory (i.e., a demanding computation) was varied. Activation was observed in several regions including the dorsolateral prefrontal cortex, the inferior frontal gyrus, and the parietal lobe. Examination of the MR amplitude response revealed that the regions do not all activate simultaneously; instead, their activation time courses reveal differential responses that correspond to their theoretical processing role in the problem-solving task. The coordination of cortical area responses reveals how the …

The effect of semantic relatedness on syntactic analysis: an fMRI study.(2010)
Sharlene D Newman, Toshikazu Ikuta and Thomas Burns Jr
Brain and language, 113 (2), 51-58

Abstract

The sentences we process in normal conversation tend to refer to information that we are familiar with rather than abstract, unrelated information. This allows for the use of knowledge stores to help facilitate comprehension processes. In many sentence comprehension studies, the stimuli are designed such that the use of world knowledge is limited. Here, we investigated how the semantic relatedness of sentence constituents influences sentence processing. A three factor design was employed in which processing phase (sentence vs. probe), syntactic complexity (object-relative vs. conjoined active) and the semantic relatedness of the nouns within the sentence was examined. We found a differential effect in two sub-regions of the left inferior frontal gyrus (LIFG). BA 44 revealed an effect of syntactic complexity while inferior portions of the LIFG (BA 47) revealed an effect of relatedness as well as an interaction …

Volitional control of attention and brain activation in dual task performance.(2007)
Sharlene D Newman, Timothy A Keller and Marcel Adam Just
Human brain mapping, 28 (2), 109-117

Abstract

This study used functional MRI (fMRI) to examine the neural effects of willfully allocating one's attention to one of two ongoing tasks. In a dual task paradigm, participants were instructed to focus either on auditory sentence comprehension, mental rotation, or both. One of the major findings is that the distribution of brain activation was amenable to strategic control, such that the amount of activation per task was systematically related to the attention‐dividing instructions. The activation in language processing regions was lower when attending to mental rotation than when attending to the sentences, and the activation in visuospatial processing regions was lower when attending to sentences than when attending to mental rotations. Additionally, the activation was found to be underadditive, with the dual‐task condition eliciting less activation than the sum of the attend sentence and attend rotation conditions. We also …

An fMRI study of the Tower of London: a look at problem structure differences.(2009)
Sharlene D Newman, John A Greco and Donghoon Lee
Brain research, 1286 123-132

Abstract

The aim of the current study was to explore the effects of problem structure, namely goal hierarchy and number of optimal solution paths, on the neural architecture that supports problem-solving and planning. Here, six-move problems with both an unambiguous and ambiguous goal hierarchy and single and multiple optimal solution paths were examined. In the task used, participants were encouraged to generate a solution plan before execution. The behavioral results revealed that problem-solving time and accuracy were both affected by both problem parameters. The fMRI activation results revealed three major findings. First, the right prefrontal cortex revealed a significantly different activation pattern than the other regions examined. This was the only region that revealed a larger response during the execution phase than the planning phase. Second, the effect of goal hierarchy was strongest during the execution …

The Tower of London: A study of the effect of problem structure on planning.(2007)
Sharlene D Newman and Gregory Pittman
Journal of Clinical and Experimental Neuropsychology, 29 (3), 333-342

Abstract

Only recently has there been any consideration of the influence of the problem structure on Tower of London task (TOL) performance. Not surprisingly, these few studies that have investigated this issue have found significant differences in the cognitive demands of individual TOL problems. Based on these previous findings, the aim of the current study was to further explore the effects of two problem characteristics on the planning process—namely, goal hierarchy and the number of optimal solution paths. A number of performance measures when solving six-move problems were examined, including preplanning time, movement time, and accuracy. Analysis of the preplanning time revealed that it was significantly affected by goal hierarchy but not the number of solution paths. The individual movement times, however, revealed effects for both goal hierarchy and the number of optimal solution paths. The number of …

Cerebellum volume and eyeblink conditioning in schizophrenia.(2008)
Chad R Edwards, Sharlene Newman, Andrew Bismark, Patrick D Skosnik, Brian F O'Donnell, Anantha Shekhar ...
Psychiatry Research: Neuroimaging, 162 (3), 185-194

Abstract

Although accumulating evidence suggests that cerebellar abnormalities may be linked to the symptoms and course of schizophrenia, few studies have related structural and functional indices of cerebellar integrity. The present study examined the relationship between the volume of specific subregions of the cerebellum and cerebellar function, as measured by eyeblink conditioning (EBC). Nine individuals with schizophrenia and six healthy comparison participants completed structural magnetic resonance imaging of the brain and a delay EBC procedure. Volumetric measurements were taken for the whole brain, whole cerebellum, cerebellar anterior lobules I–V and posterior lobules VI–VII. The schizophrenia group had smaller cerebellar anterior lobes and exhibited impaired EBC relative to the comparison group. In the comparison group, larger anterior volume correlated with earlier conditioned response onset …

The effect of individual differences in working memory capacity on sentence comprehension: an fMRI study.(2013)
Sharlene D Newman, Evie Malaia, Roy Seo and Hu Cheng
Brain topography, 26 (3), 458-467

Abstract

This study explores the interaction between working memory systems and language processing by examining how differences in working memory capacity (WMC) modulates neural activation levels and functional connectivity during sentence comprehension. The results indicate that two working memory systems may be involved in sentence comprehension, the verbal working memory system and the episodic buffer, but during different phases of the task. A sub-region of the left inferior frontal gyrus (BA 45) was correlated with WMC during the probe and not during sentence reading while the only region to reveal a correlation with WMC during sentence reading was the posterior cingulate/precuneus area, a region linked to event representation. In addition, functional connectivity analysis suggests that there were two distinct networks affected by WMC. The first was a semantic network that included the …

Disrupted modular architecture of cerebellum in schizophrenia: a graph theoretic analysis.(2014)
Dae-Jin Kim, Jerillyn S Kent, Amanda R Bolbecker, Olaf Sporns, Hu Cheng, Sharlene D Newman ...
Schizophrenia bulletin, 40 (6), 1216-1226

Abstract

Recent studies of schizophrenia have revealed cognitive and memory deficits that are accompanied by disruptions of neuronal connectivity in cortical and subcortical brain regions. More recently, alterations of topological organization of structural networks in schizophrenia are also being identified using graph theoretical analysis. However, the role of the cerebellum in this network structure remains largely unknown. In this study, global network measures obtained from diffusion tensor imaging were computed in the cerebella of 25 patients with schizophrenia and 36 healthy volunteers. While cerebellar global network characteristics were slightly altered in schizophrenia patients compared with healthy controls, the patients showed a retained small-world network organization. The modular architecture, however, was changed mainly in crus II. Furthermore, schizophrenia patients had reduced correlations …