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1.  Repetition of letter strings leads to activation of and connectivity with word-related regions 
Neuroimage  2011;59(3):2839-2849.
Individuals learn to read by gradually recognizing repeated letter combinations. However, it is unclear how or when neural mechanisms associated with repetition of basic stimuli (i.e., strings of letters) shift to involvement of higher-order language networks. The present study investigated this question by repeatedly presenting unfamiliar letter strings in a one-back matching task during an hour-long period. Activation patterns indicated that only brain areas associated with visual processing were activated during the early period, but additional regions that are usually associated with semantic and phonological processing in inferior frontal gyrus were recruited after stimuli became more familiar. Changes in activation were also observed in bilateral superior temporal cortex, also suggestive of a shift toward a more language-based processing strategy. Connectivity analyses reveal two distinct networks that correspond to phonological and visual processing, which may reflect the indirect and direct routes of reading. The phonological route maintained a similar degree of connectivity throughout the experiment, whereas visual areas increased connectivity with language areas as stimuli became more familiar, suggesting early recruitment of the direct route. This study provides insight about plasticity of the brain as individuals become familiar with unfamiliar combinations of letters (i.e., words in a new language, new acronyms) and has implications for engaging these linguistic networks during development of language remediation therapies.
doi:10.1016/j.neuroimage.2011.09.047
PMCID: PMC3254793  PMID: 21982931
letter strings; fMRI; connectivity; reading; learning; plasticity
2.  Time Course of Attentional Bias in Anxiety: Emotion and Gender Specificity 
Psychophysiology  2009;47(2):247-259.
Anxiety is characterized by cognitive biases, including attentional bias to emotional (especially threatening) stimuli. Accounts differ on the time course of attention to threat, but the literature generally confounds emotional valence and arousal and overlooks gender effects, both addressed in the present study. Nonpatients high in self-reported anxious apprehension, anxious arousal, or neither completed an emotion-word Stroop task during ERP recording. Hypotheses differentiated time course of preferential attention to emotional stimuli. Individuals high in anxious apprehension and anxious arousal showed distinct early ERP evidence of preferential processing of emotionally arousing stimuli along with some evidence for gender differences in processing. Healthy controls showed gender differences at both early and later processing stages. The conjunction of valence, arousal, and gender is critical in the time course of attentional bias.
doi:10.1111/j.1469-8986.2009.00926.x
PMCID: PMC3073148  PMID: 19863758
3.  Attentional Bias to Negative Emotion as a Function of Approach and Withdrawal Anger Styles: An ERP Investigation 
Although models of emotion have focused on the relationship between anger and approach motivation associated with aggression, anger is also related to withdrawal motivation. Anger-out and anger-in styles are associated with psychopathology and may disrupt the control of attention within the context of negatively valenced information. The present study used event-related brain potentials (ERPs) to examine whether anger styles uniquely predict attentional bias to negative stimuli during an emotion-word Stroop task. High anger-out predicted larger N200, P300, and N400 to negative words, suggesting that aggressive individuals exert more effort to override attention to negative information. In contrast, high anger-in predicted smaller N400 amplitude to negative words, indicating that negative information may be readily available (primed) for anger suppressors, requiring fewer resources. Individuals with an anger-out style might benefit from being directed away from provocative stimuli that might otherwise consume their attention and foster overt aggression. Findings indicating that anger-out and anger-in were associated with divergent patterns of brain activity provide support for distinguishing approach- and withdrawal-related anger styles.
doi:10.1016/j.ijpsycho.2010.01.008
PMCID: PMC2867457  PMID: 20109502
Anger; Emotion; Motivation; Cognitive Resources; Event-Related Potentials
4.  Specificity of emotion-related effects on attentional processing in schizotypy 
Schizophrenia research  2008;103(1-3):129-137.
Objectives
In the schizophrenia spectrum, cognitive functions such as perception, language, and attention have been shown to be adversely influenced by negative affect. The present study addressed three issues of specificity and one issue of mechanism regarding affect-related attentional disruption in schizotypy: (1) Is attentional disturbance from negative affective stimuli specific to positive (PS) but not negative schizotypy (NS)? (2) Do positive affective stimuli also foster attentional disturbance? (3) Are anxiety and depression differentially related to PS and NS? (4) Whatever the degree of specificity in these relationships, does anxiety mediate the relationship between schizotypy and attentional disturbance?
Methods
Nonpatient participants (N=162) provided responses on scales of schizotypy, anxiety, and depression and performed an emotional Stroop task, judging the ink color of positive, neutral, and negative words.
Results
PS but not NS was associated with poorer attentional performance. This attentional disturbance was specific to negative words. PS was associated with anxiety and depression, whereas NS was associated only with depression. Finally, anxiety and depression did not fully mediate the relationship between PS and attentional interference related to negative affective stimuli.
Conclusions
Findings of attentional disturbance in the presence of negative affective stimuli, particularly in positive schizotypy, have substantial theoretical implications. They provide a path by which the interplay of cognitive and affective phenomena could lead to the formation, maintenance, and exacerbation of positive symptoms, including delusions and hallucinations. Findings from this study also underscore the importance of examining the differential contribution of comorbid anxiety and depression to cognitive and affective function in the schizophrenia spectrum.
doi:10.1016/j.schres.2008.03.003
PMCID: PMC2881633  PMID: 18440784
Schizotypy; Positive schizotypy; Emotional Stroop; Anxiety; Depression
5.  Word and Letter String Processing Networks in Schizophrenia: Evidence for Anomalies and Compensation 
Brain and language  2008;107(2):158-166.
Imaging studies show that in normal language correlated activity between anterior and posterior brain regions increases as the linguistic and semantic content (i.e., from false fonts, letter strings, pseudo words, to words) of stimuli increase. In schizophrenia however, disrupted functional connectivity between frontal and posterior brain regions has been frequently reported and these disruptions may change the nature of language organization. We characterized basic linguistic operations in word and letter string processing in a region-of-interest network using structural equation modeling (SEM). Healthy volunteers and volunteers with schizophrenia performed an fMRI one-back matching task with real words and consonant letter strings. We hypothesized that left hemisphere network dysfunction in schizophrenia would be present during processes dealing with linguistic/semantic content. The modeling results suggest aberrant left hemisphere function in schizophrenia, even in tasks requiring minimal access to language. Alternative mechanisms included increases in right hemisphere involvement and increased top-down influence from frontal to posterior regions.
doi:10.1016/j.bandl.2008.04.001
PMCID: PMC2599869  PMID: 18829095
Schizophrenia and language; Lateralization; Lexical-semantic processing; Imaging; Effective Connectivity; Modeling

Results 1-5 (5)