Theresa M. Becker

A neural region of abstract working memory

Over 350 years ago, Descartes proposed that the neural basis of consciousness must be a brain region in which sensory inputs are combined. Using fMRI, we identified at least one such area for working memory, the limited information held in mind, described by William James as the trailing edge of consciousness. Specifically, a region in the left intraparietal sulcus was found to demonstrate load-dependent activity for either visual stimuli (colored squares) or a combination of visual and auditory stimuli (spoken letters). This result was replicated across two experiments with different participants and methods. The results suggest that this brain region, previously well known for working memory of visually presented materials, actually holds or refers to information from more than one modality.

Communication disturbances, working memory, and emotion in people with elevated disorganized schizotypy

This study examined whether people with elevated disorganized schizotypy would differ from control participants on characteristics associated with disorganization symptoms in schizophrenia and also whether disorganized schizotypy was associated with problems processing emotion. People with disorganized schizotypy (n=32) exhibited greater communication disturbances (CD) than control participants (n=34) for emotionally negative topics but not for positive topics. In addition, the disorganized group exhibited poorer performance on a working memory task but not on a psychometrically matched verbal intelligence task. In addition, poor working memory was associated with increased CD for negative topics and, after controlling for group differences in working memory, group differences in CD were not significant. Moreover, the disorganized group exhibited greater emotional ambivalence and ambivalence was associated with increased CD in the disorganized group. These results suggest that people with disorganized schizotypy exhibit some similar characteristics to people with schizophrenia who have disorganization symptoms and that disorganized schizotypy is also associated with poor emotion processing.

Prefrontal Dysfunction in First-Degree Relatives of Schizophrenia Patients during a Stroop Task

Schizophrenia patients perform poorly on cognitive control tasks and exhibit dysfunction in anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (DLPFC) during task performance. The unaffected relatives of patients with schizophrenia also exhibit poor cognitive control task performance. However, the relationship between these behavioral deficits in relatives and the integrity of ACC and DLPFC functioning is unclear. In the present study, we used the Stroop color-naming task and event-related fMRI to examine cognitive control task performance and associated neural activity in 17 unaffected relatives of schizophrenia patients and 17 demographically matched healthy controls. On the Stroop task, unaffected relatives exhibited intact post-conflict-related performance adjustments. fMRI data revealed that unaffected relatives exhibited reduced activity in DLPFC but they exhibited intact activity in ACC. These results suggest that DLPFC dysfunction may be related to the genetic risk for schizophrenia as both patients and their unaffected relatives show reduced activity in this region. In contrast, the current results suggest that ACC dysfunction in people with schizophrenia may reflect processes specific to the illness itself.

Differential associations between schizotypy facets and emotion traits.

Although emotional deficits in schizotypy have been reported, the exact nature of these deficits is not well understood. The goal of the current research was to further differentiate possible emotion deficits in schizotypy. In the current study, individuals with elevated social anhedonia (SocAnh; n=54) and elevated perceptual aberration/magical ideation (PerMag; n=27) were compared to control participants (n=304) on measures of attention to either positive or negative affect, level of anticipatory versus consummatory pleasure, and on the influence of negative mood on judgment of future risk. SocAnh was associated with decreased attention to positive emotions. At the same time, SocAnh was associated with both decreased anticipatory and decreased consummatory pleasure. In addition, in contrast to the other groups, there was no association in the SocAnh group between current negative mood and performance on a judgment task. In contrast to SocAnh, PerMag was associated with increased attention to negative emotions. Overall, these results suggest that SocAnh is associated with decreased attention to and experience of positive emotions and that PerMag is associated with increased attention to negative emotions.

Correspondence between psychometric and clinical high risk for psychosis in an undergraduate population.

Despite the common use of either psychometric or clinical methods for identifying individuals at risk for psychosis, previous research has not examined the correspondence and extent of convergence of these 2 approaches. Undergraduates (n = 160), selected from a larger pool, completed 3 self-report schizotypy scales: the Magical Ideation Scale, the Perceptual Aberration Scale, and the Revised Social Anhedonia Scale. They were administered the Structured Interview for Prodromal Syndromes. First, high correlations were observed for self-report and interview-rated psychotic-like experiences (rs between .48 and .61, p < .001). Second, 77% of individuals who identified as having a risk for psychosis with the self-report measures reported at least 1 clinically meaningful psychotic-like experience on the Structured Interview for Prodromal Syndromes. Third, receiver operating characteristic curve analyses showed that the self-report scales can be used to identify which participants report clinically meaningful positive symptoms. These results suggest that mostly White undergraduate participants who identify as at risk with the psychometric schizotypy approach report clinically meaningful psychotic-like experiences in an interview format and that the schizotypy scales are moderately to strongly correlated with interview-rated psychotic-like experiences. The results of the current research provide a baseline for comparing research between these 2 approaches.

The Role of Aberrant Salience and Self-Concept Clarity in Psychotic-Like Experiences

Most theories of psychotic-like experiences posit the involvement of cognitive mechanisms. The current research examined the relations between psychotic-like experiences and two cognitive mechanisms, high aberrant salience and low self-concept clarity. In particular, we examined whether aberrant salience, or the incorrect assignment of importance to neutral stimuli, and low self-concept clarity interacted to predict psychotic-like experiences. The current research included three large samples (n = 667, 724, 744) of participants and oversampled for increased schizotypal personality traits. In all three studies, an interaction between aberrant salience and self-concept clarity was found such that participants with high aberrant salience and low self-concept clarity had the highest levels of psychotic-like experiences. In addition, aberrant salience and self-concept clarity interacted to predict a supplemental measure of delusions in Study 2. In Study 3, in contrast to low self-concept clarity, neuroticism did not interact with aberrant salience to predict psychotic-like experiences, suggesting that the relation between low self-concept clarity and psychosis may not be a result of neuroticism. Additionally, aberrant salience and self-concept clarity did not interact to predict two other SPD criteria, social anhedonia or trait paranoia, which suggests the interaction is specific to psychotic-like experiences. Overall, our results are consistent with several cognitive models of psychosis suggesting that aberrant salience and self-concept clarity might be important mechanisms in the occurrence of psychotic-like symptoms.

Decreased Self-Concept Clarity in People with Schizophrenia.

Abstract Disturbances in the perception of self are thought to be central to the development of psychosis. Self-concept clarity (SCC) is the extent to which one’s beliefs about oneself are internally consistent, stable, and clear. Participants with schizophrenia (N = 54) and healthy controls (N = 32) completed the Me Not-Me Decision Task (MNMDT), in which they decided whether 60 adjectives (30 pairs of antonyms) did or did not describe themselves. SCC is conceptualized as the number of consistent responses. Participants also completed the Self-Concept Clarity Scale (SCCS). Compared to healthy controls, participants with schizophrenia scored lower on the MNMDT and SCCS, and scores were negatively correlated with positive and negative symptoms. In a simultaneous regression, SCCS scores were uniquely associated with positive symptoms, whereas MNMDT scores were uniquely associated with negative symptoms. This suggests that people with schizophrenia have decreased self-concept clarity that is related to positive and negative symptoms.

Reinforcement learning deficits in people with schizophrenia persist after extended trials

Previous research suggests that people with schizophrenia have difficulty learning from positive feedback and when learning needs to occur rapidly. However, they seem to have relatively intact learning from negative feedback when learning occurs gradually. Participants are typically given a limited amount of acquisition trials to learn the reward contingencies and then tested about what they learned. The current study examined whether participants with schizophrenia continue to display these deficits when given extra time to learn the contingences. Participants with schizophrenia and matched healthy controls completed the Probabilistic Selection Task, which measures positive and negative feedback learning separately. Participants with schizophrenia showed a deficit in learning from both positive feedback and negative feedback. These reward learning deficits persisted even if people with schizophrenia are given extra time (up to 10 blocks of 60 trials) to learn the reward contingencies. These results suggest that the observed deficits cannot be attributed solely to slower learning and instead reflect a specific deficit in reinforcement learning.

A network-level analysis of cognitive flexibility reveals a differential influence of the anterior cingulate cortex in bilinguals versus monolinguals.

Mounting evidence suggests that bilingual development may change the brain in a way that gives rise to differences in non-linguistic cognitive functioning; however, only a limited number of studies have investigated the mechanism by which bilingualism shapes the brain. The current study used a network-level analysis to investigate differences in the mechanisms by which bilinguals and monolinguals flexibly adapt their neural networks in the face of novel task demands. Three competing hypotheses concerning differences in network-level adaptation were examined using Dynamic Causal Modeling of data from 15 bilinguals and 14 monolinguals who performed a Rapid Instructed Task Learning paradigm. The results demonstrated that the best-fitting model for the data from both groups specified that novel task execution is accomplished through a modulation of the influence of the anterior cingulate cortex (ACC) on the dorsolateral prefrontal cortex (DLPFC) and on the striatum. Further examination of the best-fitting model revealed that ACC activity increased DLPFC and striatal activity in bilinguals but decreased activity in these regions in monolinguals. Interestingly, an increased positive connection between the ACC and striatum was associated with decreased accuracy across groups. Taken together, the results suggest that regardless of language experience, the ACC plays a critical role in cognitive flexibility, but the exact influence of the ACC on other primary control regions seems to be dependent on language experience. When paired with the behavioral results, these results suggest that bilinguals and monolinguals may employ different neurocognitive mechanisms for conflict monitoring to flexibly adapt to novel situations.

Examination of affective and cognitive interference in schizophrenia and relation to symptoms.

The nature of emotion deficits in schizophrenia and anhedonia is still unclear, and understanding the nature of these deficits could help improve treatment of chronic symptoms and functional disability. An important mechanism in emotional functioning is attention to affective information. People with schizophrenia (n = 48) and a nonpsychiatric comparison group (n = 28) completed an affective interference task, a task used to assess attention to affective information. Given that the affective interference task also involves prepotent response inhibition, participants also completed a very similar, but nonaffective, cognitive interference task that involves prepotent inhibition but does not require attention to affective information. Results revealed that people with schizophrenia exhibited decreased affective interference on trials with a shorter length of time between the onset of the cue and onset of the target but increased cognitive interference at all time lengths between the cue and target onsets used in the study. In addition, decreased affective interference was associated with increased anhedonia and increased reports of wanting to ignore positive emotions. In contrast, increased cognitive interference was associated with increased communication disturbances and alogia. Overall, these results suggest that there may be a decrease in attention to affective information in schizophrenia and that affective interference is related to anhedonia. At the same time, these results provide further evidence of cognitive control prepotent inhibition deficits in schizophrenia, which are related to communication disturbances and alogia.