Biomedical subjects

Marie T Banich

Publications and source records attributed to Marie T Banich.

14 recordsLinked to original sources

PubMed2007

Interhemispheric integration in psychopathic offenders.

The goal of the present study was to determine whether a reduced capacity for interhemispheric integration can explain the attention deficits seen in psychopathic individuals under conditions that place substantial demands on left-hemisphere-specific resources. The present study examined the performance of 54 incarcerated psychopathic and nonpsychopathic male offenders on a same-different global-local paradigm that permits manipulation of both the magnitude of processing demands and the demand for interhemispheric coordination. Prior studies with similar paradigms have demonstrated that the cerebral hemispheres can function more efficiently as relatively independent processors on simple tasks, whereas communication between the hemispheres improves performance when processing demands are heavy. Analyses indicated that psychopathic offenders are not deficient in interhemispheric integration but provided additional evidence consistent with the left hemisphere activation hypothesis of psychopathy.

Adolescent↗

PubMed2006

Suppression of emotional and nonemotional content in memory: effects of repetition on cognitive control.

Two experiments utilized a think/no-think paradigm to examine whether cognitive control of memories differs depending on whether they contain information with negative or neutral emotional content. During a training phase, participants learned face-word pairs (Experiment 1) or face-picture pairs (Experiment 2). In a subsequent experimental phase, participants were shown faces and told to think of the items paired with some of the faces and to try not to think of the items paired with other faces. Finally, in a test phase, participants were again shown each face and asked to recall the item with which it had been paired previously. Results for both verbal (Experiment 1) and nonverbal (Experiment 2) items indicated that the facilitatory and inhibitory influences of cognitive control were larger for negative than neutral items.

Adult↗

PubMed2006

Neural mechanisms of cognitive control: an integrative model of stroop task performance and FMRI data.

We address the connection between conceptual knowledge and cognitive control using a neural network model. This model extends a widely held theory of cognitive control [Cohen, J. D., Dunbar, K., & McClelland, J. L. On the control of automatic processes: A parallel distributed processing model of the Stroop effect. Psychological Review, 97, 332-361, 1990] so that it can explain new empirical findings. Leveraging other computational modeling work, we hypothesize that representations used for task control are recruited from preexisting representations for categories, such as the concept of color relevant to the Stroop task we model here. This hypothesis allows the model to account for otherwise puzzling fMRI results, such as increased activity in brain regions processing to-be-ignored information. In addition, biologically motivated changes in the model's pattern of connectivity show how global competition can arise when inhibition is strictly local, as it seems to be in the cortex. We also discuss the potential for this theory to unify models of task control with other forms of attention.

Algorithms↗

PubMed2005

Functional dissociation of attentional selection within PFC: response and non-response related aspects of attentional selection as ascertained by fMRI.

In this experiment using a color-word Stroop task, we explored whether different regions of prefrontal cortex bias selection of response-related processes as compared with non-response-related processes. To manipulate demands at the level of response selection, we varied the degree of overlap between stimulus-response mappings in a manual Stroop task. To vary demands at a non-response level, we compared activation for incongruent trials (e.g. the word 'purple' in blue ink) that contain two color representations, one in the word and one in the ink color, to neutral trials (e.g. the word 'drawer' in blue ink), which contain only one color representation, that in the ink color. These manipulations had differential effects within prefrontal cortex. Both a region of right inferior frontal cortex and caudal regions of the cingulate were sensitive to the selection demands at the response-level and insensitive to demands at the non-response level. In contrast, a more anterior region of left dorsolateral prefrontal cortex was sensitive to the number of color representations (i.e. incongruent versus neutral trials), but not to the overlap in stimulus-response mappings. Therefore, this study indicates a functional differentiation for implementing attentional control within prefrontal cortex.

Adult↗

PubMed2005

Hemispheric biases and the control of visuospatial attention: an ERP study.

BACKGROUND: We examined whether individual differences in hemispheric utilization can interact with the intrinsic attentional biases of the cerebral hemispheres. Evidence suggests that the hemispheres have competing biases to direct attention contralaterally, with the left hemisphere (LH) having a stronger bias than the right hemisphere. There is also evidence that individuals have characteristic biases to utilize one hemisphere more than the other for processing information, which can induce a bias to direct attention to contralateral space. We predicted that LH-biased individuals would display a strong rightward attentional bias, which would create difficulty in selectively attending to target stimuli in the left visual field (LVF) as compared to right in the performance of a bilateral flanker task. RESULTS: Consistent with our hypothesis, flanker interference effects were found on the N2c event-related brain potential and error rate for LH-biased individuals in the Attend-LVF condition. The error rate effect was correlated with the degree of hemispheric utilization bias for the LH-Bias group. CONCLUSION: We conclude that hemispheric utilization bias can enhance a hemisphere's contralateral attentional bias, at least for individuals with a LH utilization bias. Hemispheric utilization bias may play an important and largely unrecognized role in visuospatial attention.

Adolescent↗

PubMed2005

Anterior cingulate cortex: an fMRI analysis of conflict specificity and functional differentiation.

In this event-related functional magnetic resonance imaging (fMRI) study, we provide evidence that the role of the anterior cingulate cortex (ACC) in cognitive control may not be unitary, as the responses of different ACC subregions vary depending upon the nature of task-irrelevant information. More specifically, using the color-word Stroop task (congruent, incongruent, and neutral trial types), we examined the degree to which increases in neural activity within ACC are specific to conditions of conflict, as posited by the conflict monitoring theory (Botvinick et al. [1999]: Rev Neurosci 10:49-57; Carter et al. [1998]: Science 280:747-749). Although incongruent and congruent trials both involve two competing sources of color information (color word and ink color), only incongruent trials involve a direct conflict between task-relevant and task-irrelevant information. Although the anterior division of the ACC rostral zone exhibited conflict specific increases in neural activity (i.e., incongruent > congruent = neutral), the posterior division exhibited a more generalized pattern, increasing whenever the task-irrelevant information was color related, regardless of whether it was conflicting (i.e., incongruent and congruent > neutral). Our data thus suggest a possible functional differentiation within the ACC. As such, it is unlikely that the role of the ACC in cognitive control will be able to be accommodated by a single unifying theory.

Adolescent↗

PubMed2005

Neural mechanisms of affective interference in schizotypy.

Negatively valenced stimuli foster cognitive impairment in schizotypy and schizophrenia. To identify relevant brain mechanisms, the authors had 16 positive-schizotypy and 16 control participants perform an emotional Stroop task, judging the ink color of negative and neutral words during functional magnetic resonance imaging (fMRI) of regional brain activity. Schizotypy individuals showed increased right and decreased left activity in dorsolateral prefrontal cortex, indicating a deficit in maintenance of attentional set in the presence of negative emotional distractors. They also showed abnormal activity in ventral limbic areas, including decreased activity in nucleus accumbens and increased activity in hippocampus and amygdala, a circuit involved in the integration of cognitive and affective processes. These results indicate that aspects of emotion-cognition processes and the brain mechanisms that implement them are similar in schizotypy and schizophrenia.

Adult↗

PubMed2005

Emotion-modulated performance and activity in left dorsolateral prefrontal cortex.

Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unpleasant stimuli and activity in prefrontal cortex. Twenty volunteers identified the colors in which pleasant, neutral, and unpleasant words were printed. Pleasant words prompted more activity bilaterally in dorsolateral prefrontal cortex (DLPFC) than did unpleasant words. In addition, pleasant words prompted more activity in left than in right DLPFC. Response speed to pleasant words was correlated with DLPFC activity. These data directly link positive affect, enhanced performance, and prefrontal activity, providing some of the first fMRI evidence supporting models of emotional valence and frontal brain asymmetry based on electroencephalography (EEG).

Adult↗

PubMed2004

Behavioral conflict, anterior cingulate cortex, and experiment duration: implications of diverging data.

We investigated the relationship between behavioral measures of conflict and the degree of activity in the anterior cingulate cortex (ACC). We reanalyzed an existing data set that employed the Stroop task using functional magnetic resonance imaging [Milham et al., Brain Cogn 2002;49:277-296]. Although we found no changes in the behavioral measures of conflict from the first to the second half of task performance, we found a reliable reduction in the activity of the anterior cingulate cortex. This result suggests the lack of a strong relationship between behavioral measurements of conflict and anterior cingulate activity. A concomitant increase in dorsolateral prefrontal cortex activity was also found, which may reflect a tradeoff in the neural substrates involved in supporting conflict resolution, detection, or monitoring processes. A second analysis of the data revealed that the duration of an experiment can dramatically affect interpretations of the results, including the roles in which particular regions are thought to play in cognition. These results are discussed in relation to current conceptions of ACC's role in attentional control. In addition, we discuss the implication of our results with current conceptions of conflict and of its instantiation in the brain. Hum. Brain Mapping 21:96-105, 2004.

Adult↗

PubMed2004

Common and distinct neural substrates of attentional control in an integrated Simon and spatial Stroop task as assessed by event-related fMRI.

The purpose of this experiment was to directly examine the neural mechanisms of attentional control involved in the Simon task as compared to a spatial Stroop task using event-related fMRI. The Simon effect typically refers to the interference people experience when there is a stimulus-response conflict. The Stroop effect refers to the interference people experience when two attributes of the same stimulus conflict with each other. Although previous imaging studies have compared the brain activation for each of these tasks performed separately, none had done so in an integrated task that incorporates both types of interference, as was done in the current experiment. Both tasks activated brain regions that serve as a source of attentional control (dorsolateral prefrontal cortex) and posterior regions that are sites of attentional control (the visual processing stream-middle occipital and inferior temporal cortices). In addition, there were also specific brain regions activated to a significantly greater degree by one task and/or only by a single task. The brain regions significantly more activated by the Simon task were those sensitive to detection of response conflict, response selection, and planning (anterior cingulate cortex, supplementary motor areas, and precuneus), and visuospatial-motor association areas. In contrast, the regions significantly more activated by the Stroop task were those involved in biasing the processing toward the task-relevant attribute (inferior parietal cortex). These findings suggest that the interference effects of these two tasks are caused by different types of conflict (stimulus-response conflict for the Simon effect and stimulus-stimulus conflict for the Stroop effect) but both invoke similar sources of top-down modulation.

Adult↗

PubMed2003

Competition for priority in processing increases prefrontal cortex's involvement in top-down control: an event-related fMRI study of the stroop task.

Prior work indicates that various aspects of task-irrelevant information (e.g. its salience, task-relatedness, emotionality) can increase the involvement of prefrontal cortex (PFC) in top-down attentional control. In light of these findings, we hypothesize that PFC's involvement increases when task-irrelevant information competes for priority in processing. In an event-related fMRI study using an oddball variant of the Stroop task, we examine the generality of this hypothesis using three manipulations designed to increase the ability of task-irrelevant information to compete for priority in processing. First, we investigated how the frequency of occurrence of task-irrelevant information affects PFC activity. Second, we examined whether conflicting color information (i.e. incongruent trials) increases activity in regions of PFC that are similar to or distinct from those sensitive to infrequently occurring task-irrelevant information. Finally, we examined the impact of the number of levels at which conflict could occur (e.g. non-response only, non-response and response). Activity in posterior-dorsolateral and posterior-inferior PFC increased for infrequently occurring task-irrelevant information, being largest when the task-irrelevant information contained conflicting color-information. In contrast, increases in mid-dorsolateral prefrontal cortex's activity were only noted when conflicting color information was present, being largest when conflict occurred at multiple levels. The anterior cingulate was primarily sensitive to the occurrence of conflict at the response level with only a small sub-region exhibiting sensitivity to non-response conflict as well. From these findings we suggest that posterior DLPFC and PIPFC are involved in biasing processing in posterior processing systems, mid-DLPFC is involved in biasing the processing of the contents of working memory, and ACC is primarily involved in response-related processes.

Attention↗

PubMed2003

Paying attention to emotion: an fMRI investigation of cognitive and emotional stroop tasks.

In this research, we investigated the degree to which brain systems involved in ignoring emotionally salient information differ from those involved in ignoring nonemotional information. The design allowed examination of regional brain activity, using fMRI during color-word and emotional Stroop tasks. Twelve participants indicated the color of words while ignoring word meaning in conditions in which neutral words were contrasted to emotionally negative, emotionally positive, and incongruent color words. Dorsolateral frontal lobe activity was increased by both negative and incongruent color words, indicating a common system for maintaining an attentional set in the presence of salient distractors. In posterior regions of the brain, activity depended on the nature of the information to be ignored. Ignoring color-incongruent words increased left parietal activity and decreased parahippocampal gyrus activity, whereas ignoring negative emotional words increased bilateral occipito-temporal activity and decreased amygdala activity. The results indicate that emotion and attention are intimately related via a network of regions that monitor for salient information, maintain attention on the task, suppress irrelevant information, and select appropriate responses.

Adult↗

PubMed2002

Attentional control in the aging brain: insights from an fMRI study of the stroop task.

Several recent studies of aging and cognition have attributed decreases in the efficiency of working memory processes to possible declines in attentional control, the mechanism(s) by which the brain attempts to limit its processing to that of task-relevant information. Here we used fMRI measures of neural activity during performance of the color-word Stroop task to compare the neural substrates of attentional control in younger (ages: 21-27 years old) and older participants (ages: 60-75 years old) during conditions of both increased competition (incongruent and congruent neutral) and increased conflict (incongruent and congruent neutral). We found evidence of age-related decreases in the responsiveness of structures thought to support attentional control (e.g., dorsolateral prefrontal and parietal cortices), suggesting possible impairments in the implementation of attentional control in older participants. Consistent with this notion, older participants exhibited more extensive activation of ventral visual processing regions (i.e., temporal cortex) and anterior inferior prefrontal cortices, reflecting a decreased ability to inhibit the processing of task-irrelevant information. Also, the anterior cingulate cortex, a region involved in evaluatory processes at the level of response (e.g., detecting potential for error), showed age-related increases in its sensitivity to the presence of competing color information. These findings are discussed in terms of newly emerging models of attentional control in the human brain.

Aged↗

PubMed2002

A generalized role of interhemispheric interaction under attentionally demanding conditions: evidence from the auditory and tactile modality.

The present study investigated whether dividing critical information across the hemispheres in the auditory and tactile modalities aids performance more for computationally complex rather than computationally simpler task-a pattern previously observed in the visual modality [Cortex 26 (1990) 77; Neuropsychology 12 (1998) 380; Neuropsychologia 30 (1992) 923]. We conducted two experiments, one in the auditory and one in the tactile modality, that were analogous to those previously performed in the visual modality. In agreement with previous findings, for both modalities we observed that the performance advantage exhibited for within-hemisphere processing in the computationally simpler condition (that required fewer steps to reach a decision) was diminished in the computationally more complex condition. In the auditory experiment we also manipulated computational complexity by varying the amount of time available for processing information. The within-hemisphere advantage in performance was also significantly reduced when complexity was increased through temporal manipulations. These findings suggest that the brain may use interhemispheric interaction as a general strategy to increase computational resources, independent of sensory modality and the manner in which computational demands are increased.

Adult↗