Results 1 - 10
of
317
Resolving emotional conflict: A role for the rostral anterior cingulated cortex in modulating activity in the amygdala
- Neuron
, 2006
"... Effective mental functioning requires that cognition be protected from emotional conflict from interference by task-irrelevant emotionally salient stimuli. The neural mechanisms by which the brain detects and resolves emotional conflict are still largely unknown, however. Drawing on the classic Stro ..."
Abstract
-
Cited by 160 (9 self)
- Add to MetaCart
(Show Context)
Effective mental functioning requires that cognition be protected from emotional conflict from interference by task-irrelevant emotionally salient stimuli. The neural mechanisms by which the brain detects and resolves emotional conflict are still largely unknown, however. Drawing on the classic Stroop conflict task, we developed a protocol that allowed us to dissociate the generation and monitoring of emotional conflict from its resolution. Using functional magnetic resonance imaging (fMRI), we find that activity in the amygdala and dorsomedial and dorsolateral prefrontal cortices reflects the amount of emotional conflict. By contrast, the resolution of emotional conflict is associated with activation of the rostral anterior cingulate cortex. Activation of the rostral cingulate is predicted by the amount of previous-trial conflict-related neural activity and is accompanied by a simultaneous and correlated reduction of amygdalar activity. These data suggest that emotional conflict is resolved through top-down inhibition of amygdalar activity by the rostral cingulate cortex.
Cognitive control and parsing: Reexamining the role of Broca's area in sentence comprehension
- Cognitive, Affective, & Behavioral Neuroscience
, 2005
"... A century of investigation into the role of the human frontal lobes in complex cognition, including language processing, has revealed several interesting but apparently contradictory findings. In particular, the results of numerous studies suggest that left inferior frontal gyrus (LIFG), which inclu ..."
Abstract
-
Cited by 74 (7 self)
- Add to MetaCart
(Show Context)
A century of investigation into the role of the human frontal lobes in complex cognition, including language processing, has revealed several interesting but apparently contradictory findings. In particular, the results of numerous studies suggest that left inferior frontal gyrus (LIFG), which includes Broca’s area, plays a direct role in sentence-level syntactic processing. In contrast, other brain-imaging and neuropsychological data indicate that LIFG is crucial for cognitive control—specifically, for overriding highly regularized, automatic processes, even when a task involves syntactically undemanding material (e.g., single words, a list of letters). We provide a unifying account of these findings, which emphasizes the importance of general cognitive control mechanisms for the syntactic processing of sentences. On the basis of a review of the neurocognitive and sentence-processing literatures, we defend the following three hypotheses: (1) LIFG is part of a network of frontal lobe subsystems that are generally responsible for the detection and resolution of incompatible stimulus representations; (2) the role of LIFG in sentence comprehension is to implement reanalysis in the face of misinterpretation; and (3) individual differences in cognitive control abilities in nonsyntactic tasks predict correlated variation in sentence-processing abilities pertaining to the recovery from misinterpretation. In 1861, Paul Broca presented the idea that an anterior
Conflict monitoring and decision making: Reconciling two perspectives on anterior cingulate function
, 2007
"... ..."
Switching from automatic to controlled action by monkey medial frontal cortex,
- Nat Neurosci
, 2007
"... Human behavior is mostly composed of habitual actions that require little conscious control. Such actions may become invalid if the environment changes, at which point individuals need to switch behavior by overcoming habitual actions that are otherwise triggered automatically. It is unknown how th ..."
Abstract
-
Cited by 53 (3 self)
- Add to MetaCart
Human behavior is mostly composed of habitual actions that require little conscious control. Such actions may become invalid if the environment changes, at which point individuals need to switch behavior by overcoming habitual actions that are otherwise triggered automatically. It is unknown how the brain controls this type of behavioral switching. Here we show that the presupplementary motor area (pre-SMA) in the medial frontal cortex has a function in switching from automatic to volitionally controlled action in rhesus macaque monkeys. We found that a group of pre-SMA neurons was selectively activated when subjects successfully switched to a controlled alternative action. Electrical stimulation in the pre-SMA replaced automatic incorrect responses with slower correct responses. A further test suggested that the pre-SMA enabled switching by first suppressing an automatic unwanted action and then boosting a controlled desired action. Our data suggest that the pre-SMA resolves response conflict so that the desired action can be selected. Most of our everyday actions are automatic, or have automatic components, for good reasons: they are fast, demand less effort and thus occur efficiently (for example, driving home from work through a familiar route or generating a prepotent response to accelerate upon seeing a green light). The action will continue automatically unless a new or surprising situation arises in the external environment. In such novel encounters (for example, with road work or a child on a crosswalk), the automatic action must be replaced with a deliberately controlled action (for example, making a detour through unfamiliar routes or stepping on the brake instead of automatically accelerating) 1,2 . This ability to switch actions under volitional control is the hallmark of executive functions. It allows individuals to flexibly adjust behavior to a changing environment in favor of new solutions at the cost of performance speed 3 . Although the distinction between automatic and controlled processing for human cognition has long been an important theme in the psychology literature 1,2,4,5 , neural substrates for the dual processing mechanism are largely unknown. This study probes a neural account for the control process whereby automatic responses are overcome and an alternative desired response is issued. It is known that the medial frontal cortex (MFC) is important in diverse aspects of higher motor control RESULTS Two rhesus monkeys (Macaca mulatta), T and S, were trained to perform a saccade-overriding task
Reward expectation modulates feedbackrelated negativity and EEG spectra
- NeuroImage
, 2007
"... The ability to evaluate outcomes of previous decisions is critical to adaptive decision-making. The feedback-related negativity (FRN) is an eventrelated potential (ERP) modulation that distinguishes losses from wins, but little is known about the effects of outcome probability on these ERP responses ..."
Abstract
-
Cited by 48 (7 self)
- Add to MetaCart
(Show Context)
The ability to evaluate outcomes of previous decisions is critical to adaptive decision-making. The feedback-related negativity (FRN) is an eventrelated potential (ERP) modulation that distinguishes losses from wins, but little is known about the effects of outcome probability on these ERP responses. Further, little is known about the frequency characteristics of feedback processing, for example, event-related oscillations and phase synchronizations. Here, we report an EEG experiment designed to address these issues. Subjects engaged in a probabilistic reinforcement learning task in which we manipulated, across blocks, the probability of winning and losing to each of two possible decision options. Behaviorally, all subjects quickly adapted their decision-making to maximize rewards. ERP analyses revealed that the probability of reward modulated neural responses to wins, but not to losses. This was seen both acrossblocksaswellaswithinblocks,as learning progressed. Frequency decomposition via complex wavelets revealed that EEG responses to losses, compared to wins, were associated with enhanced power and phase coherence in the theta frequency band. As in the ERP analyses, power and phase coherence values following wins but not losses were modulated by reward probability. Some findings between ERP and frequency analyses diverged, suggesting that these analytic approaches provide complementary insights into neural processing. These findings suggest that the neural mechanisms of feedback processing may differ between wins and losses.
A context maintenance and retrieval model of organizational processes in free recall
, 2008
"... ..."
(Show Context)
Where and when the anterior cingulate cortex modulates attentional response: combined fMRI and ERP evidence
- J Cogn Neurosci
"... & Attentional control provides top–down inf luences that allow task-relevant stimuli and responses to be processed preferentially. The anterior cingulate cortex (ACC) plays an important role in attentional control, but the spatiotemporal dynamics underlying this process is poorly understood. We ..."
Abstract
-
Cited by 40 (3 self)
- Add to MetaCart
(Show Context)
& Attentional control provides top–down inf luences that allow task-relevant stimuli and responses to be processed preferentially. The anterior cingulate cortex (ACC) plays an important role in attentional control, but the spatiotemporal dynamics underlying this process is poorly understood. We examined the activation and connectivity of the ACC using functional magnetic resonance imaging (fMRI) along with fMRI-constrained dipole modeling of event-related potentials (ERPs) obtained from subjects who performed auditory and visual oddball attention tasks. Although attention-related responses in the ACC were similar in the two modalities, effective connectivity analyses showed modality-specific effects with increased ACC influences on the Heschl and superior temporal gyri during auditory task and on the striate cortex during visual task. Dipole modeling of ERPs based on source locations determined from fMRI activations showed that the ACC was the major generator of N2b–P3a attention-related components in both modalities, and that primary sensory regions generated a small mismatch signal about 50 msec prior to feedback from the ACC and a large signal 60 msec after feedback from the ACC. Taken together, these results provide converging neuroimaging and electrophysiological evidence for top–down attentional modulation of sensory processing by the ACC. Our findings suggest a model of attentional control based on dynamic bottom–up and top–down interactions between the ACC and primary sensory regions. &
On the relative independence of thinking biases and cognitive ability.
- Journal of Personality and Social Psychology,
, 2008
"... ..."
Source monitoring 15 years later: What have we learned from fMRI about the neural mechanisms of source memory
- Psychological Bulletin
, 2009
"... Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic ..."
Abstract
-
Cited by 36 (3 self)
- Add to MetaCart
(Show Context)
Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral information, the article considers studies assessing the qualitative characteristics of memories, the encoding and remembering of emotional information, and false memories, as well as evidence from populations that show disrupted source memory (older adults, individuals with depression, posttraumatic stress disorder, or schizophrenia). Although there is still substantial work to be done, fMRI is advancing understanding of source memory and highlighting unresolved issues. A continued 2-way interaction between cognitive theory, as illustrated by the source monitoring framework (M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993), and evidence from cognitive neuroimaging studies should clarify conceptualization of cognitive processes (e.g., feature binding, retrieval, monitoring), prior knowledge (e.g., semantics, schemas), and specific features (e.g., perceptual and emotional information) and of how they combine to create true and false memories.
A synaptic model for pain: long-term potentiation in the anterior cingulate cortex
- Mol Cells
"... Investigation of molecular and cellular mechanisms of synaptic plasticity is the major focus of many neuroscientists. There are two major reasons for searching new genes and molecules contributing to central plasticity: first, it provides basic neural mechanism for learning and memory, a key functio ..."
Abstract
-
Cited by 31 (9 self)
- Add to MetaCart
(Show Context)
Investigation of molecular and cellular mechanisms of synaptic plasticity is the major focus of many neuroscientists. There are two major reasons for searching new genes and molecules contributing to central plasticity: first, it provides basic neural mechanism for learning and memory, a key function of the brain; second, it provides new targets for treating brain-related disease. Long-term potentiation (LTP), mostly intensely studies in the hippocampus and amygdala, is proposed to be a cellular model for learning and memory. Although it remains difficult to understand the roles of LTP in hippocampus-related memory, a role of LTP in fear, a simplified form of memory, has been established. Here, I will review recent cellular studies of LTP in the anterior cingulate cortex (ACC) and then compare studies in vivo and in vitro LTP by genetic/ pharmacological approaches. I propose that ACC LTP may serve as a cellular model for studying central sensitization that related to chronic pain, as well as painrelated cognitive emotional disorders. Understanding signaling pathways related to ACC LTP may help us to identify novel drug target for various mental disorders.
