Optimal decision making and the anterior cingulate cortex

Learning the value of options in an uncertain environment is central to optimal decision making. The anterior cingulate cortex (ACC) has been implicated in using reinforcement information to control behavior. Here we demonstrate that the ACC's critical role in reinforcement-guided behavior is neither in detecting nor in correcting errors, but in guiding voluntary choices based on the history of actions and outcomes. ACC lesions did not impair the performance of monkeys (Macaca mulatta) immediately after errors, but made them unable to sustain rewarded responses in a reinforcement-guided choice task and to integrate risk and payoff in a dynamic foraging task. These data suggest that the ACC is essential for learning the value of actions.     

Damage to the right dorsal anterior cingulate cortex induces panic disorder

Brain imaging studies suggest that panic disorder (PD) is mediated by several brain regions, including the anterior cingulate cortex (ACC). In the present report we describe a patient who experienced a panic attack during awake surgery (case 1) and another patient who developed PD after surgery and radiotherapy (case 2). In case 1, the patient experienced repeated panic attacks when the tumor at the upper border of right dorsal ACC was removed during awake surgery. In case 2, the patient developed PD at six months after surgery and Cyberknife radiotherapy. MRI examination revealed that the dorsal ACC size was reduced at six months after surgery and that the dorsal ACC was absent at two years after surgery, possibly due to radiotherapy-induced damage by radiotherapy. Profile of mood states (POMS) testing characterized the presence of tension-anxiety as the common abnormal symptom in cases 1 and 2. In conclusion, these results suggest that damage to the right dorsal ACC can induce PD and that this structure likely plays a pathophysiologic role in PD.     

Functional connectivity of the anterior cingulate cortex within the human frontal lobe: a brain-mapping meta-analysis

A database of positron-emission-tomography studies published between January 1993 and November 1996 was created to address several questions regarding the function and connectivity of the human anterior cingulate cortex (ACC). Using this database, we have previously reported on the relationship between behavioural variables and the probability of blood-flow response in distinct subdivisions of the ACC. The goal of the current analysis was to discover which areas of the frontal cortex show increased blood-flow co-occurring consistently with increased blood-flow in the ACC. Analyses of the frequency distributions of peaks in the ACC and the remaining frontal cortex (FC) yielded several important findings. First, FC peaks in the precentral gyrus, superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, medial frontal gyrus and orbitomedial frontal gyri were more frequent in subtractions that also yielded a peak in the ACC than in those that did not yield an ACC peak. Second, regional differences in the frequency distribution of these FC peaks were observed when the ACC peaks were subdivided into the rostral versus caudal ACC and supracallosal versus subcallosal ACC. Peaks in the precentral gyrus and in the vicinity of the supplementary motor area were more prevalent in subtractions with co-occurring peaks in the caudal than with the rostral ACC. Peaks in the middle frontal gyrus were more frequent in subtractions with co-occurring peaks in the paralimbic part of the supracallosal ACC, relative to the subcallosal or limbic supracallosal ACC. These observations are consistent with known differences in the anatomic connectivity in these cortical regions, as defined in non-human primates. Further analyses of the influence of behavioural variables on the relationships between the ACC and other regions of the frontal cortex suggested that this type of meta-analysis may provide testable hypotheses about functional and effective connectivity within the human frontal lobe.     

Smaller volume of anterior cingulate cortex in abuse-related posttraumatic stress disorder

OBJECTIVE: The anterior cingulate cortex (ACC) plays an important role in emotion, and studies in animals have shown changes in ACC structure with early life stress. The purpose of this study was to measure volume of the ACC in PTSD. METHOD: Magnetic resonance imaging (MRI) was used to measure ACC volume in 8 subjects with abuse-related PTSD and 13 healthy subjects without PTSD. ACC volume included Brodmann's area [BA] 24 and 32. RESULTS: Right ACC volume in PTSD patients was significantly smaller than in non-PTSD subjects. CONCLUSION: These results are consistent with smaller ACC volume in PTSD.     

Uncertainty and patients’ preferred role in decision making

Objective

Experts recommend that clinicians tailor their interactions according to each patient's preferred decision style. Because participation is associated with improved clinical outcomes, factors which modify preferred role should be addressed before determining the level at which patients wish to participate. The objective of this study was to determine if certainty related to initiating treatment is related to preferred role in decision making.

Methods

We conducted face-to-face interviews with 142 patients eligible for the treatment of hepatitis C. Preferred role in decision making was measured using the Control Preferences Scale and certainty was measured with 11-point numeric rating scale.

Results

Subjects who were uncertain whether they wanted to start treatment were more likely to prefer Role 2: “to make the final selection of my treatment after seriously considering my doctor's opinion” over Role 1 “to make the final selection about which treatment I will receive” compared to those who were certain [Adjusted OR (95% CI) = 4.9 (1.7-14.5)]. Subjects who were uncertain were also more likely to prefer sharing responsibility for decision making over Role 1 compared to those who were certain [Adjusted OR (95% CI) = 3.7 (1.3-10.4)].

Conclusions

Certainty is associated with preferred decision styles. Physicians should ascertain their patients’ levels of uncertainty and adjust their input accordingly.

Practice implication

Physicians should ascertain their patients’ levels of uncertainty and adjust their input accordingly.     

Differential engagement of anterior cingulate cortex subdivisions for cognitive and emotional function

Functional differentiation of dorsal (dACC) and rostral (rACC) anterior cingulate cortex for cognitive and emotional function has received considerable indirect support. Using fMRI, parallel tasks, and within-subject analysis, the present study directly tested the proposed specialization of ACC subdivisions. A Task x Region interaction confirmed more dACC activation during color-word distractors and more rACC activation during emotion-word distractors. Activity in ACC subdivisions differentially predicted behavioral performance. Connectivity with prefrontal and limbic regions also supported distinct dACC and rACC roles. Findings provide direct evidence for differential engagement of ACC subdivisions in cognitive and emotional processing and for differential functional connectivity in the implementation of cognitive control and emotion regulation. Results point to an anatomical and functional continuum rather than segregated operations.     

Altered neuronal distribution of parvalbumin in anterior cingulate cortex of rabbits exposed in utero to cocaine

Previous studies of rabbits exposed in utero to cocaine have revealed an increase in the number of neurons which are GABA immunoreactive in the anterior cingulate cortex (ACC), suggesting a cocaine-elicited modification in the balance of excitatory and inhibitory interactions. Of the major calcium binding proteins expressed by different subgroups of GABAergic neurons, parvalbumin has been observed in conditions involving excess excitation, and may serve to protect neurons from excitotoxicity. In the present study, we used immunocy-tochemistry to compare the effects of prenatal cocaine exposure on the postnatal development of parvalbumin immunoreactivity in interneurons of the visual cortex (VC) and ACC. We determined the number and laminar distribution of parvalbumin immunoreactive neurons, and we also assessed the distribution of parvalbumin immunoreactivity within primary, secondary and tertiary dendrites of neurons in these two cortical areas. In both ACC and VC, parvalbumin immunoreactive neurons were first observed around postnatal day 10 (P10) and their number increased rapidly from P10 to P20. At all ages studied (P10 to P60) there was no difference between cocaine-exposed and saline control animals in the number or laminar distribution of parvalbumin immunoreactive neurons in either cortical area. However, the distribution of parvalbumin immunoreactivity within dendrites revealed a significant difference between cocaine-exposed and saline control animals in ACC but not in VC. In ACC, at all ages studied, there was an increase in the number of primary, secondary and tertiary dendrites which were parvalbumin immunoreactive in cocaine-exposed animals compared with saline controls. This difference was most striking in secondary dendrites, and in laminae V and VI. The effect was observed at doses of 4 and 3 mg/kg per injection but not at 2 mg/kg per injection. In contrast to ACC, in VC there was no difference in the number of immunoreactive dendrites in cocaine-exposed animals compared with saline controls. These observations are consistent with the hypothesis that the ACC of rabbits exposed in utero to cocaine is characterized by altered excitatory/inhibitory interactions. ACC receives a dense dopaminergic input, but VC receives minimal dopaminergic innervation. Mechanisms by which the action of cocaine on the developing dopaminergic system may modify the balance of excitation and inhibition in ACC are discussed.     

Identification of rat P3-like processes in the anterior cingulate cortex and hippocampus

The purpose of this study was to investigate whether the rat P3-like potential reflects “attention processes” rather than “arousal level”. After controlling for arousal levels, event-related potentials (ERPs) of the rat were recorded at the anterior cingulate cortex and hippocampal CA1 during active and passive oddball paradigms. The arousal level of the passive group was equivalent to that of the active group, while the amplitude of the P3-like potential during the active paradigm was greater than that during the passive paradigm for both sites. These results provide evidence that the rat P3-like component reflects “attention processes”, which is also the case for the human P3 component. Rats can provide a useful model for investigation of the neural mechanisms of the P3 in humans.     

Role of anterior cingulate cortex during semantic coding in verbal working memory

The relationship between working memory and long-term memory was one of the main problems in recent studies of working memory. As part of this problem, we examined the neural substrates that sustain the semantic coding process in verbal working memory using fMRI. In past experiments, we behaviorally explored whether central executive plays an important role in the process of semantic coding; thus, we especially focused on the function of anterior cingulate cortex (ACC) that is assumed to form the main neural basis of central executive. We accomplished our purpose by examining the concreteness effect reflecting semantic information. The ACC was strongly activated under the Concrete condition in contrast to the Abstract condition. Based on this result, we argue that the ACC is responsible for the semantic coding process in verbal working memory.     

Early music exposure modifies GluR2 protein expression in rat auditory cortex and anterior cingulate cortex

GluR2, a major subunit in AMPA receptor, plays an important role in brain functional activity. We studied the effect of music exposure during development on the expression level of GluR2 proteins in the auditory cortex (AC) and anterior cingulate cortex (ACC) of SD rats. Rats were divided into three groups, Music1 (exposed to Nostalgy) group, Music2 (exposed to Wishmaster) group, and control (no music exposure) group. For music exposure groups, rats were exposed to music from postnatal day (PND) 14, and the expression levels of GluR2 proteins were determined at PND 28, 42 and 56. For the control group, the expression levels of GluR2 proteins were determined at PND1, 3, 5, 7, 9, 11, 14, 21, 28, 42, and 56. Results showed an age-dependent expression of GluR2 proteins in control rats. In AC, exposure to Music2 dramatically increased the expression of GluR2, while exposure to Music1 had no effect. In ACC, we found remarkable discrepancies in time-dependent expression of GluR2 between music exposed rats and control rats. These results indicate that exposure to music can modify the expression level of GluR2 protein in AC and ACC.     

A conceptual model of the role of communication in surrogate decision making for hospitalized adults

Objective

To build a conceptual model of the role of communication in decision making, based on literature from medicine, communication studies and medical ethics.

Methods

We proposed a model and described each construct in detail. We review what is known about interpersonal and patient–physician communication, described literature about surrogate–clinician communication, and discussed implications for our developing model.

Results

The communication literature proposes two major elements of interpersonal communication: information processing and relationship building. These elements are composed of constructs such as information disclosure and emotional support that are likely to be relevant to decision making. We propose these elements of communication impact decision making, which in turn affects outcomes for both patients and surrogates. Decision making quality may also mediate the relationship between communication and outcomes.

Conclusion

Although many elements of the model have been studied in relation to patient–clinician communication, there is limited data about surrogate decision making. There is evidence of high surrogate distress associated with decision making that may be alleviated by communication-focused interventions. More research is needed to test the relationships proposed in the model.

Practice implications

Good communication with surrogates may improve both the quality of medical decisions and outcomes for the patient and surrogate.     

The anterior cingulate cortex is involved in retrieval of long-term/long-lasting but not short-term memory for step-through inhibitory avoidance in rats

It is known that the anterior cingulate cortex (ACC) is involved in the formation of contextual fear memory. It has been shown that the ACC is important for the retrieval of long-term contextual fear memory. In order to further examine the role of the ACC in fear memory, we investigated the effects of chemical lesion to or reversible inactivation of the ACC on the retrieval of long-term and short-term step-through inhibitory avoidance (IA) memory. Chemical lesion to the ACC by quinolinic acid severely impaired the retrieval of 15-day and 29-day memories for one-trial step-through IA. Pre-retrieval inactivation of the ACC by locally infusing muscimol, a selective GABA_A receptor agonist, produced a severe deficit in 7-day, 4-day and 1-day IA memories, with no effect on 2-h and 6-h memories. Thus, the ACC is required for the retrieval of long-term/long-lasting IA memory, but is dispensable for short-term one.     

Framing effect debiasing in medical decision making

OBJECTIVE: Numerous studies have demonstrated the robustness of the framing effect in a variety of contexts. The present study investigated the effects of a debiasing procedure designed to prevent the framing effect for young adults who made decisions based on hypothetical medical decision-making vignettes. METHODS: The debiasing technique involved participants listing advantages and disadvantages of each treatment prior to making a choice. One hundred and two undergraduate students read a set of three medical treatment vignettes that presented information in terms of different outcome probabilities under either debiasing or control conditions. RESULTS: The framing effect was demonstrated by the control group in two of the three vignettes. The debiasing group successfully avoided the framing effect for both of these vignettes. CONCLUSION: These results further support previous findings of the framing effect as well as an effective debiasing technique. This study improved upon previous framing debiasing studies by including a control group and personal medical scenarios, as well as demonstrating debiasing in a framing condition in which the framing effect was demonstrated without a debiasing procedure. PRACTICE IMPLICATIONS: The findings suggest a relatively simple manipulation may circumvent the use of decision-making heuristics in patients.     

Differential effects of prenatal cocaine exposure on selected subunit mRNAs of the GABA(A) receptor in rabbit anterior cingulate cortex

We have previously shown that in the dopamine-rich anterior cingulate cortex (ACC), significant changes in γ-aminobutyric acid (GABA) immunoreactivity occur in the offspring of rabbits given intravenous injections of cocaine (3 mg/kg) twice daily during pregnancy. In the present study, the effects of prenatal cocaine exposure on the developmental expression of specific GABA_A receptor subunit mRNAs were investigated. We compared the distribution of the 1, β2, and γ2 subunit mRNAs in cocaine- and saline-treated offspring aged postnatal days 20 and 60 (P20, P60). At P20, prenatal cocaine exposure resulted in a significant increase in 1 subunit mRNA in ACC lamina III and a significant reduction in the amounts of the β2 subunit mRNA in ACC lamina II. No differences between cocaine- and saline-treated controls were detected for γ2 subunit mRNA levels in ACC. Although the pattern of labeling was altered in cocaine-exposed animals, Nissl sections revealed no differences in lamination, indicating that the changes in GABA_A subunit mRNAs could not be attributed to abnormal cytoarchitectonics. In P60 brains, no significant differences were observed between cocaine- and saline-treated material, indicating that the observed differences were transient. Collectively, our data show that prenatal cocaine exposure elicits differential, lamina-specific changes in mRNA levels encoding selected subunits of the GABA_A receptor. Since these changes occur during a critical period when fine tuning of synaptic organization is achieved by processes of selective elimination or stabilization of synapses, we suggest that specific subunit mRNAs of the GABA_A receptor play a role in cortical development.     

Differential engagement of anterior cingulate and adjacent medial frontal cortex in adept meditators and non-meditators

This study investigated differences in brain activation during meditation between meditators and non-meditators. Fifteen Vipassana meditators (mean practice: 7.9 years, 2h daily) and fifteen non-meditators, matched for sex, age, education, and handedness, participated in a block-design fMRI study that included mindfulness of breathing and mental arithmetic conditions. For the meditation condition (contrasted to arithmetic), meditators showed stronger activations in the rostral anterior cingulate cortex and the dorsal medial prefrontal cortex bilaterally, compared to controls. Greater rostral anterior cingulate cortex activation in meditators may reflect stronger processing of distracting events. The increased activation in the medial prefrontal cortex may reflect that meditators are stronger engaged in emotional processing.     

Distraction produces an increase in pain-evoked anterior cingulate activity

This study examined the effects of distraction on pain-evoked activity in the anterior cingulate cortex (ACC). Twenty-eight healthy adults were given painful electrical stimulation of the sural nerve during an attend condition, where they rated the subjective magnitude of each electrical stimulus, and during a distraction condition, where they performed an arithmetic distraction task. The magnitude of the pain-evoked ACC activity was estimated from the dipole source localization analysis of the somatosensory evoked potential. Subjective pain ratings were smaller and pain-evoked ACC activity was larger during the distraction condition than during the attend condition. Recent regional cerebral blood flow studies have also reported a distraction-related increase in pain-evoked ACC activity. Our results confirm these reports, and verify that the distraction effect specifically involves pain-evoked ACC activity. The cognitive demands of the distraction task present the possibility that the pain-evoked ACC activity might be involved, at least in part, in response competition and/or orienting attention toward painful stimuli.     

The development of COMRADE--a patient-based outcome measure to evaluate the effectiveness of risk communication and treatment decision making in consultations

Some instruments have been developed to evaluate ‘decision effectiveness’ such as the ‘satisfaction with decision (SWD)’ and ‘decision conflict (DCS)’ scales and are validated for the US context. Patients identify further outcome domains that are not fully covered in these scales. We developed a patient-based outcome measure to evaluate risk communication and decision making effectiveness, addressing these further domains and validated for use in the UK. Formulation of items was based on literature review and key informant interviews. The instrument was piloted and developed (including psychometric assessment) in the context of a trial of decision making and risk communication interventions in general practice. Patients were recruited to the trial with known atrial fibrillation, prostatism, menorrhagia or menopausal symptoms. High response rates (96% in first phase) indicated acceptability to patients. A 20 item patient-based outcome measure, with two sub-scales for ‘risk communication’ and ‘confidence in decision’, was produced. It allows for paternalistic, shared or informed choice decision making models. Usage in further studies will facilitate systematic reviews. Consequently, lessons for wider application of these interventions in practice, and policy implications regarding greater patient involvement should then be clearer.     

Associations between anterior cingulate cortex glutamate and γ-aminobutyric acid concentrations and the harm avoidance temperament

Converging lines of evidence have suggested that the personality traits might have neurobiological underpinnings. The anterior cingulate cortex (ACC) has been implicated to play an important role in the human fear and anxiety. Functional and structural characteristics of ACC have been suggested to be associated with the harm avoidance (HA) temperament, one of the important temperament dimensions. Therefore, we aimed to investigate correlations between neurometabolite concentrations in ACC, specifically glutamate and γ-aminobutyric acid (GABA), which are major excitatory and inhibitory neurotransmitters, respectively, and HA scores. Neurometabolite concentrations were measured using high resolution single voxel proton magnetic resonance spectroscopy (¹H-MRS), and the HA temperament was evaluated using the Temperament and Character Inventory (TCI). Correlations between HA scores from 37 participants (21 men/16 women, age of 30.3 ± 7.0) and glutamate and GABA concentrations in the mid-ACC region were evaluated. HA scores correlated negatively with glutamate concentrations in ACC (partial correlation, R = −0.54, df = 33, P = 0.001) and positively with GABA concentrations in ACC (partial correlation, R = 0.48, df = 30, P = 0.005). These findings suggest that glutamate and GABA concentrations in ACC are closely related to levels of the HA temperament in healthy subjects.     

The role of the anterior cingulate in automatic and controlled processes: A developmental neuroanatomical study

This study examines the role of the anterior cingulate in the development of attention. Task performance relying predominantly on either automatic or controlled processes was correlated with magnetic resonance imaging based measures of the anterior cingulate in 26 normal children ages 5 to 16 years. Attentional measures were assessed with a visual discrimination paradigm. Parasagittal slices from a 3-D, T1-weighted volume data set were used to obtain area measurements of the anterior cingulate. Response latencies decreased with age for both tasks. There were significant correlations between attentional performance and right, but not left, anterior cingulate measures. Performance was faster and more accurate during trials requiring predominantly controlled processes for those children with larger right anterior cingulate measures. The results are consistent with adult neuroimaging findings of activation in the right anterior cingulate during attention tasks and with lesion studies implicating greater right hemisphere involvement in attentional processes. © 1997 John Wiley & Sons, Inc. Dev. Psychobiol 30: 61–69, 1997     

神经病理痛模型大鼠前扣带皮层不同水平磷酸化细胞外信号调节激酶表达差异比较

目的探讨痛相关情绪模型大鼠前扣带皮层(ACC)磷酸化细胞外信号调节激酶(p-ERK)的分布特点。方法将12只雄性SD大鼠随机分为对照组和模型组。模型组大鼠进行右侧腰5脊神经结扎制做模型。采用右后足跖机械痛阈检测观察行为变化,旷场实验和高架O迷宫实验检测痛相关情绪变化,免疫荧光技术检测同侧前扣带皮层前囟前3.2、2.7及2.2mm 3个水平p-ERK表达。结果大鼠经神经病理痛模型制做成功后机械痛阈显著下降,焦虑样行为产生。前扣带皮层前囟前3.2、2.7及2.2mm水平p-ERK阳性细胞表达量分别为11.89±2.57、32±4.67和17.56±2.04。对照组相应的p-ERK阳性细胞表达量分别为12.44±2.16、10±0.87和10.11±1.36。除前囟前3.2mm水平对照组与模型组相比没有显著性差异(P0.05)之外,其他两个水平p-ERK阳性细胞表达量模型组显著高于对照组(P0.01)。结论神经病理性疼痛能诱发大鼠焦虑情绪的产生及ACC脑区pERK的表达增高,这种变化可能主要与ACC脑区前囟前2.7及2.2mm水平p-ERK的变化相关,而与前囟前3.2mm水平无关。