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1.
Cogn Emot ; 37(7): 1213-1229, 2023.
Article in English | MEDLINE | ID: mdl-37706481

ABSTRACT

Previous research has found that people choose to reappraise low intensity images more often than high intensity images. However, this research does not account for image ambivalence, which is presence of both positive and negative cues in a stimulus. The purpose of this research was to determine differences in ambivalence in high intensity and low intensity images used in previous research (experiments 1-2), and if ambivalence played a role in emotion regulation choice in addition to intensity (experiments 3-4). Experiments 1 and 2 found that the low intensity images were more ambivalent than the high intensity images. Experiment 2 further found a positive relationship between ambivalence of an image and reappraisal affordances. Experiments 3 and 4 found that people chose to reappraise ambivalent images more often than non-ambivalent images, and they also chose to reappraise low intensity images more often than high intensity images. These experiments support the idea that ambivalence is a factor in emotion regulation choice. Future research should consider the impact ambivalent stimuli have on emotion regulation, including the potential for leveraging ambivalent stimuli to improve one's emotion regulation ability.


Subject(s)
Emotional Regulation , Humans , Emotions/physiology , Affect , Cognition/physiology , Cues
2.
Soc Cogn Affect Neurosci ; 18(1)2023 10 24.
Article in English | MEDLINE | ID: mdl-37756616

ABSTRACT

The neurocognitive processes underlying Pavlovian conditioning in humans are still largely debated. The conventional view is that conditioned responses (CRs) emerge automatically as a function of the contingencies between a conditioned stimulus (CS) and an unconditioned stimulus (US). As such, the associative strength model asserts that the frequency or amplitude of CRs reflects the strength of the CS-US associations. Alternatively, the expectation model asserts that the presentation of the CS triggers conscious expectancy of the US, which is responsible for the production of CRs. The present study tested the hypothesis that there are dissociable brain networks related to the expectancy and associative strength theories using a single-cue fear conditioning paradigm with a pseudo-random intermittent reinforcement schedule during functional magnetic resonance imaging. Participants' (n = 21) trial-by-trial expectations of receiving shock displayed a significant linear effect consistent with the expectation model. We also found a positive linear relationship between the expectancy model and activity in frontoparietal brain areas including the dorsolateral prefrontal cortex (PFC) and dorsomedial PFC. While an exploratory analysis found a linear relationship consistent with the associated strength model in the insula and early visual cortex, our primary results are consistent with the view that conscious expectancy contributes to CRs.


Subject(s)
Cues , Fear , Humans , Fear/physiology , Brain/physiology , Conditioning, Classical/physiology , Consciousness/physiology , Magnetic Resonance Imaging
3.
Soc Cogn Affect Neurosci ; 18(1)2023 02 06.
Article in English | MEDLINE | ID: mdl-36629508

ABSTRACT

Mental imagery is involved in both the expression and treatment of fear-related disorders such as anxiety and post-traumatic stress disorder. However, the neural correlates associated with the acquisition and generalization of differential fear conditioning to imagined conditioned stimuli are relatively unknown. In this study, healthy human participants (n = 27) acquired differential fear conditioning to imagined conditioned stimuli paired with a physical unconditioned stimulus (i.e. mild shock), as measured via self-reported fear, the skin conductance response and significant right anterior insula (aIn) activation. Multivoxel pattern analysis cross-classification also demonstrated that the pattern of activity in the right aIn during imagery acquisition was quantifiably similar to the pattern produced by standard visual acquisition. Additionally, mental imagery was associated with significant differential fear generalization. Fear conditioning acquired to imagined stimuli generalized to viewing those same stimuli as measured with self-reported fear and right aIn activity, and likewise fear conditioning to visual stimuli was associated with significant generalized differential self-reported fear and right aIn activity when imagining those stimuli. Together, the study provides a novel understanding of the neural mechanisms associated with the acquisition of differential fear conditioning to imagined stimuli and that of the relationship between imagery and emotion more generally.


Subject(s)
Emotions , Fear , Humans , Fear/physiology , Conditioning, Classical/physiology , Anxiety , Anxiety Disorders , Galvanic Skin Response
4.
Psychol Sci ; 33(9): 1423-1439, 2022 09.
Article in English | MEDLINE | ID: mdl-35895306

ABSTRACT

Many symptoms of anxiety and posttraumatic stress disorder are elicited by fearful mental imagery. Yet little is known about how visual imagery of conditioned stimuli (CSs) affects the acquisition of differential fear conditioning. Across three experiments with younger human adults (Experiment 1: n = 33, Experiment 2: n = 27, Experiment 3: n = 26), we observed that participants acquired differential fear conditioning to both viewed and imagined percepts serving as the CSs, as measured via self-reported fear and skin conductance responses. Additionally, this differential conditioning generalized across CS-percept modalities such that differential conditioning acquired in response to visual percepts generalized to the corresponding imagined percepts and vice versa. This is novel evidence that perceived and imagined stimuli engage learning processes in very similar ways and is consistent with the theory that mental imagery is depictive and recruits neural resources shared with visual perception. Our findings also provide new insight into the mechanisms of anxiety and related disorders.


Subject(s)
Conditioning, Classical , Fear , Adult , Anxiety , Conditioning, Classical/physiology , Extinction, Psychological/physiology , Fear/physiology , Galvanic Skin Response , Humans , Learning , Visual Perception
5.
Sci Rep ; 12(1): 997, 2022 01 19.
Article in English | MEDLINE | ID: mdl-35046506

ABSTRACT

Mental imagery is an important tool in the cognitive control of emotion. The present study tests the prediction that visual imagery can generate and regulate differential fear conditioning via the activation and prioritization of stimulus representations in early visual cortices. We combined differential fear conditioning with manipulations of viewing and imagining basic visual stimuli in humans. We discovered that mental imagery of a fear-conditioned stimulus compared to imagery of a safe conditioned stimulus generated a significantly greater conditioned response as measured by self-reported fear, the skin conductance response, and right anterior insula activity (experiment 1). Moreover, mental imagery effectively down- and up-regulated the fear conditioned responses (experiment 2). Multivariate classification using the functional magnetic resonance imaging data from retinotopically defined early visual regions revealed significant decoding of the imagined stimuli in V2 and V3 (experiment 1) but significantly reduced decoding in these regions during imagery-based regulation (experiment 2). Together, the present findings indicate that mental imagery can generate and regulate a differential fear conditioned response via mechanisms of the depictive theory of imagery and the biased-competition theory of attention. These findings also highlight the potential importance of mental imagery in the manifestation and treatment of psychological illnesses.


Subject(s)
Conditioning, Classical , Fear/psychology , Imagination , Adult , Electric Stimulation , Female , Galvanic Skin Response , Humans , Magnetic Resonance Imaging/methods , Male
6.
Psychophysiology ; 58(11): e13906, 2021 11.
Article in English | MEDLINE | ID: mdl-34287954

ABSTRACT

Imagery-based extinction procedures have long been used in the treatments of fear-related conditions. The assumption is that imagery can substitute for the perceptual stimuli in the extinction process. Yet, experimental validations of this assumption have been limited in number and some have relied exclusively on measures of autonomic reactivity without consideration of conscious feelings of fear. The current investigation sought to assess whether imagery-based exposure could lead to extinction of conditioned fear to the corresponding perceptual stimulus. Conditioned fear responses were measured by both a physiological (i.e., skin conductance response [SCR]) and a subjective (i.e., self-reported fear) measure. Participants (N = 56) first underwent perceptual differential fear conditioning, then imagery extinction, then perceptual extinction. SCR evidence was found for successful fear conditioning, generalization of fear from viewing to imagery, and most importantly, the absence of differential fear after imagery extinction upon re-exposure to the conditioned perceptual stimulus. Self-reported fear confirmed the acquisition and generalization of fear and provided evidence of a significant reduction in differential fear conditioning across extinction. Consistent with clinical evidence of the efficacy of imagery extinction and the existing limited experimental literature, this study offers support for fear extinction to perceptual stimuli via imagery exposure.


Subject(s)
Conditioning, Classical/physiology , Extinction, Psychological/physiology , Fear/physiology , Galvanic Skin Response/physiology , Imagination/physiology , Adult , Female , Humans , Male , Self Report , Young Adult
7.
Psychophysiology ; 58(8): e13831, 2021 08.
Article in English | MEDLINE | ID: mdl-33932035

ABSTRACT

According to the multicomponent view, emotion is expressed through subjective feelings and thoughts, physiological activation, and behavioral responses. In human fear conditioning research, the former two are much more popular than the third category. One concern is that concurrent behavioral probes may interfere with the conditioning process. To allow triangulation of emotion research through simultaneous employment of subjective, physiological, and behavioral measurement, it is necessary to find behavioral measures that meet the criteria of causing no interference while being sensitive to conditioning. In this study, a basic visual attention task was examined in terms of its impact on differential fear conditioning as measured by both subjective (i.e., self-reported fear and shock estimation) and physiological (i.e., skin conductance response/SCR) expression; and its ability to detect fear conditioning indicated by a reaction time (RT) or accuracy difference between the two conditioned stimuli (CS+ vs. CS-). While participants in the probe group (n = 86) completed differential fear conditioning with the behavioral task, those in the no-probe group (n = 76) underwent conditioning by itself. Based on self-reported fear, shock estimation, and SCR, both groups successfully acquired differential fear with no apparent between-group difference in the degree of conditioning. In the probe group, RT but not accuracy exhibited a difference between CS+ and CS-. These findings suggest that the selected visual attention task does not interfere with differential fear conditioning measured via SCR and self-report and is a sensitive measure of differential conditioning. Exploratory individual analyses also revealed significant relationships between the above measures.


Subject(s)
Conditioning, Classical/physiology , Fear/physiology , Galvanic Skin Response/physiology , Psychomotor Performance/physiology , Reaction Time/physiology , Adult , Female , Humans , Male , Self Report , Young Adult
8.
Neuroimage Clin ; 30: 102575, 2021.
Article in English | MEDLINE | ID: mdl-33588323

ABSTRACT

In people with mental health issues, approximately 20% have co-occurring substance use, often involving cannabis. Although emotion regulation can be affected both by major depressive disorder (MDD) and by cannabis use, the relationship among all three factors is unknown. In this study, we used fMRI to evaluate the effect that cannabis use and MDD have on brain activation during an emotion regulation task. Differences were assessed in 74 emerging adults aged 16-23 with and without MDD who either used or did not use cannabis. Severity of depressive symptoms, emotion regulation style, and age of cannabis use onset were also measured. Both MDD and cannabis use interacted with the emotion regulation task in the left temporal lobe, however the location of the interaction differed for each factor. Specifically, MDD showed an interaction with emotion regulation in the middle temporal gyrus, whereas cannabis use showed an interaction in the superior temporal gyrus. Emotion regulation style predicted activity in the right superior frontal gyrus, however, this did not interact with MDD or cannabis use. Severity of depressive symptoms interacted with the emotion regulation task in the left middle temporal gyrus. The results highlight the influence of cannabis use and MDD on emotion regulation processing, suggesting that both may have a broader impact on the brain than previously thought.


Subject(s)
Cannabis , Depressive Disorder, Major , Emotional Regulation , Adult , Brain/diagnostic imaging , Emotions , Humans , Magnetic Resonance Imaging
9.
Psychophysiology ; 58(7): e13688, 2021 07.
Article in English | MEDLINE | ID: mdl-33037836

ABSTRACT

Understanding the association between autonomic nervous system [ANS] function and brain morphology across the lifespan provides important insights into neurovisceral mechanisms underlying health and disease. Resting-state ANS activity, indexed by measures of heart rate [HR] and its variability [HRV] has been associated with brain morphology, particularly cortical thickness [CT]. While findings have been mixed regarding the anatomical distribution and direction of the associations, these inconsistencies may be due to sex and age differences in HR/HRV and CT. Previous studies have been limited by small sample sizes, which impede the assessment of sex differences and aging effects on the association between ANS function and CT. To overcome these limitations, 20 groups worldwide contributed data collected under similar protocols of CT assessment and HR/HRV recording to be pooled in a mega-analysis (N = 1,218 (50.5% female), mean age 36.7 years (range: 12-87)). Findings suggest a decline in HRV as well as CT with increasing age. CT, particularly in the orbitofrontal cortex, explained additional variance in HRV, beyond the effects of aging. This pattern of results may suggest that the decline in HRV with increasing age is related to a decline in orbitofrontal CT. These effects were independent of sex and specific to HRV; with no significant association between CT and HR. Greater CT across the adult lifespan may be vital for the maintenance of healthy cardiac regulation via the ANS-or greater cardiac vagal activity as indirectly reflected in HRV may slow brain atrophy. Findings reveal an important association between CT and cardiac parasympathetic activity with implications for healthy aging and longevity that should be studied further in longitudinal research.


Subject(s)
Autonomic Nervous System/physiology , Heart Rate/physiology , Longevity/physiology , Adult , Brain Cortical Thickness , Cross-Sectional Studies , Female , Humans , Male , Meta-Analysis as Topic , Prefrontal Cortex/physiology , Vagus Nerve
10.
Cogn Res Princ Implic ; 5(1): 20, 2020 05 05.
Article in English | MEDLINE | ID: mdl-32372296

ABSTRACT

Spatial reasoning is a critical skill in many everyday tasks and in science, technology, engineering, and mathematics disciplines. The current study examined how training on mental rotation (a spatial reasoning task) impacts the completeness of an encoded representation and the ability to rotate the representation. We used a multisession, multimethod design with an active control group to determine how mental rotation ability impacts performance for a trained stimulus category and an untrained stimulus category. Participants in the experimental group (n = 18) showed greater improvement than the active control group (n = 18) on the mental rotation tasks. The number of saccades between objects decreased and saccade amplitude increased after training, suggesting that participants in the experimental group encoded more of the object and possibly had more complete mental representations after training. Functional magnetic resonance imaging data revealed distinct neural activation associated with mental rotation, notably in the right motor cortex and right lateral occipital cortex. These brain areas are often associated with rotation and encoding complete representations, respectively. Furthermore, logistic regression revealed that activation in these brain regions during the post-training scan significantly predicted training group assignment. Overall, the current study suggests that effective mental rotation training protocols should aim to improve the encoding and manipulation of mental representations.


Subject(s)
Attention/physiology , Imagination/physiology , Motor Cortex/physiology , Occipital Lobe/physiology , Practice, Psychological , Space Perception/physiology , Thinking/physiology , Adolescent , Adult , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Motor Cortex/diagnostic imaging , Occipital Lobe/diagnostic imaging , Rotation , Saccades/physiology , Young Adult
11.
Neuropsychologia ; 141: 107418, 2020 04.
Article in English | MEDLINE | ID: mdl-32169318

ABSTRACT

The current study sought to examine the functional connectivity of resting state networks (RSNs) as they relate to the individual domains of executive functioning (EF). Based on the Unity and Diversity model (Miyake et al., 2000), EF performance was captured using a three-factor model proposed by Karr et al. (2018), which includes inhibition, shifting, and fluency. Publicly available data was used from the Nathan Kline Institute -Rockland project was used. Of the 722 participants who completed the Delis-Kaplan Executive Function System (D-KEFS), which was used to measure EF performance, 269 of these individuals completed resting state fMRI scans. First, a confirmatory factory analysis replicated Karr et al. (2018) revealing three components: inhibition, shifting and fluency. Next, RSNs were identified across the sample using an Independent Components Analysis (ICA) and was compared to previously established intrinsic connectivity networks (Laird et al., 2011). Finally, dual regression was used to analyze the relationships between the functional connectivity of RSNs and EF performance, which indicated that RSNs were differentially associated with inhibition and shifting. Better inhibition was related to increased connectivity between the left striatum and the attentional control network. Better shifting performance was related to increased connectivity between the pre- and postcentral gyri and the speech and sensorimotor network. These results highlight individual differences within these RSNs that are unique to the literature, as non-EF confounds are mitigated within the current measurements of EF performance.


Subject(s)
Executive Function , Magnetic Resonance Imaging , Adult , Attention , Humans , Individuality
12.
Cogn Emot ; 34(2): 352-358, 2020 03.
Article in English | MEDLINE | ID: mdl-30987523

ABSTRACT

While modern theories of emotion emphasize the role of higher-order cognitive processes such as semantics in human emotion, much research into emotional learning has ignored the potential contributions of such processes. This study aimed to determine whether emotional learning affects semantic representations of words independent of perceptual features by assessing whether fear conditioning to a neutral word generalises across languages in bilingual participants. Two sessions differing according to the reinforced language were performed by English-Spanish bilinguals. In each session, a neutral word was reinforced by an electrical shock whereas its equivalent in the other language was never paired with shock. Across two sessions within our sample, we found replicable evidence that fear conditioning consistently transferred to the non-reinforced language as measured by both self-reported fear and electrodermal activity, irrespective of the conditioned language. Our findings extend knowledge about the role of semantic similarity in fear generalisation and highlight the importance of higher-order cognitive processes in human emotions.


Subject(s)
Fear , Generalization, Psychological , Learning , Multilingualism , Semantics , Female , Humans , Language , Male , Young Adult
13.
Front Psychol ; 10: 2140, 2019.
Article in English | MEDLINE | ID: mdl-31620062

ABSTRACT

In this paper, we review basic findings from experimental studies in judgment and decision making that could contribute to designing policies and trainings to enhance police decision making. Traditional judgment and decision-making research has focused on simple choices between hypothetical gambles, which has been criticized for its lack of generalizability to real world contexts. Over the past 15 years, researchers have focused on understanding the dynamic processes in decision making. This recent focus has allowed for the possibility of more generalizable applications of basic decision science to social issues. We review recent work in three dynamic decision-making topics: dynamic accumulation of evidence in the decision to shoot or not shoot, how previous decisions influence current choices, and how the cognitive and neurological processing of fear influences decisions and decision errors. We conclude this review with a summary of how basic experimental research can apply in policing and training.

14.
Atten Defic Hyperact Disord ; 11(4): 423-432, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31089961

ABSTRACT

Although anxiety and attention-deficit/hyperactivity disorder (ADHD) symptoms are highly comorbid, research has generally examined the executive functioning (EF) deficits associated with each of these symptoms independently. The purpose of this study was to examine the unique and interactive effects of anxiety and ADHD symptoms (first respectively, then collectively) on multiple dimensions of EF (i.e., inhibition, updating, and shifting, respectively). A sample of 142 youth from the community (age range 8-17 years; Mage = 11.87 ± 2.94 years) completed the Delis-Kaplan Executive Function System and dimensional measures of anxiety, inattention, and hyperactivity/impulsivity. It was hypothesized that anxiety would moderate the effect of ADHD symptomatology on EF. Multiple regression models examined anxiety and ADHD symptom domains as predictors of EF. When examining ADHD symptom domains separately, anxiety moderated the relationship between inattention and both updating and shifting; the association between hyperactivity/impulsivity and updating was also moderated by anxiety. Within the full model including both ADHD symptom domains, results indicated that anxiety moderated the relationship between inattention and shifting. Analyses of ADHD symptoms in separate and combined models demonstrated a similar pattern: Increased inattention was associated with worse EF and when anxiety was a significant moderator, and increased ADHD symptoms were associated with worse EF only for those with high levels of anxiety. These results highlight the utility of including anxiety in studies examining the relationship between ADHD and EF. EF is related to multiple aspects of daily functioning (e.g., academic achievement), and EF deficits are often targeted in interventions for ADHD.


Subject(s)
Anxiety/psychology , Attention , Executive Function , Adolescent , Attention Deficit Disorder with Hyperactivity/psychology , Child , Child Behavior/psychology , Female , Humans , Male , Neuropsychological Tests , Psychological Tests
15.
Cognition ; 183: 277-281, 2019 02.
Article in English | MEDLINE | ID: mdl-30529682

ABSTRACT

Can mental imagery rather than external stimulation reactivate an aversive conditioned memory for the purposes of attenuating fear with subsequent extinction training? To answer this question participant underwent a three-day protocol: Day 1 entailed fear acquisition training in which two conditioned stimuli were paired with mild shock (US), while a CS- never was; day 2 included imagery-based reactivation of only one of the two CS+ followed by standard extinction training within the reconsolidation ten minutes later; day 3 included reinstatement by the unsignaled presentation of the US followed by a re-extinction phase. We observed no evidence of fear recovery on the first trial of re-extinction for the reminded, mentally imaged, CS+, whereas fear returned for the non-reminded CS+. Thus, mental imagery was sufficient to reactivate a fear memory thereby opening the reconsolidation window and facilitating fear suppression via extinction training. The clinical implications of this are potentially far-reaching as it allows for in vivo reconsolidation procedures in exposure therapy.


Subject(s)
Conditioning, Classical/physiology , Extinction, Psychological/physiology , Fear/physiology , Imagination/physiology , Memory Consolidation/physiology , Adolescent , Adult , Female , Humans , Male , Young Adult
16.
Nat Hum Behav ; 2: 356-366, 2018.
Article in English | MEDLINE | ID: mdl-30320223

ABSTRACT

In younger adults, arousal amplifies attentional focus to the most salient or goal-relevant information while suppressing other information. A computational model of how the locus coeruleus-norepinephrine (LC-NE) system can implement this increased selectivity under arousal and an fMRI study comparing how arousal affects younger and older adults' processing indicate that the amplification of salient stimuli and the suppression of non-salient stimuli are separate processes, with aging affecting suppression without impacting amplification under arousal. In the fMRI study, arousal increased processing of salient stimuli and decreased processing of non-salient stimuli for younger adults. In contrast, for older adults, arousal increased processing of both low and high salience stimuli, generally increasing excitatory responses to visual stimuli. Older adults also showed decline in LC functional connectivity with frontoparietal networks that coordinate attentional selectivity. Thus, among older adults, arousal increases the potential for distraction from non-salient stimuli.

17.
Cortex ; 101: 31-43, 2018 04.
Article in English | MEDLINE | ID: mdl-29414459

ABSTRACT

A network of cortical and sub-cortical regions is known to be important in the processing of facial expression. However, to date no study has investigated whether representations of facial expressions present in this network permit generalization across independent samples of face information (e.g., eye region vs mouth region). We presented participants with partial face samples of five expression categories in a rapid event-related fMRI experiment. We reveal a network of face-sensitive regions that contain information about facial expression categories regardless of which part of the face is presented. We further reveal that the neural information present in a subset of these regions: dorsal prefrontal cortex (dPFC), superior temporal sulcus (STS), lateral occipital and ventral temporal cortex, and even early visual cortex, enables reliable generalization across independent visual inputs (faces depicting the 'eyes only' vs 'eyes removed'). Furthermore, classification performance was correlated to behavioral performance in STS and dPFC. Our results demonstrate that both higher (e.g., STS, dPFC) and lower level cortical regions contain information useful for facial expression decoding that go beyond the visual information presented, and implicate a key role for contextual mechanisms such as cortical feedback in facial expression perception under challenging conditions of visual occlusion.


Subject(s)
Brain Mapping , Cognition/physiology , Emotions , Facial Expression , Facial Recognition/physiology , Recognition, Psychology/physiology , Analysis of Variance , Face/physiology , Female , Humans , Image Processing, Computer-Assisted/methods , Linear Models , Magnetic Resonance Imaging/methods , Male , Mental Status and Dementia Tests , Temporal Lobe/physiology , Visual Cortex/physiology
18.
Brain Imaging Behav ; 12(4): 1084-1098, 2018 Aug.
Article in English | MEDLINE | ID: mdl-28994010

ABSTRACT

Neuroscientific and psychological research posits that there are two transdiagnostic facets of anxiety: anxious arousal and anxious apprehension. Though these two facets of anxiety are distinct, they are often subsumed into one domain (e.g., trait anxiety). The primary goal of the current study was to delineate the relationship between anxious arousal and cortical thickness versus the relationship between anxious apprehension and cortical thickness in a sample of typically functioning youth. The secondary aim was to determine where in the brain cortical thickness significantly correlated with both components of anxiety. Results indicated that the right anterior insula has a stronger relationship to anxious arousal, whereas the dorsolateral prefrontal cortex and left anterior insula were found to correlate with both anxious arousal and apprehension. We also observed volumetric differences in the amygdala and hippocampus between anxious arousal and anxious apprehension. Whereas anxious arousal, but not apprehension, predicted left amygdala volume, anxious apprehension, but not arousal, predicted right hippocampal volume. These findings demonstrated that there are both differences and similarities in the neural regions that contribute to independent facets of anxiety. Results are discussed in terms of previous findings from the affective and developmental cognitive neurosciences.


Subject(s)
Anxiety/diagnostic imaging , Cerebral Cortex/diagnostic imaging , Gray Matter/diagnostic imaging , Adolescent , Anticipation, Psychological , Anxiety/pathology , Anxiety/psychology , Arousal , Cerebral Cortex/pathology , Child , Female , Functional Laterality , Gray Matter/pathology , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Models, Neurological , Models, Psychological , Organ Size
19.
Neuroimage ; 150: 329-335, 2017 04 15.
Article in English | MEDLINE | ID: mdl-28215623

ABSTRACT

The locus coeruleus (LC) is a key node of the sympathetic nervous system and suppresses parasympathetic activity that would otherwise increase heart rate variability. In the current study, we examined whether LC-MRI contrast reflecting neuromelanin accumulation in the LC was associated with high-frequency heart rate variability (HF-HRV), a measure reflecting parasympathetic influences on the heart. Recent evidence indicates that neuromelanin, a byproduct of catecholamine metabolism, accumulates in the LC through young and mid adulthood, suggesting that LC-MRI contrast may be a useful biomarker of individual differences in habitual LC activation. We found that, across younger and older adults, greater LC-MRI contrast was negatively associated with HF-HRV during fear conditioning and spatial detection tasks. This correlation was not accounted for by individual differences in age or anxiety. These findings indicate that individual differences in LC structure relate to key cardiovascular parameters.


Subject(s)
Heart Rate/physiology , Locus Coeruleus/physiology , Parasympathetic Nervous System/physiology , Adult , Aged , Biomarkers/analysis , Contrast Media/pharmacology , Electrocardiography , Female , Humans , Locus Coeruleus/diagnostic imaging , Magnetic Resonance Imaging/methods , Male , Melanins/analysis , Melanins/biosynthesis , Middle Aged , Young Adult
20.
Brain Sci ; 6(1)2016 Jan 06.
Article in English | MEDLINE | ID: mdl-26751483

ABSTRACT

Anxiety is associated with an exaggerated expectancy of harm, including overestimation of how likely a conditioned stimulus (CS+) predicts a harmful unconditioned stimulus (US). In the current study we tested whether anxiety-associated expectancy of harm increases primary sensory cortex (S1) activity on non-reinforced (i.e., no shock) CS+ trials. Twenty healthy volunteers completed a differential-tone trace conditioning task while undergoing fMRI, with shock delivered to the left hand. We found a positive correlation between trait anxiety and activity in right, but not left, S1 during CS+ versus CS- conditions. Right S1 activity also correlated with individual differences in both primary auditory cortices (A1) and amygdala activity. Lastly, a seed-based functional connectivity analysis demonstrated that trial-wise S1 activity was positively correlated with regions of dorsolateral prefrontal cortex (dlPFC), suggesting that higher-order cognitive processes contribute to the anticipatory sensory reactivity. Our findings indicate that individual differences in trait anxiety relate to anticipatory reactivity for the US during associative learning. This anticipatory reactivity is also integrated along with emotion-related sensory signals into a brain network implicated in fear-conditioned responding.

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