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2. Neural underpinnings of threat bias in relation to loss-of-control eating behaviors among adolescent girls with high weight.

Author

Byrne, Meghan E., Tanofsky-Kraff, Marian, Liuzzi, Lucrezia, Holroyd, Tom, Parker, Megan N., Bloomer, Bess F., Nugent, Allison, Brady, Sheila M., Yang, Shanna B., Turner, Sara A., Pine, Daniel S., and Yanovski, Jack A.

Subjects
FOOD habits, TEENAGE girls, EXECUTIVE function, CONTROL (Psychology), ATTENTIONAL bias, BINGE-eating disorder
Abstract

Introduction: Loss-of-control (LOC) eating, a key feature of binge-eating disorder, may relate attentional bias (AB) to highly salient interpersonal stimuli. The current pilot study used magnetoencephalography (MEG) to explore neural features of AB to socially threatening cues in adolescent girls with and without LOC-eating. Methods: Girls (12-17 years old) with overweight or obesity (BMI >85th percentile) completed an AB measure on an affective dot-probe AB task during MEG and evoked neural responses to angry or happy (vs. neutral) face cues were captured. A laboratory test meal paradigm measured energy intake and macronutrient consumption patterns. Results: Girls (N = 34; Mage = 15.5 ± 1.5 years; BMI-z = 1.7 ± 0.4) showed a blunted evoked response to the presentation of angry face compared with neutral face cues in the left dorsolateral prefrontal cortex, a neural region implicated in executive control and regulation processes, during attention deployment (p < 0.01). Compared with those without LOC-eating (N = 21), girls with LOC-eating (N = 13) demonstrated a stronger evoked response to angry faces in the visual cortex during attention deployment (p < 0.001). Visual and cognitive control ROIs had trends suggesting interaction with test meal intake patterns among girls with LOC-eating (ps = 0.01). Discussion: These findings suggest that girls with overweight or obesity may fail to adaptively engage neural regions implicated in higher-order executive processes. This difficulty may relate to disinhibited eating patterns that could lead to excess weight gain. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Abnormal hippocampal functioning and impaired spatial navigation in depressed individuals: evidence from whole-head magnetoencephalography

Author

Cornwell, Brian R., Salvadore, Giacomo, Colon-Rosario, Veronica, Latov, David R., Holroyd, Tom, Carver, Frederick W., Coppola, Richard, Manji, Husseini K., Zarate, Carlos A., Jr., and Grillon, Christian

Subjects
Depression, Mental -- Development and progression, Health, Psychology and mental health
Abstract

Objective: Dysfunction of the hippocampus has long been suspected to be a key component of the pathophysiology of major depressive disorder. Despite evidence of hippocampal structural abnormalities in depressed patients, abnormal hippocampal functioning has not been demonstrated. The authors aimed to link spatial navigation deficits previously documented in depressed patients to abnormal hippocampal functioning using a virtual reality navigation task. Method: Whole-head magnetoencephalography (MEG) recordings were collected while participants (19 patients diagnosed with major depressive disorder and 19 healthy subjects matched by gender and age) navigated a virtual Morris water maze to find a hidden platform; navigation to a visible platform served as a control condition. Behavioral measures were obtained to assess navigation performance. Theta oscillatory activity (4-8 Hz) was mapped across the brain on a voxel-wise basis using a spatial-filtering MEG source analysis technique. Results: Depressed patients performed worse than healthy subjects in navigating to the hidden platform. Robust group differences in theta activity were observed in right medial temporal cortices during navigation, with patients exhibiting less engagement of the anterior hippocampus and parahippocampal cortices relative to comparison subjects. Left posterior hippocampal theta activity was positively correlated with individual performance within each group. Conclusions: Consistent with previous findings, depressed patients showed impaired spatial navigation. Dysfunction of right anterior hippocampus and parahippocampal cortices may underlie this deficit and stem from structural abnormalities commonly found in depressed patients.

Published
2010

29. Prefrontal high gamma during a magnetoencephalographic working memory task.

Author

Carver, Frederick W., Rubinstein, Dani Y., Gerlich, Alan H., Fradkin, Samantha I., Holroyd, Tom, and Coppola, Richard

Abstract

In human electrophysiology research, the high gamma part of the power spectrum (~>60 Hz) is a relatively new area of investigation. Despite a low signal‐to‐noise ratio, evidence exists that it contains significant information about activity in local cortical networks. Here, using magnetoencephalography (MEG), we found high gamma activity when comparing data from an n‐back working memory task to resting data in a large sample of normal volunteers. Initial analysis of power spectra from 0‐back, 2‐back, and rest trials showed three frequency bands exhibiting task‐related differences: alpha, beta, and high gamma. Unlike alpha and beta, the high gamma spectrum was broad, without a peak at a single frequency. In addition, power in high gamma was highest for the 2‐back and lowest during rest, while the opposite pattern occurred in the other bands. Beamformer source localization of each of the three frequency bands revealed a distinct set of sources for high gamma. These included several regions of prefrontal cortex that exhibited greater power when both n‐back conditions were compared to rest. A subset of these regions had more power when the 2‐back was compared to 0‐back, which indicates a role in working memory performance. Our results show that high gamma will be important for understanding cortical processing during cognitive and other tasks. Furthermore, data from human intracortical recordings suggest that high gamma is the aggregate of spiking in local cortical networks, which implies that MEG could serve to bridge experimental modalities by noninvasively observing task‐related modulation of spiking rates. [ABSTRACT FROM AUTHOR]

Published
2019
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31. Isolating neural components of threat bias in pediatric anxiety

Author

Britton, Jennifer C., Bar-Haim, Yair, Carver, Frederick W., Holroyd, Tom, Norcross, Maxine A., Detloff, Allison, Leibenluft, Ellen, Ernst, Monique, and Pine, Daniel S.

Subjects
Male, Adolescent, Magnetoencephalography, Prefrontal Cortex, Anger, Anxiety, Article, United States, Facial Expression, Escape Reaction, Case-Control Studies, Humans, Attention, Female, Child
Abstract

Attention biases toward threat are often detected in individuals with anxiety disorders. Threat biases can be measured experimentally through dot-probe paradigms, in which individuals detect a probe following a stimulus pair including a threat. On these tasks, individuals with anxiety tend to detect probes that occur in a location previously occupied by a threat (i.e., congruent) faster than when opposite threats (i.e., incongruent). In pediatric anxiety disorders, dot-probe paradigms detect abnormal attention biases toward threat and abnormal ventrolateral prefrontal cortex (vlPFC) function. However, it remains unclear if this aberrant vlPFC activation occurs while subjects process threats (e.g., angry faces) or, alternatively, while they process and respond to probes. This magnetoencephalography (MEG) study was designed to answer this question. Adolescents with either generalized anxiety disorder (GAD, n = 17) or no psychiatric diagnosis (n = 25) performed a dot-probe task involving angry and neutral faces while MEG data were collected. Synthetic Aperture Magnetometry (SAM) beamformer technique was used to determine whether there were group differences in power ratios while subjects processed threats (i.e., angry vs. neutral faces) or when subjects responded to incongruent versus. congruent probes. Group differences in vlPFC activation during the response period emerged with a 1-30 Hz frequency band. No group differences in vlPFC activation were detected in response to angry-face cues. In the dot-probe task, anxiety-related perturbations in vlPFC activation reflect abnormal attention control when responding to behaviorally relevant probes, but not to angry faces. Given that motor responses to these probes are used to calculate threat bias, this study provides insight into the pathophysiology reflected in this commonly used marker of anxiety. In addition, this finding may inform the development of novel anxiety-disorder treatments targeting the vlPFC to enhance attention control to task-relevant demands.

Published
2011

33. Abnormal hippocampal functioning and impaired spatial navigation in depressed individuals

Author

Cornwell, Brian R., Salvadore, Giacomo, Colon-Rosario, Veronica, Latov, David R., Holroyd, Tom, Carver, Frederick W., Coppola, Richard, Manji, Husseini K., Zarate, Carlos A., and Grillon, Christian

Subjects
Adult, Male, Depressive Disorder, Major, Case-Control Studies, Humans, Magnetoencephalography, Spatial Behavior, Female, Theta Rhythm, Maze Learning, Hippocampus, Article, Psychomotor Performance
Abstract

Dysfunction of the hippocampus has long been suspected to be a key component of the pathophysiology of major depressive disorder. Despite evidence of hippocampal structural abnormalities in depressed patients, abnormal hippocampal functioning has not been demonstrated. The authors aimed to link spatial navigation deficits previously documented in depressed patients to abnormal hippocampal functioning using a virtual reality navigation task.Whole-head magnetoencephalography (MEG) recordings were collected while participants (19 patients diagnosed with major depressive disorder and 19 healthy subjects matched by gender and age) navigated a virtual Morris water maze to find a hidden platform; navigation to a visible platform served as a control condition. Behavioral measures were obtained to assess navigation performance. Theta oscillatory activity (4-8 Hz) was mapped across the brain on a voxel-wise basis using a spatial-filtering MEG source analysis technique.Depressed patients performed worse than healthy subjects in navigating to the hidden platform. Robust group differences in theta activity were observed in right medial temporal cortices during navigation, with patients exhibiting less engagement of the anterior hippocampus and parahippocampal cortices relative to comparison subjects. Left posterior hippocampal theta activity was positively correlated with individual performance within each group.Consistent with previous findings, depressed patients showed impaired spatial navigation. Dysfunction of right anterior hippocampus and parahippocampal cortices may underlie this deficit and stem from structural abnormalities commonly found in depressed patients.

Published
2010

34. Convergent BOLD and Beta-Band Activity in Superior Temporal Sulcus and Frontolimbic Circuitry Underpins Human Emotion Cognition

Author

Jabbi, Mbemba, primary, Kohn, Philip D., additional, Nash, Tiffany, additional, Ianni, Angela, additional, Coutlee, Christopher, additional, Holroyd, Tom, additional, Carver, Frederick W., additional, Chen, Qiang, additional, Cropp, Brett, additional, Kippenhan, J. Shane, additional, Robinson, Stephen E., additional, Coppola, Richard, additional, and Berman, Karen F., additional

Published
2014
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38. 15:30 ALTERATIONS IN MAGNETOENCEPHALOGRAPHIC GAMMA OSCILLATORY PATTERNS DURING RESTING-STATE IN PATIENTS WITH CHILDHOOD-ONSET SCHIZOPHRENIA, NON-PSYCHOTIC SIBLINGS AND HEALTHY CONTROLS

Author

Vyas, Nora S., primary, Rubinstein, Daniel Y., additional, Carver, Frederick W., additional, Mattai, Anand A., additional, Stidd, Reva, additional, Holroyd, Tom, additional, Weisinger, Brian M., additional, David, Christopher N., additional, Turner, Cheryl, additional, Clasen, Liv, additional, Miller, Rachel, additional, Tossell, Julia W., additional, Coppola, Richard, additional, Rapoport, Judith L., additional, and Gogtay, Nitin, additional

Published
2012
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44. Anterior Cingulate Desynchronization and Functional Connectivity with the Amygdala During a Working Memory Task Predict Rapid Antidepressant Response to Ketamine

Author

Salvadore, Giacomo, primary, Cornwell, Brian R, additional, Sambataro, Fabio, additional, Latov, David, additional, Colon-Rosario, Veronica, additional, Carver, Frederick, additional, Holroyd, Tom, additional, DiazGranados, Nancy, additional, Machado-Vieira, Rodrigo, additional, Grillon, Christian, additional, Drevets, Wayne C, additional, and Zarate, Carlos A, additional

Published
2010
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48. Daydreaming, Thought Blocking and Strudels in the Taskless, Resting Human Brain's Magnetic Fields.

Author

Mandell, Arnold J., Selz, Karen A., Aven, John, Holroyd, Tom, and Coppola, Richard

Subjects
BRAIN magnetic fields, MAGNETIC flux, FLUCTUATIONS (Physics), ENTROPY, THOUGHT & thinking, NEUROPHYSIOLOGY, CONSCIOUSNESS
Abstract

The incidence, i(S), and duration, l(S), of transient, intermittent, hierarchical vorticities, strudels, S, in magnetic flux fluctuations, were computed from MEG records. from 91 task-free resting subjects. The MEG's i(S) and l(S) manifested characteristic times and entropic sensitivity resembling those reported in psychological studies of daydreaming and task-unrelated thoughts, TUTs. Transient reduction or absences of strudels can be found in patients with syndromes characterized by thought blocking. Positive ergodic single orbit measures of expansiveness and mixing predict i(S) and l(S). An analogy with the relationship between intermittent pontine-geniculate-occipital waves and dreaming is made to strudels with daydreaming. Both can be interpreted as neurophysiological correlates of the spontaneous intrusions into consciousness of the never idle unconscious mind. [ABSTRACT FROM AUTHOR]

Published
2011
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49. Instability and pattern formation in the human brain during complex sensorimotor and auditory tasks as revealed by magnetoencephalography

Author

Holroyd, Tom, Florida Atlantic University (Degree Grantor), Charles E. Schmidt College of Science, Center for Complex Systems and Brain Sciences, Holroyd, Tom, Florida Atlantic University (Degree Grantor), Charles E. Schmidt College of Science, and Center for Complex Systems and Brain Sciences

Abstract

Summary: Following Kelso et al. (1991a; 1992), Wallenstein et al. (1995), Tuller et al. (1994), and Case et al. (1995); see also Fuchs et al. (1992), the experiments described in this research all used a dynamical methodology designed to produce a coherent brain state and then lead that brain state through a spontaneous reorganization via the influence of a parametric change. Magnetoencephalographic (MEG) recordings made during the spontaneous behavioral and perceptual transitions were analyzed by decomposition of the brain's high-dimensional magnetic field into a few task-relevant components. The analysis showed that the dynamics of the MEG signal, including the reorganization which occured as a result of the parametric manipulation, could be accounted for by the dynamics of the individual components. This supports the idea that the task requirements in each case placed the brain into a (relatively) low-dimensional state through the cooperative interactions among the many neuronal elements involved in the task. The experiments included two coordination experiments in which subjects were required to produce index finger flexions in time to an auditory metronome in an anti-phase pattern while the metronome rate was increased. Increases in the variability of both the behavior and the motor-associated magnetic field components prior to the transition to an in-phase pattern support the hypothesis that a dynamic instability mechanism exists for pattern formation and change during those tasks. In the third experiment a perceptual instability was explored by systematically scaling a parameter known to influence categorization of speech stimuli: biasing the transition created stimuli that were perceived in two different ways. The design of the experiment allowed the investigation of neural correlates of the physical properties of the stimuli, perceptual invariance, bistability, and perceptual reorganization. Analysis of the MEG signals suggests that presentation of a bistab, Collection: FAU Electronic Theses and Dissertations Collection, Adviser: J. A. S. Kelso., Thesis (Ph.D.)--Florida Atlantic University, 1997.

Published
1997

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