Read by QxMD icon Read

James cavanagh

Irene van de Vijver, K Richard Ridderinkhof, Helga Harsay, Liesbeth Reneman, James F Cavanagh, Jessika I V Buitenweg, Michael X Cohen
Reinforcement learning (RL) is supported by a network of striatal and frontal cortical structures that are connected through white-matter fiber bundles. With age, the integrity of these white-matter connections declines. The role of structural frontostriatal connectivity in individual and age-related differences in RL is unclear, although local white-matter density and diffusivity have been linked to individual differences in RL. Here we show that frontostriatal tract counts in young human adults (aged 18-28), as assessed noninvasively with diffusion-weighted magnetic resonance imaging and probabilistic tractography, positively predicted individual differences in RL when learning was difficult (70% valid feedback)...
October 2016: Neurobiology of Aging
Kuan-Hua Chen, Katrina L Okerstrom, Jonathan R Kingyon, Steven W Anderson, James F Cavanagh, Nandakumar S Narayanan
The ability to adapt to unexpected stimuli is critical for mental health. Here, we investigate the relationship between habituation to startling stimuli and startle-related activity in medial frontal cortex as measured by EEG in both healthy control participants and patients with Parkinson's disease (PD). We report three findings. First, patients with PD exhibited normal initial startle responses but reduced startle habituation relative to demographically matched controls. Second, control participants had midfrontal EEG theta activity in response to startling stimuli, and this activity was attenuated in patients with PD...
July 15, 2016: Journal of Cognitive Neuroscience
Matthew A Albrecht, James A Waltz, James F Cavanagh, Michael J Frank, James M Gold
The negative symptoms of schizophrenia (SZ) are associated with a pattern of reinforcement learning (RL) deficits likely related to degraded representations of reward values. However, the RL tasks used to date have required active responses to both reward and punishing stimuli. Pavlovian biases have been shown to affect performance on these tasks through invigoration of action to reward and inhibition of action to punishment, and may be partially responsible for the effects found in patients. Forty-five patients with schizophrenia and 30 demographically-matched controls completed a four-stimulus reinforcement learning task that crossed action ("Go" or "NoGo") and the valence of the optimal outcome (reward or punishment-avoidance), such that all combinations of action and outcome valence were tested...
2016: PloS One
James F Cavanagh, Joel Castellanos
Cognitive neuroscience suffers from a unique and pervasive problem of generalizability. Since neural findings are often interpreted in the context of a specific manipulation during a carefully controlled task, it is hard to transfer knowledge from one task to another. In this report we address problems of generalizability with two methodological advancements. First, we aimed to transcend status quo experimental procedures with a continuous, engaging task environment. To this end, we created a novel 8-bit style continuous space shooter video game that elicits a multitude of goal-oriented events, such as crashing into a wall or blowing up an enemy with a missile...
June 2016: NeuroImage
Cian O'Leary, Brenton Cavanagh, Ronald E Unger, C James Kirkpatrick, Shirley O'Dea, Fergal J O'Brien, Sally-Ann Cryan
Today, chronic respiratory disease is one of the leading causes of mortality globally. Epithelial dysfunction can play a central role in its pathophysiology. The development of physiologically-representative in vitro model systems using tissue-engineered constructs might improve our understanding of epithelial tissue and disease. This study sought to engineer a bilayered collagen-hyaluronate (CHyA-B) scaffold for the development of a physiologically-representative 3D in vitro tracheobronchial epithelial co-culture model...
April 2016: Biomaterials
Scott Telfer, Ahmet Erdemir, James Woodburn, Peter R Cavanagh
Integration of patient-specific biomechanical measurements into the design of therapeutic footwear has been shown to improve clinical outcomes in patients with diabetic foot disease. The addition of numerical simulations intended to optimise intervention design may help to build on these advances, however at present the time and labour required to generate and run personalised models of foot anatomy restrict their routine clinical utility. In this study we developed second-generation personalised simple finite element (FE) models of the forefoot with varying geometric fidelities...
January 25, 2016: Journal of Biomechanics
Ezemenari M Obasi, Elizabeth A Shirtcliff, Gene H Brody, James MacKillop, Delishia M Pittman, Lucia Cavanagh, Robert A Philibert
OBJECTIVE: Rurally situated African Americans suffer from stress and drug-related health disparities. Unfortunately, research on potential mechanisms that underlie this public health problem have received limited focus in the scientific literature. This study investigated the effects of perceived stress, alcohol consumption, and genotype on the hypothalamic-pituitary-adrenal (HPA) Axis. METHODS: A rural sample of African American emerging adults (n = 84) completed a battery of assessments and provided six samples of salivary cortisol at wakeup, 30 min post wakeup, 90 min post wakeup, 3:00 PM, 3:30 PM, and 4:30 PM...
2015: Frontiers in Psychology
Krystal L Parker, Kuan-Hua Chen, Johnathan R Kingyon, James F Cavanagh, Nandakumar S Narayanan
The temporal control of action is a highly conserved and critical mammalian behavior. Here, we investigate the neuronal basis of this process using an interval timing task. In rats and humans, instructional timing cues triggered spectral power across delta and theta bands (2-6 Hz) from the medial frontal cortex (MFC). Humans and rodents with dysfunctional dopamine have impaired interval timing, and we found that both humans with Parkinson's disease (PD) and rodents with local MFC dopamine depletion had attenuated delta and theta activity...
August 2015: Journal of Neurophysiology
Warren J Bradley, Bryce Cavanagh, William Douglas, Timothy F Donovan, Craig Twist, James P Morton, Graeme L Close
Rugby union (RU) is a complex high-intensity intermittent collision sport with emphasis placed on players possessing high lean body mass and low body fat. After an 8 to 12-week pre-season focused on physiological adaptations, emphasis shifts towards competitive performance. However, there are no objective data on the physiological demands or energy intake (EI) and energy expenditure (EE) for elite players during this period. Accordingly, in-season training load using global positioning system and session rating of perceived exertion (sRPE), alongside six-day assessments of EE and EI were measured in 44 elite RU players...
2015: European Journal of Sport Science
Paul Hong, Krista Ritchie, Cathy Beaton-Campbell, Lynn Cavanagh, James Belyea, Gerard Corsten
OBJECTIVES: To assess the effectiveness of nurse-led triage of outpatient referrals in an academic pediatric otolaryngology practice. METHODS: Three hundred consecutive outpatient referrals were reviewed and triaged by two otolaryngology registered nurses and two attending pediatric otolaryngologists. The nurses received triage training. The referrals were triaged as 'routine' (to be seen within 2-3 months), 'semi-urgent' (to be seen within 6 weeks), or 'urgent' (to be seen within 2 weeks)...
April 2015: International Journal of Pediatric Otorhinolaryngology
James F Cavanagh
Recent work has suggested that reward prediction errors elicit a positive voltage deflection in the scalp-recorded electroencephalogram (EEG); an event sometimes termed a reward positivity. However, a strong test of this proposed relationship remains to be defined. Other important questions remain unaddressed: such as the role of the reward positivity in predicting future behavioral adjustments that maximize reward. To answer these questions, a three-armed bandit task was used to investigate the role of positive prediction errors during trial-by-trial exploration and task-set based exploitation...
April 15, 2015: NeuroImage
Adam Bennett, Shahira Mahmoud, Donna Drury, H Dwight Cavanagh, James P McCulley, W Matthew Petroll, V Vinod Mootha
OBJECTIVE: To correlate corneal endothelium-Descemet membrane (EDM) layer parameters of scroll tightness with donor age, endothelial cell density (ECD), and history of diabetes. METHODS: Endothelium-Descemet membrane layer scrolls were harvested from 26 corneoscleral buttons using the SCUBA technique by a cornea-fellowship trained ophthalmologist masked to donor age. Two independent outcome parameters were used to characterize the scrolling severity of successfully harvested tissue: scroll width and tendency for EDM scroll formation (referred to as scroll rating on a 1-4 scale: incomplete scroll formation to tightly scrolled)...
July 2015: Eye & Contact Lens
Michael J Frank, Chris Gagne, Erika Nyhus, Sean Masters, Thomas V Wiecki, James F Cavanagh, David Badre
What are the neural dynamics of choice processes during reinforcement learning? Two largely separate literatures have examined dynamics of reinforcement learning (RL) as a function of experience but assuming a static choice process, or conversely, the dynamics of choice processes in decision making but based on static decision values. Here we show that human choice processes during RL are well described by a drift diffusion model (DDM) of decision making in which the learned trial-by-trial reward values are sequentially sampled, with a choice made when the value signal crosses a decision threshold...
January 14, 2015: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Krystal L Parker, Kuan-Hua Chen, Johnathan R Kingyon, James F Cavanagh, Nandakumar S Narayanan
Organizing behavior in time is a fundamental process that is highly conserved across species. Here we study the neural basis of timing processes. First, we found that rodents had a burst of stimulus-triggered 4 Hz oscillations in the medial frontal cortex (MFC) during interval timing tasks. Second, rodents with focally disrupted MFC D1 dopamine receptor (D1DR) signaling had impaired interval timing performance and weaker stimulus-triggered oscillations. Prior work has demonstrated that MFC neurons ramp during interval timing, suggesting that they underlie temporal integration...
December 10, 2014: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Bulent Turan, Carol Foltz, James F Cavanagh, B Alan Wallace, Margaret Cullen, Erika L Rosenberg, Patricia A Jennings, Paul Ekman, Margaret E Kemeny
Anticipation may play a role in shaping biological reactions to repeated stressors-a common feature of modern life. We aimed to demonstrate that: (a) individuals who display a larger cortisol response to an initial stressor exhibit progressive anticipatory sensitization, showing progressively higher cortisol levels before subsequent exposures, and (b) attention/emotional skills training can reduce the magnitude of this effect on progressive anticipatory sensitization. Female school teachers (N=76) were randomly assigned to attention/emotion skills and meditation training or to a control group...
February 2015: Psychoneuroendocrinology
James F Cavanagh, Sean E Masters, Kevin Bath, Michael J Frank
Conflict has been proposed to act as a cost in action selection, implying a general function of medio-frontal cortex in the adaptation to aversive events. Here we investigate if response conflict acts as a cost during reinforcement learning by modulating experienced reward values in cortical and striatal systems. Electroencephalography recordings show that conflict diminishes the relationship between reward-related frontal theta power and cue preference yet it enhances the relationship between punishment and cue avoidance...
2014: Nature Communications
Scott Telfer, Ahmet Erdemir, James Woodburn, Peter R Cavanagh
BACKGROUND: Over the past two decades finite element (FE) analysis has become a popular tool for researchers seeking to simulate the biomechanics of the healthy and diabetic foot. The primary aims of these simulations have been to improve our understanding of the foot's complicated mechanical loading in health and disease and to inform interventions designed to prevent plantar ulceration, a major complication of diabetes. This article provides a systematic review and summary of the findings from FE analysis-based computational simulations of the diabetic foot...
2014: PloS One
Warren J Bradley, Bryce P Cavanagh, William Douglas, Timothy F Donovan, James P Morton, Graeme L Close
Rugby Union (RU) is a high-speed collision sport consisting of an intermittent activity profile. Given the extreme physical demands of the sport, significant emphasis is placed on players possessing high lean body mass while minimizing body fat. Anecdotally, the most significant changes in body composition are observed during the preseason; however, there are no objective data on the physiological demands and energy intake during this time. We therefore monitored 45 elite European RU players over the 10-week preseason period by assessing training load using Global Positioning System and session rate of perceived exertion (sRPE) while also assessing changes in anthropometry and physical performance...
February 2015: Journal of Strength and Conditioning Research
James F Cavanagh, Michael J Frank
Recent advancements in cognitive neuroscience have afforded a description of neural responses in terms of latent algorithmic operations. However, the adoption of this approach to human scalp electroencephalography (EEG) has been more limited, despite the ability of this methodology to quantify canonical neuronal processes. Here, we provide evidence that theta band activities over the midfrontal cortex appear to reflect a common computation used for realizing the need for cognitive control. Moreover, by virtue of inherent properties of field oscillations, these theta band processes may be used to communicate this need and subsequently implement such control across disparate brain regions...
August 2014: Trends in Cognitive Sciences
James F Cavanagh, Joseph L Sanguinetti, John J B Allen, Scott J Sherman, Michael J Frank
pFC is proposed to implement cognitive control via directed "top-down" influence over behavior. But how is this feat achieved? The virtue of such a descriptive model is contingent on a mechanistic understanding of how motor execution is altered in specific circumstances. In this report, we provide evidence that the well-known phenomenon of slowed RTs following mistakes (post-error slowing) is directly influenced by the degree of subthalamic nucleus (STN) activity. The STN is proposed to act as a brake on motor execution following conflict or errors, buying time so a more cautious response can be made on the next trial...
November 2014: Journal of Cognitive Neuroscience
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"