CNE Lab to present at the Cognitive Neuroscience Society Meeting!
Schalles, M., Honzel, N., Larsen, J., Bacigalupo, F., Alderson, C. & Swick, D. (2017). Altered feedback responses to negative gambling outcomes in combat PTSD.
March 9, 2016
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November 9, 2015
New paper: Error Monitoring is intact in PTSD
The error-related negativity (ERN) is a neuroelectric signature of performance monitoring during speeded response time tasks. Previous studies indicate that individuals with anxiety disorders show ERN enhancements that correlate with the degree of clinical symptomology. Less is known about the error monitoring system in post-traumatic stress disorder (PTSD). PTSD is characterized by impairments in the regulation of fear and other emotional responses, as well as deficits in maintaining cognitive control. Here, combat Veterans with PTSD were compared to control Veterans in two different versions of the flanker task (n=13 or 14 per group). Replicating and extending previous findings, PTSD patients showed an intact ERN in both experiments. In addition, task performance and error compensation behavior were intact. Finally, ERN amplitude showed no relationship with self-reported PTSD, depression, or post-concussive symptoms. These results suggest that error monitoring represents a relative strength in PTSD that can dissociate from cognitive control functions that are impaired, such as response inhibition and sustained attention. A healthy awareness of errors in external actions could be leveraged to improve interoceptive awareness of emotional state. The results could have positive implications for PTSD treatments that rely on self-monitoring abilities, such as neurofeedback and mindfulness training.
Swick, D., Honzel, N. & Turken, A.U. (2015). Intact error monitoring in combat Veterans with post-traumatic stress disorder. Psychiatry Research: Neuroimaging 234: 227–238. doi: 10.1016/j.pscychresns.2015.09.016
January 12, 2015
NEW POST-DOC ARRIVES!
We welcome our new post-doc, Dr. Matt Schalles, to the lab. Matt recently completed his Ph.D. in Cognitive Science at UCSD under the guidance of Dr. Jaime Pineda. Dr. Schalles is also Adjunct Psychology Faculty at Holy Names University.
August 19, 2014
NEW! POST-DOC POSITION IN THE CNELAB
Cognitive Neuropsychology and Electrophysiology Lab
VA Northern California Health Care System
VA-funded project to study the effects of post-traumatic stress disorder and traumatic brain injury on executive control of cognition and emotion. Multidisciplinary research environment for neuropsychological and event-related potential (ERP) studies of the neural organization and dynamic interplay of distributed regions that regulate responses to cognitive and affective conflict. Opportunities for collaborative research in structural and functional MRI with other investigators at the Martinez VA. The lab is affiliated with the Department of Neurology at University of California, Davis.
Ph.D. in Neuroscience, Psychology, Cognitive Science, Neurobiology or a related field required. EEG research experience strongly preferred. MATLAB programming skills a bonus. Initial appointment is for 2 years, with the possibility of renewal. Available now, but start date flexible.
Send CV and names of three references to Diane Swick.
Tuesday May 20, 2014 is VA Research Day
VANCHCS Research Day
May 20th, 2014
Martinez, CNS 120 & Admin Building E8A&B
1:00 PM – 4:00 PM
Please join us next Tuesday for the VANCHCS celebration of Research Week (http://www.research.va.gov/researchweek/).
We’ll be having talks and demonstrations of our work here on the Martinez Campus. Refreshments will be provided.
Click here for the agenda (PDF).
A new paper by Swick, Honzel, Larsen, and Ashley has been accepted for publication at Neuropsychologia:
Increased response variability as a marker of executive dysfunction in veterans with post-traumatic stress disorder
Abstract: The stability of cognitive control processes over time can be indexed by trial-to-trial variability in reaction time (RT). Greater RT variability has been interpreted as an indicator of executive dysfunction, inhibitory inefficiency, and excessive mental noise. Previous studies have demonstrated that combat veterans with post-traumatic stress disorder (PTSD) show substantial impairments in inhibitory control, but no studies have examined response variability in this population. In the current experiment, RT variability in the Go/NoGo response inhibition task was assessed for 45 veterans with PTSD and 34 control veterans using the intra-individual coefficient of variation (ICV) and ex Gaussian analysis of RT distributions. Despite having mean RTs that were indistinguishable from controls, the PTSD patients had significantly greater RT variability as measured by ICV. More variable RTs were in turn associated with a greater number of false alarm errors in the patients, suggesting that less consistent performers were less successful at inhibiting inappropriate responses. RT variability was also highly correlated with self-reported symptoms of PTSD, depression, and attentional impulsiveness. Furthermore, response variability predicted diagnosis even when controlling for PTSD symptom severity. In turn, PTSD severity was correlated with self-rated attentional impulsiveness. Deficits in the top-down cognitive control processes that cause greater response variability might contribute to the maintenance of PTSD symptomology. Thus, the distractibility issues that cause more variable reaction times might also result in greater distress related to the trauma.
A new paper by Honzel, Justus, and Swick has been accepted for publication at Cognitive, Affective, and Behavioral Neuroscience:
Post-traumatic stress disorder is associated with limited executive resources in a working memory task
Abstract: Patients with post-traumatic stress disorder (PTSD) can show declines in working memory. A dual-task design was used to determine if these impairments are linked to executive control limitations. Participants performed a Sternberg memory task with either one or four letters. In the dual-task condition, the maintenance period was filled with an arrow flanker task. PTSD patients were less accurate on the working memory task than controls, especially in the dual-task condition. In the single-task condition, both groups showed similar patterns of brain potentials from 300-500 ms when discriminating old and new probes. However, when taxed with an additional task, the event-related potentials (ERPs) of the PTSD group no longer differentiated old and new probes. In contrast, interference resolution processes in both the single- and dual-task conditions of the flanker were intact. The lack of differentiation in the ERPs reflects impaired working memory performance under more difficult dual-task conditions. Exacerbated difficulty in performing a working memory task with concurrent task demands suggests a specific limitation in executive control resources in PTSD.