Browsing by Author "Schnakenberg Martin, Ashley M."
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Item Altered cerebellar-cortical resting-state functional connectivity in cannabis users(Sage, 2021) Schnakenberg Martin, Ashley M.; Kim, Dae-Jin; Newman, Sharlene D.; Cheng, Hu; Hetrick, William P.; Mackie, Ken; O’Donnell, Brian F.; Psychiatry, School of MedicineBackground: Cannabis use has been associated with abnormalities in cerebellar mediated motor and non-motor (i.e. cognition and personality) phenomena. Since the cerebellum is a region with high cannabinoid type 1 receptor density, these impairments may reflect alterations of signaling between the cerebellum and other brain regions. Aims: We hypothesized that cerebellar-cortical resting-state functional connectivity (rsFC) would be altered in cannabis users, relative to their non-using peers. It was also hypothesized that differences in rsFC would be associated with cannabis use features, such as age of initiation and lifetime use. Methods: Cerebellar-cortical and subcortical rsFCs were computed between 28 cerebellar lobules, defined by a spatially unbiased atlas template of the cerebellum, and individual voxels in the cerebral regions, in 41 regular cannabis users (20 female) and healthy non-using peers (N = 31; 18 female). We also investigated associations between rsFC and cannabis use features (e.g. lifetime cannabis use and age of initiation). Results: Cannabis users demonstrated hyperconnectivity between the anterior cerebellar regions (i.e. lobule I-IV) with the posterior cingulate cortex, and hypoconnectivity between the rest of the cerebellum (i.e. Crus I and II, lobule VIIb, VIIIa, VIIIb, IX, and X) and the cortex. No associations were observed between features of cannabis use and rsFC. Conclusions: Cannabis use was associated with altered patterns of rsFC from the cerebellum to the cerebral cortex which may have a downstream impact on behavior and cognition.Item Auditory feature perception and auditory hallucinatory experiences in schizophrenia spectrum disorder(Springer, 2017-09-21) Schnakenberg Martin, Ashley M.; Bartolomeo, Lisa; Howell, Josselyn; Hetrick, William P.; Bolbecker, Amanda R.; Breier, Alan; Kidd, Gary; O’Donnell, Brian F.; Psychiatry, School of MedicineSchizophrenia spectrum disorder (SZ) is associated with deficits in auditory perception as well as auditory verbal hallucinations (AVH). However, the relationship between auditory feature perception and auditory verbal hallucinations (AVH), one of the most commonly occurring symptoms in psychosis, has not been well characterized. This study evaluated perception of a broad range of auditory features in SZ and to determine whether current AVHs relate to auditory feature perception. Auditory perception, including frequency, intensity, duration, pulse-train and temporal order discrimination, as well as an embedded tone task, was assessed in both AVH (n = 20) and non-AVH (n = 24) SZ individuals and in healthy controls (n = 29) with the Test of Basic Auditory Capabilities (TBAC). The Hamilton Program for Schizophrenia Voices Questionnaire (HPSVQ) was used to assess the experience of auditory hallucinations in patients with SZ. Findings suggest that compared to controls, the SZ group had greater deficits on an array of auditory features, with non-AVH SZ individuals showing the most severe degree of abnormality. IQ and measures of cognitive processing were positively associated with performance on the TBAC for all SZ individuals, but not with the HPSVQ scores. These findings indicate that persons with SZ demonstrate impaired auditory perception for a broad range of features. It does not appear that impaired auditory perception is associated with recent auditory verbal hallucinations, but instead associated with the degree of intellectual impairment in SZ.Item Differential Cognitive Performance in Females and Males with Regular Cannabis Use(Cambridge University Press, 2021) Schnakenberg Martin, Ashley M.; D’Souza, Deepak Cyril; Newman, Sharlene D.; Hetrick, William P.; O’Donnell, Brian F.; Psychiatry, School of MedicineObjectives: Preclinical and clinical studies suggest that males and females may be differentially affected by cannabis use. This study evaluated the interaction of cannabis use and biological sex on cognition, and the association between observed cognitive deficits and features of cannabis use. Methods: Cognitive measures were assessed in those with regular, ongoing, cannabis use (N = 40; 22 female) and non-using peers (N = 40; 23 female). Intelligence, psychomotor speed, and verbal working memory were measured with the Wechsler Abbreviated Scale of Intelligence, Digit Symbol Test, and Digit Span and Hopkins Verbal Learning Test, respectively. Associations between cognitive measures and cannabis use features (e.g., lifetime cannabis use, age of initiation, time since last use of cannabis, recent high-concentration tetrahydrocannabinoid exposure) were also evaluated. Results: No main effects of group were observed across measures. Significant interactions between group and biological sex were observed on measures of intelligence, psychomotor speed, and verbal learning, with greatest group differences observed between males with and without regular cannabis use. Psychomotor performance was negatively correlated with lifetime cannabis exposure. Female and male cannabis use groups did not differ in features of cannabis use. Conclusions: Findings suggest that biological sex influences the relationship between cannabis and cognition, with males potentially being more vulnerable to the neurocognitive deficits related to cannabis use.Item Group-Based Metacognitive Reflection and Insight Therapy (MERITg) and Its Relationship to Recovery-Oriented Beliefs in Serious Mental Illness(MDPI, 2024-06-22) Musket, Christie W.; Bullock, Joshua; Fiszdon, Joanna M.; Stacy, Meaghan; Martino, Steve; James, Alison; Lysaker, Paul H.; Schnakenberg Martin, Ashley M.; Psychiatry, School of MedicineGroup-based Metacognitive Reflection and Insight Therapy (MERITg) is the group application of Metacognitive Reflection and Insight Therapy (MERIT), an evidence-based, integrative, recovery-oriented intervention to enhance insight and understanding of oneself and others in individuals with serious mental illness (SMI). MERITg may offer therapeutic interactions between participants that uniquely support recovery. The goal of the current study was to examine the relationship between MERITg participation and recovery-oriented beliefs. Thirty-one participants (outpatient = 21; inpatient = 10) in SMI treatment programs participated in MERITg as an adjunctive treatment. A short form of the Maryland Assessment of Recovery in Serious Mental Illness (MARS-12) was used to assess recovery-oriented beliefs before and after group participation. Recovery-oriented beliefs significantly improved in the outpatient MERITg group but not in the inpatient group, and change in recovery-oriented beliefs was positively correlated with the total number of groups attended. These findings suggest the promise of MERITg for enhancing recovery-oriented beliefs. The potential role of treatment setting is discussed.