assignment
NEUR3003 Marking rubric 2019 Literature Review Task In consultation with their supervisors, students should define a specific area of research on which to base their reading and then prepare a 2000-word literature review on this area. Note that the review should have an abstract no longer than 1250 characters (excluding spaces), it should have a running title of five words. The word limit is 2000 words and it may contain a maximum of four figures Assessment criteria for Final research essay/report Essays will be assessed by supervisors or another suitable academic using the marking sheet below, against Faculty grade descriptors in relation to each of the following aspects. (1) CLARITY OF PURPOSE: Does review have a central theme or hypothesis and does the title and abstract clearly and accurately summarise that theme? (20%) (2) INTEGRATION: Does the review intelligently integrate the findings of multiple research papers in a logical sequence so as to develop the central theme or working hypothesis of the review? (20%) (3) SCIENTIFIC DEPTH: Does the student convincingly explain the nature of the evidence from the individual papers upon which her/his key conclusions are based? (20%) (4) APPROPRIATE STYLE and QUALITY CONTROL: The essay should follow the style of a review article in a scientific journal, should be type written using formal English. Is the text unambiguous and easy to read? Is it largely free of typographical and spelling errors? Is the source of evidence properly cited in the text with the citations all listed at the end in a consistent and appropriate format (20%) (5) CONCLUSIONS AND SIGNIFICANCE: How well are the conclusions supported by the evidence presented? How convincingly do the conclusions address the issue/hypothesis that was defined by the title and abstract? (20%) These criteria will be assessed with reference to the grade descriptors: 50-64 PASS: The work addresses the issues posed by the task; the level of consideration is adequate in the context of the aims, objectives and expected outcomes of the unit of study, but lacks a demonstrated depth of understanding, or suggests lack of understanding of some facts. 65-74 CREDIT: The work is clearly presented, thorough and addresses the issues posed by the task at a level of consideration consistent with the aims, objectives and expected outcomes of the unit of study. The work demonstrates a good grasp of the facts. 75-84 DISTINCTION: The work meets the criteria for a CREDIT, but in addition is well written, and demonstrates understanding of the subject matter as described by the aims, objectives and expected outcomes of the unit of study, at the highest level. 85-100 HIGH DISTINCTION: The work meets the criteria for a DISTINCTION, but in addition demonstrates inquiry into, understanding of and presentation of the subject matter significantly beyond what is expected in the context of the aims, objectives and expected outcomes of the unit of study. A marking rubric for the final report/essay follows 1 Marking Rubric for Literature Review for Student name: Total (/100%): Exemplary Very Good Good Acceptable Not acceptable HD D C P CLARITY OF PURPOSE: Does review have a central theme or hypothesis and do the title and abstract (1250 character limit) clearly and accurately summarise that theme? 20 19 17 16 14 12 11 10 INTEGRATION: Does the review intelligently integrate the findings of multiple research papers in a logical sequence so as to develop the central theme or working hypothesis of the review? 20 19 17 16 14 12 11 10 SCIENTIFIC DEPTH: Does the student convincingly explain the nature of the evidence from the individual papers upon which her/his key conclusions are based? 20 19 17 16 14 12 11 10 APPROPRIATE STYLE and QUALITY CONTROL: The essay should follow the style of a review article in a scientific journal, should be type written using formal English. Is the text unambiguous and easy to read? Is it largely free of typographical and spelling errors? Is the source of evidence properly cited in the text with the citations all listed at the end using the Harvard Style? 20 19 17 16 14 12 11 10 CONCLUSIONS AND SIGNIFICANCE: How well are the conclusions supported by the evidence presented? How convincingly do the conclusions address the issue/hypothesis that was defined by the title and abstract? 20 19 17 16 14 12 11 10 Adolescent cannabis use and neurodevelopment Adolescent cannabis use and neurodevelopment: a review of anatomical and functional studies and their clinical implications (84) Cannabis use and its effects on development in adolescents is increasingly being studied due to its prevalence which raises concerns about subsequent dysfunction and dysregulation of neurodevelopmental mechanisms. This paper addresses overall concerns regarding whole brain functional connectivity and cortical abnormalities then moves onto consider specific regions of the cortex and sub-cortex and observed changes in the presence of heavy cannabis use, discussing evidence suggesting poorer mental health outcomes such as anxiety, depression and psychosis. This review aims to explore the literature surrounding adolescent cannabis use and the significance of impacts on neurodevelopment that would have taken place if not for the presumed interference. Studies have examined the issue of causality and the direction of which came first – substance use or poor mental health outcomes. Anatomical and functional studies answer to questions of general neurobiological effects, specific neuroanatomical abnormalities and psychological impairments. In all of the studies evaluated there was consistent use of controls who were matched to the cannabis group in age and demographics while users were not especially distinguished between use and abuse but ranged from 5-6 joints per day and being abstinent for 4-6 weeks prior to the study. The researchers stipulated that participants were screened for no other substances and that due to the nature of the sample pool participants were predominantly male. Is cannabis use in adolescents associated with neurobiological deficits? Neurobiological deficits associated with cannabis use in adolescents have been studied in the functional connectivity of the whole brain. In a study of 15-18 year olds (n=35) intrinsic activity was measured using resting state fMRI to show that activity was increased in the right hemisphere with increased intra-hemispheric connectivity (Orr et al., 2013). However, inter-hemispheric activity was decreased suggesting less connectivity between the left and right hemispheres and more within the right side. A study of 14-18 year olds (n=69) also using fMRI targeted the frontal-temporal network to show bilateral activation in the medial temporal lobe – higher cannabis use was correlated with higher activity in the middle frontal gyrus and lower activity in the middle temporal gyrus (Houck et al., 2013). These findings suggest changes in functional connectivity in crucial parts of the developing brain that may explain neurobiological deficits.1 Moreover, studies have shown that cannabis use in adolescents was associated with diffusion abnormalities and adverse effects on developing networks of the brain. One such study (n=28) used MRI imaging to study frontotemporal connections via the arcuate fasciculus, finding that heavy cannabis use was correlated with decreased measures of fractional anisotropy and increased measures of radial diffusivity and trace (Ashtari et al., 2009). The results are shown in Table 1. Another MRI study of 10-21 year olds (n=65) used a longitudinal design to study networks relevant to neurodevelopment, observing changes in the anterior cingulate cortex (Camchong et al., 2017). There were further changes that reflected a decreased overall functional connectivity relating to previous findings of effects on the whole brain. Longitudinal studies establish a timeline of progressive changes and control for individual risk factors and variability, in contrast with studies that use group-difference comparison cohorts. Assuming a causal relationship, meta-analyses of studies of cannabis use in adolescents suggest interference with cognitive functioning and mental health outcomes with the first containing only observational and cross-sectional studies. A meta-analysis of 69 studies with 2152 young cannabis users and 6575 comparison subjects showed a statistically significant but small effect on faculties relating to cognition (Scott et al., 2018). There were no severe effects noted in learning, attention, abstraction, inhibition, speed of processing, delayed and working memory and no significant effects on language, visuospatial or motor skills. A meta-analysis of 11 longitudinal and prospective studies (n=23317) looked at odds ratios to predict the development of mental illnesses and found statistically significant risks for depression and suicidal behaviours but not for anxiety (Gobbi et al., 2019). By looking at clinical outcomes of neurodevelopment such as executive functions and mental wellbeing, studies can identify possible detriments. 2 Fibre bundle Diffusion measures Heavy cannabis use (n=14) Left superior longitudinal fasciculus (SLF) Fractional anisotropy Decreased (p=0.11) Radial diffusivity Increased (p=0.02) Trace Increased (p=0.04) Right superior longitudinal fasciculus (SLF) Fractional anisotropy Decreased (p=0.02) Radial diffusivity Increased (p=0.01) Trace Increased (p=0.03) Table 1 Effects of heavy cannabis use on diffusion measures of the superior longitudinal fasciculus (SLF). Diffusion measures were found to be decreased in fractional anisotropy and increased in radial diffusivity and trace of the left and right SLF. Note that the value for fractional anisotropy of the left SLP is not statistically significant (Ashtari et al., 2009). Anatomical studies: which specific areas of the brain are thought to be affected? Anatomical studies have used a variety of methods to measure the effects of adolescent cannabis use on specific areas of the developing brain including structural MRI, arterial spin labelling, voxel-based morphometry, proton magnetic resonance spectroscopy and stimuli-activation tasks. One study (n=46) focused on the cerebral cortex and measured blood flow using non-invasive arterial spin labelling to determine neurovascular status (Jacobus et al., 2012). It showed decreased blood flow in four cortical regions: the left superior and middle temporal gyri, left insula, medial frontal gyrus and left supramarginal gyrus and increased blood flow to the right precuneus, shown in Figure 1. A study of 16-19