Andrew Kemp PhD, MAPS

Research Interests:

• cognitive and affective neuroscience
• neuropsychiatry and mental health
• neuropsychopharmacology and genetics
• biological bases of behaviour and individual differences
• positive psychology

I am always interested in possibilities to collaborate with other researchers and encourage potential Honours and PhD students to contact me to discuss research opportunities.

Facilities:

My laboratory has access to the latest state-of-the-art technologies and facilities including neuroimaging, electrophysiology and neuropsychology.

Funding & Grants Information:

My research is funded by the National Health & Medical Research Council (NHMRC) and the Australian Research Council (ARC).

Selected Publications:

1. Bryant, R.A., Felmingham, K.L., Kemp, A.H.; Barton, M., Rennie, C., Gordon, E., Williams, L.M. (2005). Neural Networks of Information Processing in Posttraumatic Stress Disorder: A Functional MRI Study. Biological Psychiatry, 58, 111—18. (2005 IF: 6.779) EXTENDED BIOLOGICAL MODELS OF PTSD BY DEMONSTRATING THAT THE PATTERN OF MPFC DYSREGULATION IN PTSD IS STIMULUS DEPENDENT. [abstract]
2. Das, P., Kemp, A.H., Liddell, B.J., Brown, K.J., Olivieri, G., Peduto, A., Gordon, E., Williams, L.M. (2005). Pathways for fear perception: Modulation Of Amygdala Activity By The Thalamo-Cortical Systems. Neuroimage, 26, 141—48. (2005 IF: 5.288)* FIRST DEMONSTRATION OF BRAIN CONNECTIVITY DURING FEAR PROCESSING IN VIVO. [abstract]
3. Felmingham, K., Kemp, A.H., Williams, L.M., Das, P., Hughes, G., Peduto, A., Bryant, R. (2007). Changes in anterior cingulate and amygdala after cognitive behaviour therapy of posttraumatic stress disorder. Psychological Science, 18, 127—29. (2005 IF: 4.502) CLARIFIED THE IMPACT OF EXPOSURE-BASED TREATMENT OF PTSD ON NEUROBIOLOGY. [abstract]
4. Gatt, J.M., Nemeroff, C.B., Dobson-Stone, C., Paul, R.H., Bryant, R.A., Schofield, P.R., Gordon, E., Kemp, A.H., Williams, L.M. (in press). Interactions between BDNF Val66Met polymorphism and early life stress predict brain and arousal pathways to syndromal depression and anxiety. Molecular Psychiatry. Jan 20. [Epub ahead of print]. (2007 IF: 10.900). CLARIFIED DIFFERENTIAL GENE-BRAIN-BEHAVIOURAL PATHWAYS IN DEPRESION AND ANXIETY DESPITE SUBSTANTIAL OVERLAP IN SYMPTOMATOLOGY. [abstract]
5. Kemp, A.H., Gordon, E., Rush, A.J., Williams, L.M., (2008). Improving the prediction of Treatment response in depression: Integration of clinical, cognitive, psychophysiological, neuroimaging and genetic measures. CNS Spectrums, 13(12):1066-1086 ; quiz 1087-8. (2007 IF: 3.409 for Psychiatry). FIRST COMPREHENSIVE REVIEW OF TREATMENT PREDICTORS OBTAINED FROM MULTIPLE TECHNIQUES. [abstract]
6. Kemp, A.H., Gray, M.A., Silberstein, R.B., Armstrong, S.M. & Nathan, P.J. (2005). Augmentation of Serotonin Enhances Pleasant and Suppresses Unpleasant Electrophysiological Responses to Visual Emotional Stimuli in Humans. NeuroImage, 22, 1084—96. (2005 IF: 5.288) DISCOVERED THAT 1 DOSE OF AN ANTIDEPRESSANT IMPACTS EMOTIONAL PROCESSING. [abstract]
7. Kemp, A.H., Silberstein, R.B., Armstrong, S.M. & Nathan, P.J. (2004). Gender Differences In The Cortical Electrophysiological Processing Of Visual Emotional Stimuli. NeuroImage, 21, 632—46. (2005 IF: 5.288)* CLEAR DEMONSTRATION OF THE IMPACT OF GENDER DIFFERENCES IN EMOTIONAL PROCESSING. [abstract]
8. Kemp, A.H., Hopkinson, P.J., Hermens, D.F., Rowe, D.L., Sumich, A.L., Clark, C.R., et al., (in press). Fronto-Temporal Alterations Within the First 200ms During an Attentional Task Distinguish Major Depression, Non-clinical Participants with Depressed Mood and Healthy Controls: A Potential Biomarker? Human Brain Mapping, 30(2): 602-614. (2006 IF: 4.888)* IDENTIFIED A POTENTIAL BIOMARKER OF ATTENTIONAL IMPAIRMENT IN DEPRESSION. [abstract]
9. Williams, L.M., Brown, K.J., Palmer, D., Liddell, B.J., Kemp, A.H., Olivieri, G., Peduto, A.S., Gordon, E (2006). The ‘mellow years’: Neural basis of improving emotional stability over age. Journal of Neuroscience, 26, 6422—30. (2005 IF: 7.506) INNOVATIVE ASSESSMENT USING AN INTEGRATIVE APPROACH TO EXAMINE EMOTIONAL-RELATED CHANGE OVER 7-DECADES. [abstract]
10. Williams, L.M., Das, P., Liddell, B.J., Kemp, A.H., Rennie, C.J., Gordon, E. (2006). Mode of functional connectivity in amygdala pathways dissociates level of awareness for signals of fear. Journal of Neuroscience, 26, 9264—71. (2005 IF: 7.506) DEMONSTRATED THAT AWARENESS DEPRENDS ON CONNECTIONS IN THE BRAIN RATHER THAN ACTIVATION IN SPECIFIC STRUCTURES. [abstract]

Current Projects

Predicting Response to Antidepressant Treatment: A prolonged effort to find the right medication for a particular patient results in prolonged suffering, substantial morbidity, and potential mortality, as well as absence from work and other productive activities and increased burden for their family/caregivers. Each treatment trial may require 4–8 weeks to determine if the treatment will be effective. This study will determine the ability to predict treatment response and non-response. We have recently published a peer-reviewed review article, which comprehensively reviews potential treatment predictors Kemp et al., (2008), CNS Spectrums, 13(12):1066-1086. Available at: http://www.cnsspectrums.com/aspx/articledetail.aspx?articleid=1913

Towards a Better Understanding of Depression Heterogeneity: Although current classifications of depression suggest a homogeneous disorder, depression comprises multiple subtypes and significant co-morbidity (especially anxiety and substance abuse), which may contribute to whether or not a patient responds to antidepressant treatment. This project seeks to better determine the impact of more homogeneous subtypes of depression on neuropsychological and brain function.

Neurobiological Basis for Depression and Anxiety: Current theoretical models of emotion highlight the importance of distinguishing depression and anxiety. This project will critically evaluate a number of these models and provide a practical framework that could be applied in future studies to better understand the neural substrates that contribute to variation in anxiety and depressed mood. We have recently published a peer-reviewed review article, which provides a theoretical rationale for this project: Kemp & Felmingham (2008), Psychology & Neuroscience, 1(2):171-175. Available at: http://www.psycneuro.org/index.php/psycneuro/article/view/41/134

Honours Student Opportunities

Psychometric Specificity of Depression and Anxiety: The tripartite model suggests that depression and anxiety is marked by increased negative affect and, once clinical status is reached, may be distinguished on the basis of anhedonia and hyperarousal. The quadripartite model proposes that symptoms may be classified along two quantitative dimensions including the magnitude of the general distress component and the level of specifity vis-à-vis depression versus anxiety. In addition, the valence – arousal model distinguishes between anxious apprehension (e.g. worry, which is consistent with symptoms displayed by patients with generalized anxiety disorder) and anxious arousal (which is consistent with symptoms displayed by patients with panic disorder and post-traumatic stress disorder). The aim of this study is to determine the validity of these models in distinguishing depression and anxiety using a variety of questionnaires. It is hypothesised that depression and anxiety will display increased negative affect relative to healthy controls, but that negative affect will not distinguish these disorders. In addition, clinical depression and clinical anxiety will be distinguished on the basis of anhedonia and arousal, such that depression will display heightened anhedonia (relative to anxiety, and healthy controls) and that anxiety will display heightened arousal (relative to healthy controls, and MDD) (although arousal displayed in participants with anxiety will depend on level of anxious apprehension versus arousal as determined using the Depression, Anxiety and Stress scales). Key reference: Watson, Annual Review of Clinical Psychology 5: 221-47.

Visual Awareness and Detection of Affective Images: Impact of Depression and Anxiety Affective images are processed rapidly and may impact on brain and body function despite not being consciously perceived. While neuroimaging and skin conductance studies are increasingly reporting on the impact of non-consciously presented emotional stimuli. The degree to which these stimuli can be consciously detected remains a subject of considerable debate. Furthermore, while Pessoa and colleagues (2005) have reported that 64% of participants are capable of reliably detecting fearful facial expressions presented at 33ms, the extent to which these findings can be generalised to more complex emotion stimuli remains unclear. Another crucial question is the degree to which mood and anxiety impacts on visual awareness. In this regard, it is possible that participants with anxiety are more likely to detect negative stimuli more quickly than non-anxious participants. Key references: Pessoa et al., 2005, Emotion 5: 243-247.

The Neurobiological Specificity of Depression and Anxiety: Current theoretical models of emotion highlight the importance of distinguishing depression and anxiety. One influential model, the tripartite model, suggests that depression and anxiety is marked by increased negative affect and, once clinical status is reached, may be distinguished on the basis of anhedonia and hyperarousal. Yet this model is based predominantly on questionnaire data. A more direct and powerful method to test this model is to identify biological markers of anhedonia and arousal. Neuroimaging studies highlight a role for ventro-lateral PFC and caudate/putamen in anhedonia and right temporoparietal cortex and amygdala in arousal. Recent research further highlights common and distinct neurobiological perturbations in depression and anxiety, however, studies have seldom compared individuals with depression and anxiety. Other influential models, including the approach-withdrawal and valence-arousal models, distinguish between depression and anxiety such that depression is associated with reduced approach-behaviour, lower levels of positive affect and hypoarousal, while anxiety is associated with increased withdrawal-behaviour, higher levels of negative affect and hyperarousal. These models are also based on biological measures, yet research has generally restricted empirical enquiry into resting state paradigms, without extending investigation into emotion processing paradigms to maximally challenge impaired neural circuitry. The goal of this project is to identify neurobiological markers of depression and anxiety during conscious emotional processing using functional magnetic resonance imaging. Key reference: Kemp & Felmingham, 2008, Psychology & Neuroscience 1: 171-175.

Impact of Vipassana Meditation on Psychophysiology: Affective neuroscience has progressed from understanding the neurobiological correlates of the basic emotions to more complex social emotions such as empathy and compassion. Better understanding the neurobiological basis and the regulation of social emotions and the impact of mindfulness meditation to improve the regulation of these emotions are important areas of research given that emotion is a key vulnerability factor to psychiatric illness. Moreover, the utility of meditative practice in non-clinical populations is highlighted by findings indicating that a focus on health rather than illness may reduce health costs and increase longevity. The goal of this project is to examine the impact of a 10-day intensive vipassana training program on neural function and behaviour. Key reference: Tang et al., Proceedings of the National Academy of Sciences of the United States of America 106: 8865-70.

Impact of Oxytocin on Psychophysiology: Social behaviour is a crucial component of most aspects of human life and abnormalities in social behaviour underlie almost all mental health disorders (e.g., social anxiety and depression). Oxytocin (OT) has emerged as having a central role in the regulation of approach and withdrawal behaviours, yet until recently, research findings were largely based on animal studies. The goal of this project is to examine the effect of OT using psychophysiological procedures including measures of the electroencephalogram and heart rate. A number of theories (including the approach-withdrawal, and polyvagal theories) propose a specific relationship between these psychophysiological measures and approach and withdrawal behaviors, providing a basis for explicit hypotheses to be made. Key reference: Donaldson & Young, Science (New York, N.Y.) 322: 900-904.

Impact of Alcohol on Heart Rate Variability: Heart Rate Variability (HRV) indexes beat-to-beat changes in heart rate and is mediated by the parasympathetic and sympathetic nervous systems. High parasympathetic tone protects against possible adverse cardiac events, while increased sympathetic tone heightens risk of sudden cardiac death.  Reduced HRV has been related to impaired emotional regulation and is present in depression and anxiety disorders. Alcohol abuse is a commonly comorbid with mental illness, however, few studies have investigated the impact of alcohol on HRV experimentally. The few studies that have investigated this have revealed conflicting results, which may be due to not controlling for mood effects. For instance, alcohol consumption may enhance positive affect and suppress negative affect thereby increasing HRV. Alternatively, alcohol consumption may impair emotional regulation thereby decreasing HRV. Thayer and colleagues have reported that alcoholics may have lower levels of HRV compared with a control group, although an increase in HRV was observed in the alcoholics when exposed to an imaginary alcohol script. The goal of this project is to examine the impact of acute alcohol consumption in low, moderate and heavy drinkers on HRV while controlling for state and trait mood. Key reference: Ingjaldsson et al., 2003, Biological Psychiatry, 54: 1427-1436.