Current Research

Learning, neuronal plasticity and psychophathology

Research on this topic targets the development and maintenance of emotional memories and their neuronal correlates in the context of psychopathology. Herta Flor is the spokesperson of DFG collaborative research grant 636 on „Learning, memory and neuronal plasticity: Implications for psychopathology“. Rather than taking a nosological approach to mental disorder, which leads to the problem of overlapping psychopathological characteristics, similarities and differences of the underlying mechanisms of learning and neural plasticity across a variety of disorders are examined. The Flor group pursues the role of basic associative and non-associative learning mechanisms and their neuronal correlates, which are fundamental for the understanding of disorders characterized by hyper excitable neuronal fear circuits (e.g., post-traumatic stress disorder, social phobia), disorders characterized by a deficit in associative learning of aversive consequences(e.g. psychopathy) as well as disorders characterized by altered appetitive and aversive motivational processes (e.g. depression, bipolar disorder, addiction). One major theme is the relative contribution of learning processes and genetic variables in the development of these disorders. Behavioral and combined pharmacological-behavioral interventions, that address learning related maladaptive plasticity are developed and their influence on cortical and subcortical plasticity are studied. The group is also involved in a collaborative EU grant that studies reinforcement-related learning processes, their neuronal correlates and genetic determinants with respect to the development of mental disorders in adolescents. Finally, aging-related alterations in memory and learning and associated neuronal plasticity are also investigated.
 
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Fig. 1: T-maps revealing increases in functional coupling for the contrasts between genotype-groups during the early acquisition phase/extinction phase and genotype dependent functional coupling during early acquisition between left amygdala and prefrontal cortex, and during the extinction phase between left prefrontal cortex and left amygdala.

Learning and neuronal plasticity in chronic pain and abnormal body sensation

The Flor group was the first to describe the role of cortical reorganization for the development and maintenance of phantom limb pain as well as other pain syndromes such as chronic back pain and fibromyalgia. Within the framework of the DFG Clinical Research Group “Learning, Plasticity and Pain” (CRG 107) and within two BMBF-funded collaborative grants „Pain Perception“ and „Neuropathic Pain“ cortical and subcortical alterations related to chronic pain are examined and novel treatment options that target the extinction of central pain memories by behavioral and pharmacological interventions are developed and tested. Another focus is the development of indicators for differential assignments of treatments to psychologically and neurobiologically characterized subgroups of pain patients. In this context we are also studying how early pain experience may affect the processing of nociceptive input in children and how this may induce neuronal plasticity of the somatosensory system. A related EU grant focuses upon the development of innovative procedures to assess phantom phenomena and the exploration of the bases of phantom perception and phantom pain. The differential contribution of frontal and parietal brain areas to painful versus nonpainful phantoms and related body illusions is examined. Novel brain-based interventions that use brain-computerinterfaces, transcranial magnetic stimulation, mirror treatment or virtual reality are examined in their capabilityto alter central processes involved in pain and abnormal somatosensory phenomena.

Fig.2: The mirror box experiment. When a mirror is placed between the two hands of healthy persons or between the intact and phantom hand in amputees, movements of the hand that can be seen in the mirror are perceived as movements of the hand that is hidden behind the mirror(or the phantom in amputees). The brain activation that is then seen in primary somatosensory and motor cortex is not only present contralateral to the moved hand but can also be seen in the hemisphere contralateral to the hand that is perceived in the mirror. Activation in the brain is thus also related to perceived not only to actual movement.

Neuronal plasticity in the auditory system

One important line of research concerns the contribution of neuronal plasticity in the auditory system to the development and maintenance of Tinnitus symptoms. After having demonstrated that Tinnitus phenomena are associated with a reorganization of the tonotopic map in primary auditory cortex and general cortical hyperexcitability, we have developed several new approaches to the treatment of Tinnitus. These include behavioral auditory discrimination and extinction trainings with or without additional pharmacological interventions designed to enhance extinction processes. Our most recent research focuses on the interaction of limbic and auditory areas in the processing of emotional stimuli in Tinnitus patients and factors that contribute to the long-term-development of Tinnitus. This research is currently being extended to focus on affective sensory interaction and the brain processes involved in these interactions in general.

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Fig. 3: Tinnitus sufferers showed a higher BOLD response in the left auditory association cortex (BA 22) to negative versus neutral pictures compared to controls.

Method development

In all research areas methods of experimental psychology are combined with non invasive brain imaging, brain stimulation and peripheral psychophysiological methods as well as genetic testing and behavioral and pharmacological interventions to comprehensively study brain-behavior interactions in healthy humans and patients. A special focus is on the development of multimodal imaging methods that integrates structural and functional aspects and trace also dynamic alterations of cortical and subcortical changes related to the perceptual phenomena studied by the group. This also includes the analyses of the interaction between peripheral and central physiological changes. These methodological developments are made in close interaction with the members of the South German Brain Imaging Center that includes researchers from the Universities of Mannheim and Heidelberg as well as the Central Institute of Mental Health.

Editor: A. Summerfield
Latest Revision: 2013-02-07
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