Fred Mast
Embodied Cognition and Sensorimotor Processing
Authors
Fred Mast (University of Lausanne)
Cognitive psychologists have moved away from the study of formal operations on abstract symbols and rather focus on the study of situated-appropriate behavior as it is involved when we anticipate future events or when we plan an action. It has been shown that mechanisms normally involved in direct interactions with the environment are also engaged when no immediate response or action is required. This is the reason why the brain's sensory and motor systems are so fundamentally involved in many cognitive processes. I will present recent findings (based on fMRI and psychophysical techniques) from our group showing how motor, vestibular, and visual perception is nested and intertwined with cognitive processes. The results suggest the involvement of early brain structures like visual cortex when we extract information from mental images in the absence of any visual input. In this context, the function of mental imagery is conceived as serving the purpose to anticipate future events. Regarding the motor aspects we investigated how cognitive processes are specifically influenced by concomitant vestibular stimulation or motor actions, thereby also testing the influence in the reverse direction (from cognition to motor execution). We were able to demonstrate how motor performance can be improved by repeated motor imagery training. The results will be discussed with respect to plasticity and the possibilities given by mental training techniques to improve cognitive capacities.
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Lutz Jäncke
Neuropsychology of Spatial Presence
Authors
Lutz Jäncke (University of Zurich)
Spatial presence is an unusual concept for psychologists and neuroscientists. Spatial presence is considered a sense of being physically situated within a spatial environment portrayed by a medium (e.g., television, virtual reality). Although this feeling is prominent and frequently experienced in our modern society with extensive use of video games, internet operations, watching TV or movies, only little is known about the neural underpinnings of this extraordinary and important psychological aspect. In this talk I will present recent findings of our group demonstrating the importance of the dorsal frontal cortex and the interconnected parietal lobe for the modulation and generation of spatial presence. I will also discuss the influence of frontal cortex maturation on the modulation of spatial presence experience. For example, the frontal cortex matures relatively late (until the age of 18 years) and is the first to degrade in the context of normal and pathological aging. Associated with this age related frontal cortex changes there are also changes with respect to the spatial presence experience. Although neuroanatomical maturation influences spatial presence experience there are also learning and experience related influences on frontal cortex functions and the associated spatial presence experience. These experience dependent changes of spatial presence experience are also discussed with respect to possible consequences for education and handling of new media.
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Peter Klaver
Neural Mechanisms of Memory: the Role of Sensory, Conceptual and Response Information on Memory Operations
Authors
Peter Klaver (University Children's Hospital Zurich)
Memory studies in recent years have delineated a network of brain areas including the medial temporal lobe (MTL), frontal cortex and the parietal lobule as key areas in the establishment of stable memory representations and their retrieval. Yet, the latter two areas are primarily thought to reflect directing and successful orientation towards memory representations, rather than the actual access to specific memories that are associated with concepts and sensory information in the outer world. So far we know little about the involvement of brain areas that are associated with sensory processing in the establishment of memory representations. Here, I present functional brain imaging experiments to demonstrate the role of stimulus and response information in memory operations. The first repetition priming study demonstrates the sensitivity of memory related brain activity to stimulus-response associations, attention and picture-word priming. In a recognition memory study using high and low imageable words we also show that word image ability induces memory related activity in brain areas related to object processing. Together, these studies emphasize the role of sensory processing areas in memory operations. Brain activity in these areas depended highly on learned semantic and response associations. These findings are discussed in the context of training and education programs and an outlook is made to developmental studies of memory.
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Boris B. Quednow
The Neuropsychological Sequelae of Ecstasy Use
Authors
Boris B. Quednow (University of Zurich)
A representative survey from the Swiss Institute for the Prevention of Alcoholism and Drug Addiction revealed that in 2002, 2.2% of young adults (age 15-39 years) had consumed ecstasy tablets containing the substituted amphetamine derivate MDMA (3,4-methylenedioxymethamphetamine) at least once in their lifetime. According to this report, MDMA placed number three in the ranking of most popular illicit drugs used in Switzerland. Chronic administration of MDMA is associated with long-term depletion of serotonin (5-HT) and loss of 5-HT axons in the brains of rodents and non-human primates. In addition, accumulating evidence suggests that recreational MDMA consumption may also affect the human 5-HT system. In humans, 5-HT is supposed to play an important role in the regulation of memory, impulse control and decision-making cognition. In fact, a number of cross-sectional studies reported deficits in various neurocognitive domains in MDMA users and especially memory disturbances have been consistently shown. However, most of these studies were criticized with respect to confounding factors such as polydrug use, pre-existing traits, and differences in lifestyle. Questions about the neurotoxic effects of MDMA remain highly topical in the face of its popularity among young people. However, due to the influence of confounding factors in recent cross-sectional studies more longitudinal studies are needed in order to investigate the possible long-term sequelae of ecstasy use in humans.
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