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A number of empirical studies indicate that both laypeople and experts struggle with Bayesian inference problems that involve updating the probability of a hypothesis in light of a relevant piece of evidence. Such difficulties, and in particular a general tendency to discount or even ignore base rate information, appear to be more pronounced when hypothesis and evidence have medical rather than non-medical content (Siegrist & Keller, 2011; Binder et al., 2015; Böcherer-Linder et al., 2019, Bruckmaier et al., 2019; but see Pighin et al, 2017, for a different finding). In order to account for this pattern, some authors speculated that reasoning on medical hypotheses might be particularly intimidating or unfamiliar to participants (Johnson & Tubau, 2015; Siegrist & Keller, 2011), while others argued that medical tests might be misinterpreted as being infallible, despite information given to the contrary (Hammerton, 1973). Another possibility is that the medical problems considered in the literature are simply more difficult because they typically depict hypotheses with extremely low priors, which tend to be rare in other contexts. Overall, due to the lack of systematicity in the comparison across contexts in the literature, it remains unclear whether the difficulty of handling Bayesian inferences is actually more severe in the medical domain and, if so, to what this would be ascribable. The aim of this study is to answer these questions.

Data for Filimon, F.; Nelson, J.D.; Sejnowski, T. J.; Sereno, M. I.; and Cottrell, G. W. (2020). "The Ventral Striatum dissociates information expectation, reward anticipation, and reward receipt." Proceedings of the National Academy of Sciences of the USA. doi: doi:10.1073/pnas.1911778117, http://www.pnas.org/cgi/doi/10.1073/pnas.1911778117

A number of empirical studies indicate that both laypeople and experts struggle with Bayesian inference problems that involve updating the probability of a hypothesis in light of a relevant piece of evidence. Such difficulties, and in particular a general tendency to discount or even ignore base rate information, appear to be more pronounced when hypothesis and evidence have medical rather than non-medical content (Siegrist & Keller, 2011; Binder et al., 2015; Böcherer-Linder et al., 2019, Bruckmaier et al., 2019; but see Pighin et al, 2017, for a different finding). In order to account for this pattern, some authors speculated that reasoning on medical hypotheses might be particularly intimidating or unfamiliar to participants (Johnson & Tubau, 2015; Siegrist & Keller, 2011), while others argued that medical tests might be misinterpreted as being infallible, despite information given to the contrary (Hammerton, 1973). Another possibility is that the medical problems considered in the literature are simply more difficult because they typically depict hypotheses with extremely low priors, which tend to be rare in other contexts. Overall, due to the lack of systematicity in the comparison across contexts in the literature, it remains unclear whether the difficulty of handling Bayesian inferences is actually more severe in the medical domain and, if so, to what this would be ascribable. The aim of this study is to answer these questions.

A number of empirical studies indicate that both laypeople and experts struggle with Bayesian inference problems that involve updating the probability of a hypothesis in light of a relevant piece of evidence. Such difficulties, and in particular a general tendency to discount or even ignore base rate information, appear to be more pronounced when hypothesis and evidence have medical rather than non-medical content (Siegrist & Keller, 2011; Binder et al., 2015; Böcherer-Linder et al., 2019, Bruckmaier et al., 2019; but see Pighin et al., 2017, for a different finding). In order to account for this pattern, some authors speculated that reasoning on medical hypotheses might be particularly intimidating or unfamiliar to participants (Johnson & Tubau, 2015; Siegrist & Keller, 2011), while others argued that medical tests might be misinterpreted as being infallible, despite information given to the contrary (Hammerton, 1973). Another possibility is that the medical problems considered in the literature are simply more difficult because they typically depict hypotheses with extremely low priors, which tend to be rare in other contexts. Overall, due to the lack of systematicity in the comparison across contexts in the literature, it remains unclear whether the difficulty of handling Bayesian inferences is actually more severe in the medical domain and, if so, to what this would be ascribable. The aim of this study is to answer these questions.

The posterior parietal cortex of human and non-human primates has been implicated in sensorimotor transformations, whereby sensory input (vision, touch, sound) is converted into motor commands. For instance, visual information regarding a target can be used to appropriately guide reaching movements towards the relevant part of space. These sensorimotor and multisensory representations suggest that the role of the posterior parietal lobe is to implement perception for action, rather than create a passive, purely perceptual representation of space. This dissertation consists of three different studies that map such multimodal and sensorimotor representations in the human brain, using functional magnetic resonance imaging (fMRI). The first study shows that observation, imagery, and execution of reaching rely on similar neural substrates in the posterior parietal lobe, specifically involving more superior (dorsal) areas. These 'mirror neuron' activations are in agreement with macaque parieto-frontal circuits underlying reaching movements, and differ from the more ventral (inferior) activations for grasping or for hand- object interactions. This suggests that (visuomotor) mirror neurons are specific to the hand action that is executed (reaching versus grasping). The second study attempts to dissociate visual and proprioceptive feedback from the reaching hand, to identify visuomotor and proprioceptive-motor areas involved in the control of reaching. Reaching without visual feedback from the moving hand involves more anterior and medial parietal areas than reaching with visual feedback. This indicates a posterior- to-anterior organization for sensorimotor representations that use visual versus somatosensory input, respectively, within posterior parietal cortex. Finally, the third study investigates tactile and visual representations of target location. Identifying target location using exploratory hand movements in the absence of visual input activates similar intraparietal and superior parietal areas as does visual identification of spatial location. The common activation by visual and tactile input suggests multisensory processing in these areas

The use and neural representation of egocentric spatial reference frames is well-documented. In contrast, whether the brain represents spatial relationships between objects in allocentric, object-centered, or world-centered coordinates is debated. Here, I review behavioral, neuropsychological, neurophysiological (neuronal recording), and neuroimaging evidence for and against allocentric, object-centered, or world-centered spatial reference frames. Based on theoretical considerations, simulations, and empirical findings from spatial navigation, spatial judgments, and goal-directed movements, I suggest that all spatial representations may in fact be dependent on egocentric reference frames.