Cognitive neuroscience research has begun to explore the mental processes underlying what a belief and what believing are. Recent evidence suggests that believing involves fundamental brain functions that result in meaningful probabilistic representations, called beliefs. When relatively stable, these beliefs allow for guidance of behavior in individuals and social groups. However, they are also fluid and can be modified by new relevant information, interpersonal contact, social pressure, and situational demands. We present a theoretical model of believing that can account for the formation of both empirically grounded and metaphysical beliefs.

Silent reading and reading aloud of German words and pseudowords were used in a PET study using ( 15 O) butanol to examine the neural correlates of reading and of the phonological conversion of legal letter strings, with or without meaning. The results of 11 healthy, right-handed volunteers in the age range of 25 to 30 years showed activation of the lingual gyri during silent reading in comparison with viewing a fixation cross. Comparisons between the reading of words and pseudo-words suggest the involvement of the middle temporal gyri in retrieving both the phonological and semantic code for words. The reading of pseudowords activates the left inferior frontal gyrus, including the ventral part of Broca's area, to a larger extent than the reading of words. This suggests that this area might be involved in the sublexical conversion of orthographic input strings into phonological output codes. (Pre)motor areas were found to be activated during both silent reading and reading aloud. On the basis of the obtained activation patterns, it is hypothesized that the articulation of high-frequency syllables requires the retrieval of their concomitant articulatory gestures from the SMA and that the articulation of low-frequency syllables recruits the left medial premotor cortex.