In this study, we investigated the neural substrate involved in the comprehension of novel metaphoric sentences by comparing the findings to those obtained with literal and anomalous sentences using event-related functional magnetic resonance imaging (fMRI). Stimuli consisted of 63 copula sentences ("An A is a B") in Japanese with metaphorical, literal, or anomalous meanings. Thirteen normal participants read these sentences silently and responded as to whether or not they could understand the meaning of each sentence. When participants read metaphoric sentences in contrast to literal sentences, higher activation was seen in the left medial frontal cortex (MeFC: Brodmann's area (BA) 9/10), the left superior frontal cortex (SFC: BA 9), and the left inferior frontal cortex (IFC: BA 45). The opposite contrast (literal sentences in contrast to metaphoric sentences) gave higher activation in the precuneus (BA 7) and the right middle and SFC (BA 8/9). These findings suggest that metaphor comprehension is involved in specific neural mechanisms of semantic and pragmatic processing which differ from those in literal comprehension. Especially, our results suggest that activation in the left IFC reflects the semantic processing and that activation in the MeFC reflects the process of inference for metaphorical interpretation to establish semantic coherence.

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The occurrence of PIH may be related to the region of epileptic focus and the region of spread of epileptic discharges.

We investigated post-ictal headaches (PIH) using a questionnaire to ascertain their characteristics and compare them among different types of epilepsy. The subjects consisted of 34 patients with occipital lobe epilepsy (OLE) and 75 patients with temporal lobe epilepsy (TLE). PIH occurred in 62% of OLE and 23% of TLE (P < 0.05). The quality of pain in PIH was 'steady' in 71% of OLE and 29% of TLE (P < 0.05) as opposed to 'pounding'. Other factors, such as frequency, severity, duration, and accompanying symptoms showed no significant differences. We found very few patients with migraine-like headaches. Analyses of clinical factors, such as age at onset, duration of epilepsy, seizure frequency, family history of headache, and interictal headache did not reveal any relationship to PIH, although generalized tonic-clonic seizures are associated with PIH in TLE (P < 0.05). These results suggest that the nature of PIH may be different between OLE and TLE, and that the region of epileptic focus or spreading area of epileptic discharge may have a close relation to the induction of PIH. An association with migraine, which has been reported previously, was unclear in our study.