Patients will receive the oral doses of study drug in the mornings of Days 1, 2, and 3. All patients will receive a single dose of placebo on Day 1, a single dose of JNJ-26489112 on Day 2, and a second single dose of placebo on Day 3. Blood samples will be taken for evaluation of JNJ-26489112 drug concentrations in plasma and blood. Blood samples will also be collected for laboratory safety assessments and measurement of antiepileptic drug concentrations. Further safety will be assessed by the reporting of adverse events, vital signs, 12-lead ECG, physical and neurological examinations. Patients will be discharged on the evening of Day 3 after the pharmacokinetic samples have been collected, and after assessment by the investigator, unless there are any ongoing adverse events which require in-house monitoring. EEG tracings, recorded during intermittent photic stimulation sessions, will be digitally recorded on a CD-ROM, coded and evaluated independently by one blinded clinical expert to determine the effects on the photosensitivity range. If complete suppression of photosensitivity or reduction of the photosensitivity range by at least 3 points on the photosensitivity scale in at least one eye condition (during closure, closed, open) is not observed in at least 3 of the 4 patients and a maximum tolerated dose has been reached, the study will be stopped. If reduction of the photosensitivity range by at least 3 points on the photosensitivity scale in at least one eye condition (during closure, closed, open) is observed in at least 3 of the 4 patients (with complete suppression in at least 2 patients) in the first cohort, the dose level of JNJ-26489112 may be reduced in subsequent cohorts until the reduction or suppression of photosensitivity is seen in fewer than 2 out of 4 patients in one cohort. Once an effective dose has been reached an additional open-label cohort may be enrolled in which no study drug (JNJ-26489112 or placebo) will be administered to patients. Study drug (i.e., JNJ-26489112 or placebo) will be administered orally as single doses on Days 1 to 3. Placebo will be administered on Days 1 and 3, and a single dose of JNJ-26489112 will be administered on Day 2.