Observation of a patient suffering from a double softening of the brain (inner side of right temporal lobe, left occipital lobe). Clinically, Korsakoff's syndrome, right quadranopsia, pure alexia, tactile and visual agnosia concerning objects, colors and faces. Relative integrity of elementary perceptions (matching tests), impairments of stimulus identification (Lissauer's associative agnosia). Phenomena of sensoriphasic interactions are reported: normal speech in conversation, contrasting with confabulant anomia when naming or describing visual or tactile stimuli: then, escaping the control of sight, a relative "autonomy" of speech appears, with word perseverations and semantic "slipping" and filiations. Discussion of optical aphasia.