Cerebral asymmetries in processing proper names: evidence of an efficiency difference

Comprehension of famous personal and geographical names in global aphasic subjects

This experiment compared comprehension of famous personal and geographical names with that of common nouns in three groups of severe aphasic subjects across three modalities. Results revealed that the global aphasic group comprehended famous personal names significantly better than they did common nouns and were better in the reading comprehension modality. Comprehension of famous geographical names in the global aphasic group, however, was as impaired as that of common nouns. CT images suggested that the left occipital lobe and the left posterior inferior temporal gyrus, as well as the right hemisphere, may have relevance to the comprehension of written famous personal names.

Hemispheric asymmetry in memory search for four-letter names and human faces

Two memory search experiments were conducted using vertically oriented four-letter names and human faces as stimuli. Subjects were required to indicate as quickly and as accurately as possible whether or not a single probe stimulus (presented for 150 msec to either the left or right visual field) was contained in a set of 2, 3, 4, or 5 items being held in short-term memory. The probe stimuli were presented alone (clear condition) or centrally embedded in a matrix of dots (degraded condition). In Experiment 1 (involving names), a right visual field/left hemisphere advantage was obtained and pinpointed at the encoding stage rather than at the memory comparison stage of the information-processing system. For Experiment 2 (involving human faces), no hemispheric advantage was readily observed. In each experiment, both the left hemisphere and the right hemisphere employed an abstract memory comparison operation from which the effects of probe degradation have been removed. These results are discussed in terms of their implications for various models of hemispheric asymmetry.