The roles of word concreteness and cognitive load on interhemispheric processes of recognition

Previous studies on hemispheric specialisation suggest that the cerebral hemispheres differ in the way verbal information is processed. There is also evidence that functional asymmetries are attributable to differences in stimulus properties and/or task complexity. To study these asymmetries in the domain of explicit recognition, concrete and abstract nouns were presented either in the right or left visual fields and recognised with foveal vision at different retention levels. We propose that different hemispheric mechanisms underlie the encoding of abstract and concrete information, which can be modulated by cognitive or mental load. To accomplish this goal, 92 right-handed undergraduate Portuguese students with normal or corrected-to-normal vision were randomly sampled from a university campus. The results showed that concrete words were discriminated better than abstract words when previously encoded in the right hemisphere for the longest retention interval between encoding and retrieval. These data suggest that there are different neural mechanisms for the semantic encoding of concrete and abstract concepts. The practical implications are discussed.