1 ? The Split Brain and the Integrated Mind.- 2 ? The Nature of Interhemispheric Communication.- 3 ? Cerebral Lateralization and Hemisphere Specialization: Facts and Theory.- 4 ? Brain and Language.- 5 ? Brain and Intelligence.- 6 ? Brain, Imagery, and Memory.- 7 ? On the Mechanisms of Mind.- Author Index.

The Integrated Mind

Behavioral and neurophysiological effects of word imageability and concreteness remain a topic of central interest in cognitive neuroscience and could provide essential clues for understanding how the brain processes conceptual knowledge. We examined these effects using event-related functional magnetic resonance imaging while participants identified concrete and abstract words. Relative to nonwords, concrete and abstract words both activated a left-lateralized network of multimodal association areas previously linked with verbal semantic processing. Areas in the left lateral temporal lobe were equally activated by both word types, whereas bilateral regions including the angular gyrus and the dorsal prefrontal cortex were more strongly engaged by concrete words. Relative to concrete words, abstract words activated left inferior frontal regions previously linked with phonological and verbal working memory processes. The results show overlapping but partly distinct neural systems for processing concrete and abstract concepts, with greater involvement of bilateral association areas during concrete word processing, and processing of abstract concepts almost exclusively by the left hemisphere.

Distinct Brain Systems for Processing Concrete and Abstract Concepts

http://neurocog.ull.es/wp-content/uploads/2012/04/Vigliocco-Vinson-Druks-Barber-Cappa-2011.pdf

Nouns and verbs in the brain: A review of behavioural, electrophysiological, neuropsychological and imaging studies

Dual-coding theory argues that processing advantages for concrete over abstract (verbal) stimuli result from the operation of 2 systems (i.e., imaginal and verbal) for concrete stimuli, rather than just 1 (for abstract stimuli). These verbal and imaginal systems have been linked with the left and right hemispheres of the brain, respectively. Context-availability theory argues that concreteness effects result from processing differences in a single system. The merits of these theories were investigated by examining the topographic distribution of event-related brain potentials in 2 experiments (lexical decision and concrete-abstract classification). The results were most consistent with dual-coding theory. In particular, different scalp distributions of an N400-like negativity were elicited by concrete and abstract words.

Concreteness effects in semantic processing: ERP evidence supporting dual-coding theory.

Recognizing words, pictures, and concepts: A comparison of lexical, object, and reality decisions

Three experiments were conducted to investigate the verbal performance of the right cerebral hemisphere in right-handed individuals with normal intact brains. A manual reaction time (RT) measure was used to assess the relative efficiency of lateral stimulus-response pathways (e.g., left visual field-right hemisphere-left hand) in processing linguistic information. Experiment 1 showed that the right and left hemispheres were equally efficient at recognizing concrete object nouns in a lexical decision task. The RT data also suggested that abstract nouns may be recognized only by the left hemisphere. Experiments 2 and 3 demonstrated the right hemisphere's ability to detect semantic relationships between concrete nouns and their superordinate categories. The findings were discussed in terms of their consistency with data from split-brain research and their implications for models of the functional organization of language skills in the normal brain. It was proposed that the right hemisphere in the intact brain can play a functional role in processing language.

Right-Hemisphere Language Processing in Normal Right-Handers.

Visual half-field word recognition as a function of syntactic class and imageability.

Two closely related semantic processing tasks were studied under identical procedural conditions in order to examine lateral visual field effects on reaction times. In Experiment 1, reaction times did not differ as a function of visual field when subjects decided whether a lateral word was a member of a foveally presented category word (category membership task). On the other hand, reaction times were faster for right than for left visual field stimulus presentations when subjects decided whether two words, one lateral and one foveal, belonged to the same category (category matching task), although this advantage did not occur immediately. In Experiment 2, the laterality effect in the category matching task was studied as a function of word familiarity. Two groups of subjects performed the matching task for two blocks of trials, one group receiving the same word list in each block and the other receiving different lists. No visual field differences in reaction times were observed for either group during the first block of trials, but a distinct right field advantage appeared for both during the second block. The data from these experiments suggest that category matching strategies rely upon structures or processes localized in the left hemisphere, although their influence is not immediate. Category membership strategies, on the other hand, do not depend upon such localized structures.

/pdf/hemispheric-differences-in-semantic-processing-category-3n1ixr7u1v.pdf

James Day

Papers

Right-Hemisphere Language Processing in Normal Right-Handers.

Visual half-field word recognition as a function of syntactic class and imageability.

Hemispheric differences in semantic processing: Category matching is not the same as category membership