An early electrophysiological sign of semantic processing in basal extrastriate areas

Abstract

Recognition potential (RP), a recently discovered electrophysiological response of the brain, is sensitive to semantic aspects of stimuli. Given its peak values (about 250 ms), RP may be a good candidate for the study of semantic processing during its occurrence. However, its topography and neural generators are largely unknown. To improve this state of affairs, high-resolution electroencephalography and brain electrical source analysis were carried out. Results suggest a possible origin of RP in the lingual gyrus, hence reflecting the activity of the basal extrastriate areas. RP therefore appears to be a highly valuable tool in the study of those regions considered to be the "third language areas" (in addition to Broca's and Wernicke's areas), whose precise role in language processing is still largely unknown. Another important finding was that RP amplitude in the left hemisphere differed as a function of the semantic category of the stimuli, providing evidence for the sensitivity of this component to semantic categorization. A tentative proposal is made with regard to the role of the basal extrastriate areas.

Semantic categorization in aphasic patients with impaired language comprehension: An event–related potentials study

“…Furthermore, similar topographical distribution for animate and inanimate objects could indicate similar neural substrate of processing these two categories, which is again in accordance with Tyler et al (2003) claiming that the same semantic system is active regardless of the categories processed. Our results are also in accordance with the results of Hinojosa et al (2001) who found, by applying the ERP technique, differences in latencies and amplitudes of the recognition potential (RP) between animals and objects as sensitivity to early visual categorization processing (Martín-Loeches et al 2001). They also found no differences either in ERP amplitudes and latencies or in a topographical distribution between these categories.…”

The recognition potential during sentence presentation: stimulus probability, background stimuli, and SOA

“…Hence, the confluence of certain manipulations, that is, the presence of at least two background stimuli preceding each word, an SOA of 250 ms, and the use of an average-reference method (as reported in Martın-Loeches et al, 2001a) would guarantee a remarkable RP. Even so, it seems clear from this study that not all the mentioned manipulations are required simultaneously Thus, if RP is a potentially relevant component in the study of semantic manipulations (e.g.…”

“…In addition, not only is RP better seen in parietooccipital leads, but its distribution is indeed limited to that region, its amplitude largely decaying as we move from PO7 or PO8 (see, for instance, Martın-Loeches et al, 2001a). Curiously, thesé electrodes are quite scarcely used in ERP research, where the mean number of electrodes used is not usually larger than 20, and neither PO7 nor PO8 have been included.…”

Individual differences in the early recognition of moral information in lexical processing: An event-related potential study

“…The rapid rate of stimulus presentation in the procedure (normally, the stimulus onset asynchrony [SOA] of each stimulus is 250 ms) is able to force the participants to process the stimuli with their full attention and to attenuate the contamination of irrelevant variables in the electrophysiological signals of interest 16 . It has been suggested that the RP is linked to the pre-semantic processing of words and that it is particularly related to the processing of semantic categorical features 17, 18 . Several groups of moral researchers have proposed in their work that the early stage of the temporal dynamics in moral judgment may involve a rapid and intuitive “right-or-wrong” categorization process 5, 6, 10 .…”