The Role of the Anterior Attention System in Semantic Processing of both Foveal and Parafoveal Words

Abstract

This research takes advantage of combined cognitive and anatomical studies to ask whether attention is necessary for high-level word processing to occur. In Experiment 1 we used a lexical decision task in which two prime words, one in the fovea and the other in the parafovea, appeared simultaneously for 150 msec, followed by a foveal target (word/nonword). Target words were semantically related either to the foveal or to the parafoveal word, or unrelated to them. In one block of trials subjects were also required to perform an auditory shadowing task. From PET studies we know that shadowing activates the anterior cingulate cortex, involved in selective attention. If the anterior attention system is always involved in semantic processing, shadowing should reduce semantic priming obtained from both foveal and parafoveal words. In contrast, if semantic priming by parafoveal words is independent of activation in that attention area, priming will not be affected by shadowing. Our results supported the latter hypothesis. A large priming effect arose from foveal primes, which was reduced by shadowing. For parafoveal primes a smaller priming effect arose, which was not affected by shadowing. In Experiment 2 prime words were masked. Semantic priming was reliable for both foveal and parafoveal words but there were then no differences between them. Most important, the size of priming was similar to that obtained from parafoveal words in Experiment 1. We conclude that the anterior attention system increases the potency of processing of consciously perceived stimuli, but there is a component of semantic priming that occurs without both focusing of attention and awareness, involving different cerebral areas to those involved in attention to language.

Priming and interference effects can be dissociated in the Stroop task: New evidence in favor of the automaticity of word recognition

“…However, Fuentes and Ortells also observed that congruent color words produced facilitation effects and that the size of this effect did not change as a function of distractor eccentricity. This means that stimulus words were processed even when they were presented far from fixation, a result that is in accord with our previous studies that have shown semantic priming from parafoveal words presented up to 4º from fixation (Fuentes, Carmona, Agis, & Catena, 1994;Fuentes & Tudela, 1992).…”

“…Thus, according to our account, positive priming in the singleletter-colored condition was the product of two components: an automatic component that could be delayed by the unfamiliar configuration in the prime, 2 and a controlled component that was initiated once attention was allocated to the word level in the probe display. The idea that semantic priming can reflect the action of two components is not new and has been proposed in previous research (Fuentes et al, 1994;Fuentes & Tudela, 1992;Neely, 1977;Posner & Raichle, 1994;Posner et al, 1989;Posner & Snyder, 1975).…”

“…However, priming might reflect that lexical/semantic analysis has occurred and therefore might be a more appropriate measure to assess the nature of word processing. Literature on priming shows a considerable bulk of evidence favoring the idea that at least a componentof semantic priming is automatic (for further evidence, see Fuentes et al, 1994;Fuentes & Tudela, 1992;Marcel, 1983;Neely, 1977Neely, , 1991Posner & Carr, 1992;Posner & Raichle, 1994;Posner, Sandson, Dhawan, & Shulman, 1989). Why can this automatic component not be involved in the Stroop task too?…”

Even frequent and expected words are not identified without spatial attention

“…2002; Fuentes, Carmona, Agis, & Catena, 1994;Fuentes & Tudela, 1992;Heil, Rolke, & Pecchinenda, 2004;LaBerge & Samuels, 1974;Siéroff & Posner, 1988), whereas others have indicated an important role of spatial attention (e.g., Besner, Stolz, & Boutilier, 1997;Chiappe, Smith, & Besner, 1996;Dark, Johnston, Myles-Worsley, & Farah, 1985;Stolz & Besner, 1999;Stolz & McCann, 2000;Stolz & Neely, 1995;Stolz & Stevanovski, 2004).…”

Semantic priming in the prime task effect: Evidence of automatic semantic processing of distractors

“…For instance, Fuentes and colleagues (Fuentes, Carmona, Agis, & Catena, 1994;Fuentes & Tudela, 1992) have reported semantic facilitation from parafoveal words presented 4°of visual angle from fixation. They also argued that semantic priming from parafovea1 words was automatic, since it was not affected either by a simultaneous task or by masking, in contrast to semantic priming from foveal words, which was affected (reduced) by both (Fuentes et aI., 1994).…”