In this event-related potential study a masking technique that prevents conscious perception of words and non-words through attentional distraction was used to reveal the temporal dynamics of word processing under non-conscious and conscious conditions. In the non-conscious condition, ERP responses differed between masked words and non-words from 112 to 160 ms after stimulus-onset over posterior brain areas. The early onset of the word–non-word differences was compatible with previous studies that reported non-conscious access to orthographic information within this time period. Moreover, (...) source localisations provided evidence for automatic activation of prelexical phonological information, whereas no evidence for non-conscious semantic processing was found. When subjects were informed about the masking technique, lexical differences occurred at later time intervals, suggesting conscious access to additional word related information. These results indicate that early visual word processing does not depend entirely on attentional resources, but that non-conscious processing probably is restricted to rather lower-level linguistic information. (shrink)

Homonyms, i.e. ambiguous words like ‘score’, have different meanings in different contexts. Previous research indicates that all potential meanings of a homonym are first accessed in parallel before one of the meanings is selected in a competitive race. If these processes are automatic, these processes of selection should even be observed when homonyms are shown subliminally. This study measured the time course of subliminal and supraliminal priming by homonyms with a frequent and a rare meaning in a neutral context, using (...) a lexical decision task. In the subliminal condition, priming across prime-target asynchronies ranging from 100 ms to 1.5 s indicated that the dominant meaning of homonyms was facilitated and the subordinate meaning was inhibited. This indicates that selection of meaning was much faster with subliminal presentation than with supraliminal presentation. Awareness of a prime might decelerate an otherwise rapid selection process. (shrink)

Jesse Prinz proposes that attended intermediate-level representations are sufficient for conscious awareness. He extends this claim to emotion, arguing that attention is the mechanism that separates conscious from unconscious emotions. Prior studies call this entailment into question. However, they do not directly address the intermediate-level requirement, and thus cannot decisively refute the AIR theory of consciousness. This thesis tests that theory by manipulating participants’ attention to different features of subliminally processed words while recording both behavioral and electroencephalogram data. Both measures (...) suggest that subliminally processed stimuli are attended according to participants’ conscious intention to complete a task. In addition, the EEG data demonstrate that intermediate-level neural activity was modulated by the subliminal stimuli. Thus, these results suggest that AIRs are not sufficient for conscious emotion. This finding undermines Prinz’s AIR theory, and its account of the distinction between conscious and unconscious emotion. (shrink)

Comparisons of indirect measures with direct measures can help elucidate the relationship between nonconscious and conscious perception. We report three experiments on masked word priming in which we observed a negative correlation between prime discriminability and priming , i.e. where priming decreased with increasing prime visibility. While such observations are rare , they may indicate a conflict between conscious and nonconscious processing when primes are shown close to the subjective visibility threshold for the priming-relevant information. For instance, such a conflict (...) could occur between nonconscious processing of a prime’s meaning and conscious perception of prime letters. Theoretical accounts that discuss similar conflicts assume that the conflict is resolved either by automatically prioritising conscious processes or by discounting the estimated confusion caused by a prime-target pair . In both cases, priming is predicted to decrease when prime visibility increases from below threshold to perithreshold levels. Therefore, we suggest that negative priming-d’ relationships are most likely observed when the d’ measure assesses prime visibility at a level of representation that is below the level of representation at which priming arises, in terms of a putative hierarchy of word processing. (shrink)