Age-related increases in the effects of automatic semantic activation.

Automatic semantic activation was assessed in a version of the flanker task, in which nominally irrelevant words were presented above and below a target word. The category membership of the flanking word was consistent, inconsistent, or neutral with respect to the target word. Older adults showed greater inhibition and equivalent facilitation in the time taken to classify the target words than did younger adults in 2 of 3 experiments, in contrast to previous findings. The present results are generally consistent with 3 dominant perspectives in cognitive aging: the complexity hypothesis, environmental support, and the inhibition-deficit view. Manipulation of the overall magnitude of the flanker effect produced results most consistent with the inhibition-deficit view that older adults are less able to inhibit automatic processes than are younger adults. Some problems with the inhibition-deficit view are also discussed.     

Viewing-position effects in the Stroop task: Initial fixation position modulates Stroop effects in fully colored words

In two experiments that we conducted with adult (Experiment 1) and child (Experiment 2) participants, we experimentally controlled the eyes' first fixation in the word using a variable viewing-position technique in a classical all-letter-coloring Stroop procedure. We explored the impact of initial-fixation position (optimal viewing position [OVP] vs. end of the word) on the magnitude of Stroop effects (both interference and facilitation). The results showed that both interference and facilitation effects were reduced when the first fixation was located at the end of the word rather than at the OVP. These data make a new contribution to the study of the role of low-level processes in Stroop effects and add support to the growing body of research indicating that oculomotor processes can act as moderators of cognitive processes in the determination of Stroop effects.     

Differential effects of viewing positions on standard versus semantic Stroop interference

From their finding that the substantial magnitude of the Stroop interference that occurs when a participant’s initial fixation is directed at the optimal viewing position is eliminated when the initial fixation is directed at the end of a word, Perret and Ducrot (2010) concluded that initial fixation at the latter position likely prevents reading. In the present study, we further examined this interpretation. To this end, the two conflict dimensions (semantic vs. response) that were confounded in the original work were separated within a semantically based Stroop paradigm (Neely & Kahan, 2001) that was administered with vocal (instead of manual) responses. In line with past findings showing greater interference in the vocal task, the reported results indicated that standard Stroop interference was reduced, but not eliminated, thus making the initial interpretation in terms of reading suppression unlikely. This conclusion is further strengthened by the presence of isolated semantic interference, the magnitude of which remained significant and was unaffected by viewing position. In sum, these results show that initial fixation of the end of a word simply reduces (nonsemantic) response competition.     

Processing visual words with numbers: Electrophysiological evidence for semantic activation

Perea, Duñabeitia, and Carreiras (Journal of Experimental Psychology: Human Perception and Performance 34:237–241, 2008) found that LEET stimuli, formed by a mixture of digits and letters (e.g., T4BL3 instead of TABLE), produced priming effects similar to those for regular words. This finding led them to conclude that LEET stimuli automatically activate lexical information. In the present study, we examined whether semantic activation occurs for LEET stimuli by using an electrophysiological measure called the N400 effect. The N400 effect, also known as the mismatch negativity, reflects detection of a mismatch between a word and the current semantic context. This N400 effect could occur only if the LEET stimulus had been identified and processed semantically. Participants determined whether a stimulus (word or LEET) was related to a given category (e.g., APPLE or 4PPL3 belongs to the category “fruit,” but TABLE or T4BL3 does not). We found that LEET stimuli produced an N400 effect similar in magnitude to that for regular uppercase words, suggesting that LEET stimuli can access meaning in a manner similar to words presented in consistent uppercase letters.     

Learning new meanings for old words: effects of semantic relatedness

Changes to our everyday activities mean that adult language users need to learn new meanings for previously unambiguous words. For example, we need to learn that a "tweet" is not only the sound a bird makes, but also a short message on a social networking site. In these experiments, adult participants learned new fictional meanings for words with a single dominant meaning (e.g., "ant") by reading paragraphs that described these novel meanings. Explicit recall of these meanings was significantly better when there was a strong semantic relationship between the novel meaning and the existing meaning. This relatedness effect emerged after relatively brief exposure to the meanings (Experiment 1), but it persisted when training was extended across 7?days (Experiment 2) and when semantically demanding tasks were used during this extended training (Experiment 3). A lexical decision task was used to assess the impact of learning on online recognition. In Experiment 3, participants responded more quickly to words whose new meaning was semantically related than to those with an unrelated meaning. This result is consistent with earlier studies showing an effect of meaning relatedness on lexical decision, and it indicates that these newly acquired meanings become integrated with participants' preexisting knowledge about the meanings of words.     

Age differences in the automatic accessibility of emotional words from semantic memory

Using a speeded word fragment completion task, we assessed age differences in the automatic accessibility of emotional versus neutral words from semantic memory. Participants were instructed to complete a series of single-solution word fragments as quickly as possible. The results demonstrate that older adults are biased against accessing both positive and negative words relative to neutral words, whereas young adults are biased against accessing positive words only. These findings suggest an arousal-based accessibility bias favouring neutral stimuli in older adults coupled with a valence-based bias accessing negative and neutral stimuli for young adults.     

Limitations of semantic priming procedures for automatic goal activation

According to the auto-motive model, behavioral goals can be automatically activated by situational cues and may subsequently guide behavior without individual awarness. Semantic priming has become a popular paradigm for investigating effects of automatic goal activation. Nevertheless, a critical assumption of the model, i.e., that goals can be activated by semantic primes related to situational features associated with the goal, is often assumed rather than tested in experiments using semantic priming procedures. Results of four studies testing the potential of such a prime for goal activation by assessing emotional responses, subjective goal importance, behavioral intentions, and enhanced perception of goal-related stimuli do not support this assumption. The implications of these findings and a critical evaluation of results of other studies are discussed in terms of possible limitations of semantic priming procedures for testing hypotheses derived from the auto-motive model.     

The effects of lexical and semantic information on same-different visual comparison of words

Previous research has indicated that phonemic and orthographic factors cannot account for the fact that words (clear/clear) are responded to more rapidly than orthographically legal nonwords (creal/creal) in a same-different visual comparison task. However, the role of semantic and lexical factors is less certain. The effects of semantic similarity on both same and different judgments were evaluated in several experiments. In the first experiment, subjects were not any slower on semantically related (rang/rung) than on unrelated (rang/rank) different judgments even with a 3,000-msec interval between the first and second word. In Experiment 2, subjects based their judgments on whether or not the first letter of each word was visually identical. Same judgments were not any faster for semantically related than unrelated items even though other evidence indicated that subjects were processing the whole word and not just the first letter. Experiment 3 showed that the word/orthographically legal nonword difference could be replicated with the first-letter visual comparison task employed in Experiment 2. These and related results were discussed with reference to the idea that the word/orthographically legal nonword difference is due to the facilitating effects of a lexical entry upon the encoding, but not the comparison of an item.     

The face wins: Stronger automatic processing of affect in facial expressions than words in a modified Stroop task

Affective words and faces each seem to be evaluated automatically, but it is unclear if they differ from one another in perceptual salience as measured by automaticity. The current study examined a possible hierarchy among affective stimuli using a modified photo–word Stroop task. Positive and negative words were superimposed across faces expressing positive (happy) and negative (angry, sad) emotions. Participants categorised the valence of faces and words. Across two experiments, interference effects were seen for both stimulus types. However, larger interference effects occurred during judgements of words than expressions, suggesting affective faces are processed more automatically than affective words. When the strength of positive and negative expressions is compared, angry expressions resulted in a larger interference effect than sad, and happy expressions produce interference similar to that of angry faces. The latter result contrasts with research suggesting potential threat stimuli are processed more automatically than positive stimuli. Implications are discussed.     

Stroop effects for masked threat words: Pre‐attentive bias or selective awareness?

The single‐trial emotional Stroop effect for masked threat words, and its association with anxiety, anger, and depression was studied in a group of men (n = 24) and women (n = 24) while controlling for possible differential thresholds for threat words versus neutral words. Stroop interference for masked threat words was found to correlate with trait anxiety, and the effect could not be explained by any differences in thresholds due to valence, neither at a subjective (conscious identification task) nor at an objective (lexical decision task) level of awareness. Jacoby's exclusion task was explored as an alternative measure of conscious awareness, and the results corroborated the conclusion that the Stroop effect for masked threat words was the result of preattentive processes. Unexpectedly, however, the correlation between Stroop interference for masked threat words and trait anxiety was found only among the men.     

Similarity neighborhoods of spoken two-syllable words: retroactive effects on multiple activation

This research examines the recognition of two-syllable spoken words and the means by which the auditory word recognition process deals with ambiguous stimulus information. The experiments reported here investigate the influence of individual syllables within two-syllable words on the recognition of each other. Specifically, perceptual identification of two-syllable words comprised of two monosyllabic words (spondees) was examined. Individual syllables within a spondee were characterized as either "easy" or "hard" depending on the syllable's neighborhood characteristics; an easy syllable was defined as a high-frequency word in a sparse neighborhood of low-frequency words, and a hard syllable as a low-frequency word in a high-density, high-frequency neighborhood. In Experiment 1, stimuli were created by splicing together recordings of the component syllables of the spondee, thus equating for syllable stress. Additional experiments tested the perceptual identification of naturally produced spondees, spliced nonwords, and monosyllables alone. Neighborhood structure had a strong effect on identification in all experiments. In addition, identification performance for spondees with a hard-easy syllable pattern was higher than for spondees with an easy-hard syllable pattern, indicating a primarily retroactive pattern of influence in spoken word recognition. Results strongly suggest that word recognition involves multiple activation and delayed commitment, thus ensuring accurate and efficient recognition.     

The automatic access of emotion: Emotional Stroop effects in Spanish–English bilingual speakers

The emotional Stroop task provides an experimental measure of selective attention to emotional information. In the current study, the emotional Stroop effect was examined in a Spanish–English bilingual speaking population. The results revealed that the emotional Stroop effect is a robust phenomenon and replicable within a bilingual population. Furthermore, highly proficient bilinguals demonstrated equal interference effects in both their first language and their second language. The current study provides evidence of the automatic activation of emotional components in words appearing in more than one language. These results are discussed with reference to previous findings in the literature on bilingual emotion word representation.     

Item-specific control of automatic processes: Stroop process dissociations

The influence of word reading on Stroop color naming decreases as a function of the proportion of test items that are incongruent. This proportion-congruent effect is usually ascribed to strategies (e.g., maintaining task set) that operate at a general level to moderate the extent to which participants are influenced by word reading. However, in three experiments, effects at the level of specific items were found. Interference and facilitation were smaller for color names usually presented in an incongruent color than for color names usually presented in their congruent colors. This item-specific proportioncongruent manipulation affected the process dissociation (PD) estimate of the influence of word-reading processes but not that of color-naming processes. The results (1) indicate that item-specific, as opposed to general, mechanisms can reduce the influence of word-reading processes on Stroop performance and (2) demonstrate the PD procedure’s utility in studying Stroop phenomena.     

Don't be afraid of irrelevant words: the emotional Stroop effect is confined to attended words

The emotional Stroop effect denotes slower responses to the colour of negative words (e.g., death) compared to neutral words (e.g., mug). Popular explanations assume a general power of negative words to capture visual attention. However, in the typical task, the irrelevant word stimulus and the relevant colour stimulus are perceptually integrated. We compared interference from negative words, which were part of the relevant visual object, to interference from negative words that were part of an irrelevant object, or occurred in the background, respectively. Results showed that only negative words in the relevant object delayed colour-naming responses, compared to neutral words. Negative words outside the relevant object failed to affect performance. This finding is at odds with the claim that negative words could capture spatial or object-based mechanisms of visual attention. However, the finding is consistent with the idea that negative words interfere with the allocation of dimensional attention to different features of an attended object.     

Don't be afraid of irrelevant words: The emotional Stroop effect is confined to attended words

The emotional Stroop effect denotes slower responses to the colour of negative words (e.g., death) compared to neutral words (e.g., mug). Popular explanations assume a general power of negative words to capture visual attention. However, in the typical task, the irrelevant word stimulus and the relevant colour stimulus are perceptually integrated. We compared interference from negative words, which were part of the relevant visual object, to interference from negative words that were part of an irrelevant object, or occurred in the background, respectively. Results showed that only negative words in the relevant object delayed colour-naming responses, compared to neutral words. Negative words outside the relevant object failed to affect performance. This finding is at odds with the claim that negative words could capture spatial or object-based mechanisms of visual attention. However, the finding is consistent with the idea that negative words interfere with the allocation of dimensional attention to different features of an attended object.     

Filling a gap in the semantic gradient: Color associates and response set effects in the Stroop task

In the Stroop task, incongruent color associates (e.g., LAKE) interfere more with color identification than neutral words do (e.g., SEAT). However, color associates have historically been related to colors in the response set. Response set membership is an important factor in Stroop interference, because color words in the response set interfere more than color words not in the response set. It has not been established whether response set membership plays a role in the ability of a colorassociate to interfere with color identification. This issue was addressed in two experiments (one using vocal responses and one using manual responses) by comparing the magnitude of interference caused by color associates related to colors in the response set with that of interference caused by color associates unrelated to colors in the response set. The results of both experiments show that color associates unrelated to colors in the response set interfered with color identification more than neutral words did. However, the amount of interference was less than that from color associates that were related to colors in the response set. In addition, this pattern was consistent across response modalities. These results are discussed with respect to various theoretical accounts of Stroop interference.     

Influence of prime-target relationship on semantic priming effects from words in a lexical-decision task

The present research examines the influence of prime-target relationship (associative and categorical versus categorical only) on priming effects from attended and ignored parafoveal words. Participants performed a lexical-decision task on a single central target, which was preceded by two parafoveal prime words, one of which (the attended prime) was spatially precued. The results showed reliable positive and negative priming effects from attended and ignored words, respectively. However, this priming pattern was observed only for the "associative and categorical", but not for the "categorical only" relationship condition. These results suggest that the lack of semantic priming effects from words in some prior studies may be attributed to the kind of material used (i.e. weakly-associated word pairs).     

Clauses and the semantic representation of words

When a sentence with more than one clause is processed, words of the first clause become less available for recall or recognition once the clause boundary has been passed. One common interpretation of this observation is that the representation of a given word shifts from a predominantly surface form (e.g., phonological or lexical) to a semantic form, after the clause boundary. Two experiments that test that interpretation are reported. In the first experiment, two-clause spoken sentences were followed by spoken word or picture probes. Pictures were intended to provide a fast semantic match to probed words, but a slow surface match. Although response times exhibited a robust main effect of the clause position of the probe, no interaction with probe type was found. Similar results were obtained in a second experiment that compared pictures with written word probes. The faster response to picture than to word probes in the second experiment indicates that subjects did not covertly name the picture, but made a semantic match (as intended). These observations suggest the following reinterpretation of earlier sentence memory experiments: Words in the most recent clause of a sentence are more available than words in an earlier clause because their semantic representations are more active, not because their surface representations are more active.