The Effects of Cueing Target Location and Response Mode on Interference and Negative Priming Using a Visual Selection Paradigm

Two experiments are reported that examine the effects of cueing the location of a target in the prime display on interference and subsequent negative priming. The prime and probe displays comprised two words, a target and a distractor. In the prime display, the two words were either the same (response compatible) or different (response incompatible). The target in the probe display was unrelated to the prime distractor (control), the same word as the distractor (ignored repetition), or semantically related to the distractor (ignored semantic repetition). In Experiment 1, cueing the location of the prime target significantly reduced the interference effect but not the subsequent identity negative priming (NP) effect. In contrast, not cueing the prime target resulted in the elimination of the identity NP. There was no evidence of semantic NP in this experiment. In Experiment 2, where a categorization response was required, significant interference was obtained in the prime display that was not influenced by cueing the location of the target. Although there was significant semantic NP, identity NP failed to reach significance. The two experiments were analysed together, and findings are discussed in relation to current models of negative priming.     

Dissociative prime-probe contextual similarity effects on negative priming and repetition priming: a challenge to episodic retrieval as a unified account of negative priming

This study examined the dependence of repetition priming (RP) and negative priming (NP) as a function of prime-probe contextual similarity in a paradigm in which participants were required to respond to a letter flanked by incompatible distractor letters (e.g., ABA). Experiment 1 used prime and probe displays containing a pair of "+" symbols that were presented horizontally or vertically. Experiments 2 and 3 manipulated whether the letter triplets contained the "!" symbol. In all experiments, regardless of whether the RP trials were intermixed with the NP trials (Experiment 2) or not (Experiment 3), RP was stronger in the prime-probe similar conditions than in the prime-probe dissimilar conditions, but NP was independent of prime-probe contextual similarity. These findings suggest that NP is not necessarily stronger in conditions in which episodic retrieval of the prime is more likely.     

Automatic semantic activation is no myth: semantic context effects on the N400 in the letter-search task in the absence of response time effects

The claim that semantic activation is an automatic process was recently called a myth, on the basis of the finding that if letter search is performed on a prime word, semantic priming effects on response time are eliminated, whereas repetition effects are preserved. The absence of semantic activation, however, cannot be validly inferred from the lack of response time effects, and converging evidence is needed. To this end, we examined the event-related potential correlate of priming, the N400 amplitude modulation, in a letter-search priming paradigm. Our experiment replicated the response time effects and demonstrated that the N400 amplitude successfully differentiates cross-case repetition priming, semantic priming, and neutral conditions. The results clearly indicate that the meaning of the prime word was processed and that semantic activation indeed was present in the letter-search task. The notion that semantic activation is an automatic process should not be abandoned prematurely.     

Transfer of processing in repetition priming: some inappropriate findings.

Transfer effects in repetition priming were found with both picture and word naming, but varied with the type of prime list. Unmixed lists of word or picture primes produced equivalent intra-modal and cross-modal repetition priming in both picture-naming (Experiment 1) and word-naming (Experiment 5) tasks. However, mixing word and picture primes resulted in greater intra-modal than cross-modal priming for both picture-naming (Experiment 2) and word-naming (Experiment 6) tasks. This mixed-list difference between intra-modal and cross-modal priming was reduced by blocking prime types at input (Experiment 3). These findings suggest that differences in priming as a function of prime stimulus format should be cautiously interpreted when mixed prime lists are used.     

Being forward not backward: lexical limits to masked priming

This study investigated whether masked priming is mediated by existing memory representations by determining whether nonwords targets would show repetition priming. To avoid the potential confound that nonword repetition priming would be obscured by a familiarity response bias, the standard lexical decision and naming tasks were modified to make targets unfamiliar. Participants were required to read a target string from right to left (i.e., "ECAF" should be read as "FACE") and then make a response. To examine if priming was based on lexical representations, repetition primes consisted of words when read forwards or backwards (e.g., "face", "ecaf") and nonwords (e.g., "pame", "emap"). Forward and backward primes were used to test if task instruction affected prime encoding. The lexical decision and naming tasks showed the same pattern of results: priming only occurred for forward primes with word targets (e.g., "face-ECAF"). Additional experiments to test if response priming affected the LDT indicated that the lexical status of the prime per se did not affect target responses. These results showed that the encoding of masked primes was unaffected by the novel task instruction and support the view that masked priming is due to the automatic triggering of pre-established computational processes based on stored information.     

Priming complex words: evidence for supralexical representation of morphology

Effects of morphologically related primes were examined in two masked prime experiments. Responses to both free root and derived suffixed word targets were facilitated when primes were derived suffixed words containing the target’s root, and this facilitation effect showed a time course similar to that for the facilitation effect of repetition primes (though systematically smaller in magnitude). In a control experiment only the longest prime duration of Experiment 1 was used; responses to derived suffixed word targets were facilitated by both free root primes and derived suffixed word primes sharing the target’s root (relative to unrelated and form-related control primes). The free root and derived suffixed word prime conditions did not differ significantly. In Experiment 2, only true derived word primes produced facilitation, whereas morphologically simple primes containing a pseudoroot did not influence performance relative to the unrelated prime condition. We argue that this supports a supralexical account of morphological representation.     

Evidence from the attentional blink for different sources of word repetition effects

T2 in an attentional blink paradigm served as a high- or low-frequency prime word for a subsequent repeated target. Consistent with research in visual word identification, only reported primes facilitated the identification of a target repeated approximately 8 s after RSVP. Priming was greater for low- than high-frequency words. Analogous with masked priming, a blinked T2 facilitated report of a repeated target occurring 318 ms after T2 in RSVP. The blinked repetition priming effect was additive with target frequency. These results indicate that: (1) the outcomes of processing prime words are a key factor in repetition priming effects, with blinked and reported T2s behaving like masked and unmasked primes, respectively, (2) there may be different sources of repetition effects, (3) there is a consistent cross-paradigm pattern of repetition effects that occurs as a function of prime–target interval and the ability to identify the word on its first and second presentation.     

Revisiting the role of probe distractors in negative priming: Location negative priming is observed when probe distractors are consistently absent

Negative priming (NP) refers to the delayed response to a probe target that was previously a prime distractor. One peculiar problem in NP literature is the observation that the manifestation of identity NP is contingent on the presence and type of probe distractors. When the probe distractors were completely removed, positive priming, rather than NP, was usually observed. This study investigated whether location NP was affected by the same manipulations. The proportion of ignored repetition trials, attended repetition trials, and control trials was manipulated across Experiments 1–3. These three experiments showed reliable location NP effect when the probe distractor was consistently absent. Experiment 4 showed that the presence of probe distractors did not increase the magnitude of the location NP effect. Experiment 5 showed that the location NP effect observed was not contingent on perceptual mismatching. These findings suggest that the presence of probe distractors is not a necessary component for the manifestation of location NP. Theoretical implications were discussed.     

Response conflict reverses priming: a replication

Subjects named target words that followed a masked prime word of 33-msec (Experiments 1A and 1B) or 200-msec (Experiment 2) duration. The target word was either presented alone or accompanied by an interleaved distractor word. Targets presented alone were named more quickly following an identical prime than following an unrelated prime (repetition priming). In Experiment 1A, targets with distractors were named more slowly following an identical prime than following an unrelated prime (negative priming), replicating Milliken, Joordens, Merikle, and Seiffert (Psychological Review, 1998). In Experiments 1B and 2, repetition priming was reduced, although not reversed, for targets with distractors. The results of all three experiments are opposite to the usual finding of enhanced priming for perceptually degraded targets and suggest that response conflict engages retrospective mechanisms that counteract the facilitatory effects of priming.     

On the interaction between linguistic and pictorial systems in the absence of semantic mediation: Evidence from a priming paradigm

Use of the letter search task in the context of the priming paradigm has proved to be an invaluable tool for the investigation of the strategic control of processes involved in word recognition. In particular, previous findings that letter search on a prime word interferes with the priming of semantically/associatively related targets, but not with the priming of either identical or morphologically related targets, suggests that letter search may selectively interfere with semantic processing, leaving other levels of processing intact. In the present experiments, this investigation was extended by exploring the priming of pictures following letter search of either a same-concept word (repetition priming) or a semantically/associatively related word (semantic priming). There was significant repetition priming of picture categorization following both silent reading and letter search of the prime word (Experiments 1 and 2). In contrast, semantic priming of pictures was found only following silent reading of the prime; there was no semantic priming following letter search of the prime (Experiment 2). This pattern of results suggests that focusing attention at the letter level during prime processing selectively attenuates activation of the semantic system by the prime. It does not prevent the spread of activation between the lexical and pictogen levels of representation of a given concept.     

Where has all the inhibition gone? Insights from electrophysiological measures into negative priming without probe distractors

Responses to probe targets that have been distractors in a prime display are slower than responses to unrepeated stimuli, a finding labeled negative priming (NP). However, without probe distractors the NP effect usually diminishes. The present study is the first to investigate ERP correlates of NP without probe distractors to shed light on the processes underlying NP. Based on existing findings in the field, we analyzed two ERP correlates that have been associated with the visual NP effect so far, namely the N200 and the P300. As expected, no behavioral NP effect as well as no N200 modulation emerged. However, the P300 component was enhanced when a prime distractor was repeated as the probe target. This effect is interpreted as reflecting automatic retrieval of the prime episode occurring independently of the presence of probe distractors.     

Repetition priming effects from attended vs. ignored single words in a semantic categorization task

The present research examines priming effects from a centrally presented single-prime word to which participants were instructed to either attend or ignore. The prime word was followed by a single central target word to which participants made a semantic categorization (animate vs. inanimate) task. The main variables manipulated across experiments were attentional instructions (attend vs. ignore the prime word), presentation duration of the prime word (20, 50, 80 or 100 ms), prime-target stimulus onset asynchrony (SOA; 300 vs. 800 ms), and temporal presentation of instructions (before vs. after the prime word). The results showed (a) a consistent interaction between attentional instructions and repetition priming and (b) a qualitatively different ignored priming pattern as a function of prime duration: reduced positive priming (relative to the attend instruction) for prime exposures of 80 and 100 ms, and reliable negative priming for the shorter prime exposures of 20 and 50 ms. In addition (c), the differential priming pattern for attend and ignore trials was observed at a prime-target SOA of 800 ms (but not at a shorter 300-ms SOA) and only when instructions were presented before the prime word. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.     

Competition between automatic and controlled processes

We investigated the competition between automatic and controlled processes in a word stem completion task. Prime-display duration and the prime-target interval were manipulated. On each trial a masked prime was displayed briefly, followed either immediately or after a delay by a word stem. The subjects were required to complete each stem with the first word that came to mind, to report any prime they could identify, and not to give as completion any identified prime. By the assumption that automatic processes require less stimulus input and can be completed faster than consciously controlled processes we expected a stronger performance contribution from automatic processes with the shorter prime-display durations and in the immediate stems condition. The results confirmed this expectation. The findings highlight that consciously controlled processes require more time to run their course than unconscious automatic processes.     

Rats are sensitive to ambiguity

In the present study, we investigated response decisions made under conditions of incomplete information in rats. In Experiment 1, rats were trained on either a positive patterning (PP; A-, B-, AB+) or a negative patterning (NP; A+, B+, AB-) instrumental lever-press discrimination. Subjects that had learned an NP discrimination responded less to Cue A when Cue B was covered at test. The cover did not, however, affect test responses to Cue A in the PP condition. In Experiment 2, rats received concurrent training on both PP and NP discriminations. After concurrent training, responses to Cue A were different with B covered versus uncovered for both NP and PP discriminations. We discuss possible accounts for why exposure to a nonlinearly soluble discrimination (NP) may have affected sensitivity to cue ambiguity produced by the cover. These results have interesting implications for representational processes engaged in problem solving.     

Automatic evaluation of body-related images

An affective priming task was used to determine whether females automatically evaluate body-related images, and to establish whether this is moderated by appearance schematicity, thin internalisation, body dissatisfaction, and dietary restraint. In a within participants design, the valence congruence of the prime and target pairs was manipulated, as was the interval between them. Undergraduate females (N=87, Experiment 1 and N=72, Experiment 2) individually selected colour images as the primes. Each prime was presented briefly, followed by a target word which the participant judged as "good" or "bad". The dependent variable was response latency to the target word. Automatic evaluation was evident; responding to congruent pairs was faster than responding to incongruent pairs. The individual difference variables were not related to automaticity. The findings suggest that brief encounters with body-related images are likely to produce automatic affective responses in young women irrespective of body-related concerns.     

Connection between the evaluation of positive or negative valence and verbal responses to a lexical decision making task]

Evaluation of the positive or negative valence of a stimulus is an activity that is part of any emotional experience that has been mostly studied using the affective priming paradigm. When the prime and the target have the same valence (e.g. positive prime and positive target), the target response is facilitated as a function of opposing valence conditions (e.g. negative prime and positive target). These studies show that this evaluation is automatic but depends on the nature of the task's implied response because the priming effects are only observed for positive responses, not for negative responses. This result was explained in automatic judgmental tendency model put forth by Abelson and Rosenberg (1958) and Klauer and Stern (1992). In this model, affective priming assumes there is an overlap between both responses, the first response taking precedence as a function of the prime-target valence, and the second response one that is required by the task. We are assuming that another type of response was not foreseen under this model. In fact, upon activating the valence for each of the prime-target elements, two preliminary responses would be activated before the response on the prime-target valence relationship. These responses are directly linked to the prime and target evaluation independently of the prime-target relationship. This hypothesis can be linked to the larger hypothesis whereby the evaluative process is related to two distinct motivational systems corresponding to approach and avoidance behaviour responses (Lang, Bradley, & Cuthbert, 1990; Neuman & Strack, 2000; Cacciopo, Piester & Bernston, 1993). In this study, we use the hypothesis that when a word leads to a positive valence evaluation, this favours a positive verbal response and inversely, a negative valence word favours a negative response. We are testing this hypothesis outside the affective priming paradigm to study to what extent evaluating a word, even when it is not primed, activates both motivational systems and consequently, positive verbal responses for approach and negative responses for avoidance. To validate this hypothesis, we are re-using both versions of the lexical decision task proposed by Wentura (2000). The classic version leads participants to a positive response for words, and the modified version leads to a no response. This experiment, carried out with thirty-two participants, measures the influence on response time of two experimental factors, the intrasubject valence of words (positive and negative) and the inter-subject factor (yes and no responses to words). Results show an interaction between the type of response and word valence. It is temporally more onerous to give a no response to positive words than to negative words. This result confirms that there is a direct relation between the evaluation of a valence stimulus and the response to this stimulus, a relation that had up to now been essentially observed with motor behaviours, and more rarely with verbal responses. We propose integrating the existence of this link between evaluation and verbal response (yes and no) in interpreting the effects of affective priming.     

Event-related FMRI study of context processing in dorsolateral prefrontal cortex of patients with schizophrenia

Context processing is conceptualized as an executive function involved in voluntary, complex actions such as overcoming automatic responses. The present study tested the hypothesis that context-processing deficits in patients with schizophrenia are associated with a dysfunction of left dorsolateral prefrontal cortex (DLPFC). Using event-related functional magnetic resonance imaging (fMRI), 17 controls and 17 medicated patients performed a version of the AX task in which a learned, automatic response had to be inhibited. In controls, left DLPFC activity increased when preparing to overcome an automatic response, whereas patients with schizophrenia showed no differential activation. In controls, context processing appeared to be associated with the differential representation of cues associated with the need to provide top-down support for overcoming automatic responses. This mechanism appeared to be impaired in patients with schizophrenia.     

Early activity in the lateralized readiness potential suggests prime-response retrieval as a source of negative priming

Negative priming (NP) refers to increased response time (RT) for a probe target that was a distractor in a preceding prime presentation (distractor-target shift, DT), compared to novel targets. The present study used the lateralized readiness potential (LRP) to investigate, in a four-choice identification task, a novel episodic-retrieval explanation of NP introduced by Rothermund, Wentura, and de Houwer (2005). This theory proposes that retrieval reactivates the prime response which interferes with selection of the correct probe response, thereby producing NP. 20 participants responded to pairs of red and blue digits, contingent on the identity of the digit presented in the target color. Behavioral NP involved RT increase by 16 ms. With shift trials (different hands used for prime and probe responses), in the DT condition LRP onset was delayed relative to control. By contrast, earlier LRP onset was observed for DT relative to control with no-shift trials (same hand used for prime and probe responses). Behavioral NP effects showed similar magnitude for shift and no-shift trials. Results support the Rothermund et al. (2005) theory of prime-response retrieval.     

Why do non-color words interfere with color naming?

In the non-color-word Stroop task, university students' response latencies were longer for low-frequency than for higher frequency target words. Visual identity primes facilitated color naming in groups reading the prime silently or processing it semantically (Experiment 1) but did not when participants generated a rhyme of the prime (Experiment 3). With auditory identity primes, generating an associate or a rhyme of the prime produced interference (Experiments 2 and 3). Color-naming latencies were longer for nonwords than for words (Experiment 4). There was a small long-term repetition benefit in color naming for low-frequency words that had been presented in the lexical decision task (Experiment 5). Facilitation of word recognition speeds color naming except when phonological activation of the base word increases response competition.     

Target-to-target repetition cost and location negative priming are dissociable: evidence for different mechanisms

In a location-selection task, the repetition of a prior distractor location as the target location would slow down the response. This effect is termed the location negative priming (NP) effect. Recently, it has been demonstrated that repetition of a prior target location as the current target location would also slow down response. Because such target-to-target repetition cost is similar to the phenomenon of inhibition of return (IOR), the possibility of a common mechanism underlying target-to-target repetition cost, location NP, and IOR has been proposed. The current study evaluated this hypothesis by combining a spatial-cuing task with a location NP task. The results of three experiments demonstrated that although IOR interacted with target-to-target repetition cost, there was no interaction between IOR and location NP. These findings suggest that target-to-target repetition cost is more likely to share a common mechanism with IOR, and target-to-target repetition cost and location NP should be attributed to different processes.