A Neural Habituation Account of the Negative Compatibility Effect

The Negative Compatibility Effect (NCE) is slower reaction times (RTs) to report the direction of a target arrow that follows a matching prime arrow. The cause has been debated, with some studies indicating perception, while others indicate a response effect. We applied the neural habituation model of Huber and O’Reilly (2003) to the NCE, explaining the varied results as reflecting changes in the timing of events. We developed a novel variant of the NCE task, specifying the perceptual dynamics of orientation priming as measured with threshold accuracy. This revealed a transition from positive to negative priming as a function of prime duration, and a second experiment ruled out response priming. The perceptual dynamics of the neural habituation model were fit to these results and the parameter values were fixed in applying the model to the NCE literature. Application of the model to RTs necessitated a response representation that accumulates response information during the trial. Our results indicate that the NCE reflects rapid perceptual priming and slower response priming. Because the accumulation of response information is slow and does not suffer from habituation, the response factor of the prime is a positive effect (lingering response information). In contrast, because perceptual activation is fast and habituates, the perceptual factor can be positive or negative priming depending on the timing of the display sequence. These factors interact with the post-prime mask, which can prime the alternative direction when the mask is a related mask created by combining arrows pointing in both directions.

Mid-level Priming by Completion vs. Mosaic Solutions

We report two experiments on the role of mid-level processes in image segmentation and completion. In the primed matching task of Experiment 1, a cue→prime sequence was presented before the imperative stimulus consisting of target shapes with positive versus negative contour curvature polarity and one versus two axes of mirror symmetry. Priming shapes were included in two composite occlusion displays with the same T-junction information and different geometric features supporting a distinct balance between completion and mosaic solutions. A cue, either congruent or incongruent with targets, preceded the presentation of the composite priming display. Matching performance was affected by primes in the expected direction, while cue congruency participated only in a marginally significant three-way interaction, and prime duration had no effect. In Experiment 2, the cue→prime sequence was replaced by a fixation cross to control for the priming effect obtained in Experiment 1. The study confirmed that contour connectability and curvature polarity are effective structural factors capable of competing with symmetry in mid-level image segmentation and completion processes.

Role of Surprise in the Discrimination of the Facial Expression of Fear

The facilitating role of the facial expression of surprise in the discrimination of the facial expression of fear was analyzed. The sample consisted of 202 subjects that undertook a forced-choice test in which they had to decide as quickly as possible whether the facial expression displayed on-screen was one of fear, anger or happiness. Variations were made to the prime expression (neutral expression, or one of surprise); the target expression (facial expression of fear, anger or happiness), and the prime duration (50 ms, 150 ms or 250 ms). The results revealed shorter reaction times in the response to the expression of fear when the prime expression was one of surprise, with a prime duration of 50 ms (p = .009) and 150 ms (p = .001), compared to when the prime expression was a neutral one. By contrast, the reaction times were longer in the discrimination of an expression of fear when the prime expression was one of surprise with a prime duration of 250 ms (p < .0001), compared to when the prime expression was a neutral one. This pattern of results was obtained solely in the discrimination of the expression of fear. The discussion focuses on these findings and the possible functional continuity between surprise and fear.

The Role of Representation Strength of the Prime in Subliminal Visuomotor Priming

This study investigated the role of representation strength of the prime in subliminal visuomotor priming in two experiments. Prime/target compatibility (compatible and incompatible) and preposed object type (jumbled lines, strong masking; and rectangular outlines, weak masking) were manipulated in Experiment 1. A significant negative compatibility effect (NCE) was observed in the rectangle condition, whereas no compatibility effect was found in the line condition. However, when a new variable, prime duration, was introduced in Experiment 2, the NCE was reversed with an increase in the prime duration in the rectangle condition, whereas the NCE was maintained in the line condition. This result is consistent with the claim that increasing the prime duration causes the prime representation to be too strong for inhibition in the rectangle condition but strong enough to reliably trigger inhibition in the line condition. The findings demonstrated that prime representation has a causal role in subliminal visuomotor priming.

Is translation priming asymmetry due to partial awareness of the prime?

A 50ms prime duration is often adopted in both L1-L2 and L2-L1 directions in the cross-language priming paradigm. It is unknown how aware bilinguals are of the briefly presented primes of different scripts; and whether the degree of awareness of L1 and L2 primes is at a similar level. Kouider and Dupoux's (2004) proposal of partial awareness suggests that 50ms English primes were sufficient to make a semantic interpretation. It is unclear whether this is the case when processing one's L2 or a different script. Experiment 1 was designed to measure the comparable prime durations for semantic interpretation of Chinese primes vs. English primes. Experiment 2 tested whether partial awareness of primes would cause priming asymmetry. Our findings demonstrate that a 50ms prime duration gave rise to different degrees of semantic activation in different scripts and L1/L2. However, increasing prime duration on L2 primes did not produce L2-L1 priming.

Repetition-priming effect: a cognitive task for the definition of a clinical assessment

This research aims to study how semantic priming words can influence behavioral measures (RTs, accuracy), to develop an experimental paradigm to differentiate visual neglect and hemianopia. 69 experimental subjects were involved in four experiments. In each experiment target words were preceded by word primes semantically related, neutral or unrelated to the target. The four experiments differed in terms of: number of prime, prime duration and distance between pc monitor and subject. In general, related primes should improve facilitatory effect in target recognition more than unrelated primes, reducing RTs and increasing response accuracy. After repeated ANOVA analysis applied to each experiment and paired comparisons, it is possible to point out that single related primes, shown for 150 ms, greatly improve response behavior in terms of RTs reduction. For future applications to the clinical field, we assume that neglect patients should be facilitated in these specific experimental conditions, due to implicit contralesional prime processing. On the contrary, hemianopics should nowise be facilitated, due to visual field deficit.

Masked and Unmasked Priming Effects as a Function of Semantic Relatedness and Associative Strength

The study presented in this paper aimed to investigate the pattern of semantic priming effects, under masked and unmasked conditions, in the lexical decision task, manipulating type of semantic relation and associative strength. Three different kinds of word relations were examined in two experiments: only-semantically related words [e.g., codo (elbow)-rodilla (knee)] and semantic/associative related words with strong [e.g., mesa (table)-silla (chair) and weak association strength [e.g., sapo (toad)-rana (frog)]. In Experiment 1 a masked priming procedure was used with a prime duration of 56 ms, and in Experiment 2, the prime was presented unmasked for 150 ms. The results showed that there were masked priming effects with strong associates, but no evidence of these effects was found with weak associates or only-semantic related word pairs. When the prime was presented unmasked, the three types of relations produced significant priming effects and they were not influenced by association strength.