Yonghui Wang

Lexical- and perceptual-based object effects in the two-rectangle cueing paradigm

Previous studies demonstrate that attentional selection can be object-based, in which the object is defined in terms of Gestalt principles or lexical organizations. Here we investigate how attentional selection functions when the two types of objects are manipulated jointly. Experiment 1 replicated Li and Logan (2008) by showing that attentional shift between two Chinese characters is more efficient when they form a compound word than when they form a nonword. Experiment 2A presented characters either alone or within rectangles (Egly, Driver, & Rafal, 1994) and the characters in a rectangle formed either a word or a nonword. Experiment 2B differed from Experiment 2A in that the two characters forming a word were in different rectangles. Experiment 3A presented the two characters of a word either within a rectangle or in different rectangles. Experiment 3B used the same design as Experiment 3A but presented stimuli of different types in random orders, rather than in blocks as in Experiments 2A, 2B and 3A. In blocked presentation, detection responses to the target color on a character were faster when this character and the cue character formed a word than when they did not, and the size of this lexical-based object effect did not vary according to whether the two characters were presented alone or within or between rectangles. In random presentation, however, the lexical-based object effect was diminished when the two characters of a word were presented in different rectangles. Overall, these findings suggest that the processes that constrain attention deployment over conjoined objects can be strategically adjusted.

Perceptual and motor contributions to the negative compatibility effect.

The current study focused on contributions to the negative compatibility effect (NCE) from object-updating at the perceptual level and self-inhibition (i.e., automatic motor inhibition) at the response (motor) level. We hypothesized that contributions to the NCE from these two levels were moderated by the strength of stimulus and reaction (S-R) link: object-updating should have greater impact on the NCE with weak S-R links, but both object-updating and self-inhibition should impact on the NCE when the S-R links became strong. To test this hypothesis, in two experiments we used a novel type of stimuli and manipulated mask relevance (relevant versus irrelevant mask) and prime/target compatibility. Participants performed two tasks over three successive days. Results showed that under equivalent masking effectiveness between the two conditions of mask, a significant NCE was observed only in the relevant mask condition when the S-R links were weak, but both close to equal NCE sizes were observed in the two mask conditions when the S-R links were acquired through practice. The results indicated that perceptual and motor contributions to the NCE were moderated by the strength of S-R links, if the strength of the links was too weak to trigger the following inhibition, the NCE primarily originated from object-updating at the perceptual level; if the strength of the links was reinforced by practice, which exceeded the inhibitory threshold, the NCE originated from both object-updating and self-inhibition, but the latter was primarily responsible.

Response readiness modulates the development of association-based automaticity in masked priming.

The current study investigated the role of the automatization of stimulus and response (S-R) associations and response readiness in triggering the motor activation for masked primes in two experiments. The automatization of associations was manipulated by employing different types of stimuli, and response readiness was manipulated by varying the relative frequency of Go trials in a modified Go/No-Go task. Compatibility (compatible and incompatible), stimulus type (arrows and parallel lines), and test session (Sessions 1, 2, and 3) were manipulated in a high response-readiness condition (Experiment 1) and in a low response-readiness condition (Experiment 2). Negative compatibility effects (NCEs) occurred regardless of session and experiment in the arrow stimuli condition. However, in the parallel-line stimuli condition, no significant compatibility effect (CE) appeared regardless of the experiment in Sessions 1 and 2, whereas a significant NCE appeared in Experiment 1 but not in Experiment 2 in Session 3. These results are consistent with the claim that motor activation can only occur if the association between specific stimuli and specific responses has been automatized by previous practice, and response readiness can modulate the development of automaticity, but this modulation will have a minimal effect once the association is automatized. The findings also provide experimental evidence for the assumption that the formation of association-based automaticity could be modulated by top-down control (e.g., response readiness).

Strength of object representation: its key role in object-based attention for determining the competition result between Gestalt and top-down objects

It was found in previous studies that two types of objects (rectangles formed according to the Gestalt principle and Chinese words formed in a top-down fashion) can both induce an object-based effect. The aim of the present study was to investigate how the strength of an object representation affects the result of the competition between these two types of objects based on research carried out by Liu, Wang and Zhou [(2011) Acta Psychologica, 138(3), 397–404]. In Experiment 1, the rectangles were filled with two different colors to increase the strength of Gestalt object representation, and we found that the object effect changed significantly for the different stimulus types. Experiment 2 used Chinese words with various familiarities to manipulate the strength of the top-down object representation. As a result, the object-based effect induced by rectangles was observed only when the Chinese word familiarity was low. These results suggest that the strength of object representation determines the result of competition between different types of objects.

Electrophysiological Responses to Expectancy Violations in Semantic and Gambling Tasks: A Comparison of Different EEG Reference Approaches

Dynamically evaluating the outcomes of our actions and thoughts is a fundamental cognitive ability. Given its excellent temporal resolution, the event-related potential (ERP) technology has been used to address this issue. The feedback-related negativity (FRN) component of ERPs has been studied intensively with the averaged linked mastoid reference method (LM). However, it is unknown whether FRN can be induced by an expectancy violation in an antonym relations context and whether LM is the most suitable reference approach. To address these issues, the current research directly compared the ERP components induced by expectancy violations in antonym expectation and gambling tasks with a within-subjects design and investigated the effect of the reference approach on the experimental effects. Specifically, we systematically compared the influence of the LM, reference electrode standardization technique (REST) and average reference (AVE) approaches on the amplitude, scalp distribution and magnitude of ERP effects as a function of expectancy violation type. The expectancy deviation in the antonym expectation task elicited an N400 effect that differed from the FRN effect induced in the gambling task; this difference was confirmed by all the three reference methods. Both the amplitudes of the ERP effects (N400 and FRN) and the magnitude as the expectancy violation increased were greater under the LM approach than those under the REST approach, followed by those under the AVE approach. Based on the statistical results, the electrode sites that showed the N400 and FRN effects critically depended on the reference method, and the results of the REST analysis were consistent with previous ERP studies. Combined with evidence from simulation studies, we suggest that REST is an optional reference method to be used in future ERP data analysis.

Critical role of top-down processes and the push-pull mechanism in semantic single negative priming

The present study investigated the roles of bottom-up mask-triggered inhibition and top-down inhibition in semantic categorization using the single negative priming (NP) paradigm. The masking (bottom-up) and ignore instructions (top-down, i.e., instructing participants to ignore the primes) were manipulated in Experiments 1-3 and Experiment 4, respectively. No priming was observed when only the masking was manipulated (Experiments 2 and 3), but NP was observed when a possible top-down ignore strategy (Experiment 1) or an ignore instruction (Experiment 4) was added. The results indicate that bottom-up mask-triggered inhibition cannot elicit semantic single NP by itself. However, top-down inhibition from an ignore instruction or ignore strategy is critical for triggering reliable semantic single NP. The findings suggest that semantic single NP originates from a push-pull mechanism by facilitating responses to unrelated trials and inhibiting responses to related trials. The experimental evidence also suggests that unconscious processes can be modulated by top-down control.

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.