Synthesis of tetracycline-imprinted polymer microspheres by reversible addition-fragmentation chain-transfer precipitation polymerization using polyethylene glycol as a coporogen.

Tetracycline (TC)-imprinted microspheres have been synthesized by reversible addition-fragmentation chain-transfer precipitation polymerization using PEG as a coporogen. In the synthesis, methacrylic acid and ethylene dimethacrylate were used as the functional monomer and cross-linker, respectively. 2,2'-Azobisisobutyronitrile was the initiator, and cumyl dithiobenzoate was the chain-transfer reagent. Although monodispersed microspheres were obtained using acetonitrile as porogen, the particles cannot be used in the column extraction because of the high backpressure. To increase the porosity of the material, PEG was introduced as a coporogen. The influence of the molecular weight and concentration of PEG on the morphology, binding affinity, and porosity of the molecularly imprinted polymers (MIPs) have been studied. The results demonstrated that PEG as a macroporogen increased the porosity of the polymers. Meanwhile, the column backpressure was reduced using the MIPs with higher porosity. The binding affinity of the MIPs was increased when a low concentration of PEG was employed, while it was decreased when the ratio of PEG 12,000/monomers was >0.8%. Under the optimized conditions, TC-imprinted microspheres with good selectivity and size uniformity have been obtained, which facilitates its application in the column extraction for TC determinations.

Attentional Control in Subjective Cognitive Decline.

BACKGROUND: Attention is an essential cognitive ability that is necessary in other cognitive processes. Only few studies have focused on decline in specific functions of attention in older adults with cognitive decline. No research explores the difference in the proactive and reactive mode of control between the healthy control (HC) and older adults with subjective cognitive decline (SCD). OBJECTIVE: The current work investigated whether there was any decline in alerting, orienting, and executive control in SCD. Particularly, the present study further explored the impairment of the proactive and reactive control in SCD. METHODS: We recruited 25 HC and 26 SCD. All participants first finished a set of neuropsychological assessments. They then completed an Attention Network Test for measuring the alerting, orienting, and executive control, the List-wide and the Item-specific Proportion Congruency Effect task for measuring the proactive and reactive mode of control, respectively. RESULTS: No difference was found in alerting, orienting, and executive control measured by the ANT between SCD and HC. The results also indicated no difference in the reactive control between SCD and HC. However, older adults with SCD performed worse in the proactive control as compared to HC. CONCLUSION: Older adults with SCD showed an impairment in the proactive control. The current findings help us better understand objective decline in cognitive domains other than memory and shed light on early assessment and prevention of AD.

Perceiving the facial trustworthiness: Facial age, emotional expression, and attractiveness.

People can make trustworthiness judgements based on facial characteristics. However, the previous findings regarding whether facial age influences interpersonal trust are inconsistent. Using the trust game, the current study investigated the interactions of facial age with attractiveness and emotional expression in regard to trustworthiness judgements. In Experiments 1 and 2, younger participants were asked to invest in either younger or older faces that were shown for 2,000 and 33 ms, respectively. The results showed that people trust the faces of older people more than they do younger people. There was also an interaction between facial age and attractiveness. Participants invested more money in older faces than in younger faces only when they perceived the faces to be less attractive. However, the interaction between facial age and emotional expression was slightly inconsistent in the two experiments. Participants invested more money in older faces that were shown for 2,000 ms when they perceived the happy and sad emotions, but they invested more money in older faces that were shown for 33 ms when they perceived the happy emotion. These results reveal that people make trustworthiness judgements based on multiple facial cues when they view strangers of different ages.

The Effect of Trustor Age and Trustee Age on Trustworthiness Judgments: An Event-Related Potential Study.

Perceived trustworthiness based on facial appearance plays an important role in interpersonal trust and cooperative behavior. Interpersonal trust behaviors involve both trustors and trustees. However, there is no clear conclusion on how the age of the two individuals affects interpersonal trust behaviors. Therefore, this study used the trust game task to explore the differences in trust behaviors between two different age groups in response to faces of different ages and analyzed whether such differences were apparent in the face processing stage. The behavioral results showed that only younger adults invested more money with older partners than younger ones; that is, younger adults trusted older faces more. The event-related potential (ERP) analyses showed that in the early stage of face processing, younger faces elicited more negative N170 than older faces; at the same time, older faces elicited more positive VPP than younger faces, and younger adults had more positive VPP than older adults. In the middle and late stages of face processing, younger faces elicited more negative FRN than older faces in younger adults but not in older adults. In addition, older faces elicited more positive LPP than younger faces in older adults but not in younger adults. The neural analyses suggested that age-related differences in facial trustworthiness judgments might occur in the later stages of face processing. Combining the behavioral and neural results, we found a dissociation between trustworthiness perceptions and trust behaviors in both younger and older adults, which may provide insight into how to prevent older adults from being deceived.

Age differences in facial trustworthiness judgement based on multiple facial cues.

Multiple facial cues such as facial expression and face gender simultaneously influence facial trustworthiness judgement in adults. The current work was to examine the effect of multiple facial cues on trustworthiness judgement across age groups. Eight-, 10-year-olds, and adults detect trustworthiness from happy and neutral adult faces (female and male faces) in Experiment 1. Experiment 2 included both adult and child faces wearing happy, angry, and neutral expressions. Nine-, 11-, 13-year-olds, and adults had to rate facial trustworthiness with a 7-point Likert scale. The results of Experiments 1 and 2 revealed that facial expression and face gender independently affected facial trustworthiness judgement in children aged 10 and below but simultaneously affected judgement in children aged 11 and above, adolescents, and adults. There was no own-age bias in children and adults. The results showed that children younger than 10 could not process multiple facial cues in the same manner as in older children and adults when judging trustworthiness. The current findings provide evidence for the stable-feature account, but not for the own-age bias account or the expertise account.

Effects of Facial Expression and Facial Gender on Judgment of Trustworthiness: The Modulating Effect of Cooperative and Competitive Settings.

People often judge trustworthiness based on others' faces (e.g., facial expression and facial gender). However, it is unclear whether social context plays a moderating role in forming trustworthiness judgments. Based on the emotions as social information (EASI) model, differing contexts may impact the effect of facial expression; however, there is no evidence demonstrating that differing contexts will or will not influence the effect of facial gender. In this study, we used two experiments to examine how facial expression and facial gender affect facial trustworthiness judgments and whether the effects on facial trustworthiness judgments are consistent in cooperative and competitive settings. Twenty-seven undergraduates (14 female; M age = 21.81 years, SD = 2.66) participated in experiment 1. The results showed significant main effects of facial expression and facial gender as well as the interaction between them. To examine the social context effect, 28 undergraduates (18 female; M age = 20.93 years, SD = 2.94) participated in experiment 2. The results showed the main effects of facial expression, facial gender, and social context. Moreover, there was a significant interaction between facial gender and facial expression and a marginally significant interaction between social context and facial expression. These results suggest that in the process of judging facial trustworthiness, individuals' judgments are affected by both facial expression and facial gender. Furthermore, the effect of facial gender on facial trustworthiness judgments presents cross-situational stability, and the role of facial expression is influenced by the settings. These findings support and expand the EASI model.

Interference among the Processing of Facial Emotion, Face Race, and Face Gender.

People can process multiple dimensions of facial properties simultaneously. Facial processing models are based on the processing of facial properties. The current study examined the processing of facial emotion, face race, and face gender using categorization tasks. The same set of Chinese, White and Black faces, each posing a neutral, happy or angry expression, was used in three experiments. Facial emotion interacted with face race in all the tasks. The interaction of face race and face gender was found in the race and gender categorization tasks, whereas the interaction of facial emotion and face gender was significant in the emotion and gender categorization tasks. These results provided evidence for a symmetric interaction between variant facial properties (emotion) and invariant facial properties (race and gender).

Additivity of Feature-Based and Symmetry-Based Grouping Effects in Multiple Object Tracking.

Multiple object tracking (MOT) is an attentional process wherein people track several moving targets among several distractors. Symmetry, an important indicator of regularity, is a general spatial pattern observed in natural and artificial scenes. According to the "laws of perceptual organization" proposed by Gestalt psychologists, regularity is a principle of perceptual grouping, such as similarity and closure. A great deal of research reported that feature-based similarity grouping (e.g., grouping based on color, size, or shape) among targets in MOT tasks can improve tracking performance. However, no additive feature-based grouping effects have been reported where the tracking objects had two or more features. "Additive effect" refers to a greater grouping effect produced by grouping based on multiple cues instead of one cue. Can spatial symmetry produce a similar grouping effect similar to that of feature similarity in MOT tasks? Are the grouping effects based on symmetry and feature similarity additive? This study includes four experiments to address these questions. The results of Experiments 1 and 2 demonstrated the automatic symmetry-based grouping effects. More importantly, an additive grouping effect of symmetry and feature similarity was observed in Experiments 3 and 4. Our findings indicate that symmetry can produce an enhanced grouping effect in MOT and facilitate the grouping effect based on color or shape similarity. The "where" and "what" pathways might have played an important role in the additive grouping effect.

Effects of contextual similarity and target-repetition proportion on negative priming in RT distributional analyses.

Participants' reaction time (RT) data in a prime-probe flanker task (e.g., ABA-CAC) were analyzed in terms of the characteristics of RT distribution to examine possible mechanisms that produce negative priming. When the prime and probe were presented in the same context and the proportion of repetition-target trials (TRP) was 0.33, negative priming increased as a function of RT bins, supporting the episodic retrieval account (Neill, 1997). Manipulations that discourage the use of episodic retrieval (i.e., switching context between prime and probe or 0.00 TRP) eliminated the increase in negative priming across RT bins, even though the overall effect remained significant. These data support a dual-mechanism account in which, depending on task demands, both selective inhibition and episodic retrieval can be involved in producing negative priming.

The effect of semantic relatedness on immediate serial recall and serial recognition.

The present study examined the effects of semantic relatedness on immediate serial recall and serial recognition. Each participant received either blocked or randomly intermixed serial recall or serial recognition trials. Replicating the findings of previous studies (e.g., Saint-Aubin, Ouellette, & Poirier, 2005), semantic relatedness boosted percentage serial recall but also increased order errors, after taking into account the proportion of correctly recalled items, regardless of their orders, in serial recall trials. In serial recognition trials, participants' responses were slower and less accurate for related lists than for unrelated lists. There were intraindividual correlations among order memory measures in serial recall versus serial recognition trials. The implications of these findings for item redintegration theories are discussed.

Dissociative effects of phonological vs. semantic associates on recognition memory in the Deese/Roediger-McDermott paradigm.

Using a variation of the Deese/Roediger-McDermott paradigm in four experiments, we examined hit rate, false alarm rate, and memory discriminability (d') for critical items (e.g., sleep) after their semantic associates (e.g., dream, rest, and awake), phonological associates (e.g., bleep, sheep, and cheap) or unrelated items were studied. Replicating previous research (e.g., Neely & Tse, 2007), d' was lower for critical items than for yoked associates in semantic lists. However, d' was higher for critical items than for yoked associates in phonological lists, even when the same critical items were used for these two list types. The memory discriminability of critical items was enhanced by phonological lists via a larger increase in their hit rates than in their false alarm rates, relative to the same critical items in lists of unrelated words. These findings (a) could not be fully accounted for by the activation-based theories proposed in the false memory literature, and (b) may suggest that the memory discriminabilities of semantic and phonological lists are modulated by two distinct activation mechanisms.