Exploring conflict- and target-related movement of visual attention

Intermixing trials of a visual search task with trials of a modified flanker task, the authors investigated whether the presentation of conflicting distractors at only one side (left or right) of a target stimulus triggers shifts of visual attention towards the contralateral side. Search time patterns provided evidence for lateral attention shifts only when participants performed the flanker task under an instruction assumed to widen the focus of attention, demonstrating that instruction-based control settings of an otherwise identical task can impact performance in an unrelated task. Contrasting conditions with response-related and response-unrelated distractors showed that shifting attention does not depend on response conflict and may be explained as stimulus-conflict-related withdrawal or target-related deployment of attention.     

Control processes in voluntary and explicitly cued task switching

Explicitly cued task switching slows performance relative to performing the same task on consecutive trials. This effect appears to be due partly to more efficient encoding of the task cue when the same cue is used on consecutive trials and partly to an additional task-switching process. These components were examined by comparing explicitly cued and voluntary task switching groups, with external cues presented to both groups. Cue-switch effects varied in predictable ways to dissociate explicitly cued and voluntary task switching, whereas task-switch effects had similar characteristics for both instructional groups. The data were well fitted by a mathematical model of task switching that included a cue-encoding mechanism (whereby cue repetition improves performance) and an additional process that was invoked on task-switch trials. Analyses of response-time distributions suggest that this additional process involves task-set reconfiguration that may or may not be engaged before the target stimulus is presented.     

Intentional attention switching in dichotic listening: Exploring the efficiency of nonspatial and spatial selection

Using an auditory variant of task switching, we examined the ability to intentionally switch attention in a dichotic-listening task. In our study, participants responded selectively to one of two simultaneously presented auditory number words (spoken by a female and a male, one for each ear) by categorizing its numerical magnitude. The mapping of gender (female vs. male) and ear (left vs. right) was unpredictable. The to-be-attended feature for gender or ear, respectively, was indicated by a visual selection cue prior to auditory stimulus onset. In Experiment 1, explicitly cued switches of the relevant feature dimension (e.g., from gender to ear) and switches of the relevant feature within a dimension (e.g., from male to female) occurred in an unpredictable manner. We found large performance costs when the relevant feature switched, but switches of the relevant feature dimension incurred only small additional costs. The feature-switch costs were larger in ear-relevant than in gender-relevant trials. In Experiment 2, we replicated these findings using a simplified design (i.e., only within-dimension switches with blocked dimensions). In Experiment 3, we examined preparation effects by manipulating the cueing interval and found a preparation benefit only when ear was cued. Together, our data suggest that the large part of attentional switch costs arises from reconfiguration at the level of relevant auditory features (e.g., left vs. right) rather than feature dimensions (ear vs. gender). Additionally, our findings suggest that ear-based target selection benefits more from preparation time (i.e., time to direct attention to one ear) than gender-based target selection.     

Distinct effects of positive and negative music on older adults' auditory target identification performances

Older adults, compared to younger adults, are more likely to attend to pleasant situations and avoid unpleasant ones. Yet, it is unclear whether such a phenomenon may be generalized to musical emotions. In this study, we investigated whether there is an age-related difference in how musical emotions are experienced and how positive and negative music influences attention performances in a target identification task. Thirty-one young and twenty-eight older adults were presented with 40 musical excerpts conveying happiness, peacefulness, sadness, and threat. While listening to music, participants were asked to rate their feelings and monitor each excerpt for the occurrence of an auditory target. Compared to younger adults, older adults reported experiencing weaker emotional activation when listening to threatening music and showed higher level of liking for happy music. Correct reaction times (RTs) for target identification were longer for threatening than for happy music in older adults but not in younger adults. This suggests that older adults benefit from a positive musical context and can regulate emotion elicited by negative music by decreasing attention towards it (and therefore towards the auditory target).     

Attentional capture by emotional faces in adolescence

Poor decision making during adolescence occurs most frequently when situations are emotionally charged. However, relatively few studies have measured the development of cognitive control in response to emotional stimuli in this population. This study used both affective (emotional faces) and non-affective (letter) stimuli in two different flanker tasks to assess the ability to ignore task-irrelevant but distracting information, in 25 adults and 25 adolescents. On the non-emotional (letter) flanker task, the presence of incongruent flanking letters increased the number of errors, and also slowed participants’ ability to identify a central letter. Adolescents committed more errors than adults, but there were no age-related differences for the reaction time interference effect in the letter condition. Post-hoc testing revealed that age-related differences on the task were driven by the younger adolescents (11-14 years); adults and older adolescents (15-17 years) were equally accurate in the letter condition. In contrast, on the emotional face flanker task, not only were adolescents less accurate than adults but they were also more distracted by task-irrelevant fearful faces as evidenced by greater reaction time interference effects. Our findings suggest that the ability to self-regulate in adolescents, as evidenced by the ability to suppress irrelevant information on a flanker task, is more difficult when stimuli are affective in nature. The ability to ignore irrelevant flankers appears to mature earlier for non-affective stimuli than for affective stimuli.     

Realism in confidence judgements of performance based on implicit learning

In two experiments we employed calibration methods to investigate the realism of participants' confidence ratings of their own classification performance based on knowledge acquired after training on an artificial grammar. In Experiment 1 participants showed good realism (but overconfidence) for grammatical strings but very poor realism for non-grammatical strings. Method of training (string repetition in writing or mere exposure) did not affect the realism. Furthermore, the participants underestimated their overall performance. In Experiment 2, using a more complex grammar and controlling for two types of associative chunk-strength, participants showed good realism (but still overconfidence) for both letter and symbol strings, irrespective of grammaticality. Together, these experiments show that implicit learning can give rise to knowledge products that are associated with fairly realistic meta-knowledge. It is argued that both the zero-correlation criterion and the guessing criterion are misplaced when used to define implicit knowledge; two reasons being that confidence judgements may be affected both by implicit knowledge and by inferences.     

Make the manikin move: Symbolic approach–avoidance responses affect implicit and explicit face evaluations

The present research aimed to replicate and extend findings of Huijding, Muris, Lester, Field, and Joosse (2011), investigating whether symbolic approach–avoidance responses can induce implicit and explicit evaluation biases. Faces with a neutral expression were shown on a computer screen, and participants were instructed to repeatedly move a manikin towards some faces (approach) and away from other faces (avoidance). An affective priming task and a face rating task were used to assess training-compatible differences in implicit and explicit face evaluations, respectively. Results showed that the manikin training was successful: The priming task revealed more positive implicit evaluations of approached than avoided faces, and approached faces were rated more positively than avoided ones in the face rating task. These findings replicate those of Huijding and colleagues by demonstrating training effects on explicit evaluations, and they extend them by demonstrating effects on implicit evaluations.     

Are bilingual advantages dependent upon specific tasks or specific bilingual experiences?

Paap and Greenberg concluded that there is no coherent evidence for bilingual advantages in executive processing. More optimistic researchers believe that the advantages may be restricted to certain types of bilinguals. Recent large-scale and lifespan investigations that tested highly fluent bilinguals from communities where the same two languages are spoken by most residents reported no bilingual advantages in any age group or in any of the tasks used to measure executive functioning. The present study takes a complementary approach by examining a sample that is quite homogeneous in terms of current life experiences, but heterogeneous in terms of its exposure to second languages. The composite database of 168 bilinguals and 216 monolinguals is used to explore for differences based on: (1) the age of acquiring a second language (L2), (2) the relative proficiency of an L2 and (3) the number of languages used. Across 12 different measures of executive function, derived from 4 different nonverbal tasks, there was no consistent evidence supporting the hypotheses that either early bilingualism, highly fluent balanced bilingualism, or trilingualism enhances inhibitory control, monitoring or switching. In fact, when statistically significant effects did occur, they more often disconfirmed than confirmed these hypotheses.     

Visual context does not promote concurrent sequence learning

Concurrent sequence learning (CSL) of two or more sequences refers to the concurrent maintenance, in memory, of the two or more sequence representations. Research using the serial reaction time task has established that CSL is possible when the different sequences involve different dimensions (e.g., visuospatial locations versus manual keypresses). Recently some studies have suggested that visual context can promote CSL if the different sequences are embedded in different visual contexts. The results of these studies have been difficult to interpret because of various limitations. Addressing the limitations, the current study suggests that visual context does not promote CSL and that CSL may not be possible when the different sequences involve the same elements (i.e., the same target locations, response keys and effectors).     

儿童分离焦虑的发展变化研究

采用图画辅助程序和图示评定量表,对四个年龄组80名儿童的分离焦虑进行了探讨。结果发现:(1)随年龄增加,儿童分离焦虑逐渐下降;(2)3—5岁儿童分离焦虑最高;(3)儿童直接分离焦虑高于间接分离焦虑;(4)直接分离与间接分离情景有两个完全不同的因素。