Independent operation of implicit working memory under cognitive load

Implicit working memory (WM) has been known to operate non-consciously and unintentionally. The current study investigated whether implicit WM is a discrete mechanism from explicit WM in terms of cognitive resource. To induce cognitive resource competition, we used a conjunction search task (Experiment 1) and imposed spatial WM load (Experiment 2a and 2b). Each trial was composed of a set of five consecutive search displays. The location of the first four displays appeared as per pre-determined patterns, but the fifth display could follow the same pattern or not. If implicit WM can extract the moving pattern of stimuli, response times for the fifth target would be faster when it followed the pattern compared to when it did not. Our results showed implicit WM can operate when participants are searching for the conjunction target and even while maintaining spatial WM information. These results suggest that implicit WM is independent from explicit spatial WM.     

Distance perception during self-movement

The perception of distance in open fields was widely studied with static observers. However, it is a fact that we and the world around us are in continuous relative movement, and that our perceptual experience is shaped by the complex interactions between our senses and the perception of our self-motion. This poses interesting questions about how our nervous system integrates this multisensory information to resolve specific tasks of our daily life, for example, distance estimation. This study provides new evidence about how visual and motor self-motion information affects our perception of distance and a hypothesis about how these two sources of information can be integrated to calibrate the estimation of distance. This model accounts for the biases found when visual and proprioceptive information is inconsistent.     

Unconscious processing of coarse visual information during anticipatory threat

Rapid detection of threats has been proposed to rely on automatic processing of their coarse visual features. However, it remains unclear whether such a mechanism is restricted to detection of threat cues, or whether it reflects a broader sensitivity to even neutral coarse visual information features during states of threat. We used a backward masking task in which participants discriminated the orientation of subliminally presented low (3 cpd) and high (6 cpd) spatial frequency gratings, under threat (of shock) and safe conditions. Visual awareness of the gratings was assessed objectively using an additional localization task. When participants were unaware of the gratings, above chance and improved discrimination of low-spatial frequency gratings was observed under threat compared to safe trials. These findings demonstrate unconscious processing of neutral coarse visual information during threat state, supporting the view that automatic threat detection may rely on a general facilitation of coarse features irrespective of threat content.     

Translating experimental paradigms into individual-differences research: Contributions,challenges, and practical recommendations

Psychological science has long been cleaved by a fundamental divide between researchers who experimentally manipulate variables and those who measure existing individual-differences. Increasingly, however, researchers are appreciating the value of integrating these approaches. Here, we used visual attention research as a case-in-point for how this gap can be bridged. Traditionally, researchers have predominately adopted experimental approaches to investigating visual attention. Increasingly, however, researchers are integrating individual-differences approaches with experimental approaches to answer novel and innovative research questions. However, individual differences research challenges some of the core assumptions and practices of experimental research. The purpose of this review, therefore, is to provide a timely summary and discussion of the key issues. While these are contextualised in the field of visual attention, the discussion of these issues has implications for psychological research more broadly. In doing so, we provide eight practical recommendations for proposed solutions and novel avenues for research moving forward.     

Effects of word frequency and visual complexity on eye movements of young and older Chinese readers

Research using alphabetic languages shows that, compared to young adults, older adults employ a risky reading strategy in which they are more likely to guess word identities and skip words to compensate for their slower processing of text. However, little is known about how ageing affects reading behaviour for naturally unspaced, logographic languages like Chinese. Accordingly, to assess the generality of age-related changes in reading strategy across different writing systems we undertook an eye movement investigation of adult age differences in Chinese reading. Participants read sentences containing a target word (a single Chinese character) that had a high or low frequency of usage and was constructed from either few or many character strokes, and so either visually simple or complex. Frequency and complexity produced similar patterns of influence for both age groups on skipping rates and fixation times for target words. Both groups therefore demonstrated sensitivity to these manipulations. But compared to the young adults, the older adults made more and longer fixations and more forward and backward eye movements overall. They also fixated the target words for longer, especially when these were visually complex. Crucially, the older adults skipped words less and made shorter progressive saccades. Therefore, in contrast with findings for alphabetic languages, older Chinese readers appear to use a careful reading strategy according to which they move their eyes cautiously along lines of text and skip words infrequently. We propose they use this more careful reading strategy to compensate for increased difficulty processing word boundaries in Chinese.     

本族和异族面孔的视觉工作记忆容量:面孔特征的影响

采用延迟探测刺激匹配再认任务,考察面孔种族和内外部特征是否会影响面孔视觉工作记忆容量。被试先识记2或4张中国人或白人的真实面孔图片,一半有内部特征(眼睛、鼻子和嘴巴),另一半有内部和外部特征(脸型、发型),再进行面孔再认判断。采用Cowan’s K值的分析显示,我国被试对本族和异族面孔的视觉工作记忆容量没有差异,但面孔数量与特征多少会影响面孔工作记忆容量,表明对本族和异族面孔的视觉加工不同。     

The time course of working memory effects on visual attention

Previous work has generated inconsistent results with regard to what extent working memory (WM) content guides visual attention. Some studies found effects of easy to verbalize stimuli, whereas others only found an influence of visual memory content. To resolve this, we compared the time courses of memory-based attentional guidance for different memory types. Participants first memorized a colour, which was either easy or difficult to verbalize. They then looked for an unrelated target in a visual search display and finally completed a memory test. One of the distractors in the search display could have the memorized colour. We varied the time between the to-be-remembered colour and the search display, as well as the ease with which the colours could be verbalized. We found that the influence of easy to verbalize WM content on visual search decreased with increasing time, whereas the influence of visual WM content was sustained. However, visual working memory effects on attention also decreased when the duration of visual encoding was limited by an additional task or when the memory item was presented only briefly. We propose that for working memory effects on visual attention to be sustained, a sufficiently strong visual representation is necessary.     

Hydrocortisone infusion exerts dose- and sex-dependent effects on attention to emotional stimuli

Glucocorticoid administration has been shown to exert complex effects on cognitive and emotional processing. In the current study we investigated the effects of glucocorticoid administration on attention towards emotional words, using an Affective Go/No-go task on which healthy humans have shown an attentional bias towards positive as compared to negative words. Healthy volunteers received placebo and either low-dose (0.15 mg/kg) or high-dose (0.45 mg/kg) hydrocortisone intravenously during two separate visits in a double-blind, randomized design. Seventy-five minutes post-infusion, the subjects performed tests of attention (Rapid Visual Information Processing [RVIP]), spatial working memory (Spatial Span) and emotional processing (Affective Go/No-go task [AGNG]). On the attention task, performance was impaired under both hydrocortisone doses relative to placebo, though the effect on error rate was not significant after controlling for age; Spatial Span performance was unaffected by hydrocortisone administration. On the AGNG task, relative to the placebo condition the low-dose hydrocortisone infusion decreased response time to emotional words while high-dose hydrocortisone increased response time. In the females specifically, both high and low dose hydrocortisone administration attenuated the normal attentional bias toward positively valenced words. These data suggest that, in healthy women, the modulation of attention by the emotional salience of stimuli is influenced by glucocorticoid hormone concentrations.     

空格减少汉语发展性阅读障碍儿童的视觉拥挤效应：来自眼动的证据

使用眼动仪记录汉语发展性阅读障碍儿童、正常年龄匹配和能力匹配儿童阅读插入空格文本时的眼动,考察在字、词以及非词间插入空格呈现文本对汉语发展性阅读障碍儿童阅读加工过程的影响。结果发现,阅读障碍儿童在字间空格条件下平均注视时间减少的程度大于正常儿童,注视次数在字间和词间空格条件下未见显著增加,能力匹配儿童的注视次数在这两种空格条件下却显著增加。结果说明,在字间和词间插入空格能够减少儿童的平均阅读时间,且字间空格文本呈现显著地提高了其阅读效率,说明空格对汉语阅读障碍儿童具有促进作用,这种促进主要是由于空格减少了其视觉拥挤效应所致。     

考试焦虑对错误记忆的影响

采用认知考试焦虑量表从550名高一学生中筛选出75名不同考试焦虑水平的学生,运用Deese-Roediger-McDermott范式(DRM范式)诱发错误记忆,考察考试焦虑对错误记忆的影响。结果显示:(1)DRM范式能有效诱发个体对未呈现的关键诱词产生错误记忆;(2)中等考试焦虑水平的学生产生的错误记忆最少;(3)高考试焦虑水平的学生在高唤醒情境下对关键诱词的再认错误率显著高于中、低唤醒情境下的个体。使学生保持中度考试焦虑能减少错误记忆,提高认知成绩。