Individual differences in working memory capacity predict sleep-dependent memory consolidation

Decades of research have established that "online" cognitive processes, which operate during conscious encoding and retrieval of information, contribute substantially to individual differences in memory. Furthermore, it is widely accepted that "offline" processes during sleep also contribute to memory performance. However, the question of whether individual differences in these two types of processes are related to one another remains unanswered. We investigated whether working memory capacity (WMC), a factor believed to contribute substantially to individual differences in online processing, was related to sleep-dependent declarative memory consolidation. Consistent with previous studies, memory for word pairs reliably improved after a period of sleep, whereas performance did not improve after an equal interval of wakefulness. More important, there was a significant, positive correlation between WMC and increase in memory performance after sleep but not after a period of wakefulness. The correlation between WMC and performance during initial test was not significant, suggesting that the relationship is specific to change in memory due to sleep. This suggests a fundamental underlying ability that may distinguish individuals with high memory capacity.     

The amygdala is involved in affective priming effect for fearful faces

The object of this study was to investigate whether the amygdala is involved in affective priming effect after stimuli are encoded unconsciously and consciously. During the encoding phase, each masked face (fearful or neutral) was presented to participants six times for 17ms each, using a backward masking paradigm. During the retrieval phase, participants made a fearful/neutral judgment for each face. Half of the faces had the same valence as that seen during encoding (congruent condition) and the other half did not (incongruent condition). Participants were divided into unaware and aware groups based on their subjective and objective awareness assessments. The fMRI results showed that during encoding, the amygdala elicited stronger activation for fearful faces than neutral faces but differed in the hemisphere according to the awareness level. During retrieval, the amygdala showed a significant repetition priming effect, with the congruent faces producing less activation than the incongruent faces, especially for fearful faces. These data suggest that the amygdala is important in unconscious retrieving of memories for emotional faces whether they are encoded consciously or unconsciously.     

The Rumsfeld effect: the unknown unknown

A set of studies tested whether people can use awareness of ignorance to provide enhanced test consistency over time if they are allowed to place uncertain items into a "don't know" category. For factual knowledge this did occur, but for a range of other forms of knowledge relating to conceptual knowledge and personal identity, no such effect was seen. Known unknowns would appear to be largely restricted to factual kinds of knowledge.     

Cognitive mechanisms of false facial recognition in older adults

Older adults show elevated false alarm rates on recognition memory tests involving faces in comparison to younger adults. It has been proposed that this age-related increase in false facial recognition reflects a deficit in recollection and a corresponding increase in the use of familiarity when making memory decisions. To test this hypothesis, we examined the performance of 40 older adults and 40 younger adults on a face recognition memory paradigm involving three different types of lures with varying levels of familiarity. A robust age effect was found, with older adults demonstrating a markedly heightened false alarm rate in comparison to younger adults for "familiarized lures" that were exact repetitions of faces encountered earlier in the experiment, but outside the study list, and therefore required accurate recollection of contextual information to reject. By contrast, there were no age differences in false alarms to "conjunction lures" that recombined parts of study list faces, or to entirely new faces. Overall, the pattern of false recognition errors observed in older adults was consistent with excessive reliance on a familiarity-based response strategy. Specifically, in the absence of recollection older adults appeared to base their memory decisions on item familiarity, as evidenced by a linear increase in false alarm rates with increasing familiarity of the lures. These findings support the notion that automatic memory processes such as familiarity remain invariant with age, while more controlled memory processes such as recollection show age-related decline.     

中文阅读中基于字和词的跳读与返回抑制:来自眼动方面的证据

该研究通过记录读者自然阅读中的眼动过程,对比考察了中文阅读中基于字和词的跳读与返回抑制事件。结果发现:(1)跳读事件并不影响眼跳前注视的持续时间,说明阅读过程中的眼跳计划被同时制定;(2)在一定范围内,眼跳幅度越大,跳读后注视的持续时间越长,这反映了基本的预视效应;(3)中文阅读中存在返回抑制现象,但这个现象产生的基本依据是低级的空间线索,而非词汇语义单元。     

中文阅读中的认知滞后效应

该研究应用EyelinkⅡ眼动仪,采用眼动随动显示技术操纵注视点左侧文本被掩蔽词汇的范围,考察中文阅读过程中词汇加工的认知滞后效应。结果发现:掩蔽词n以左的文本可严重影响被试的总阅读时间;掩蔽词n-1以左文本则不影响被试的总阅读时间。结果表明,相对于注视位置,中文阅读的认知过程存在明显的滞后效应。     

Medial prefrontal cortex is selectively involved in response selection using visual context in the background

The exact roles of the medial prefrontal cortex (mPFC) in conditional choice behavior are unknown and a visual contextual response selection task was used for examining the issue. Inactivation of the mPFC severely disrupted performance in the task. mPFC inactivations, however, did not disrupt the capability of perceptual discrimination for visual stimuli. Normal response selection was also observed when nonvisual cues were used as conditional stimuli. The results strongly suggest that the mPFC is not necessarily involved in the inhibition of response or flexible response selection in general, but is rather critical when response selection is required conditionally using visual context in the background.     

Roles of domain knowledge and working memory capacity in components of skill in Texas Hold’Em poker

Domain knowledge is a powerful predictor of success in many complex tasks, but do general cognitive abilities also play a role? To investigate this question, we had 155 participants representing a wide range of poker experience and skill complete tests of poker knowledge, working memory capacity (WMC), and two components of skill in Texas Hold’Em poker: the ability to remember hands and the ability to evaluate hands. Not surprisingly, poker knowledge positively predicted performance in all of the Hold’Em tasks. However, WMC added significantly to the prediction, and there was no evidence for interactions between poker knowledge and WMC. That is, WMC was as important as a predictor of performance at high levels of poker knowledge as at low levels, suggesting that domain knowledge may not always enable circumvention of WMC in domain-relevant tasks.     

Early detection of drug use and bullying in secondary school children by using a three-dimensional simulation program

The current study analyzes the psychometric properties of an innovative three-dimensional (3D) simulation program, entitled Mii-School (MS), designed for the early detection of drug use and bullying in Secondary School children. This computer program showed adequate reliability and construct validity. The factorial structure, as well as the explanatory weight of the different factors, is presented. In addition, the results of a parallel version in paper and pencil format are also presented and compared with those of the computerized version (i.e., MS). There was a statistically significant difference between the two formats in the total (i.e., combined) sore of risk. When drug use and bullying were separately analyzed, differences were found only with regard to drug use. The relevance of these results as well as the suitability of this type of 3D instrument for the early detection of risky behaviors in young people are discussed.     

Neonatal Intensive-Care Unit Graduates Show Persistent Difficulties in an Intradimensional Shift Card Sort

Neonatal intensive-care unit (NICU) graduates, a group at risk for attention problems and attention-deficit hyperactivity disorder, performed an intradimensional shift card sort at 34, 42, 51, and 60 months to assess executive function and to examine effects of individual risk factors. In the “silly” game, children sorted cards (airplanes and dogs) so they were not the same as targets. In the “same” game, they did the opposite. Performance on the “silly” game was poor, especially when it was presented first. Success in following “silly” game rules improved with age and was significantly linked to maternal education and birth weight for gestational age, a measure of intrauterine stress. Degree of central nervous system injury differentiated children who completed the task from children who did not, and it also affected the need to repeat instructions in the “same” game. These results confirm an increased likelihood of impairments in executive function during preschool years in NICU graduates.