Neural correlates of audiovisual integration of semantic category information

Previous studies have found a late frontal-central audiovisual interaction during the time period about 150-220 ms post-stimulus. However, it is unclear to which process is this audiovisual interaction related: to processing of acoustical features or to classification of stimuli? To investigate this question, event-related potentials were recorded during a words-categorization task with stimuli presented in the auditory-visual modality. In the experiment, congruency of the visual and auditory stimuli was manipulated. Results showed that within the window of about 180-210 ms post-stimulus more positive values were elicited by category-congruent audiovisual stimuli than category-incongruent audiovisual stimuli. This indicates that the late frontal-central audiovisual interaction is related to audiovisual integration of semantic category information.     

Anterior cingulate cortex activation is related to learning potential on the WCST in schizophrenia patients

The remediation of executive function in patients with schizophrenia is important in rehabilitation because these skills affect the patient's capacity to function in the community. There is evidence that instructional techniques can improve deficits in the Wisconsin Card Sorting Test (WCST) in some schizophrenia patients. We used a standard test/training phase/standard test format of the WCST to classify 36 schizophrenia patients as high-achievers, learners or non-retainers. All healthy controls performed as high-achievers. An event-related fMRI design assessed neural activation patterns during post-training WCST performance. Patients showed a linear trend between set-shifting related activation in the anterior cingulate cortex and learning potential, i.e. increased activation in high-achievers, a trend for increased activation in learners, and no activation in non-retainers compared to controls. In addition, activation in the temporoparietal cortex was highest in patients classified as learners, whereas in non-retainers activation was increased in the inferior frontal gyrus compared to controls and high-achieving patients. These results emphasize the relevance of the ACC's neural integrity in learning set-shifting strategies for patients with schizophrenia. Also, our results support the hypothesis that compensatory neural activation in patients with schizophrenia helps them to catch up with healthy controls on cognitive tasks.     

Evidence for mental ability related individual differences in the attentional blink obtained by an analysis of the P300 component

Attentional blink (AB) refers to impaired identification of a target (T2) when this target follows a preceding target (T1) after about 150-450 ms within a stream of rapidly presented stimuli. Previous research on a possible relation between AB and mental ability (MA) turned out to be highly ambiguous. The present study investigated MA-related individual differences in consolidation of T2 in working memory during the AB as indicated by the P300 component of the event-related potential. Thirty high (HA) and 30 low MA (LA) female participants performed an AB task while their brain activity was recorded. The AB did not differ between the two groups. HA individuals exhibited a larger P300 amplitude and longer P300 latencies during the AB suggesting higher mental effort. This higher mental effort, however, did not result in better performance presumably because of more competition between target and distractor stimuli in HA than LA individuals.     

Exploring the enactment effect from an information processing view: What can we learn from serial position analyses?

The focus of the present article was to analyze processes that determine the enactment and age effect in a multi-trial free recall paradigm by looking at the serial position effects. In an experimental study (see Schatz et al 2010), the performance-enhancing effect of enactive encoding and repeated learning was tested with older and younger participants. As expected, there was a steady improvement of memory performance as a function of repeated learning regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Furthermore, younger adults outperformed the elderly regardless of type of encoding. Analyses in the present article show that encoding by enacting seems to profit especially from remembering the last items of a presented list. Regarding age differences, younger outperformed older participants in nearly all item positions. The performance enhancement after task repetition is due to a higher amount of recalled items in the middle positions in a subject performed task (SPT) and a verbal task (VT) as well as the last positions of a learned list in VT.     

Age-related differences in working memory: ERPs reveal age-related delays in selection- and inhibition-related processes

Faulty inhibition is implicated in age-related working memory decline. ERP signs of selection and inhibition of items in working memory (WM) are, respectively, a cue-locked parietal positivity (～350 ms) and a probe-locked frontal negativity (～520 ms). To determine when in the older age range differences in selective and inhibitory processes might occur, ERPs were recorded in a WM task from 20 young (20–28), 20 young–old (60–70), and 20 old–old (71–82) adults. A 4-digit display was followed by a cue indicating which 2 of 4 digits were relevant. Proactive interference (PI), the reaction time difference between a matching and non-matching to-be-ignored digit was larger, relative to the young, in both older groups. Compared to the young, both the cue- and probe-locked activities were prolonged in the older groups. Although there were no topographic differences among the age groups, the prolonged PI and associated ERPs suggest a relative age-related deficit in inhibition.     

分段是视频学习的有效方式吗?

教育心理学中的分段原则认为,将视频学习材料分割成几个小片段进行学习的效果更好。以往关于分段的研究通过两个角度的操纵考察了分段在学习中的作用,一方面是交互性角度,学习者自己控制的分段及系统分段;另一方面是结构性角度,分段是在任意时间点划分和有意义时间点上划分。通过对以往研究结果的整理发现,大部分研究证明分段学习相较于连续学习的成绩更好,并且能降低学习者在学习过程中的感知难度, 提高积极的情感状态,但是对心理努力的影响比较微弱。研究者们从事件分割理论和认知负荷理论的视角对分段的效果做出了解释。未来研究需要继续关注分段的边界条件、拓宽研究的范围、探究分段的认知神经基础等不断完善分段原则在教学中的应用。     

The relationship between procrastination,delay of gratification,and job satisfaction among high school teachers

The present study aimed at determining whether a significant relationship exists between procrastination, delay of gratification, and job satisfaction, with work‐related stress as an intervening variable among high school teachers. The sample consisted of 150 high school teachers from Karachi, Pakistan. The analysis showed a negative correlation between procrastination and job satisfaction, and a positive correlation between delay of gratification and job satisfaction. Also, procrastination and delay of gratification were significant predictors of work‐related stress, and work‐related stress was also a significant predictor of job satisfaction. In conclusion, when the teachers are not procrastinating on their job and score high on delay of gratification they will be more satisfied with their job and feel less stressed.     

Investigating letter recognition in the brain by varying typeface: An event-related potential study

We aimed to investigate the contributions of visual letter form and abstract letter identity to the time course of letter recognition, by manipulating the typeface (i.e. font) in which letters were presented. Twenty-six adult participants completed a modified one-back task, where letters where presented in easy-to-read typefaces (“fluent” letter stimuli) or difficult-to-read typefaces (“disfluent” letter stimuli). Task instructions necessitated that participant’s focus on letter identity not visual letter form. Electroencephalography was collected and event-related potentials (ERPs) were calculated relative to letter stimuli. It was found that typeface affected both early-mid (N1 amplitude and P2–N2 amplitude and latency) and late processing (450–600 ms), thereby including time points whereby it is theorised that abstract identity is extracted from visual letter form (that is, 300 ms post-stimulus). Visual features of the letter therefore affect its processing well beyond the currently theorised point at which abstract information is extracted; which could be explained by a feedback loop between abstract letter representations and lower-level visual form processing units, which is not included in current cognitive reading models.     

Neurophysiological marker of inhibition distinguishes language groups on a non-linguistic executive function test

Successful interaction with the environment depends on flexible behaviors which require shifting attention, inhibiting primed responses, ignoring distracting information, and withholding motor responses. These abilities, termed executive function (EF), are believed to be mediated by inhibitory processes in the frontal lobes. Superior performance on EF tests (i.e., faster reaction times (RT), and fewer errors) has been shown in bilinguals compared to monolingual speakers. However, findings are inconsistent, and no study has directly linked this bilingual advantage to frontal lobe inhibitory processes. To clarify this uncertainty, we concomitantly tested neural inhibitory processes and behavioral responses on an EF test in bilinguals and monolinguals. Specifically, we compared English monolinguals (N = 15) to Spanish/English bilinguals (N = 13) on event-related brain potentials (ERP) during a non-linguistic, auditory Go/NoGo task, a task linked to non-motor, cognitive inhibition in monolinguals. Participants responded with a button press on trials in which target tone-pairs (Go trials) were presented and withheld their responses on non-target trials (NoGo trials). Results revealed significantly greater inhibition (i.e., greater mean N2 amplitude) in bilinguals compared to monolinguals during NoGo trials even though both groups performed the task equally well (i.e., withheld a motor response). On Go trials where participants pressed a response button, neither ERPs nor RT distinguished the groups. Additionally, scores on a second language proficiency test (i.e., English in our bilingual group) were positively correlated with N2 amplitude. These findings are the first to directly link this bilingual advantage to a neural correlate of inhibition and to reveal that inhibition in bilinguals is moderated by second language proficiency. Results are discussed in the context of plasticity, and we propose that evaluating bilinguals at varying levels of second-language proficiency may serve as a model of human neuroplasticity.