Neuromagnetic correlates of intra- and extra-dimensional set-shifting

Set-shifting is essential to cognitive flexibility and relies on frontal lobe function. Previous studies have mostly focused on feedback processes following shifting rather than set-shifting itself. We designed an MEG paradigm without feedback to directly investigate the neural correlates of set-shifting. Adults (n = 16) matched one of two coloured images with a third stimulus, the target, by either the colour or shape dimension of the target. Half of the shift trials involved colour-to-colour or shape-to-shape (intra-dimensional: ID) shifting and the other half involved colour-to-shape or shape-to-colour (extra-dimensional: ED) shifting. MEG was continuously recorded on a 151 channel CTF system. We used beamforming to analyze responses to the first (shift) and the third (repeat) trials in each set. These trials were contrasted separately for ID and ED sets. Shift versus repeat trials showed larger MEG activations for intra-dimensional shifting in the right inferior frontal gyrus (BA 47), left medial frontal gyrus (BA 10) and right superior frontal gyrus (BA 9) as early as 100 ms, and in left middle frontal gyrus (BA 11) between 250–500 ms. Activations related to extra-dimensional shifting were detected in left inferior frontal gyrus (BA 44), left middle frontal gyrus (BA 11), and right middle frontal gyrus (BA 46) between 100 ms and 350 ms, followed by superior frontal gyrus (BA 8/BA 10) between 250–500 ms. Intra-dimensional and extra-dimensional shifting also activated bilateral and right parietal areas, respectively. This study establishes the location and timing of frontal and parietal activations during an intra-dimensional versus extra-dimensional shifting task.     

Risky decision making and cognitive flexibility among online sports bettors in Nigeria

Online sports betting is a popular recreational activity in Nigeria. Like other forms of gambling, risk of pathological progression exists for gamblers who continue betting despite severe financial and psychosocial consequences. In the present study, we examined whether this population of gamblers shows deficits in decision making and cognitive flexibility that have been documented in Western gambling populations. Thirty-six online sports bettors and 42 non-gambling participants completed a version of the Iowa gambling task (IGT) and an established set-shifting task for the assessment of cognitive flexibility. The two groups did not differ significantly in the selection of disadvantageous decks on the IGT. In contrast, sports bettors committed significantly more errors on the set-shifting task than non-gambling control participants. As this performance deficit was not specific to trials requiring a set shift, it most likely resulted from gambling-related changes in general cognitive or motivational abilities that are required to successfully complete challenging mental tasks. While our results illustrate that findings from Western populations cannot automatically be generalised to other contexts, it should be noted that we focused on only one particular type of gambling and included mostly participants with mild gambling-related problems.     

认知风格影响归类过程中的神经活动-来自fMRI研究的证据

行为学研究表明归类过程中的反应具有认知风格上的不同,但未有研究明确探讨归类过程的神经活动是否也受认知风格的影响。本研究通过双重认知风格分型任务筛选出分析型和整体型被试,以探讨归类过程中二者之间是否表现出神经活动的差异。实验任务要求被试从两个待选物中选出与目标物属于同一类别的一个。同时,采用fMRI技术扫描并记录他们完成任务时的BOLD信号。结果发现,与基线任务相比,整体型和分析型个体均激活了额-枕网络的一些脑区,包括额下回、楔前叶、枕中回等,表明不同认知风格个体在任务中可能共享与工作记忆等相关的脑区。另外,与分析型个体相比,整体型个体在右额下回、右旁海马回呈现更广泛的特异性激活,提示,认知风格可以影响归类过程中的脑活动,而整体型个体大脑右半球更强烈的活动表明这一类型认知风格个体在归类时更依赖于远距离的语义联结。     

Individual differences in cognitive-flexibility: the influence of spontaneous eyeblink rate, trait psychoticism and working memory on attentional set-shifting

Individual differences in psychophysiological function have been shown to influence the balance between flexibility and distractibility during attentional set-shifting [e.g., Dreisbach et al. (2005). Dopamine and cognitive control: The influence of spontaneous eyeblink rate and dopamine gene polymorphisms on perseveration and distractibility. Behavioral Neuroscience, 119(2), 483-490]. Here we replicate both the facilitatory and detrimental influence of spontaneous eyeblink rate upon switch costs across the two distinct conditions of a set-shifting task. We extend this by presenting additional, putatively dopamine related, individual differences that also influence attentional control. Whereas trait psychoticism showed a pattern of effects opposite to that of eyeblink rate, greater working memory served to decrease switch costs across both conditions. These results highlight the need for further exploration of the role of dopaminergic neurotransmission and component processes involved in such attentional paradigms, and illustrates the importance of considering individual differences in cognitive control.     

Derived Trail Making Test indices: demographics and cognitive background variables across the adult life span

We examined the contribution of demographics and cognitive background variables (processing speed, visuospatial skill, working memory, and interference control) on derived Trail Making Test (TMT) scores in a large sample of Greek healthy participants. We included 775 participants and administered the TMT (TMT-A and TMT-B) and the Wechsler Intelligence Adult Scale (WAIS). Direct (TMT-A & TMT-B time-to-completion) and derived [difference TMT-(B ? A) & ratio TMT-(B/A)] scores were calculated. Demographics (age, age², education, and gender) and WAIS Full Intelligence Quotient significantly predicted the direct TMT-A (R² = 0.426) and TMT-B (R² = 0.593) scores and to a lesser extent, the derived TMT-(B ? A) (R² = 0.343) and TMT-(B/A) (R² = 0.088) scores. In a subsample of 537 healthy participants who also completed the Stroop Neuropsychological Screening Test (SNST), demographics (age and education), WAIS Digit Symbol, Block Design, Arithmetic, and SNST accounted for 44.8% and 59.7% of the variance on TMT-A and TMT-B, and 32.5% and 9.6% of the variance on TMT-(B ? A) and TMT-(B/A), respectively. We found minimal influence of Block Design and Arithmetic on TMT-(B ? A) and an absence of significant influence of any cognitive variable on TMT-(B/A) score. Concluding, derived TMT scores are suggested as indices to detect impairment in cognitive flexibility across the adult life span, since they minimize the effect of demographics and other cognitive background variables.     

The effects of simulated stuttering and prolonged speech on the neural activation patterns of stuttering and nonstuttering adults

Functional magnetic resonance imaging was used to investigate the neural correlates of passive listening, habitual speech and two modified speech patterns (simulated stuttering and prolonged speech) in stuttering and nonstuttering adults. Within-group comparisons revealed increased right hemisphere biased activation of speech-related regions during the simulated stuttered and prolonged speech tasks, relative to the habitual speech task, in the stuttering group. No significant activation differences were observed within the nonstuttering participants during these speech conditions. Between-group comparisons revealed less left superior temporal gyrus activation in stutterers during habitual speech and increased right inferior frontal gyrus activation during simulated stuttering relative to nonstutterers. Stutterers were also found to have increased activation in the left middle and superior temporal gyri and right insula, primary motor cortex and supplementary motor cortex during the passive listening condition relative to nonstutterers. The results provide further evidence for the presence of functional deficiencies underlying auditory processing, motor planning and execution in people who stutter, with these differences being affected by speech manner.     

The role of cognitive factors in body-size perception and recall-size estimation in normal-weight women

ObjectiveBased on the hypothesis that remembered body size differs from perceived body size, the objectives of this study were to assess the difference between body-size perception and recall size and to investigate the neuropsychological correlates of body-size estimation.MethodNinety-one normal-weight women were randomized into three body-size estimation conditions: photo-size estimation, mirror-size estimation and recall-size estimation without a photo or mirror. All participants first estimated the size of a neutral object, then adjusted distorted images of themselves according to experimental conditions. Finally, the participants completed the Trail Making Test (TMT) as a neuropsychological measure.ResultsBody-size estimations were influenced by the experimental condition in opposite directions for body-size perception and recall-size estimation. Participants who overestimated their body size took longer to complete the TMT-B, a measure of cognitive flexibility.ConclusionBody perception and body memory are clearly separable components of body image. An individual's amount of mental flexibility appears to be associated with body-size distortions, particularly body-size overestimations. Further research is needed on the nature of potential causal mechanisms for this phenomenon, including the use of relevant tests to explore cognitive flexibility and the effects of potentially confounding variables.     

Behind the wheels with autism and ADHD: Brain networks involved in driving hazard detection

Driving is a cognitively challenging task, and many individuals with autism spectrum disorder (ASD) or with attention-deficit/hyperactivity disorder (ADHD) struggle to drive safely and effectively. Previous evidence suggests that core neuropsychological deficits in executive functioning (EF) and theory of mind (ToM) may impact driving in ASD and ADHD. This functional magnetic resonance imaging (fMRI) study compares the brain mechanisms underlying ToM and EF during a hazard perception driving task. Forty-six licensed drivers (14 ASD, 17 ADHD, 15 typically developing (TD)), ages 16–27 years, viewed a driving scenario in the MRI scanner and were instructed to respond to driving hazards that were either “social” (contained a human component such as a pedestrian) or “nonsocial” (physical objects such as a barrel). All groups of participants recruited regions part of the “social brain” (anterior insula, angular gyrus, right middle occipital gyrus, right cuneus/precuneus, and right inferior frontal gyrus) when processing social hazards, and regions associated with motor planning and object recognition (postcentral gyrus, precentral gyrus, and supplementary motor area) when processing nonsocial hazards. While there were no group differences in brain activation during the driving task, years licensed was predictive of greater prefrontal and temporal activation to social hazards in all participants. Findings of the current study suggest that high-functioning ASD and ADHD licensed drivers may be utilizing similar cognitive resources as TD controls for decisions related to driving-related hazard detection.     

Differential effects of inactivation of the orbitofrontal cortex on strategy set-shifting and reversal learning

Different subregions of the rodent prefrontal cortex (PFC) mediate dissociable types of behavioral flexibility. For example, lesions of the medial or orbitofrontal (OFC) regions of the PFC impair extradimensional shifts and reversal learning, respectively, when novel stimuli are used during different phases of the task. In the present study, we assessed the effects of inactivation of the OFC on strategy set-shifting and reversal learning, using a maze based set-shifting task mediated by the medial PFC. Long–Evans rats were trained initially on a visual-cue discrimination to obtain food. On the subsequent day, rats had to shift to using a response strategy (e.g., always turn left). On Day 3 (reversal), rats were required to reverse the direction of their turn (e.g., always turn right). Infusions of the local anesthetic bupivacaine into the OFC did not impair initial visual discrimination learning, nor did it impair performance on the set-shift. In contrast, inactivation of the OFC did impair reversal learning; yet, these rats ceased using the previously acquired response rule as readily as controls. Instead, rats receiving OFC inactivations made a disproportionate number of erroneous arm entries towards the visual-cue, suggested that these animals reverted back to using the original visual-cue based strategy. These findings, in addition to previous data, further support the notion that the OFC and medial PFC play dissociable roles in reversal learning and set-shifting. Furthermore, the lack of effect of OFC inactivations on the set-shift indicates that this type of behavioral flexibility does not require cognitive operations related to reversal learning.     

身体形式和社会环境对SNARC效应的影响:基于具身认知观的理解

目前SNARC效应在认知心理学领域得到了广泛研究,然而较少有研究考察身体形式和社会环境对SNARC效应的影响.研究以127名在校大学生为被试,使用奇偶判断任务、Go/No-go任务以及合作情境下的Go/No-go任务依次展开了三个研究,拟揭示身体形式和社会环境对SNARC效应的影响.实验一要求被试双手完成奇偶判断任务,结果出现了经典的SNARC效应.实验二要求被试完成Go/No-go任务,并让被试单手(左手或右手)对奇数或偶数进行反应,结果SNARC效应没有出现,这表明认知主体的身体形式对SNARC效应产生了影响.实验三要求被试合作完成Go/No-go任务,该实验按照被试所坐的位置(左边和右边)和反应手(左手和右手),设计了四个条件,结果只有身体位置和反应手完全一致时出现了 SNARC 效应.以上结果一方面表明了具身认知观的合理性,另外一方面扩展了以往对SNARC效应本质的理解.     

Neuro-cognitive aspects of “OM” sound/syllable perception: A functional neuroimaging study

The sound “OM” is believed to bring mental peace and calm. The cortical activation associated with listening to sound “OM” in contrast to similar non-meaningful sound (TOM) and listening to a meaningful Hindi word (AAM) has been investigated using functional magnetic resonance imaging (MRI). The behaviour interleaved gradient technique was employed in order to avoid interference of scanner noise. The results reveal that listening to “OM” sound in contrast to the meaningful Hindi word condition activates areas of bilateral cerebellum, left middle frontal gyrus (dorsolateral middle frontal/BA 9), right precuneus (BA 5) and right supramarginal gyrus (SMG). Listening to “OM” sound in contrast to “non-meaningful” sound condition leads to cortical activation in bilateral middle frontal (BA9), right middle temporal (BA37), right angular gyrus (BA 40), right SMG and right superior middle frontal gyrus (BA 8). The conjunction analysis reveals that the common neural regions activated in listening to “OM” sound during both conditions are middle frontal (left dorsolateral middle frontal cortex) and right SMG. The results correspond to the fact that listening to “OM” sound recruits neural systems implicated in emotional empathy.     

认知判断中手部动作模拟的fMRI研究

该研究采用功能磁共振成像技术,考察不同条件下进行工具认知判断时手部姿势对认知判断的影响及动作模拟的神经机制。实验发现：手部姿势存在显著的主效应,冲突手部姿势条件下反应时最慢,且冲突手部姿势条件下与不冲突手部姿势条件下、自然状态条件下反应时存在显著差异,自然状态条件与不冲突手部姿势条件下反应时不存在显著差异。另外,f MRI成像结果发现,额中回、额下回、顶下小叶以及辅助运动区在自然状态下有显著激活,表明个体在进行认知判断过程中有动作模拟过程;海马结构、扣带回及楔前叶等与记忆有关的脑区有显著激活,表明身体经验在认知过程的作用。总的研究表明,不同的手部姿势状态对认知判断有不同影响,冲突手部姿势会对动作模拟产生干扰作用,手部动作模拟的神经机制主要涉及镜像神经元区,且在认知判断时存在具身效应。     

Sustained attention to local and global target features is different: Performance and tympanic membrane temperature

Vision researchers have investigated the differences between global and local feature perception. No one has, however, examined the role of global and local feature discrimination in sustained attention tasks. In this experiment participants performed a sustained attention task requiring either global or local letter target discriminations or watched the same displays without any work imperative. Reaction time to targets was slower when global feature discriminations were required than when local feature discriminations were required. Tympanic membrane temperature (TMT) was utilized in this study as an index of cerebral activation. Participants in the global letter detection condition had elevated post-task right TMT, indicative of reduced cerebral activation in the right hemisphere, in comparison to participants in the local letter detection or no-work imperative conditions. Both the performance and physiological results of this study indicate increased cognitive fatigue when global feature discriminations are required.     

中文音素言语流畅性任务的近红外脑功能成像研究

本文使用近红外脑功能成像技术探测正常被试在中文音素言语流畅性任务时的脑激活模式,34名右利手大学生被试参加了实验,实验任务为音素言语流畅性任务,采用近红外脑功能成像仪检测被试额颞区在任务时的激活情况,结果发现该任务激活了大脑双侧的额颞区,双侧缘上回的激活可能为中文音素言语流畅性任务的语言特异性激活脑区,该研究为临床诊断提供了参考价值,并说明了近红外脑功能成像仪可用于中文言语流畅性任务的研究     

外显和内隐情绪韵律加工的脑机制：近红外成像研究

准确识别言语中的情绪韵律信息对社会交往非常重要。本研究采用功能近红外成像技术, 探索外显和内隐情绪加工条件下愤怒、恐惧、快乐三种情绪韵律加工过程中的大脑皮层神经活动。结果表明, 对愤怒、恐惧、快乐韵律进行特异性加工的脑区分别为左侧额极/眶额叶、右侧缘上回、左侧额下回, 其中右侧缘上回脑区同时受到情绪和任务的调控。此外, 右侧颞中回、颞下回和颞极在情绪外显任务中的激活明显强于内隐任务。本研究的结果部分支持了情绪韵律的层次模型, 也对该模型的第三层次, 即“额区对语音情绪信息的精细加工需要外显性情绪加工任务参与”提出了质疑。     

Switch detection in preschoolers' cognitive flexibility

The current study addressed the role of switch detection in cognitive flexibility by testing the effect of transition cues (i.e., cues that directly signal the need to switch or maintain a given task goal) in a cued set-shifting paradigm at 5 years of age. Children performed better, especially on switch trials, when transition cues were combined with traditional task cues (i.e., cues that directly signal the relevant task on a given trial) relative to conditions without transition cues. This effect was not influenced by explicit knowledge of transition cues or transition cue transparency, suggesting that transition cues did not need to be semantically processed to be beneficial. These findings reveal that young children’s difficulties in set-shifting situations stem partially from failures to monitor for the need to switch.     

Behavioral and fMRI evidence that cognitive ability modulates the effect of semantic context on speech intelligibility

Text cues facilitate the perception of spoken sentences to which they are semantically related (Zekveld, Rudner, et al., 2011). In this study, semantically related and unrelated cues preceding sentences evoked more activation in middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) than nonword cues, regardless of acoustic quality (speech in noise or speech in quiet). Larger verbal working memory (WM) capacity (reading span) was associated with greater intelligibility benefit obtained from related cues, with less speech-related activation in the left superior temporal gyrus and left anterior IFG, and with more activation in right medial frontal cortex for related versus unrelated cues. Better ability to comprehend masked text was associated with greater ability to disregard unrelated cues, and with more activation in left angular gyrus (AG). We conclude that individual differences in cognitive abilities are related to activation in a speech-sensitive network including left MTG, IFG and AG during cued speech perception.     

积极情绪影响任务转换的性别和发展特点

情绪研究中的性别和年龄因素一直是不容忽视的问题.已有研究表明,积极情绪能够提高认知的灵活性,任务转换是认知灵活性的主要成分.本研究以52名大学生3、6名高中生4、5名初中生为被试考察积极情绪影响任务转换的发展变化和性别差异.结果发现,对于女性,积极情绪促进任务转换的现象,在三个年龄段上具有发展上的稳定性;对于男性,只在初中阶段表现出此特点,在高中阶段和大学阶段,积极情绪促进任务转换的现象不再明显.