Reorganization of functional and effective connectivity during real-time fMRI-BCI modulation of prosody processing

Mechanisms of cortical reorganization underlying the enhancement of speech processing have been poorly investigated. In the present study, we addressed changes in functional and effective connectivity induced in subjects who learned to deliberately increase activation in the right inferior frontal gyrus (rIFG), and improved their ability to identify emotional intonations by using a real-time fMRI Brain-Computer Interface. At the beginning of their training process, we observed a massive connectivity of the rIFG to a widespread network of frontal and temporal areas, which decreased and lateralized to the right hemisphere with practice. Volitional control of activation strengthened connectivity of this brain region to the right prefrontal cortex, whereas training increased its connectivity to bilateral precentral gyri. These findings suggest that changes of connectivity in a functionally specific manner play an important role in the enhancement of speech processing. Also, these findings support previous accounts suggesting that motor circuits play a role in the comprehension of speech.     

Distinct modes of executing movement sequences: reacting, associating, and chunking

Responding to individual key-specific stimuli in entirely unfamiliar keying sequences is said to involve a reaction mode. With practice, short keying sequences can be executed in the chunking mode. This is indicated by the first stimulus sufficing for rapid execution of the entire sequence. The present study explored whether an associative mode develops also in participants who practice short keying sequences. This associative mode would involve priming by earlier events of responses to external stimuli, and is believed to be responsible for skill in the Serial Reaction Time task. In the present study participants practiced two discrete 6-key sequences. In the ensuing test phase, participants were prevented from using the chunking mode by including two deviant stimuli in most sequences. The results from the remaining - unchanged - familiar sequences confirmed that participants no longer used the chunking mode, but as predicted by associative learning these sequences were executed faster than unfamiliar sequences.     

Effect of Sensory Deprivation on Maximal Force Abilities from Local to Non-local Digits

Abstract

The present study investigates the effect of sensory deprivation of the index and middle finger on motor function of all digits during maximal voluntary force production tasks. A total of 27 subjects performed maximal isometric pressing tasks by using different instructed finger combinations. Subjects completed the same tasks in two visits: a control visit when they had normal sensory feedback in all fingers, and an anesthesia visit when digital nerve blocks were performed on their right index and middle fingers. We evaluated three aspects of motor adaptation on both local (anesthetized) and non-local (non-anesthetized) digits during maximal force production: (1) task-relevant and overall force magnitude, (2) force directional application, and (3) digital individuation and force sharing. Our results indicate that selective digital anesthesia resulted in decreased maximal force magnitude, changed direction of force production, and significant changes extended to non-local digits. The motor weakness and inefficiency revealed in the non-local digits implies that sensory information from each digit can be shared across the digits to assist motor execution within the same hand.     

Effects of Fencing Training on Motor Performance and Asymmetry Vary With Handedness

Abstract

Previous studies showed that motor asymmetries are reduced in left-handers and after a long-term fencing training in right-handers. Interestingly, left-handed athletes are substantially over-represented in elite fencing. These findings have been speculatively explained by imbalance in experience of fighting opposite handedness opponents resulted from skewed distribution of handedness, i.e. lefties encounter more righties than righties encounter lefties. Whereas these assumptions could be accurate, the underlying mechanisms remain ambiguous. In this study, we investigated effects of fencing training on motor performance and asymmetry with respect to handedness. We compared fencing performance of left- and right-handed fencers in both training and combat conditions. In the combat condition, left-handers won seven out of twelve matches consisted of twelve bouts each. They also showed a significantly longer hit detection time, a measure indicating better quality of fencing attack. In the training condition, left-handed fencers completed fencing board tests significantly faster than right-handers. These findings provide additional factor of superior motor performance to be considered when interpreting over-representation of lefties in elite fencing. Furthermore, our left-handers were less lateralized, which could explain that superior motor performance. This idea is consistent with previous findings of reduced asymmetry in right-handed fencers when comparing to non-athletes.     

The time machine in our mind

This article provides the first comprehensive conceptual account for the imagistic mental machinery that allows us to travel through time--for the time machine in our mind. It is argued that language reveals this imagistic machine and how we use it. Findings from a range of cognitive fields are theoretically unified and a recent proposal about spatialized mental time travel is elaborated on. The following novel distinctions are offered: external versus internal viewing of time; 'watching" time versus projective 'travel" through time; optional versus obligatory mental time travel; mental time travel into anteriority or posteriority versus mental time travel into the past or future; single mental time travel versus nested dual mental time travel; mental time travel in episodic memory versus mental time travel in semantic memory; and 'seeing" versus 'sensing" mental imagery. Theoretical, empirical, and applied implications are discussed.     

Sequential dependencies in driving

The effect of recent experience on current behavior has been studied extensively in simple laboratory tasks. We explore the nature of sequential effects in the more naturalistic setting of automobile driving. Driving is a safety-critical task in which delayed response times may have severe consequences. Using a realistic driving simulator, we find significant sequential effects in pedal-press response times that depend on the history of recent stimuli and responses. Response times are slowed up to 100 ms in particular cases, a delay that has dangerous practical consequences. Further, we observe a significant number of history-related pedal misapplications, which have recently been noted as a cause for concern in the automotive safety community. By anticipating these consequences of sequential context, driver assistance systems could mitigate the effects of performance degradations and thus critically improve driver safety.     

Imagining thin: Why vanity sizing works

Vanity sizing, the practice of clothing manufacturers, whereby smaller size labels are used on clothes than what the clothes actually are, has become very common. Apparently, it helps sell clothes—women prefer small size clothing labels to large ones. We propose and demonstrate that smaller size labels evoke more positive self-related mental imagery. Thus, consumers imagine themselves more positively (thinner) with a vanity sized size-6 pant versus a size-8 pant. We also show that appearance self-esteem moderates the (mediating) effect of imagery on vanity sizing effectiveness—while vanity sizing evokes more positive mental imagery for both low and high appearance self-esteem individuals, the effect of the positive imagery on clothing preference is significant (only) for people with low appearance self-esteem, supported by the theory of compensatory self-enhancement.Our suggestion of simple marketing communications affecting valence of imagery and consequent product evaluation have implications for many other marketing domains.     

儿童的人际运动同步

人际运动同步是一种“社会胶粘剂”,能促进儿童产生更多的亲社会行为。儿童的人际运动同步能力随着年龄的增长不断提升,其同步表现受到运动方式、节奏刺激类型、同步对象等因素影响。在人际运动同步过程中,时间感知、运动计划和运动执行三大认知因素参与其中,既制约着个体同步能力的发展,也影响个体同步的表现。孤独症作为一种神经发育性障碍,孤独症儿童表现出异常的人际运动同步。未来的研究不仅要探讨孤独症儿童人际运动同步的异常机制,还要更多关注人际运动同步训练在孤独症群体中的实际应用和干预效果。