The Brain Is Faster than the Hand in Split-Second Intentions to Respond to an Impending Hazard: A Simulation of Neuroadaptive Automation to Speed Recovery to Perturbation in Flight Attitude.

The goal of this research is to test the potential for neuroadaptive automation to improve response speed to a hazardous event by using a brain-computer interface (BCI) to decode perceptual-motor intention. Seven participants underwent four experimental sessions while measuring brain activity with magnetoencephalograpy. The first three sessions were of a simple constrained task in which the participant was to pull back on the control stick to recover from a perturbation in attitude in one condition and to passively observe the perturbation in the other condition. The fourth session consisted of having to recover from a perturbation in attitude while piloting the plane through the Grand Canyon constantly maneuvering to track over the river below. Independent component analysis was used on the first two sessions to extract artifacts and find an event related component associated with the onset of the perturbation. These two sessions were used to train a decoder to classify trials in which the participant recovered from the perturbation (motor intention) vs. just passively viewing the perturbation. The BCI-decoder was tested on the third session of the same simple task and found to be able to significantly distinguish motor intention trials from passive viewing trials (mean = 69.8%). The same BCI-decoder was then used to test the fourth session on the complex task. The BCI-decoder significantly classified perturbation from no perturbation trials (73.3%) with a significant time savings of 72.3 ms (Original response time of 425.0-352.7 ms for BCI-decoder). The BCI-decoder model of the best subject was shown to generalize for both performance and time savings to the other subjects. The results of our off-line open loop simulation demonstrate that BCI based neuroadaptive automation has the potential to decode motor intention faster than manual control in response to a hazardous perturbation in flight attitude while ignoring ongoing motor and visual induced activity related to piloting the airplane.

Early neural activation during facial affect processing in adolescents with Autism Spectrum Disorder.

Impaired social interaction is one of the hallmarks of Autism Spectrum Disorder (ASD). Emotional faces are arguably the most critical visual social stimuli and the ability to perceive, recognize, and interpret emotions is central to social interaction and communication, and subsequently healthy social development. However, our understanding of the neural and cognitive mechanisms underlying emotional face processing in adolescents with ASD is limited. We recruited 48 adolescents, 24 with high functioning ASD and 24 typically developing controls. Participants completed an implicit emotional face processing task in the MEG. We examined spatiotemporal differences in neural activation between the groups during implicit angry and happy face processing. While there were no differences in response latencies between groups across emotions, adolescents with ASD had lower accuracy on the implicit emotional face processing task when the trials included angry faces. MEG data showed atypical neural activity in adolescents with ASD during angry and happy face processing, which included atypical activity in the insula, anterior and posterior cingulate and temporal and orbitofrontal regions. Our findings demonstrate differences in neural activity during happy and angry face processing between adolescents with and without ASD. These differences in activation in social cognitive regions may index the difficulties in face processing and in comprehension of social reward and punishment in the ASD group. Thus, our results suggest that atypical neural activation contributes to impaired affect processing, and thus social cognition, in adolescents with ASD.

Resilience of developing brain networks to interictal epileptiform discharges is associated with cognitive outcome.

The effects of interictal epileptiform discharges on neurocognitive development in children with medically-intractable epilepsy are poorly understood. Such discharges may have a deleterious effect on the brain's intrinsic connectivity networks, which reflect the organization of functional networks at rest, and in turn on neurocognitive development. Using a combined functional magnetic resonance imaging-magnetoencephalography approach, we examine the effects of interictal epileptiform discharges on intrinsic connectivity networks and neurocognitive outcome. Functional magnetic resonance imaging was used to determine the location of regions comprising various intrinsic connectivity networks in 26 children (7-17 years), and magnetoencephalography data were reconstructed from these locations. Inter-regional phase synchronization was then calculated across interictal epileptiform discharges and graph theoretical analysis was applied to measure event-related changes in network topology in the peri-discharge period. The magnitude of change in network topology (network resilience/vulnerability) to interictal epileptiform discharges was associated with neurocognitive outcomes and functional magnetic resonance imaging networks using dual regression. Three main findings are reported: (i) large-scale network changes precede and follow interictal epileptiform discharges; (ii) the resilience of network topologies to interictal discharges is associated with stronger resting-state network connectivity; and (iii) vulnerability to interictal discharges is associated with worse neurocognitive outcomes. By combining the spatial resolution of functional magnetic resonance imaging with the temporal resolution of magnetoencephalography, we describe the effects of interictal epileptiform discharges on neurophysiological synchrony in intrinsic connectivity networks and establish the impact of interictal disruption of functional networks on cognitive outcome in children with epilepsy. The association between interictal discharges, network changes and neurocognitive outcomes suggests that it is of clinical importance to suppress discharges to foster more typical brain network development in children with focal epilepsy.

Temporal-spatial neural activation patterns linked to perceptual encoding of emotional salience.

It is well known that we continuously filter incoming sensory information, selectively allocating attention to what is important while suppressing distracting or irrelevant information. Yet questions remain about spatiotemporal patterns of neural processes underlying attentional biases toward emotionally significant aspects of the world. One index of affectively biased attention is an emotional variant of an attentional blink (AB) paradigm, which reveals enhanced perceptual encoding for emotionally salient over neutral stimuli under conditions of limited executive attention. The present study took advantage of the high spatial and temporal resolution of magnetoencephalography (MEG) to investigate neural activation related to emotional and neutral targets in an AB task. MEG data were collected while participants performed a rapid stimulus visual presentation task in which two target stimuli were embedded in a stream of distractor words. The first target (T1) was a number and the second (T2) either an emotionally salient or neutral word. Behavioural results replicated previous findings of greater accuracy for emotionally salient than neutral T2 words. MEG source analyses showed that activation in orbitofrontal cortex, characterized by greater power in the theta and alpha bands, and dorsolateral prefrontal activation were associated with successful perceptual encoding of emotionally salient relative to neutral words. These effects were observed between 250 and 550 ms, latencies associated with discrimination of perceived from unperceived stimuli. These data suggest that important nodes of both emotional salience and frontoparietal executive systems are associated with the emotional modulation of the attentional blink.

Differential activation of brain regions involved with error-feedback and imitation based motor simulation when observing self and an expert's actions in pilots and non-pilots on a complex glider landing task.

In this fMRI study we investigate neural processes related to the action observation network using a complex perceptual-motor task in pilots and non-pilots. The task involved landing a glider (using aileron, elevator, rudder, and dive brake) as close to a target as possible, passively observing a replay of one's own previous trial, passively observing a replay of an expert's trial, and a baseline do nothing condition. The objective of this study is to investigate two types of motor simulation processes used during observation of action: imitation based motor simulation and error-feedback based motor simulation. It has been proposed that the computational neurocircuitry of the cortex is well suited for unsupervised imitation based learning, whereas, the cerebellum is well suited for error-feedback based learning. Consistent with predictions, pilots (to a greater extent than non-pilots) showed significant differential activity when observing an expert landing the glider in brain regions involved with imitation based motor simulation (including premotor cortex PMC, inferior frontal gyrus IFG, anterior insula, parietal cortex, superior temporal gyrus, and middle temporal MT area) than when observing one's own previous trial which showed significant differential activity in the cerebellum (only for pilots) thought to be concerned with error-feedback based motor simulation. While there was some differential brain activity for pilots in regions involved with both Execution and Observation of the flying task (potential Mirror System sites including IFG, PMC, superior parietal lobule) the majority was adjacent to these areas (Observation Only Sites) (predominantly in PMC, IFG, and inferior parietal loblule). These regions showing greater activity for observation than for action may be involved with processes related to motor-based representational transforms that are not necessary when actually carrying out the task.

From Augustine of Hippo's Memory Systems to Our Modern Taxonomy in Cognitive Psychology and Neuroscience of Memory: A 16-Century Nap of Intuition before Light of Evidence.

Over the last half century, neuropsychologists, cognitive psychologists and cognitive neuroscientists interested in human memory have accumulated evidence showing that there is not one general memory function but a variety of memory systems deserving distinct (but for an organism, complementary) functional entities. The first attempts to organize memory systems within a taxonomic construct are often traced back to the French philosopher Maine de Biran (1766-1824), who, in his book first published in 1803, distinguished mechanical memory, sensitive memory and representative memory, without, however, providing any experimental evidence in support of his view. It turns out, however, that what might be regarded as the first elaborated taxonomic proposal is 14 centuries older and is due to Augustine of Hippo (354-430), also named St Augustine, who, in Book 10 of his Confessions, by means of an introspective process that did not aim at organizing memory systems, nevertheless distinguished and commented on sensible memory, intellectual memory, memory of memories, memory of feelings and passion, and memory of forgetting. These memories were envisaged as different and complementary instances. In the current study, after a short biographical synopsis of St Augustine, we provide an outline of the philosopher's contribution, both in terms of questions and answers, and focus on how this contribution almost perfectly fits with several viewpoints of modern psychology and neuroscience of memory about human memory functions, including the notion that episodic autobiographical memory stores events of our personal history in their what, where and when dimensions, and from there enables our mental time travel. It is not at all meant that St Augustine's elaboration was the basis for the modern taxonomy, but just that the similarity is striking, and that the architecture of our current viewpoints about memory systems might have preexisted as an outstanding intuition in the philosopher's mind.

St. Augustine's Reflections on Memory and Time and the Current Concept of Subjective Time in Mental Time Travel.

Reconstructing the past and anticipating the future, i.e., the ability of travelling in mental time, is thought to be at the heart of consciousness and, by the same token, at the center of human cognition. This extraordinary mental activity is possible thanks to the ability of being aware of 'subjective time'. In the present study, we attempt to trace back the first recorded reflections on the relations between time and memory, to the end of the fourth century's work, the Confessions, by the theologian and philosopher, St. Augustine. We concentrate on Book 11, where he extensively developed a series of articulated and detailed observations on memory and time. On the bases of selected paragraphs, we endeavor to highlight some concepts that may be considered as the product of the first or, at least, very early reflections related to our current notions of subjective time in mental time travel. We also draw a fundamental difference inherent to the frameworks within which the questions were raised. The contribution of St. Augustine on time and memory remains significant, notwithstanding the 16 centuries elapsed since it was made, likely because of the universality of its contents.

Dynamic visuomotor transformation involved with remote flying of a plane utilizes the 'Mirror Neuron' system.

Brain regions involved with processing dynamic visuomotor representational transformation are investigated using fMRI. The perceptual-motor task involved flying (or observing) a plane through a simulated Red Bull Air Race course in first person and third person chase perspective. The third person perspective is akin to remote operation of a vehicle. The ability for humans to remotely operate vehicles likely has its roots in neural processes related to imitation in which visuomotor transformation is necessary to interpret the action goals in an egocentric manner suitable for execution. In this experiment for 3(rd) person perspective the visuomotor transformation is dynamically changing in accordance to the orientation of the plane. It was predicted that 3(rd) person remote flying, over 1(st), would utilize brain regions composing the 'Mirror Neuron' system that is thought to be intimately involved with imitation for both execution and observation tasks. Consistent with this prediction differential brain activity was present for 3(rd) person over 1(st) person perspectives for both execution and observation tasks in left ventral premotor cortex, right dorsal premotor cortex, and inferior parietal lobule bilaterally (Mirror Neuron System) (Behaviorally: 1(st)>3(rd)). These regions additionally showed greater activity for flying (execution) over watching (observation) conditions. Even though visual and motor aspects of the tasks were controlled for, differential activity was also found in brain regions involved with tool use, motion perception, and body perspective including left cerebellum, temporo-occipital regions, lateral occipital cortex, medial temporal region, and extrastriate body area. This experiment successfully demonstrates that a complex perceptual motor real-world task can be utilized to investigate visuomotor processing. This approach (Aviation Cerebral Experimental Sciences ACES) focusing on direct application to lab and field is in contrast to standard methodology in which tasks and conditions are reduced to their simplest forms that are remote from daily life experience.

Objective estimation of visual acuity with preferential looking.

PURPOSE: A novel preferential looking (PL) procedure that uses quantitative analysis of visual scanning parameters is presented. METHODS: Nine adult subjects were presented with a set of 14 visual stimuli (stimuli included three uniform gray fields and one field with black-and-white square wave gratings) spanning the range of spatial frequencies from 1.5 cyc/deg to 35.1 cyc/deg (1.3 logMAR to -0.07 logMAR). A remote gaze-tracking system was used to monitor the subject's eye movements and the relative fixation time (RFT) on the grating target. Subsequently, a four alternative forced-choice psychophysical test (4AFC) was performed with the same visual stimuli. RESULTS: For visual stimuli for which the gratings' positions in the 4AFC test were identified correctly in 100% of the trials (reliably discriminated), the mean RFT was 72.5% ± 9.0%. For stimuli for which the spatial frequencies were higher than the subject's psychophysically determined visual acuity (VA) threshold (nondiscriminated), the mean RFT was 25.3% ± 8.5%. Using three repeated trials at each spatial frequency and a VA detector based on the conditional probability density functions of the RFT, the average VA was underestimated by 0.06 logMAR (range, 0.00-0.20 logMAR). CONCLUSIONS: In adults, automated quantitative analysis of visual scanning patterns can be used to estimate VA objectively and rapidly (210 seconds) with a mean error of 0.06 logMAR. The novel approach may form the basis for PL procedures that are more objective and more accurate than the traditional clinical PL procedures.

Automated analysis of sleep-wake state in rats.

A fully automated computer-based sleep scoring system is described and validated for use in rats. The system was designed to emulate visual sleep scoring by using the same basic features of the electroencephalogram (EEG) and electromyogram (EMG), and a similar set of decision-making rules. State indices are calculated for each 5s epoch by combination of amplitudes (microVrms) of 6 filtered EEG frequency bands (EEGlo, d.c.-1.5Hz; delta, 1.5-6Hz; theta, 6-9Hz; alpha, 10.5-15Hz; beta, 22-30Hz; gamma, 35-45Hz; Sigma(EEG)=delta+theta+alpha+beta+gamma) and EMG (10-100Hz) yielding dimensionless ratios: WAKE-index=(EMGxgamma)/theta; NREM-index=(deltaxalpha)/gamma(2); REM-index=theta(3)/(deltaxalphaxEMG); artifact-index=[(2xEEG(lo))+beta]*(gamma/Sigma(EEG)). The index values are re-scaled and normalized, thereby dispensing with the need for animal-specific threshold values. The system was validated by direct comparison with visually scored data in 9 rats. Overall, the computer and visual scores were 96% concordant, which is similar to inter-rater agreement in visual scoring. False-positive error rate was <5%. A re-test protocol in 7 rats confirmed the long-term stability of the system in studies lasting 5 weeks. The system was implemented and further validated in a study of sleep architecture in 7 rats under a 12:12h LD cycle.

Adverse drug events in cognitively impaired elderly patients.

BACKGROUND/AIMS: Adverse drug events (ADEs) are a frequent problem encountered in the elderly. The aim of this study was to elucidate the factors that influence ADEs in an elderly population with cognitive impairment. METHODS: 242 patients were recruited from dementia clinics and assessed after 6 months for ADEs. The use of natural health products (NHPs) was also documented. RESULTS: Backward logistic regression found that higher age (OR = 1.06; 95% CI 1.01-1.12), and greater cognitive impairment (OR = 0.94; 95% CI 0.90-0.98) were associated with an increased risk of developing an ADE while the use of NHPs (OR = 0.32; 95% CI 0.13-0.79) was associated with a decreased risk (chi(2) = 27.6, p < 0.001). CONCLUSION: Risk of ADEs increased with greater age and cognitive impairment but decreased with the use of NHPs.