Neural correlates of visuospatial working memory in the ‘at-risk mental state’

Background. Impaired spatial working memory (SWM) is a robust feature of schizophrenia and has been linked to the risk of developing psychosis in people with an at-risk mental state (ARMS). We used functional magnetic resonance imaging (fMRI) to examine the neural substrate of SWM in the ARMS and in patients who had just developed schizophrenia. Method. fMRI was used to study 17 patients with an ARMS, 10 patients with a first episode of psychosis and 15 agematched healthy comparison subjects. The blood oxygen level-dependent (BOLD) response was measured while subjects performed an object–location paired-associate memory task, with experimental manipulation of mnemonic load. Results. In all groups, increasing mnemonic load was associated with activation in the medial frontal and medial posterior parietal cortex. Significant between-group differences in activation were evident in a cluster spanning the medial frontal cortex and right precuneus, with the ARMS groups showing less activation than controls but greater activation than first-episode psychosis (FEP) patients. These group differences were more evident at the most demanding levels of the task than at the easy level. In all groups, task performance improved with repetition of the conditions. However, there was a significant group difference in the response of the right precuneus across repeated trials, with an attenuation of activation in controls but increased activation in FEP and little change in the ARMS. Conclusions. Abnormal neural activity in the medial frontal cortex and posterior parietal cortex during an SWM task may be a neural correlate of increased vulnerability to psychosis

Protocol for the Reconstructing Consciousness and Cognition (ReCCognition) Study

Important scientific and clinical questions persist about general anesthesia despite the ubiquitous clinical use of anesthetic drugs in humans since their discovery. For example, it is not known how the brain reconstitutes consciousness and cognition after the profound functional perturbation of the anesthetized state, nor has a specific pattern of functional recovery been characterized. To date, there has been a lack of detailed investigation into rates of recovery and the potential orderly return of attention, sensorimotor function, memory, reasoning and logic, abstract thinking, and processing speed. Moreover, whether such neurobehavioral functions display an invariant sequence of return across individuals is similarly unknown. To address these questions, we designed a study of healthy volunteers undergoing general anesthesia with electroencephalography and serial testing of cognitive functions (NCT01911195). The aims of this study are to characterize the temporal patterns of neurobehavioral recovery over the first several hours following termination of a deep inhaled isoflurane general anesthetic and to identify common patterns of cognitive function recovery. Additionally, we will conduct spectral analysis and reconstruct functional networks from electroencephalographic data to identify any neural correlates (e.g., connectivity patterns, graph-theoretical variables) of cognitive recovery after the perturbation of general anesthesia. To accomplish these objectives, we will enroll a total of 60 consenting adults aged 20–40 across the three participating sites. Half of the study subjects will receive general anesthesia slowly titrated to loss of consciousness (LOC) with an intravenous infusion of propofol and thereafter be maintained for 3 h with 1.3 age adjusted minimum alveolar concentration of isoflurane, while the other half of subjects serves as awake controls to gauge effects of repeated neurobehavioral testing, spontaneous fatigue and endogenous rest-activity patterns

Individual differences in face cognition

Zusammenhänge zwischen neurokognitiven Indikatoren und Verhaltensindikatoren der Gesichterkognition können Gehirnsysteme und neuronale Subprozesse identifizieren, die individuellen Unterschieden im Verhalten zugrunde liegen. Diese Dissertation zeigt, dass Ereigniskorrelierte Potentiale (EKPs) als neurokognitive Indikatoren für die Erforschung individueller Unterschiede eingesetzt werden können, denn sie weisen die gleichen hohen psychometrischen Qualitäten wie andere Fähigkeitsindikatoren auf und messen daher individuelle Unterschiede in der neuronalen Verarbeitung zuverlässig und stabil über die Zeit. Auf der Verhaltensebene wurden drei Teilfähigkeiten der Gesichterkognition etabliert: Gesichterwahrnehmung, Gesichtergedächtnis und Gesichtergeschwindigkeit. EKPs wurden in Strukturgleichungsmodellen verwendet, um den Beitrag neurokognitiver Indikatoren an individuellen Unterschieden dieser Gesichterkognitionsfähigkeiten zu schätzen. Für 85 Probanden wurden Beziehungen zwischen den Gesichterkognitionsfähigkeiten und der P100, N170, der sogenannten Differenz aufgrund des Gedächtnisses (Dm) und dem frühen sowie späten Wiederholungseffekt (ERE und LRE) etabliert. Spezifische Anteile individueller Unterschiede in der Gesichterkognition auf der Verhaltensebene wurden durch individuelle Unterschiede im Zeitverlauf der strukturellen Gesichteranalyse (N170 Latenz) sowie in der Reaktivierung von Repräsentationen gespeicherter Gesichtsstrukturen (ERE) als auch personen-spezifischen Wissens (LRE) erklärt. Keinen Anteil an individuellen Unterschieden erklärten hingegen frühe Wahrnehmungsprozesse (P100), die neuronale Aktivierung während der strukturellen Gesichteranalyse (N170 Amplitude) und Prozesse der Gedächtnisenkodierung von Gesichtern (Dm). Diese Ergebnisse zeigen, dass individuelle Unterschiede in der Gesichterkognition von der strukturellen Gesichteranalyse sowie von der Effizienz und Geschwindigkeit des Zugriffs auf Gedächtnisinhalte zu Gesichtern und Personen abhängt.Individual differences in perceiving, learning, and recognizing faces were shown on the behavioral and neural level but were rarely related to one another. By determining relationships between behavioral and neurocognitive indicators of face cognition, brain systems and neural sub-processes can be identified that underlie individual variations on the behavioral level. The present dissertation laid the foundation for using event-related potentials (ERPs) as neurocognitive indicators in individual differences research. ERP components were shown to possess the same high psychometric qualities as behavioral ability measures and thus to measure individual differences of neural processing reliably and stably across time. On the behavioral level, three component abilities of face cognition were established: face perception, face memory, and the speed of face cognition. ERP components were used in structural equation models that estimated contributions of neurocognitive indicators to the individual differences in these face cognition abilities. Regression analysis was used to determine the contributions of P100, N170, the so called difference due to memory (Dm), as well as early and late repetition effects (ERE and LRE) to face cognition abilities in 85 participants. Certain amounts of variance in face cognition as seen on the behavioral level were accounted for by individual differences in the temporal dimension of structural encoding of a face (N170 latency) and in the re-activation of both stored facial structures (ERE) and person-identity information (LRE). In contrast, processes of early vision (P100), the neural activation of structural face encoding (N170 amplitude), and memory encoding of new faces (Dm) did not show any contribution to individual differences in face cognition. These findings show that individual differences in face cognition depend on the speed of structurally encoding faces and on the efficiency and speed of accessing face and person memory

Advances in functional neuroanatomy: a review of combined DTI and fMRI studies in healthy younger and older adults.

Structural connections between brain regions are thought to influence neural processing within those regions. It follows that alterations to the quality of structural connections should influence the magnitude of neural activity. The quality of structural connections may also be expected to differentially influence activity in directly versus indirectly connected brain regions. To test these predictions, we reviewed studies that combined diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) in younger and older adults. By surveying studies that examined relationships between DTI measures of white matter integrity and fMRI measures of neural activity, we identified variables that accounted for variability in these relationships. Results revealed that relationships between white matter integrity and neural activity varied with (1) aging (i.e., positive and negative DTI-fMRI relationships in younger and older adults, respectively) and (2) spatial proximity of the neural measures (i.e., positive and negative DTI-fMRI relationships when neural measures were extracted from adjacent and non-adjacent brain regions, respectively). Together, the studies reviewed here provided support for both of our predictions

Cognitive Deficit of Deep Learning in Numerosity

Subitizing, or the sense of small natural numbers, is an innate cognitive function of humans and primates; it responds to visual stimuli prior to the development of any symbolic skills, language or arithmetic. Given successes of deep learning (DL) in tasks of visual intelligence and given the primitivity of number sense, a tantalizing question is whether DL can comprehend numbers and perform subitizing. But somewhat disappointingly, extensive experiments of the type of cognitive psychology demonstrate that the examples-driven black box DL cannot see through superficial variations in visual representations and distill the abstract notion of natural number, a task that children perform with high accuracy and confidence. The failure is apparently due to the learning method not the CNN computational machinery itself. A recurrent neural network capable of subitizing does exist, which we construct by encoding a mechanism of mathematical morphology into the CNN convolutional kernels. Also, we investigate, using subitizing as a test bed, the ways to aid the black box DL by cognitive priors derived from human insight. Our findings are mixed and interesting, pointing to both cognitive deficit of pure DL, and some measured successes of boosting DL by predetermined cognitive implements. This case study of DL in cognitive computing is meaningful for visual numerosity represents a minimum level of human intelligence.Comment: Accepted for presentation at the AAAI-1

Using Sparse Semantic Embeddings Learned from Multimodal Text and Image Data to Model Human Conceptual Knowledge

Distributional models provide a convenient way to model semantics using dense embedding spaces derived from unsupervised learning algorithms. However, the dimensions of dense embedding spaces are not designed to resemble human semantic knowledge. Moreover, embeddings are often built from a single source of information (typically text data), even though neurocognitive research suggests that semantics is deeply linked to both language and perception. In this paper, we combine multimodal information from both text and image-based representations derived from state-of-the-art distributional models to produce sparse, interpretable vectors using Joint Non-Negative Sparse Embedding. Through in-depth analyses comparing these sparse models to human-derived behavioural and neuroimaging data, we demonstrate their ability to predict interpretable linguistic descriptions of human ground-truth semantic knowledge.Comment: Proceedings of the 22nd Conference on Computational Natural Language Learning (CoNLL 2018), pages 260-270. Brussels, Belgium, October 31 - November 1, 2018. Association for Computational Linguistic

Examining College Student Athlete Attitudes Towards Concussion Testing and Reporting Concussions

Examining College Student Athlete Attitudes and Behaviors Toward Baseline Neurocognitive Concussion Testing FryK, Anderson, M, Anderson, M, Schatz, P, Elbin, RJ: University of Arkansas, Fayetteville, Arkansas Context: Examining athletes’ attitudes toward concussion diagnosis, management, and treatment can lead to improved multi-faceted management of a concussion injury. Although attitudes towards concussion injuries have been studied, the examination of athletes’ attitudes towards baseline computerized neurocognitive testing is understudied and is warranted. Objective: To examine the relationship between sex, concussion history, and previous exposure to baseline testing on athletes’ perceptions of effort provided during baseline testing and the utility of neurocognitive testing. Methods: College athletes (18-23 years) completing a baseline neurocognitive test (Immediate Post-Concussion Assessment and Cognitive Test: ImPACT) were asked to complete an anonymous 33-item online survey. Survey questions included demographics and inquired about athletes’ effort and utility of baseline and post-concussion neurocognitive testing. A series of chi-square analyses measured the association between sex, concussion history, and previous exposure to baseline testing on effort provided during testing and utility of the test. Level of statistical significance was p \u3c .05. Results: One hundred eighty-two (88 males, 95 females) athletes (M =19.05, SD = 1.15 years) completed the survey. Thirty-eight percent (70/183) reported prior concussion history and 27% (50/182) were first time test takers. Ninety-four percent (172/183) reported providing above average to maximal effort on the baseline test they completed prior to completing the survey. Ninety percent (158/176) and 87% (156/179) of the sample reported that the baseline and post-concussion test results were useful in mitigating premature return to play, respectively. There was no association between sex, concussion history, or previous exposure to baseline testing on reported effort or perceptions of utility for baseline neurocognitive testing (p \u3e .05). Conclusion: The majority of athletes report high effort on baseline neurocognitive testing and recognize the utility of this measure for safe return to play