Oculomotor learning revisited: a model of reinforcement learning in the basal ganglia incorporating an efference copy of motor actions

In its simplest formulation, reinforcement learning is based on the idea that if an action taken in a particular context is followed by a favorable outcome, then, in the same context, the tendency to produce that action should be strengthened, or reinforced. While reinforcement learning forms the basis of many current theories of basal ganglia (BG) function, these models do not incorporate distinct computational roles for signals that convey context, and those that convey what action an animal takes. Recent experiments in the songbird suggest that vocal-related BG circuitry receives two functionally distinct excitatory inputs. One input is from a cortical region that carries context information about the current “time” in the motor sequence. The other is an efference copy of motor commands from a separate cortical brain region that generates vocal variability during learning. Based on these findings, I propose here a general model of vertebrate BG function that combines context information with a distinct motor efference copy signal. The signals are integrated by a learning rule in which efference copy inputs gate the potentiation of context inputs (but not efference copy inputs) onto medium spiny neurons in response to a rewarded action. The hypothesis is described in terms of a circuit that implements the learning of visually guided saccades. The model makes testable predictions about the anatomical and functional properties of hypothesized context and efference copy inputs to the striatum from both thalamic and cortical sources

Online Orientation: An Investigation of Its Effect on Graduate Students’ First-Course Retention

This mixed-methods study targeted one semester of 428 graduate-level students in the fall of 2016 who completed, or did not complete the five quizzes in a non-mandatory, online orientation to determine the impact of the orientation from enrollment through first-course retention. From the total population of 428 graduate-level students’ contact information, 53 students were not found in any orientation, but were listed as completing their first course, and were removed, resulting in 375 students who received a weekly email over a five-week period with a link to voluntarily participate in the study. This resulted in a convenience sample of 108 students included those who agreed to participate in the study. As noted in the study, 110 of 375 students completed orientation within the semester, while 265 of 375 students did not complete the orientation, with 71 of 108 non-completers who agreed to participate in the study compared to 37 of 108 completers. Phone interviews were established from 5 of 8 students from the convenience sample who did not complete their online orientation and who failed their first course. Student completion of the orientation was compared to first-course retention rates, and a generalization of Fisher’s Exact Chi Square used to evaluate the efficacy of the orientation program on retention with the grade of an A or B at the graduate level. This allowed for an exact analysis of tables with more than two rows and/or columns, and evaluated whether orientation completers and non-completers differed in their perceptions of the online master’s program orientation, academic performance, and subsequent retention from enrollment through the end of their first course. The quantitative data revealed that the generalization of Fisher’s Exact chi square analyses showed no statistical significance

How host organizations prepare for and learn from expatriate assignments

© 2019 Wiley Periodicals, Inc. This article reveals what goes on inside host organizations prior to and during expatriate assignments. On the basis of analyzing organizational documents and conducting 43 interviews with host country nationals (HCNs) and expatriates in 30 Vietnamese organizations that host external foreign assignments, we provide a detailed account of HCNs' experiences and unearth sophisticated preparation and management activities designed to maximize these organizations' learning. We depict what we call “a host organization lifecycle” and extract five lessons: (a) host organizations prepare carefully in advance to learn as much as possible from expatriates; (b) HCNs experience quite dramatic adjustments and burdens during expatriates' placements; (c) mutual trust between expatriates and HCNs is a prerequisite for HCNs' learning; (d) most of HCNs' learning occurs informally via interactions with expatriates or observing how they work; (e) host organization managers actively manage HCN–expatriate relationships. Our findings outline a “wish list” of practices that expatriate-using organizations could consider deploying for expatriate assignments that focus on the benefit of the host organization' development

An Automated Procedure for Evaluating Song Imitation

Songbirds have emerged as an excellent model system to understand the neural basis of vocal and motor learning. Like humans, songbirds learn to imitate the vocalizations of their parents or other conspecific “tutors.” Young songbirds learn by comparing their own vocalizations to the memory of their tutor song, slowly improving until over the course of several weeks they can achieve an excellent imitation of the tutor. Because of the slow progression of vocal learning, and the large amounts of singing generated, automated algorithms for quantifying vocal imitation have become increasingly important for studying the mechanisms underlying this process. However, methodologies for quantifying song imitation are complicated by the highly variable songs of either juvenile birds or those that learn poorly because of experimental manipulations. Here we present a method for the evaluation of song imitation that incorporates two innovations: First, an automated procedure for selecting pupil song segments, and, second, a new algorithm, implemented in Matlab, for computing both song acoustic and sequence similarity. We tested our procedure using zebra finch song and determined a set of acoustic features for which the algorithm optimally differentiates between similar and non-similar songs.National Institutes of Health (U.S.) (R01 MH067105

Rukun Negara teras pembinaan modal insan: satu komentar

In the process of achieving the status of a developed nation physically as well as spiritually by 2020, Malaysia is confronted by various complex issues. The issues come in various aspects, forms and levels like the moral issues, crime, ethnic relations, family, and the impact of globalization amongst others. In all the endeavours made by the government, the effort of human capital development can be considered spiritually and morally important. This agenda is significant in the formation of human capital with high quality and a first class mentality in the competitive era of globalization. Therefore, it is important to examine the effectiveness of all the human capital development efforts. The effectiveness of a policy very much relies upon the foundation that supports the policy to ensure its continuity. In line with this, this paper proposes that the national ideology, the Rukun Negara become the foundation of human capital development. It is expected that there will be problems in the integrated effort to inculcate the national ideology amongst Malaysians. Therefore, some challenges like the lack of monitoring system and the negative political influences will be discussed. Finally, several moderate proposals will be provided to strengthen the implementation of Rukun Negara towards the formation of human capital with a first class mentality and vision

Control of Vocal and Respiratory Patterns in Birdsong: Dissection of Forebrain and Brainstem Mechanisms Using Temperature

Learned motor behaviors require descending forebrain control to be coordinated with midbrain and brainstem motor systems. In songbirds, such as the zebra finch, regular breathing is controlled by brainstem centers, but when the adult songbird begins to sing, its breathing becomes tightly coordinated with forebrain-controlled vocalizations. The periods of silence (gaps) between song syllables are typically filled with brief breaths, allowing the bird to sing uninterrupted for many seconds. While substantial progress has been made in identifying the brain areas and pathways involved in vocal and respiratory control, it is not understood how respiratory and vocal control is coordinated by forebrain motor circuits. Here we combine a recently developed technique for localized brain cooling, together with recordings of thoracic air sac pressure, to examine the role of cortical premotor nucleus HVC (proper name) in respiratory-vocal coordination. We found that HVC cooling, in addition to slowing all song timescales as previously reported, also increased the duration of expiratory pulses (EPs) and inspiratory pulses (IPs). Expiratory pulses, like song syllables, were stretched uniformly by HVC cooling, but most inspiratory pulses exhibited non-uniform stretch of pressure waveform such that the majority of stretch occurred late in the IP. Indeed, some IPs appeared to change duration by the earlier or later truncation of an underlying inspiratory event. These findings are consistent with the idea that during singing the temporal structure of EPs is under the direct control of forebrain circuits, whereas that of IPs can be strongly influenced by circuits downstream of HVC, likely in the brainstem. An analysis of the temporal jitter of respiratory and vocal structure suggests that IPs may be initiated by HVC at the end of each syllable and terminated by HVC immediately before the onset of the next syllable.United States. National Institutes of Health (Grant R01 DC009183)United States. National Institutes of Health (Grant R01 MH067105

Unsupervised discovery of temporal sequences in high-dimensional datasets, with applications to neuroscience.

Identifying low-dimensional features that describe large-scale neural recordings is a major challenge in neuroscience. Repeated temporal patterns (sequences) are thought to be a salient feature of neural dynamics, but are not succinctly captured by traditional dimensionality reduction techniques. Here, we describe a software toolbox-called seqNMF-with new methods for extracting informative, non-redundant, sequences from high-dimensional neural data, testing the significance of these extracted patterns, and assessing the prevalence of sequential structure in data. We test these methods on simulated data under multiple noise conditions, and on several real neural and behavioral datas. In hippocampal data, seqNMF identifies neural sequences that match those calculated manually by reference to behavioral events. In songbird data, seqNMF discovers neural sequences in untutored birds that lack stereotyped songs. Thus, by identifying temporal structure directly from neural data, seqNMF enables dissection of complex neural circuits without relying on temporal references from stimuli or behavioral outputs

Protecting expatriates in hostile environments: institutional forces influencing the safety and security practices of internationally active organisations

© 2017, © 2017 Informa UK Limited, trading as Taylor & Francis Group. The operations of internationally active organisations continue to encroach on hostile locations that are vulnerable to the negative consequences of crises such as political upheaval, terrorist attacks or natural disasters. Yet research into how firms ensure the physical and psychological safety and security of international staff in these locations is limited. This article reports an empirical study exploring the expatriate safety and security practices of 28 internationally active organisations from three industries that commonly operate in hostile environments. We unveil starkly different approaches across the three industries, and label these approaches ‘regulatory’ (mining and resources), ‘informal mentoring’ (news media) and ‘empowering’ (international aid and development). We use institutional theory to propose that these configurations reflect legitimacy-seeking choices that these organisations make in response to the various institutional environments that affect each sector. Our results provide a platform for initial theory building into the interrelated elements of organisations’ safety and security practices, and the institutional factors that shape the design of these