Several Days Of Training Research Articles

Poster Session II: Spillover effects of color discrimination training on color category boundaries and color appearance.

Perceptual learning refers to the increase in perceptual sensitivity that results from several days of training on a perceptual task. Although perceptual learning has been shown to be effective in a variety of perceptual tasks, few studies have examined perceptual learning in color perception. In this study, we investigated how color discrimination training at a base color affected various aspects of color perception for entire hues. The training consisted of five days of S color discrimination (300 trials/day) at either the negative or positive L-M base color, depending on the observer groups. Before and after the training, three types of color perception tests (color difference, unique hue, and color category boundary) were conducted for colors with various hues to examine the changes in color perception due to the training. The results showed that the color discrimination thresholds in the training decreased as expected with repeated trials. Interestingly, the training also affected the performance of the three types of tests; the perceived color difference around the training color tended to increase, and some of the unique hues and the color category boundaries shifted significantly toward the training color. These results suggest that only a few days of color discrimination training can spill over to the entire color space and induce distortion of the perceptual color space.

Implicit Visuomotor Adaptation Remains Limited after Several Days of Training.

Learning in sensorimotor adaptation tasks has been viewed as an implicit learning phenomenon. The implicit process affords recalibration of existing motor skills so that the system can adjust to changes in the body or environment without relearning from scratch. However, recent findings suggest that the implicit process is heavily constrained, calling into question its utility in motor learning and the theoretical framework of sensorimotor adaptation paradigms. These inferences have been based mainly on results from single bouts of training, where explicit compensation strategies, such as explicitly re-aiming the intended movement direction, contribute a significant proportion of adaptive learning. It is possible, however, that the implicit process supersedes explicit compensation strategies over repeated practice sessions. We tested this by dissociating the contributions of explicit re-aiming strategies and the implicit process in human participants over five consecutive days of training. Despite a substantially longer duration of training, the implicit process still plateaued at a value far short of complete learning and, as has been observed in previous studies, was inappropriate for a mirror-reversal task. Notably, we find significant between subject differences that call into question traditional interpretation of these group-level results.

Training a Deep Learning Network with an Insignificantly Small Dataset

In the last few years, Deep Learning is one of the top research areas in academia as well as in industry. Every industry is now looking for a deep learning-based solution to the problems in hand. As a researcher, learning “Deep Learning” through practical experiments will be a very challenging task. Particularly, training a deep learning network with huge amount of training data will make it impractical to do this on a normal desktop computer or laptop. Even a small-scale application in computer vision using deep learning techniques will require several days of training the deep network model on a very higher end Graphical Processing Unit (GPU) clusters or Tensor Processing Unit (TPU) clusters that makes impractical to do that research on a conventional laptop. In this work, we address the possibilities of training a deep learning network with an insignificantly small dataset. Here we mean “significantly small dataset’ as a dataset with only few images (<10) per class. Since we are going to design a prototype drone detection system which is a single class classification problem, we hereby try to train the deep learning network only with few drone images (2 images only). Our research question is: will it be possible to train a YOLO deep learning network model only with two images and achieve a descent detection accurate on a constrained test dataset of drones? This paper addresses that issue and our results prove that it is possible to train a deep learning network only with two images and achieve good performance under constrained application environments.

P2-37. Effects of kinesthetic illusion induced by visual stimulus on the mu rhythm

Kinesthetic illusion can be induced by observing repetitive movements of a particular body part from the first-person point-of-view; this is called KiNvis (kinesthetic illusion induced by visual stimulus). The purpose of the present study was to elucidate the characteristics of electroencephalogram (EEG) oscillations in sensorimotor area during KiNvis. We focused on the mu rhythm, typically oscillating at a frequency of 8–13 Hz and attenuated by the various motor processes. Seven healthy subjects participated in this study. Before EEG measurement, KiNvis was induced in all the participants during several days of training. Experimental conditions included motor execution of the right wrist flexion, motor imagery, KiNvis, and motor observation (observing the same movie as during KiNVIS; however, the screen position was placed anatomically incongruent). EEG signal was recorded from the left sensorimotor area during each condition. EEG spectra were estimated using fast Fourier transformation. The power of the mu rhythm during KiNvis, motor execution, and motor imagery significantly suppressed to be lower than that during motor observation respectively. These findings suggest that suppression effect of KiNvis on the mu rhythm was larger than simple motor observation, and was not inferior to motor imagery and motor execution.

Rapid and long-lasting reduction of crowding through training.

Crowding is the failure to identify an object in the peripheral visual field in the presence of nearby objects. Recent studies have shown that crowding can be alleviated after several days of training, but the processes underlying this improvement are still unclear. Here we tested whether a few hundred trials within a short period of training can alleviate crowding, whether the learning is location specific, and whether the improvement reflects facilitation by target enhancement or flankers suppression. Observers were asked to identify the orientation of a letter in the periphery surrounded by two flanker letters. Observers were tested before (pretest) and after (posttest) training (600 trials). In Experiment 1 we tested whether learning is location specific or can transfer to a different location; the training and test occurred at the same or different hemifields. In a control experiment, we ruled out alternative explanations for the learning effect in Experiment 1. In Experiment 2, we assessed different components of feature selection by training with either the same flanker polarity as the pre/posttest but opposite polarity group (flanker polarity group) or the same target polarity as the pre/posttest but opposite flanker polarity (target polarity group). Following training, overall performance increased in all four conditions, but only the same-location group (Experiment 1) and the same flanker polarity (Experiment 2) showed a significant reduction in crowding as assessed by the distance at which the flankers no longer interfere with target identification, that is, the critical spacing. These results show that training can rapidly reduce crowding and that improvement primarily reflects learning to ignore the irrelevant flankers. Remarkably, in the two conditions in which training significantly reduced crowding, the benefit of short training persisted for up to a year.

The medial prefrontal cortex is crucial for the maintenance of persistent licking and the expression of incentive contrast.

We examined the role of the medial prefrontal cortex (mPFC) in reward processing and the control of consummatory behavior. Rats were trained in an operant licking procedure in which they received alternating access to solutions with relatively high and low levels of sucrose (20 and 4%, w/v). Each level of sucrose was available for fixed intervals of 30 s over 30 min test sessions. Over several days of training, rats came to lick persistently when the high level of sucrose was available and suppressed licking when the low level of sucrose was available. Pharmacological inactivations of the mPFC, specifically the rostral part of the prelimbic area, greatly reduced intake of the higher value fluid and only slightly increased intake of the lower value fluid. In addition, the inactivations altered within-session patterns and microstructural measures of licking. Rats licked equally for the high and low levels of sucrose at the beginning of the test sessions and “relearned” to reduce intake of the low value fluid over the test sessions. Durations of licking bouts (clusters of licks with inter-lick intervals <0.5 s) were reduced for the high value fluid and there were many more brief licking bouts (<1 s) when the low value fluid was available. These effects were verified using an alternative approach (optogenetic silencing using archaerhodopsin) and were distinct from inactivation of the ventral striatum, which simply increased overall intake. Our findings suggest that the mPFC is crucial for the maintenance of persistent licking and the expression of learned feeding strategies.

Cell-based therapy and rehabilitation with prosthetic limbs in a dog

A 5-year-old male dog was presented with the complaint of a chronic nonhealing wound on both hind legs. The wound occurred during a serious train accident that caused loss of both hind limbs below the hock joint. Since then, the wound did not respond to any standard treatment for up to 4 months. Again it was dressed for 15 days, but it did not show any improvement. With the consent of the owner, cell-based therapy was conducted by collecting bone marrow from the proximal anteromedial aspect of the tibia. After the application of bone marrow derived mesenchymal stem cells (BM-MSCs) the time to complete healing was 24 days. Due to pressure at the bony cut stump, the dog was noted to have pain while walking, and walked on his forelegs. An artificial limb was subsequently applied. The dog managed to walk normally after several days of training.

Training-dependent associative learning induced neocortical structural plasticity: a trace eyeblink conditioning analysis.

Studies utilizing general learning and memory tasks have suggested the importance of neocortical structural plasticity for memory consolidation. However, these learning tasks typically result in learning of multiple different tasks over several days of training, making it difficult to determine the synaptic time course mediating each learning event. The current study used trace-eyeblink conditioning to determine the time course for neocortical spine modification during learning. With eyeblink conditioning, subjects are presented with a neutral, conditioned stimulus (CS) paired with a salient, unconditioned stimulus (US) to elicit an unconditioned response (UR). With multiple CS-US pairings, subjects learn to associate the CS with the US and exhibit a conditioned response (CR) when presented with the CS. Trace conditioning is when there is a stimulus free interval between the CS and the US. Utilizing trace-eyeblink conditioning with whisker stimulation as the CS (whisker-trace-eyeblink: WTEB), previous findings have shown that primary somatosensory (barrel) cortex is required for both acquisition and retention of the trace-association. Additionally, prior findings demonstrated that WTEB acquisition results in an expansion of the cytochrome oxidase whisker representation and synaptic modification in layer IV of barrel cortex. To further explore these findings and determine the time course for neocortical learning-induced spine modification, the present study utilized WTEB conditioning to examine Golgi-Cox stained neurons in layer IV of barrel cortex. Findings from this study demonstrated a training-dependent spine proliferation in layer IV of barrel cortex during trace associative learning. Furthermore, findings from this study showing that filopodia-like spines exhibited a similar pattern to the overall spine density further suggests that reorganization of synaptic contacts set the foundation for learning-induced neocortical modifications through the different neocortical layers.

One-Session Mindfulness Meditation: A Randomized Controlled Study of Effects on Cognition and Mood

Participants in previous studies of brief mindfulness meditation (MM) are often tested immediately following a meditation session, making it difficult to separate several days of training from one-session effects. The current study examined the effects of a single session of 25 min of MM compared with a sham meditation (sham M) and a book-listening control. One session of both MM and sham M had a significant effect on state mindfulness compared with the control. Several mood subscales as well as total distress score on the Profile of Mood States (POMS) were also significantly different from control. However, neither meditation condition had significant effects on any of the attention and working memory tasks. These results indicate that one session of meditation was not sufficient to affect the cognitive tasks used in this study. Both MM and sham M positively affected mood states and heightened state mindfulness.

The N2pc Is Increased by Perceptual Learning but Is Unnecessary for the Transfer of Learning

BackgroundPractice improves human performance in many psychophysical paradigms. This kind of improvement is thought to be the evidence of human brain plasticity. However, the changes that occur in the brain are not fully understood.Methodology/Principal FindingsThe N2pc component has previously been associated with visuo-spatial attention. In this study, we used event-related potentials (ERPs) to investigate whether the N2pc component changed during long-term visual perceptual learning. Thirteen subjects completed several days of training in an orientation discrimination task, and were given a final test 30 days later. The results showed that behavioral thresholds significantly decreased across training sessions, and this decrement was also present in the untrained visual field. ERPs showed training significantly increased the N2pc amplitude, and this effect could be maintained for up to 30 days. However, the increase in N2pc was specific to the trained visual field.Conclusion/SignificanceTraining caused spatial attention to be increasingly focused on the target positions. However, this process was not transferrable from the trained to the untrained visual field, which suggests that the increase in N2pc may be unnecessary for behavioral improvements in the untrained visual field.

Circadian modulation of passive avoidance is not eliminated in arrhythmic hamsters with suprachiasmatic nucleus lesions

The expression of passive avoidance (PA) learning in rats displays a daily or circadian rhythm in that optimal performance is displayed when the time of testing matches the time of training. Lesions of the suprachiasmatic nucleus (SCN) were later shown to abolish this rhythm. Using golden hamsters, we have since demonstrated similar rhythms of performance in a conditioned place avoidance (CPA) task but unlike the PA results in rats, the rhythmic expression of CPA was maintained in arrhythmic hamsters with lesions of the SCN. We determined whether PA performance in hamsters is dependent on the SCN (as in the rat) or independent (as in the hamster CPA). Performance on the PA task was rhythmic in intact control animals with optimal performance occurring when training and testing time matched and significantly diminished at both 6h before and 6h after training time. SCN-lesions, verified by the loss of behavioral circadian rhythms, had no effect on the rhythmic expression. Therefore, time of day modulation of PA performance in the hamster does not depend on the SCN circadian clock.

A Single High-Altitude Training Bout Improves High-Altitude Aerobic Performance Following 1 Week of Low-Altitude Training

Consecutive bouts of aerobic exercise at high-altitude are known to improve subsequent aerobic exercise performance at high altitude due to a variety of acute and chronic adaptations referred to as altitude acclimatization. However, it is unclear whether these benefits can be elicited by a single bout of high-altitude exercise followed by several days of training at lower altitude. PURPOSE: We investigated whether a single bout of hill running exercise performed at high-altitude improves running performance, arterial oxygen saturation (SaO2), hematocrit (HCT) and perceived exertion (RPE) during a strenuous timed run at high-altitude performed 1 week following the training stimulus. METHODS: Participants were well-trained competitive runners (VO2max 52 ± 2 ml/kg/min, aged 42 ± 5 yrs, n = 8) living in Fort Collins, CO (5003 ft) that were naïve to higher altitudes for at least 8 weeks. All were training regularly (66 ± 3 miles/wk) and refrained from any non-prescribed altitude exposure for the duration of the study. Baseline testing consisted of a timed run on the Mt. Evans Scenic Byway in Colorado (11.5 miles at 11500-14100ft) followed by one week of training in Fort Collins. Runners were then randomized to perform a 12 mile hill running workout in Fort Collins (LOW; 6000-7000ft, n = 4)) or Mt. Evans (HIGH; 13100-14100ft, n = 4). All runners then engaged in 1 week of routine training in Fort Collins followed by a post-test run at Mt. Evans that was identical to the baseline test. RESULTS: The HIGH group experienced a 4.7 ± 2 % improvement in high-altitude run time (7.1 min faster; P = 0.09), while the LOW group ran 0.5 ± 1.5 % (1.3 min) slower (P = NS). Mean SaO2 was 3% higher in the HIGH in the post vs. pre-test at 14100ft (P = 0.02), but 1% lower in the LOW group (P < 0.05 for group difference). In addition, SaO2 tended to stabilize at higher levels in the HIGH vs. LOW (+2.25% vs., -2.99%, respectively) following completion of the post-test at 14100ft (P = 0.10). HCT tended to increase in both groups from pre to post testing, but there were no differences in HCT, or RPE, between HIGH and LOW groups. CONCLUSIONS: A single high-altitude training bout prior to 1 week of low-altitude training improves subsequent aerobic performance and arterial O2 saturation at high-altitude, while a single bout performed 2 weeks prior to testing is ineffective.

How to Get Congress to Listen

How to Get Congress to Listen

Psychiatrists Lobby Congress on Health Reform, Privacy Issues

Psychiatrists Lobby Congress on Health Reform, Privacy Issues

Dynamic neuroplasticity and the automation of motivated behavior

Dynamic neuroplasticity and the automation of motivated behavior

One hour of tongue-task training is associated with plasticity in corticomotor control of the human tongue musculature

Corticomotor control of the human tongue has been reported to undergo neuroplastic changes following several days of training in a tongue-protrusion task. The aims of the present study were to determine if a 1 h tongue-task training is sufficient to induce signs of neuroplastic changes in the corticomotor pathways, and to obtain preliminary information on the time course of such changes. Corticomotor excitability was assessed by changes in electromyographic activity evoked by transcortical magnetic stimulation (TMS) in 11 healthy subjects. Motor evoked potentials (MEPs) recorded in the tongue musculature and the first dorsal interosseous (FDI) muscle were assessed at four sessions: at baseline before training, 30 min after training, and 1 and 7 days after training. All subjects performed successfully the task (success rate: 38+/-4%). Thresholds for evoking MEPs by TMS in the tongue were decreased at 30 min, 1 and 7 days after training compared with baseline (ANOVA: P<0.001). Tongue MEP amplitudes were significantly increased at 1 day follow-up and had returned to baseline values at 7 days follow-up (ANOVA: P<0.001). No significant effect of tongue-task training on FDI MEPs was observed (ANOVA: P=0.160). Corticomotor topographic maps revealed increases (ANOVA: P<0.001) in area at the 1 day follow-up. The success rate was significantly correlated to the net increases in tongue MEPs at 1 day follow-up (Spearman: 0.615; P=0.0039). The present findings confirm that tongue task training is associated with plasticity of corticomotor excitability specifically related to the tongue musculature and further document that plasticity is evident within 30 min post-training and may last up to at least 7 days.

Acquisition and contextual switching of multiple internal models for different viscous force fields

Humans can learn an enormous number of motor behaviors in different environments. To explain this, the MOSAIC model proposes that multiple internal models are acquired in the brain, which can be switched. However, previous behavioral studies that examined arm-movement adaptations to multiple environments reported a rather limited learning capability. Hitherto, humans have been believed incapable of learning two opposite viscous force fields, which are both dynamic transformations and depend on the same state variable, presented in a random order with only a visual cue. In contrast, this study found that humans are capable of this. Elbow joint movements to specified targets were perturbed by either resistive or assistive viscous force fields generated by a single degree-of-freedom manipulandum. The resistive or assistive viscous force fields were cued by a blue or red color on a CRT screen, respectively. The squared distance between the end point and the target, and the variance of the joint angular velocities were used as kinematic performance indices. These movement errors decreased significantly as a function of the training days. Aftereffects and learning consolidation were demonstrated in the random presentation of the two force fields. Consequently, humans were able to learn the multiple and distinct internal models of the two force fields and appropriately switch them even for a random presentation cued only by color after several days of training. This study suggests that none of the previously proposed conditions for multiple internal model learning are necessary prerequisites, and indicates that the difficulty in learning is determined by the balance between the effectiveness of contextual information and the similarity of force fields.

Learning to find a shape.

We studied the transition of stimuli from novel to familiar in visual search and in the guidance of attention to a particular object. Ability to identify an object improved dramatically over several days of training. The learning was specific for the object's position in the visual field, orientation and configuration. Improvement was initially localized to one or two positions near the fixation spot and then expanded radially to include the full area of the stimulus array. Characteristics of this learning process may reflect a shift in the cortical representation of complex features toward earlier stages in the visual pathway.

Dentate gyrus-selective colchicine lesion and disruption of performance in spatial tasks: difficulties in "place strategy" because of a lack of flexibility in the use of environmental cues?

The effects of intradentate colchicine injections on the performance of tasks requiring spatial working and reference memory are controversial. Multiple-site colchicine injections (7 microg/microl; via a drawn micropipette) throughout the dentate gyrus (DG) of rats (nine sites in each hemisphere, 0.06 microl at each site) selectively destroy about 90% of the DG granule cells, as revealed by quantitative stereological estimates; stereology also revealed minor neuronal losses in the CA4 (33%) and CA1 (23%) subfields, but lack of damage to the CA3 hippocampal subfield. Spatial reference and working memory were assessed in Morris' water maze; in the reference memory task, the rats were required to learn a single, fixed location for the platform over several days of training; in the working memory task, animals were required to learn a new platform location every day, in a matching-to-place procedure. Compared to sham-operated controls, lesioned rats showed significant disruption in acquisition of the reference memory water maze task; however, the data reveal that these rats did acquire relevant information about the task, probably based on guidance and orientation strategies. In a subsequent probe test, with the platform removed, lesioned rats showed disruption in precise indexes of spatial memory (e.g., driving search towards the surroundings of the former platform location), but not in less precise indexes of spatial location. Finally, the lesioned rats showed no improvement in the match-to-place procedure, suggesting that their working memory for places was disrupted. Thus, although capable of acquiring relevant information about the task, possibly through guidance and/or orientation strategies, DG-lesioned rats exhibit a marked difficulty in place strategies. This is particularly evident when these rats are required to deal with one-trial place learning in a familiar environment, such as in the working memory version of the water maze task, which requires flexibility in the use of previously acquired information.

Exemplar similarity and the development of automaticity.

Effects of exemplar similarity on the development of automaticity were investigated with a task in which participants judged the numerosity of random patterns of between 6 and 11 dots. After several days of training, response times were the same at all levels of numerosity, signaling the development of automaticity. In Experiment 1, response times to new patterns were a function of their similarity to old patterns. In Experiment 2, responses to patterns with high within-category similarity became automatized more quickly than responses to patterns with low within-category similarity. In Experiment 3, responses to patterns with high between-category similarity became automatized more slowly than responses to patterns with low between-category similarity. A new theory, the exemplar-based random walk (EBRW) model, was used to explain the results. Combining elements of G. D. Logan's (1988) instance theory of automaticity and R. M. Nosofsky's (1986) generalized context model of categorization, the theory embeds a dynamic similarity-based memory retrieval mechanism within a competitive random walk decision process.