Learning Process In Patients Research Articles

The Effects and Adverse Effects of tDCS on Motor Learning Process in Chronic Unilateral Stroke Patients

Objectives: It seems that psycho-physical factors of stroke patients undergoing Transcranial direct current stimulation (tDCS) treatment can affect implicit motor learning process in patient with stroke. The aim of this study was to determine the effects and adverse effects of tDCS on motor learning process in chronic unilateral stroke patients. Methods & Materials: This crossover, sham-controlled, randomized, blinded study was conducted in 2020 on 12 patients with chronic unilateral stroke (Mean±SD age, 60.33±1.87 years), (The Mean±SD time elapsed since the onset of the disease, 1.96±1.36 years) referred to Mobasher Kashani clinic in Hamadan, Iran who were selected using a convenience sampling technique. Patients were randomly divided in to 2 groups: experimental (dual tDCS+SRTT) (n=6) and sham (sham tDCS+SRTT) (n=6) groups. After 3 weeks of washing out period, patients in each group were treated in other brain stimulation group again. Data were collected using the record of reaction time and error of sequenced blocks by related software. Also, adverse effects of tDCS, pain or discomfort, attention and fatigue of patients were assessed by visual analogue scale (VAS) questionnaire. The data were analyzed using linear mixed effects. Results: Data analysis showed a considerable improvement in implicit motor learning in both brain stimulation groups. The most reported sensations were itching and tingling, which continued during all stimulation sessions. The pain or discomfort of the patients was negligible during the intervention sessions. Moreover, the type of brain stimulation, the time and their interaction had no significant effect on the fatigue, attention and pain of the patients (P>0.05). Conclusion: Dual-tDCS technique does not cause serious adverse effects in patients with stroke. It can be used as an effective and useful therapeutic strategy for increase in implicit motor learning in chronic stroke patients.

Verbal Learning Processes in Patients with Glioma of the Left and Right Temporal Lobes.

Recent research supports the utility of process variables in understanding mechanisms underlying memory impairments. The Hopkins Verbal Learning Test-Revised (HVLT-R) was administered to 84 patients with left (LTL, n = 58) or right temporal lobe glioma (RTL, n = 26) prior to surgical resection. Primary HVLT-R measures of learning and memory and numerous learning process indices were computed. Both groups exhibited frequent memory impairment (>30%), with greater severity in the LTL group. Patients with LTL glioma also exhibited lower semantic clustering scores than RTL patients, which were highly associated with Total Recall (ρ = 0.83) and Delayed Recall (ρ = 0.68). Learning slope and a novel measure of learning efficiency were also significantly associated with primary memory measures, though scores were similar across the LTL and RTL groups. While lesions to either temporal lobe impact verbal memory, semantic encoding appears to depend upon the integrity of LTL structures in particular.

The Rubber Hand Illusion paradigm as a sensory learning process in patients with schizophrenia

ObjectiveThe Rubber Hand Illusion (RHI) has previously been used to depict the hierarchy between visual, tactile and perceptual stimuli. Studies on schizophrenia inpatients (SZs) have found mixed results in the ability to first learn the illusion, and have yet to explain the learning process involved. This study's aim was two-fold: to examine the learning process of the RHI in SZs and healthy controls over time, and to better understand the relationship between psychotic symptoms and the RHI. MethodThirty schizophrenia inpatients and 30 healthy controls underwent five different trials of the RHI over a two-week period. ResultsAs has been found in previous studies, SZs felt the initial illusion faster than healthy controls did, but their learning process throughout the trials was inconsistent. Furthermore, for SZs, no correlations between psychotic symptoms and the learning of the illusion emerged. ConclusionHealthy individuals show a delayed reaction to first feeling the illusion (due to latent inhibition), but easily learn the illusion over time. For SZs, both strength of the illusion and the ability to learn the illusion over time are inconsistent. The cognitive impairment in SZ impedes the learning process of the RHI, and SZs are unable to utilize the repetition of the process as healthy individuals can.

Multidimensional analysis of the learning curve for robotic total mesorectal excision for rectal cancer: lessons from a single surgeon's experience.

Little data are available about the learning curve for robotic rectal resection. The purpose of this work was to provide a multidimensional analysis of the learning process in patients undergoing robotic total mesorectal excision for rectal cancer. This was a retrospective review of a prospectively collected database designed to evaluate the results of robotic rectal resection. The study was conducted at a tertiary-care hospital. From December 2007 to August 2012, 167 patients who underwent robotic total mesorectal excision for rectal cancer were included. A single hybrid variable including operative time, conversion, perioperative morbidity, and circumferential margin was generated to measure the success of the procedure. A moving average method for operative time and a risk-adjusted cumulative sum analysis were used to derive the learning curve. Overall conversion was noted in 2 cases (1.2%). The cumulative sum plot of a single hybrid variable representing the success of each operation demonstrated that the composite event was more frequent at the beginning of the series and began to decrease after 32 cases. The moving average for robotic console time decreased steadily and showed 2 plateaus; the first plateau was noted after 33 cases, and the second plateau was noted after 72 cases. The learning process was divided into 3 phases based on 2 cutoff points. The robotic console time decreased significantly with each phase (p < 0.001). Complicated rectal cancer was more frequent in the later phases; however, the incidence of postoperative complications remained constant throughout the series (p = 0.82). This study is limited by a single surgeon's experience. The learning process for robotic total mesorectal excision has a greater effect on the first 32 cases. These results help form a basis for performance monitoring of robotic total mesorectal excision.

Size of Error Affects Cerebellar Contributions to Motor Learning

Small errors may affect the process of learning in a fundamentally different way than large errors. For example, adapting reaching movements in response to a small perturbation produces generalization patterns that are different from large perturbations. Are distinct neural mechanisms engaged in response to large versus small errors? Here, we examined the motor learning process in patients with severe degeneration of the cerebellum. Consistent with earlier reports, we found that the patients were profoundly impaired in adapting their motor commands during reaching movements in response to large, sudden perturbations. However, when the same magnitude perturbation was imposed gradually over many trials, the patients showed marked improvements, uncovering a latent ability to learn from errors. On sudden removal of the perturbation, the patients exhibited aftereffects that persisted much longer than did those in healthy controls. That is, despite cerebellar damage, the brain maintained the ability to learn from small errors and the motor memory that resulted from this learning was strongly resistant to change. Of note was the fact that on completion of learning, the motor output of the cerebellar patients remained distinct from healthy controls in terms of its temporal characteristics. Therefore cerebellar degeneration impaired the ability to learn from large-magnitude errors, but had a lesser impact on learning from small errors. The neural basis of motor learning in response to small and large errors appears to be distinct.

Differential temporal dynamics of cognitive learning processes in patients with schizophrenia: An event-related fMRI study

Differential temporal dynamics of cognitive learning processes in patients with schizophrenia: An event-related fMRI study