Easy Trials Research Articles

You Can Make it Too Easy: Simulating Easy-To-Hard Effects in Auditory Perceptual Learning with an Unsupervised Neural Network Model of Plasticity

ABSTRACT The easy-to-hard effect is a phenomenon where training on initially easy perceptual discrimination contrasts before introducing hard contrasts yields greater perceptual learning than training with hard contrasts for the same amount of time. However, easy-to-hard effects can be erased if initial easy trials are made too easy. Here, we show that this seemingly paradoxical result naturally emerges out of an artificial neural network model of perceptual learning based on the incremental differentiation of stimulus representations: the self-organizing map (SOM). Like human listeners, networks show a sweet spot for easy-to-hard effects at intermediate levels of easy contrast somewhere between too easy and too hard. This trend is apparent across a wide range of free parameters. Analysis of network learning dynamics shows that easy-to-hard effects manifest when competition for network representational space is reduced (relative to constant hard training), but the learned stimuli are still similar enough to hard contrast stimuli to allow generalization. The data show that an incremental perceptual learning model can account for subtle characteristics of easy-to-hard effects where learning theories grounded in attentional discovery of relevant features cannot. We suggest several avenues for further development of the model in order to account for a wider range of auditory learning phenomena, its use in the optimization of auditory training regimens, and its role in elucidating perceptual learning mechanisms.

Intermixed levels of visual search difficulty produce asymmetric probability learning.

When performing novel tasks, we often apply the rules we have learned from previous, similar tasks. Knowing when to generalize previous knowledge, however, is a complex challenge. In this study, we investigated the properties of learning generalization in a visual search task, focusing on the role of search difficulty. We used a spatial probability learning paradigm in which individuals learn to prioritize their search toward the locations where a target appears more often (i.e., high-probable location) than others (i.e., low-probable location) in a search display. In the first experiment, during a training phase, we intermixed the easy and difficult search trials within blocks, and each was respectively paired with a distinct high-probable location. Then, during a testing phase, we removed the probability manipulation and assessed any generalization of spatial biases to a novel, intermediate difficulty task. Results showed that, as training progressed, the easy search evoked a stronger spatial bias to its high-probable location than the difficult search. Moreover, there was greater generalization of the easy search learning than difficult search learning at test, revealed by a stronger bias toward the former's high-probable location. Two additional experiments ruled out alternatives that learning during difficult search itself is weak and learning during easy search specifically weakens learning of the difficult search. Overall, the results demonstrate that easy search interferes with difficult search learning and generalizability when the two levels of search difficulty are intermixed.

Trying Harder: How Cognitive Effort Sculpts Neural Representations during Working Memory.

While the exertion of mental effort improves performance on cognitive tasks, the neural mechanisms by which motivational factors impact cognition remain unknown. Here, we used fMRI to test how changes in cognitive effort, induced by changes in task difficulty, impact neural representations of working memory (WM). Participants (both sexes) were precued whether WM difficulty would be hard or easy. We hypothesized that hard trials demanded more effort as a later decision required finer mnemonic precision. Behaviorally, pupil size was larger and response times were slower on hard compared with easy trials suggesting our manipulation of effort succeeded. Neurally, we observed robust persistent activity during delay periods in the prefrontal cortex (PFC), especially during hard trials. Yet, details of the memoranda could not be decoded from patterns in prefrontal activity. In the patterns of activity in the visual cortex, however, we found strong decoding of memorized targets, where accuracy was higher on hard trials. To potentially link these across-region effects, we hypothesized that effort, carried by persistent activity in the PFC, impacts the quality of WM representations encoded in the visual cortex. Indeed, we found that the amplitude of delay period activity in the frontal cortex predicted decoded accuracy in the visual cortex on a trial-wise basis. These results indicate that effort-related feedback signals sculpt population activity in the visual cortex, improving mnemonic fidelity.

Pupils Dilate More to Harder Vocabulary Words than Easier Ones.

Understanding cognitive effort expended during assessments is essential to improving efficiency, accuracy, and accessibility within these assessments. Pupil dilation is commonly used as a psychophysiological measure of cognitive effort, yet research on its relationship with effort expended specifically during language processing is limited. The present study adds to and expands on this literature by investigating the relationships among pupil dilation, trial difficulty, and accuracy during a vocabulary test. Participants (n = 63, Mage = 19.25) completed a subset of trials from the Peabody Picture Vocabulary Test while seated at an eye-tracker monitor. During each trial, four colored images were presented on the monitor while a word was presented via audio recording. Participants verbally indicated which image they thought represented the target word. Words were categorized into Easy, Medium, and Hard difficulty. Pupil dilation during the Medium and Hard trials was significantly greater than during the Easy trials, though the Medium and Hard trials did not significantly differ from each other. Pupil dilation in comparison to trial accuracy presented a more complex pattern, with comparisons between accurate and inaccurate trials differing depending on the timing of the stimulus presentation. These results present further evidence that pupil dilation increases with cognitive effort associated with vocabulary tests, providing insights that could help refine vocabulary assessments and other related tests of language processing.

Foveal feedback in perceptual processing: Contamination of neural representations and task difficulty effects.

Visual object recognition was traditionally believed to rely on a hierarchical feedforward process. However, recent evidence challenges this notion by demonstrating the crucial role of foveal retinotopic cortex and feedback signals from higher-level visual areas in processing peripheral visual information. The nature of the information conveyed through foveal feedback remains a topic of debate. To address this, we conducted a study employing a foveal mask paradigm with varying stimulus-mask onset asynchronies in a peripheral same/different task, where peripheral objects exhibited different degrees of similarity. Our hypothesis posited that simultaneous arrival of feedback and mask information in the foveal cortex would lead to neural contamination, biasing perception. Notably, when the two peripheral objects were identical, we observed a significant increase in the number of "different" responses, peaking at approximately 100 ms. Similar effect was found when the objects were dissimilar, but with an overall later timing (around 150 ms). No significant difference was found when comparing easy (dissimilar objects) and difficult trials (similar objects). The findings challenge the hypothesis that foveation planning alone accounts for the observed effects. Instead, these and previous observations support the notion that the foveal cortex serves as a visual sketchpad for maintaining and manipulating task-relevant information.

The Impact of Adding a Fourth Item to the Traditional 3-Item Remote Associates Test

ABSTRACT The compound Remote Associates Test (RAT) is a classic measure of creativity. Participants are shown three cue words (sore-shoulder-sweat) and asked to generate a word that connects them (cold). Theoretical views of RAT performance differ in the degree to which they conceptualize performance as depending on automatic spreading activation across semantic networks, strategic generation of bi-associations, and other analytical processes (e.g. executive processes that support fluid intelligence). We tested these views by adding a fourth cue word to determine whether it impaired RAT accuracy (e.g. generation of bi-associations), impaired response times (analytic processes), or improved RAT accuracy without changing response times (e.g. spreading activation). Across four experiments, 551 adults completed 3- and 4-item RAT trials that were matched on linguistic and semantic metrics. Across experiments, adding the fourth word improved accuracy by 27.91%. This performance gain occurred with either modest or no changes to response times or ratings of insight/strategy use. Interestingly, the fourth word predominantly benefited accuracy and response times on difficult trials; on easy trials, the fourth word impaired or did not change performance. The findings suggest that both automatic and strategic/analytical processes contribute to successful RAT performance, with relative dependence on these processes dynamically adapting to the demands of the individual trial.

The spectral profile of cortical activation during a visuospatial mental rotation task and its correlation with working memory.

The search for a cortical signature of intelligent behavior has been a longtime motivation in Neuroscience. One noticeable characteristic of intelligence is its association with visuospatial skills. This has led to a steady focus on the functional and structural characteristics of the frontoparietal network (FPN) of areas involved with higher cognition and spatial behavior in humans, including the question of whether intelligence is correlated with larger or smaller activity in this important cortical circuit. This question has broad significance, including speculations about the evolution of human cognition. One way to indirectly measure cortical activity with millisecond precision is to evaluate the event-related spectral perturbation (ERSP) of alpha power (alpha ERSP) during cognitive tasks. Mental rotation, or the ability to transform a mental representation of an object to accurately predict how the object would look from a different angle, is an important feature of everyday activities and has been shown in previous work by our group to be positively correlated with intelligence. In the present work, we evaluate whether alpha ERSP recorded over the parietal, frontal, temporal, and occipital regions of adolescents performing easy and difficult trials of the Shepard-Metzler's mental rotation task, correlates or are predicted by intelligence measures of the Weschler's intelligence scale. We used a database obtained from a previous study of intellectually gifted (N = 15) and average intelligence (N = 15) adolescents. Our findings suggest that in challenging task conditions, there is a notable difference in the prominence of alpha event-related spectral perturbation (ERSP) activity between various cortical regions. Specifically, we found that alpha ERSP in the parietal region was less prominent relative to those in the frontal, temporal and occipital regions. Working memory scores predict alpha ERSP values in the frontal and parietal regions. In the frontal cortex, alpha ERSP of difficult trials was negatively correlated with working memory scores. Thus, our results suggest that even though the FPN is task-relevant during mental rotation tasks, only the frontal alpha ERSP is correlated with working memory score in mental rotation tasks.

How children speak with their voice assistant Sila depends on what they think about her

Children encounter artificial intelligence, e.g., voice assistants, at an increasingly younger age. However, we know far too little about children's communicative behavior with a voice-only interaction partner and whether and how their assumptions about the interaction partner predict how they communicate. To address these aspects, we ran a treasure hunt game with 50 5-6-year-olds who were guided through the hunt by a voice-only interaction partner “Sila” – acted by a human and connected via loudspeakers. Crucially, Sila was introduced either as a human or a voice assistant. We employed easy communication trials in which communication went smoothly and challenging communication trials that contained staged misunderstandings. Results showed that at the group level, children differed in the way they adjusted their speech across experimental phases – both in quantity (fewer grounding turns and fewer syllables in speech directed to voice assistants) and quality (reduced increase in f0 and intensity in speech directed to voice assistants). Notably, the communicative behavior was predicted by children's individual parasocial relationship with their voice-only interaction partner. We discuss the relevance of our findings for developmental science at the interface with communication science and phonetics, and the direct practical implications we can infer for speech technology.

Information-seeking across auditory scenes by an echolocating dolphin.

Dolphins gain information through echolocation, a publicly accessible sensory system in which dolphins produce clicks and processreturning echoes, thereby both investigating and contributing to auditory scenes. How their knowledge of these scenes contributes to their echoic information-seeking is unclear. Here, we investigate their top-down cognitive processes in an echoic matching-to-sample task in which targets and auditory scenes vary in their decipherability and shift from being completely unfamiliar to familiar. A blind-folded adult male dolphin investigated a target sample positioned in front of a hydrophone to allow recording of clicks, a measure of information-seeking and effort; the dolphin received fish for choosing an object identical to the sample from 3 alternatives. We presented 20 three-object sets, unfamiliar in the first five 18-trial sessions with each set. Performance accuracy and click counts varied widely across sets. Click counts of the four lowest-performance-accuracy/low-discriminability sets (X = 41%) and the four highest-performance-accuracy/high-discriminability sets (X = 91%) were similar at the first sessions' starts and then decreased for both kinds of scenes, although the decrease was substantially greater for low-discriminability sets. In four challenging-but-doable sets, number of clicks remained relatively steady across the 5 sessions. Reduced echoic effort with low-discriminability sets was not due to overall motivation: the differential relationship between click number and object-set discriminabilitywas maintained when difficult and easy trials were interleaved and when objects from originally difficult scenes were grouped with more discriminable objects. These data suggest that dolphins calibrate their echoic information-seeking effort based on their knowledge and expectations of auditory scenes.

Effects of an afternoon nap on sustained attention and working memory: The role of physiological arousal and sleep variables

Taking a short midday nap has been associated with higher alertness and better cognitive task performance. Yet, the mechanisms associated with nap-dependent performance enhancement are unclear. The current study was conducted to explore the impact of physiological arousal during cognitive task and sleep architecture during a pre-task nap on post-nap behavioral outcomes. A within-subjects design (N = 18) was employed, in which participants either took a nap or remained awake for 40 min during the post-lunch period. The psychomotor vigilance test (PVT) and n-back task were administered to assess sustained attention and working memory, respectively, with each task including one block of easy trials and one block of difficult trials. Results showed that a short midday nap improved sustained attention but not working memory. In addition, a midday nap induced lower physiological arousal during the performance on both cognitive tasks, with relatively higher delta and lower beta activity. The relative power of theta and alpha were positively correlated with performance on the easy PVT, whereas the alpha power was negatively correlated with performance on the difficult PVT, and the theta power was negatively correlated with reaction speed in the n-back task regardless of the task difficulty. Meanwhile, the shorter total sleep time and longer time of wake after sleep onset were associated with the faster overall reaction speed in PVT easy trials. These findings suggested that both changes in physiological arousal and sleep variables might account for changes in task performance after a short midday nap.

The effect of applied effort on MATB-II performance

Some of the variability found in measures of mental workload (see e.g. Singleton, Fox, and Whitfield 1973; Wierwille and Connor 1983; Steel­man, McCarley, and Wickens 2011; Casner and Gore 2010) may be due to the effort applied to the task by participants, rather than by the independent variable of interest. If true, capturing and removing the variation due to ‘applied effort’ could improve the ability of studies to detect effects of interest. While introducing participants to two sub-tasks derived from Multi-Attribute Task Battery II (Santiago-Espada et al. 2011), the study investigated the influence of applied effort on MATB-II performance measures while holding other effects constant. Two groups of participants each completed easy and hard trials of MATB-II-derived sub-tasks. Treatment group of participants was offered an additional reward if they achieved a sufficiently high performance. The treatment group performed better by just under 4% in both easy and hard trials which provides a suggestion about the size of the effect of applied effort in this study. Measuring or controlling for applied effort can improve the ability of researchers to determine the effects of interventions on workload measures by reducing the amount of variability that is captured as error.

Cerebellar tDCS does not modulate language processing performance in healthy individuals

Clinical and neuroscientific studies have established that the cerebellum contributes to language processing. Yet most evidence is correlational and the exact role of the cerebellum remains unclear. The aim of this study was to investigate the role of the right cerebellum in language comprehension and production using non-invasive brain stimulation. In this double-blind, sham-controlled experiment, thirty-six healthy participants received anodal or sham transcranial direct current (tDCS) stimulation to the right cerebellum while performing a lexical decision, sentence comprehension, verbal fluency and a non-language control task. Active tDCS did not modulate performance in any of the tasks. Additional exploratory analyses suggest difficulty-specific performance modulation in the sentence comprehension and lexical decision task, with tDCS improving performance in easy trials of the sentence comprehension task and difficult trials in the lexical decision task. Overall, our findings provide no evidence for the involvement of the right posterior cerebellum in language processing. Further research is needed to dissociate the influence of task difficulty of the underlying cognitive processes.

End-to-End Speaker Verification via Curriculum Bipartite Ranking Weighted Binary Cross-Entropy

End-to-end speaker verification achieves the verification through estimating directly the similarity score between a pair of utterances, which is formulated as a binary (i.e., target versus non-target) classification problem. Unlike the stage-wise method, an end-to-end verification approach optimizes the evaluation metrics directly and its output layer is parameter-free, which can save great computing and memory resources. However, there are two important issues that need to be meticulously handled in training an end-to-end speaker verification model. The first one is how to deal with severely imbalanced trials, i.e., the number of target trials is much smaller than that of nontarget trials, and the other is about how to handle easy trials that do not help improve the model in training. To circumvent these two issues, we propose in this paper a binary cross-entropy (BCE) type of loss function and present a method to train the deep neural network (DNN) models based on the proposed loss function for end-to-end speaker verification. The training process employs a bipartite ranking method to deal with the trial imbalance problem and a curriculum learning method to help improve both the training stability and performance of the model by selecting non-target trials from easy to hard ones gradually along the convergence process. Since the training process employs bipartite ranking and curriculum learning and the loss function is of the generalized BCE form, we name the new approach \textit{curriculum bipartite ranking weighted binary cross-entropy} (CBRW-BCE). Experimental results show that the model trained with CBRW-BCE not only achieves the state-of-the-art performance but is also well calibrated.

Motor Preparation and Execution for Performance Difficulty: Centroparietal Beta Activation during the Effort Expenditure for Rewards Task as a Function of Motivation

Debate exists as to the effects of anxiety in performance-based studies. However, no studies have examined the influence of motivation both in preparation of a motor movement and during movement performance. The present study measured beta activation in preparation for and during execution of the effort expenditure for rewards task (EEfRT), a button-pressing task consisting of easy and hard trials. Results indicated that motor preparation (i.e., reduced beta activation) was greater in preparation for hard trials than for easy trials. Additionally, motor preparation decreased (i.e., beta activation increased) over the course of hard trial execution. These results suggest that motor preparation is enhanced prior to more challenging tasks but that motor preparation declines as participants become closer to completing their goal in each challenging trial. These results provide insight into how beta activation facilitates effort expenditure for motor tasks varying in difficulty and motivation. The impact of these results on models of anxiety and performance is discussed.

The Possibility of Conducting a Clinical Trial on Palliative Care: A Survey of Whether a Clinical Study on Cancer Dyspnea Is Acceptable to Cancer Patients and Their Relatives

ContextConducting randomized controlled trials on palliative care is difficult owing to barriers like fragility of the patients’ health status and health care providers’ concerns for patients. However, quality randomized controlled trials are required for care improvement. ObjectivesTo investigate the willingness of cancer patients and their relatives to participate in a clinical study on cancer dyspnea and identify feasible clinical study designs for this condition. MethodsA nationwide, cross-sectional, web-based survey was conducted with 206 cancer patients and 206 relatives of cancer patients. Their willingness to participate in clinical studies on cancer dyspnea and factors influencing this willingness were assessed in two scenarios: outpatients receiving anticancer treatment and terminally ill inpatients. ResultsAbout 23% patients and 23% relatives were willing to participate in clinical trials while 40% and 32%, respectively, were unwilling. Factors related to patient participation were quick and easy trials (outpatient 57%, terminally ill 53%) and oral medication with minimal potential side effects (outpatient 48%). Factors related to unwillingness to participate were placebo-controlled trials (outpatient 51%, terminally ill 50%), disagreements about participation between patients and families (outpatient 49%, terminally ill 49%), and continuous injections (outpatient 61%, terminally ill 47%). Compared to patients, relatives responded more reluctantly, especially for patients in terminal care. Conversely, patients were less reluctant in the terminal setting than the outpatient setting. ConclusionSome patients and relatives were reluctant to participate in clinical trials on cancer dyspnea. Thus, trials need to be minimally invasive, quick, and fully explained to and understood by patients and families.

042 A look at sex differences on sleep’s impact on working memory improvement

Abstract Introduction Studies have shown that sleep affects working memory (WM) improvement, but specific electrophysiological features are unclear (Sattari et al., 2019; MacDonald et al., 2018). In addition, sex differences have been found in both sleep and working memory (Mong, 2016; Harness, 2008). The goal of this study is to identify sex differences in EEG correlates of working memory over a night of sleep. Methods Sixty-three healthy (33 females), college-aged adults without sleep disorder were enrolled. A 32-channel electroencephalogram (EEG) cap was used to record brain activity during sleep. Operation span (OS) task was used to evaluate WM performance. Participants reported to the laboratory in the evening, performed OS before sleep (test1) and after sleep (test2). Trials were divided into easy and hard trials based on the number of letters subjects had to recall. A repeated-measure analysis of variance was conducted to examine the effects of time and trial difficulty. Paired-sample t-tests between test 1 and test 2 were conducted for males and females. Pearson’s correlations were examined between WM performance at test 1 and the difference score between test 1 and test 2 and EEG frequency bands. The Benjamini–Hochberg method was used to control for multiple comparisons. Results There was an increase in performance across the night in WM hard trials across all subjects (F(1,62)=4.86, p=0.03), no effect for easy trials (p>0.05). Females, but not males, showed a significant decrease in easy trials (t62= 2.40, p=0.02), while both males and females showed improvement in hard trials across the night. Females showed a positive correlation between test 1 hard trials and slow sigma, delta, slow oscillation in stage 3, this correlation is not seen in males. No correlations between overnight improvement and EEG bands were found. Conclusion Consistent with previous studies, participants showed better memory performance over a night of sleep, and the WM performance was associated with slow wave activity in females. Slow sigma also plays a role in the WM performance for females, indicating a possible role of sleep spindles. These associations were not shown in males, suggesting sex hormones mediate sleep’s impact on WM performance. Support (if any):

Slower prefrontal metastable dynamics during deliberation predicts error trials in a distance discrimination task

SUMMARYCortical activity related to erroneous behavior in discrimination or decision-making tasks is rarely analyzed, yet it can help clarify which computations are essential during a specific task. Here, we use a hidden Markov model (HMM) to perform a trial-by-trial analysis of the ensemble activity of dorsolateral prefrontal cortex (PFdl) neurons of rhesus monkeys performing a distance discrimination task. By segmenting the neural activity into sequences of metastable states, HMM allows us to uncover modulations of the neural dynamics related to internal computations. We find that metastable dynamics slow down during error trials, while state transitions at a pivotal point during the trial take longer in difficult correct trials. Both these phenomena occur during the decision interval, with errors occurring in both easy and difficult trials. Our results provide further support for the emerging role of metastable cortical dynamics in mediating complex cognitive functions and behavior.

Effects of motor response pattern on serial dependence in visual confidence

Visual confidence -- the evaluation of one’s own performance in a visual task -- demonstrates serial dependence when the visual task is performed over a series of trials. Despite the converging evidence for such serial effects on visual confidence, the underlying mechanisms remain unclear. The present study investigated the effects of motor response pattern on serial dependence in visual confidence using a novel paradigm. In each trial, participants performed a left-right, direction-discrimination task on a random-dot motion pattern. Simultaneously, they rated their confidence by pressing one of the 8 keys (2 directions x 4 points). Task difficulty was manipulated by varying motion coherence, which had been calibrated to individual participant’s direction discriminability using adaptive staircase. In the main experiment, we sequenced trials based on their difficulty levels, such that a (target) medium-difficulty trial was preceded by either easy or difficult trials. In Experiment 1, we found that confidence rating in target trials was higher when they were preceded by easy trials than by hard trials, despite matched task performance of the target trials between the two conditions. This suggests that confidence judgments can be biased in a series of tasks. In Experiment 2, we employed the same paradigm but instructed participants to respond either using the keyboard as in Experiment 1 or using the mouse to indicate confidence on one of two (left and right) on-screen, continuous sliders. We found the same serial confidence bias only when mouse was used in both preceding and target trials. Interestingly, using the meta-d’ analysis, we found that metacognitive sensitivity was higher when participants switched from mouse (preceding) to keyboard (target). In other words, repeatedly responding in the same motor pattern could impair metacognitive sensitivity. This suggests that the continuity in motor response pattern may contribute in producing serial effects on visual confidence.

Evaluation of cognitive effort in rats is not critically dependent on ventrolateral orbitofrontal cortex.

Organisms must frequently evaluate the amount of effort to invest in pursuing future rewards. Despite explicit awareness of the potential benefits of cognitive work, individuals vary in their willingness to attempt cognitively demanding tasks, regardless of intellectual ability. Such differences may suggest that the degree to which cognitive effort degrades perceived outcome value is a subjective, rather than objective, process, similar to risk and delay discounting. Although numerous studies suggest the orbitofrontal cortex (OFC) is important for allowing subjective value estimates to be updated and/or used in cost/benefit decision-making, the causal role of the OFC in valuations of mental effort has received scant investigation. We therefore trained 24 female Long-Evans rats on the rodent cognitive effort task (rCET) and assessed performance following temporary bilateral inactivation of the ventrolateral OFC (vlOFC). In the rCET, rats decide at trial outset whether to perform an easy or hard attentional challenge, namely to localize a brief visual stimulus to one of five possible locations. The difficulty of the challenge is determined by the stimulus duration (1.0 vs. 0.2s for easy vs. hard trials respectively), and success on hard trials results in double the sugar pellet rewards. Somewhat surprisingly, inactivations of the vlOFC did not affect rats' willingness or ability to exert cognitive effort for larger rewards, despite increasing omissions and motor impulsivity on-task. When considered with previous work, it appears the vlOFC plays a minimal role in cognitive effort allocation specifically, and in valuations of effort more generally.

No effect of feedback, level of processing or stimulus presentation protocol on perceptual learning when easy and difficult trials are interleaved

The role of feedback during training is a topic of great theoretical importance in perceptual learning. Feedback can be provided externally by the environment or internally by the observer. In order to evaluate the effectiveness of learning with internal versus external feedback, we performed a large multi-level experiment, varying the type of training task (Motion or Form), the level of processing (Local or Global), the presence of feedback (With or Without) and finally the method of stimulus presentation (Adaptive staircase or Method of constant stimuli). 140 participants were randomly assigned to one of ten groups and undertook 3 days of training in one condition only. Detection thresholds were measured daily before and after training with a pre- and post-assessment. A 75% detection threshold was calculated and used to estimate that day’s training levels (65% and 85% accuracy for difficult and easy trials respectively). The group trained with MOCS were presented with predefined randomly interleaved easy and difficult trials ranging from 50% to 95% stimulus intensity. Our findings indicate that improvement was generally robust across training-tasks, processing levels and feedback conditions. This suggests that internal reinforcement is as effective as external feedback in a discrete-noise-paradigm for local and global tasks when easy and difficult trials are interleaved.