Dual mechanisms governing reward-driven perceptual learning.

Research suggests autistic children learn and generalize visual family-resemblance categories atypically (e.g., Church, et al., 2010, 2015), particularly when learning incidentally from exposure. This may reflect differences in perceptual learning (Mercado et al., 2020). However, it is unknown whether perceptual discrimination learning is also atypical and if differences extend to other modalities. To address this, autistic children with normal language abilities and IQ and typically developing (TD) matched comparison children completed auditory and visual discrimination tasks, after either incidental exposure to or direct training with stimuli presented in either progressive (easy-to-hard) or random orders of difficulty. In the visual task, both autistic and TD children only performed well after progressive training, suggesting limited perceptual learning from incidental visual exposure. In the auditory task, autistic children showed a progressive learning advantage after both exposure and training, but TD children only showed this advantage after training. They also had significantly better auditory discrimination than TD children after progressive training. These findings suggest typical visual discrimination learning after progressive training and enhanced auditory discrimination learning after progressive training and exposure. This enhanced auditory perceptual learning may help explain why these autistic children are socially impaired while retaining the capacity to learn language.

Human performance in visual detection, discrimination, identification, and search tasks typically improves with practice. Psychophysical studies suggest that perceptual learning is mediated by an enhancement in the coding of the signal, and physiological studies suggest that it might be related to the plasticity in the weighting or selection of sensory units coding task relevant information (learning through attention optimization). We propose an experimental paradigm (optimal perceptual learning paradigm) to systematically study the dynamics of perceptual learning in humans by allowing comparisons to that of an optimal Bayesian algorithm and a number of suboptimal learning models. We measured improvement in human localization (eight-alternative forced-choice with feedback) performance of a target randomly sampled from four elongated Gaussian targets with different orientations and polarities and kept as a target for a block of four trials. The results suggest that the human perceptual learning can occur within a lapse of four trials (<1 min) but that human learning is slower and incomplete with respect to the optimal algorithm (23.3% reduction in human efficiency from the 1st-to-4th learning trials). The greatest improvement in human performance, occurring from the 1st-to-2nd learning trial, was also present in the optimal observer, and, thus reflects a property inherent to the visual task and not a property particular to the human perceptual learning mechanism. One notable source of human inefficiency is that, unlike the ideal observer, human learning relies more heavily on previous decisions than on the provided feedback, resulting in no human learning on trials following a previous incorrect localization decision. Finally, the proposed theory and paradigm provide a flexible framework for future studies to evaluate the optimality of human learning of other visual cues and/or sensory modalities.

Sensory Plasticity in Human Motor Learning

Evidence has indicated that the size of the visual span (the number of identifiable letters without movement of the eyes) and reading speed can be boosted through perceptual learning in alphabetic scripts. In this study, we investigated whether benefits of perceptual learning could be extended to visual-span size and sentence reading (all characters are presented at the same time) for Chinese characters and explored changes in sensory factors contributing to changes in visual-span size following training. We randomly assigned 26 normally sighted subjects to either a control group (n = 13) or a training group (n = 13). Pre- and posttests were administered to evaluate visual-span profiles (VSPs) and reading speed. Training consisted of trigram (sequences of three characters) character-recognition trials over 4 consecutive days. VSPs are plots of recognition accuracy as a function of character position. Visual-span size was quantified as the area under VSPs in bits of information transmitted. A decomposition analysis of VSPs was used to quantify the effects of sensory factors (crowding and mislocation). We compared the size and sensory factors of visual span and reading speed following training. Following training, the visual-span size significantly increased by 11.7 bits, and reading speed increased by 50.8%. The decomposition analysis showed a significant reduction for crowding (-13.1 bits) but a minor increase in the magnitude of mislocation errors (1.46 bits) following training. These results suggest that perceptual learning expands the visual-span size and further improves Chinese text sentence-reading speed, indicating that visual span may be a common sensory limitation on reading that can be overcome with practice.

Background and Purpose: The COVID-19 pandemic has altered the landscape of human life all over the world, including the conventional face-to-face teaching method, which has been replaced with online classes. The drastic changes without a holistic planning makes online teaching prone to various shortcomings. Thus, this article aims to address two research objectives. The first objective is to determine Malay Literature students ‘online learning experiences, and the second objective is to analyse the demographic factors influencing students’ perceptions of online learning during the COVID-19 pandemic.&#x0D; &#x0D; Methodology: This descriptive study employed a survey questionnaire to gather data. A sample consisting of 67 undergraduate students majoring in Malay Literature at a public university were recruited as respondents in the present study using a simple random sampling method. After following 14 weeks of online lessons, a questionnaire form was distributed to the students. The research instrument is a questionnaire, which has been adapted and modified from a study by Baczek et al. (2020). The questionnaire form consists of two sections. Section A contains eight items related to respondents’ demographic background. Section B contains items related to students’ perceptions of online learning, in which six items are related to the benefits of online learning, five items are based on the disadvantages of online learning, and four items on students’ general perceptions of online learning. The responses from the questionnaire were analysed using Statistical Package for the Sosial Science 22.0 for descriptive analysis.&#x0D; &#x0D; Findings: The study found that online learning is perceived by students as being more disadvantageous than beneficial. Respondents concluded that the advantage of online learning is that they could learn from their own homes according to the suitability of their time. They also acknowledged that they could access learning resources better in online classes. One of the factors influencing students’ perceptions of online learning is the speed of Internet connection.&#x0D; &#x0D; Contributions: The study highlights the need for lecturers to be adequately prepared and to consider factors such as quality of Internet access, home location, students’ readiness and constraints faced by students.&#x0D; &#x0D; Keywords: COVID-19, learning, literature, online learning, quality education.&#x0D; &#x0D; Cite as: Veeramuthu, S. P., Ganapathy, M., Abdul Rahman, M. L., Harun, J., &amp; Ramganesh, E. (2022). Malay literature students’ perceptions of online learning experiences during the Covid-19 pandemic at a public university. Journal of Nusantara Studies, 7(2), 44-60. http://dx.doi.org/10.24200/jonus.vol7iss2pp44-60

Perceptual learning has been extensively studied in both human and nonhuman animals, but the two lines of research have, for the most part, developed independently, addressing seemingly rather different issues by rather different methods. It has been argued, however, that analysis of the disparate phenomena studied in experiments on perceptual learning reveals that in all the studies, the essential feature is that appropriate training allows behavior to come to be controlled by the unique features, rather than by the common features, of similar stimuli. It has further been argued that experiments with nonhuman animals have established the existence of a range of learning processes that allow this to occur, and that these processes have general relevance, applying to humans as well as to animals.

Perceptual learning as a result of concerted changes in prefrontal and visual cortex

Todd and Mackintosh (1990) found that recognition memory of pigeons for pictures was better when the same pictures were used each session (a recency task) than when different slides were used (a novelty task); they attributed the superior performance on the recency task to perceptual learning. Three experiments explored two alternative accounts. One was that their use of a within-subject design could have allowed the strategy adopted in the recency task to influence adversely the strategy used in the novelty task. This possibility was ruled out by Experiment 1, which showed superior performance in the recency task when a between-subject design was used. A second account proposes that slide-reward associations formed (in both tasks) during first presentations of slides interfere with appropriate performance during second presentations (associative interference); in the recency task, however, the high long-term associative strength of the slides restricts the consequence of a single slide-reward pairing to a short-term effect, and associative interference occurs at short retention intervals only. This account was explored in Experiment 2, which found no evidence that increases in retention interval resulted in reduction of associative interference in the recency task, and in Experiment 3, where associative interference was shown to occur but was of comparable magnitude in the recency and novelty tasks. By elimination, the results support a perceptual learning interpretation.

Perceptual learning is usually feature-specific. Recently, we showed that perceptual learning is even specific for the motor response type. In a three-line bisection task, participants indicated whether the central line was offset either to the left or right by pressing a left or a right button, respectively. We found no transfer when the same participants adjusted the offset by using a computer mouse. Here, we first show that perceptual learning with mouse adjustments transfers to the untrained hand, but only for the trained adjustment condition. There was no transfer to the button press conditions, neither for the trained nor the untrained hand. Second, we show that a double training procedure enables transfer from the mouse adjustment to the button press condition. Hence, the specificity of perceptual learning to the motor response type can be overcome by double training as it is the case for visual features. Our results suggest that during perceptual learning, perceptuo-decisional signals are encoded together with the corresponding actions.

The amount of exposure determines generalization in animal perceptual learning using short inter-stimulus intervals

Perceptual Learning: Complete Transfer across Retinal Locations

BackgroundHumans and other animals change the way they perceive the world due to experience. This process has been labeled as perceptual learning, and implies that adult nervous systems can adaptively modify the way in which they process sensory stimulation. However, the mechanisms by which the brain modifies this capacity have not been sufficiently analyzed.Methodology/Principal FindingsWe studied the neural mechanisms of human perceptual learning by combining electroencephalographic (EEG) recordings of brain activity and the assessment of psychophysical performance during training in a visual search task. All participants improved their perceptual performance as reflected by an increase in sensitivity (d') and a decrease in reaction time. The EEG signal was acquired throughout the entire experiment revealing amplitude increments, specific and unspecific to the trained stimulus, in event-related potential (ERP) components N2pc and P3 respectively. P3 unspecific modification can be related to context or task-based learning, while N2pc may be reflecting a more specific attentional-related boosting of target detection. Moreover, bell and U-shaped profiles of oscillatory brain activity in gamma (30–60 Hz) and alpha (8–14 Hz) frequency bands may suggest the existence of two phases for learning acquisition, which can be understood as distinctive optimization mechanisms in stimulus processing.Conclusions/SignificanceWe conclude that there are reorganizations in several neural processes that contribute differently to perceptual learning in a visual search task. We propose an integrative model of neural activity reorganization, whereby perceptual learning takes place as a two-stage phenomenon including perceptual, attentional and contextual processes.

Learning to better discriminate a specific visual feature (i.e., a specific orientation in a specific region of space) has been associated with plasticity in early visual areas (sensory modulation) and with improvements in the transmission of sensory information from early visual areas to downstream sensorimotor and decision regions (enhanced readout). However, in many real-world scenarios that require perceptual expertise, observers need to efficiently process numerous exemplars from a broad stimulus class as opposed to just a single stimulus feature. Some previous data suggest that perceptual learning leads to highly specific neural modulations that support the discrimination of specific trained features. However, the extent to which perceptual learning acts to improve the discriminability of a broad class of stimuli via the modulation of sensory responses in human visual cortex remains largely unknown. Here, we used functional MRI and a multivariate analysis method to reconstruct orientation-selective response profiles based on activation patterns in the early visual cortex before and after subjects learned to discriminate small offsets in a set of grating stimuli that were rendered in one of nine possible orientations. Behavioral performance improved across 10 training sessions, and there was a training-related increase in the amplitude of orientation-selective response profiles in V1, V2, and V3 when orientation was task relevant compared with when it was task irrelevant. These results suggest that generalized perceptual learning can lead to modified responses in the early visual cortex in a manner that is suitable for supporting improved discriminability of stimuli drawn from a large set of exemplars.

Neuronal mechanisms of visual perceptual learning

Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT), a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.