Labels as features (not names) for infant categorization: a neurocomputational approach

A substantial body of experimental evidence has demonstrated that labels have an impact on infant categorization processes. Yet little is known regarding the nature of the mechanisms by which this effect is achieved. We distinguish between two competing accounts: supervised name-based categorization and unsupervised feature-based categorization. We describe a neurocomputational model of infant visual categorization, based on self-organizing maps, that implements the unsupervised feature-based approach. The model successfully reproduces experiments demonstrating the impact of labeling on infant visual categorization reported in Plunkett, Hu, and Cohen (2008) . It mimics infant behavior in both the familiarization and testing phases of the procedure, using a training regime that involves only single presentations of each stimulus and using just 24 participant networks per experiment. The model predicts that the observed behavior in infants is due to a transient form of learning that might lead to the emergence of hierarchically organized categorical structure and that the impact of labels on categorization is influenced by the perceived similarity and the sequence in which the objects are presented. The results suggest that early in development, say before 12 months old, labels need not act as invitations to form categories nor highlight the commonalities between objects, but they may play a more mundane but nevertheless powerful role as additional features that are processed in the same fashion as other features that characterize objects and object categories.     

Dual-learning systems during speech category learning

Dual-system models of visual category learning posit the existence of an explicit, hypothesis-testing reflective system, as well as an implicit, procedural-based reflexive system. The reflective and reflexive learning systems are competitive and neurally dissociable. Relatively little is known about the role of these domain-general learning systems in speech category learning. Given the multidimensional, redundant, and variable nature of acoustic cues in speech categories, our working hypothesis is that speech categories are learned reflexively. To this end, we examined the relative contribution of these learning systems to speech learning in adults. Native English speakers learned to categorize Mandarin tone categories over 480 trials. The training protocol involved trial-by-trial feedback and multiple talkers. Experiments 1 and 2 examined the effect of manipulating the timing (immediate vs. delayed) and information content (full vs. minimal) of feedback. Dual-system models of visual category learning predict that delayed feedback and providing rich, informational feedback enhance reflective learning, while immediate and minimally informative feedback enhance reflexive learning. Across the two experiments, our results show that feedback manipulations that targeted reflexive learning enhanced category learning success. In Experiment 3, we examined the role of trial-to-trial talker information (mixed vs. blocked presentation) on speech category learning success. We hypothesized that the mixed condition would enhance reflexive learning by not allowing an association between talker-related acoustic cues and speech categories. Our results show that the mixed talker condition led to relatively greater accuracies. Our experiments demonstrate that speech categories are optimally learned by training methods that target the reflexive learning system.     

Spatial sonification of letters on tablets to stimulate literacy skills and handwriting in 5 y-o children: A pilot study

We evaluate the effects of multisensory training on letters, including sonification of graphic symbols. We used “spatial sonification” where letter handwriting movements recorded in a two dimensional plan, vertical and horizontal, are systematically assigned to two acoustic features, spectral composition for the horizontal axis and frequency for the vertical axis. Forty-six kindergarten children were recruited. They were randomly assigned to three multisensory training groups: with sonification (Son) of letters, with a melody unrelated to the shape of the letters (Mel) and without any sound (Sil). We observed a significant effect of training, with the Son group performing better than the other groups in the reading and spelling tasks. We also observed a modification of two kinematic cues (time and in-air time) during handwriting, also in the Son group. We conclude that letter sonification could act as a binder between the visual and auditory dimensions of the letter. The processes underlying this benefit are discussed in the light of the Act-In model, a cognition memory model.     

Task and distribution sampling affect auditory category learning

There is substantial evidence that two distinct learning systems are engaged in category learning. One is principally engaged when learning requires selective attention to a single dimension (rule-based), and the other is drawn online by categories requiring integration across two or more dimensions (information-integration). This distinction has largely been drawn from studies of visual categories learned via overt category decisions and explicit feedback. Recent research has extended this model to auditory categories, the nature of which introduces new questions for research. With the present experiment, we addressed the influences of incidental versus overt training and category distribution sampling on learning information-integration and rule-based auditory categories. The results demonstrate that the training task influences category learning, with overt feedback generally outperforming incidental feedback. Additionally, distribution sampling (probabilistic or deterministic) and category type (information-integration or rule-based) both affect how well participants are able to learn. Specifically, rule-based categories are learned equivalently, regardless of distribution sampling, whereas information-integration categories are learned better with deterministic than with probabilistic sampling. The interactions of distribution sampling, category type, and kind of feedback impacted category-learning performance, but these interactions have not yet been integrated into existing category-learning models. These results suggest new dimensions for understanding category learning, inspired by the real-world properties of auditory categories.     

Contextual self-organizing map: software for constructing semantic representations

In this article, we introduce a software package that applies a corpus-based algorithm to derive semantic representations of words. The algorithm relies on analyses of contextual information extracted from a text corpus—specifically, analyses of word co-occurrences in a large-scale electronic database of text. Here, a target word is represented as the combination of the average of all words preceding the target and all words following it in a text corpus. The semantic representation of the target words can be further processed by a self-organizing map (SOM; Kohonen, Self-organizing maps, 2001), an unsupervised neural network model that provides efficient data extraction and representation. Due to its topography-preserving features, the SOM projects the statistical structure of the context onto a 2-D space, such that words with similar meanings cluster together, forming groups that correspond to lexically meaningful categories. Such a representation system has its applications in a variety of contexts, including computational modeling of language acquisition and processing. In this report, we present specific examples from two languages (English and Chinese) to demonstrate how the method is applied to extract the semantic representations of words.     

短期习得的语言范畴使成人大脑右半球颜色范畴知觉转为左半球颜色范畴知觉

本研究探讨了色词与颜色重组训练能否让被试习得与真实情境相似的色词与颜色范畴联结, 并引起相应的偏侧化颜色范畴知觉, 从而进一步揭示语言编码对颜色范畴知觉的影响。采用六种蓝色作为材料。B1与B2为先前研究的两种蓝色。B11和B12, B21和B22分别为使B1, B2变浅和变深所得, 四者是连续的蓝色。训练被试分别用“duān”和“kěn”命名B1和B2。由于被试可能习得色词与颜色范畴的联结, 因此B12与B21为可能变范畴间颜色, B11和B12, B21和B22为可能变范畴内颜色。训练前后分别让被试完成一个视觉搜索测验。结果发现：前测中可能变范畴间颜色的辨别优于可能变范畴内颜色, 且在左视野呈现时更显著; 后测中可能变范畴间颜色的辨别同样优于可能变范畴内颜色, 但在右视野呈现时更显著。这提示：(1)人们在知觉同一语言范畴的不同颜色时可能会区分深浅范畴, 并因此引发右半球颜色范畴知觉; (2)短期习得的语言范畴能引起偏左半球颜色范畴知觉, 且使右半球颜色范畴知觉转为左半球颜色范畴知觉; (3)被试在训练中习得了色词与颜色范畴的联结; (4)范畴学习可以在仅学习一个样例的条件下自动发生。     

习得的语言范畴影响颜色知觉的机制:来自ERP的证据

本研究以两个实验探讨了习得的语言范畴影响颜色知觉的机制.实验1让被试接受短期“色-词”重组训练,使原先范畴内的两种颜色变为范畴间的颜色,训练前后完成视觉搜索任务.反应时结果显示,在训练后,与训练的两种颜色近似的另外两种颜色的知觉表现出边缘显著的偏侧化颜色范畴效应.实验2让被试接受与实验1相同的训练后,完成视觉Oddball任务.ERP结果显示,在训练后,与训练的两种颜色近似的另外两种颜色的偏差刺激在早期知觉阶段就表现出偏侧化vMMN效应.这些结果表明:习得的语言范畴能影响早期的、注意前的颜色知觉机能,且这一影响过程可以在短期内完成;习得的语言范畴会影响颜色知觉范畴,而非仅影响特定颜色点的知觉机能.     

Neuromagnetic evidence for a featural distinction of English consonants: sensor- and source-space data

Speech sounds can be classified on the basis of their underlying articulators or on the basis of the acoustic characteristics resulting from particular articulatory positions. Research in speech perception suggests that distinctive features are based on both articulatory and acoustic information. In recent years, neuroelectric and neuromagnetic investigations provided evidence for the brain's early sensitivity to distinctive features and their acoustic consequences, particularly for place of articulation distinctions. Here, we compare English consonants in a Mismatch Field design across two broad and distinct places of articulation - labial and coronal - and provide further evidence that early evoked auditory responses are sensitive to these features. We further add to the findings of asymmetric consonant processing, although we do not find support for coronal underspecification. Labial glides (Experiment 1) and fricatives (Experiment 2) elicited larger Mismatch responses than their coronal counterparts. Interestingly, their M100 dipoles differed along the anterior/posterior dimension in the auditory cortex that has previously been found to spatially reflect place of articulation differences. Our results are discussed with respect to acoustic and articulatory bases of featural speech sound classifications and with respect to a model that maps distinctive phonetic features onto long-term representations of speech sounds.     

语言范畴可否引起偏侧化颜色范畴知觉？

本研究考查了语言范畴是否会引起偏侧化颜色范畴知觉,并探讨了偏侧化颜色范畴知觉是语言范畴即时分类颜色还是长期与颜色联结的结果。实验中,以测量差别阈限的方法选定的渐变、相邻颜色知觉距离相当的A、B、C、D四种颜色（A、B为绿色,C、D为蓝色）为材料,以色词与颜色重组模式训练被试用4个人造词汇分别命名4种颜色,并让被试在训练前、第一次训练和第八次训练后均完成视觉搜索任务测试。经训练,原范畴内颜色（AB,CD）变成了范畴间颜色,原范畴间颜色（BC）仍为范畴间颜色。结果显示：被试在一次训练后能以新名字区分4种颜色,八次训练后掌握了4种颜色的新名字;在训练前测试中,出现了与蓝绿色相应的偏侧化颜色范畴知觉;在第八次训练后测试中,出现了与习得的语言范畴相应的偏侧化颜色范畴知觉,但在第一次训练后测试中并未出现这一效应。这些结果表明,语言范畴能引起偏侧化颜色范畴知觉,偏侧化颜色范畴知觉是语言范畴长期与颜色联结,而非即时分类颜色的结果。     

Cross-species differences in color categorization

Berlin and Kay (1969) found systematic restrictions in the color terms of the world’s languages and were inclined to look to the primate visual system for their origin. Because the visual system does not provide adequate neurophysiological discontinuities to supply natural color category boundaries, and because recent evidence points to a linguistic origin (Davidoff, Davies, & Roberson, 1999), a new approach was used to investigate the controversial issue of the origin of color categories. Baboons and humans were given the same task of matching-to-sample colors that crossed the blue/green boundary. The data and consequent modeling were remarkably clear-cut. All human subjects matched our generalization probe stimuli as if to a sharp boundary close to the midpoint between their training items. Despite good color discrimination, none of the baboons showed any inclination to match to a single boundary but rather responded with two boundaries close to the training stimuli. The data give no support to the claim that color categories are explicitly instantiated in the primate color vision system.     

Associative learning in baboons (Papio papio) and humans (Homo sapiens): species differences in learned attention to visual features

We examined attention shifting in baboons and humans during the learning of visual categories. Within a conditional matching-to-sample task, participants of the two species sequentially learned two two-feature categories which shared a common feature. Results showed that humans encoded both features of the initially learned category, but predominantly only the distinctive feature of the subsequently learned category. Although baboons initially encoded both features of the first category, they ultimately retained only the distinctive features of each category. Empirical data from the two species were analyzed with the 1996 ADIT connectionist model of Kruschke. ADIT fits the baboon data when the attentional shift rate is zero, and the human data when the attentional shift rate is not zero. These empirical and modeling results suggest species differences in learned attention to visual features. Received: 30 May 1998 / Accepted after revision: 13 September 1998     

The role of long-term familiarity and attentional maintenance in short-term memory for timbre

We study short-term recognition of timbre using familiar recorded tones from acoustic instruments and unfamiliar transformed tones that do not readily evoke sound-source categories. Participants indicated whether the timbre of a probe sound matched with one of three previously presented sounds (item recognition). In Exp. 1, musicians better recognised familiar acoustic compared to unfamiliar synthetic sounds, and this advantage was particularly large in the medial serial position. There was a strong correlation between correct rejection rate and the mean perceptual dissimilarity of the probe to the tones from the sequence. Exp. 2 compared musicians' and non-musicians' performance with concurrent articulatory suppression, visual interference, and with a silent control condition. Both suppression tasks disrupted performance by a similar margin, regardless of musical training of participants or type of sounds. Our results suggest that familiarity with sound source categories and attention play important roles in short-term memory for timbre, which rules out accounts solely based on sensory persistence.     

Incremental Bayesian Category Learning From Natural Language

Models of category learning have been extensively studied in cognitive science and primarily tested on perceptual abstractions or artificial stimuli. In this paper, we focus on categories acquired from natural language stimuli, that is, words (e.g., chair is a member of the furniture category). We present a Bayesian model that, unlike previous work, learns both categories and their features in a single process. We model category induction as two interrelated subproblems: (a) the acquisition of features that discriminate among categories, and (b) the grouping of concepts into categories based on those features. Our model learns categories incrementally using particle filters, a sequential Monte Carlo method commonly used for approximate probabilistic inference that sequentially integrates newly observed data and can be viewed as a plausible mechanism for human learning. Experimental results show that our incremental learner obtains meaningful categories which yield a closer fit to behavioral data compared to related models while at the same time acquiring features which characterize the learned categories. (An earlier version of this work was published in Frermann and Lapata 2014 .)     

习得的语言范畴对注意前颜色范畴知觉的影响:一项ERP研究

该研究探讨了语言范畴对注意前颜色知觉的影响依赖于语言范畴与颜色长期联结还是其即时分类颜色,同时检验了习得的语言范畴是否能因果性地改变早期颜色知觉机能。采用G1、G2、B1、B2（前两者为绿色,后两者为蓝色）4种连续变化的颜色为材料。学习组和分类组被试分别接受6次和1次色词与颜色重组训练,学习4种颜色不同的新名称,并在之后均接受视觉Oddball脑电测试。训练结果显示：学习组稳定地习得了4种颜色的新名称,分类组能以新名称将颜色分为4类。测试结果显示：学习组的颜色知觉中出现了与习得语言范畴对应的偏侧化注意前颜色范畴知觉,分类组的颜色知觉中未出现与颜色分类对应的偏侧化注意前颜色范畴知觉。研究结果表明：语言范畴对注意前颜色知觉的影响依赖于语言范畴与颜色长期联结而非其即时分类颜色;习得的语言范畴能引起偏侧化注意前颜色范畴知觉,提示习得的语言范畴能因果性地改变早期颜色知觉机能。     

Speech perception by budgerigars (Melopsittacus undulatus): spoken vowels

Discrimination of natural, sustained vowels was studied in 5 budgerigars. The birds were trained using operant conditioning procedures on a same-different task, which was structured so that response latencies would provide a measure of stimulus similarity. These response latencies were used to construct similarity matrices, which were then analyzed by multidimensional scaling (MDS) procedures. MDS produced spatial maps of these speech sounds where perceptual similarity was represented by spatial proximity. The results of the three experiments suggest that budgerigars perceive natural, spoken vowels according to phonetic categories, find the acoustic differences among different talkers less salient than the acoustic differences among vowel categories, and use formant frequencies in making these complex discriminations.     

Effects of training on attention to acoustic cues

Learning new phonetic categories in a second language may be thought of in terms of learning to focus one's attention on those parts of the acoustic-phonetic structure of speech that are phonologically relevant in any given context. As yet, however, no study has demonstrated directly that training can shift listeners' attention between acoustic cues given feedback about the linguistic phonetic category alone. In this paper we discuss the results of a training study in which subjects learned to shift their attention from one acoustic cue to another using only category-level identification as feedback. Results demonstrate that training redirects listeners' attention to acoustic cues and that this shift of attention generalizes to novel (untrained) phonetic contexts.     

Acoustic and perceptual categories of vocal elements in the warble song of budgerigars (Melopsittacus undulatus)

The warble songs of budgerigars (Melopsittacus undulatus) are composed of a number of complex, variable acoustic elements that are sung by male birds in intimate courtship contexts for periods lasting up to several minutes. If these variable acoustic elements can be assigned to distinct acoustic-perceptual categories, it provides the opportunity to explore whether birds are perceptually sensitive to the proportion or sequential combination of warble elements belonging to different categories. By the inspection of spectrograms and by listening to recordings, humans assigned the acoustic elements in budgerigar warble from several birds to eight broad, overlapping categories. A neural-network program was developed and trained on these warble elements to simulate human categorization. The classification reliability between human raters and between human raters and the neural network classifier was better than 80% both within and across birds. Using operant conditioning and a psychophysical task, budgerigars were tested on large sets of these elements from different acoustic categories and different individuals. The birds consistently showed high discriminability for pairs of warble elements drawn from between acoustic categories and low discriminability for pairs drawn from within acoustic categories. With warble elements reliably assigned to different acoustic categories by humans and birds, it affords the opportunity to ask questions about the ordering of elements in natural warble streams and the perceptual significance of this ordering.     

On the usefulness of 'what' and 'where' pathways in vision

The primate visual brain is classically portrayed as a large number of separate 'maps', each dedicated to the processing of specific visual cues, such as colour, motion or faces and their many features. In order to understand this fractionated architecture, the concept of cortical 'pathways' or 'streams' was introduced. In the currently prevailing view, the different maps are organised hierarchically into two major pathways, one involved in recognition and memory (the ventral stream or 'what' pathway) and the other in the programming of action (the dorsal stream or 'where' pathway). In this review, we question this heuristically influential but potentially misleading linear hierarchical pathway model and argue instead for a 'patchwork' or network model.     

Role of the secondary visual cortex in HMAX model for object recognition

The models inspired by visual systems of life creatures (e.g., human, mammals, etc.) have been very successful in addressing object recognition tasks. For example, Hierarchical Model And X (HMAX) effectively recognizes different objects by modeling the V1, V4, and IT regions of the human visual system. Although HMAX is one of the superior models in the field of object recognition, its implementation has been limited due to some disadvantages such as the unrepeatability of the process under constant conditions, extreme redundancy, high computational load, and time-consuming. In this paper, we aim at revising the HMAX approach by adding the model of the secondary region (V2) in the human visual system which leads to removing the mentioned drawbacks of standard HMAX. The added layer selects repeatable and more informative features that increase the accuracy of the proposed method by avoiding the redundancy existing in the conventional approaches. Furthermore, this feature selection strategy considerably reduces the huge computational load. Another contribution of our model is highlighted when a small number of training images is available where our model can efficiently cope with this issue. We evaluate our proposed approach using Caltech5 and GRAZ-02 database as two famous benchmarks for object recognition tasks. Additionally, the results are compared with standard HMAX that validate and highlight the efficiency of the proposed method.     

The Dynamics of Cultural and Technological Evolution: Domination Versus Partnership

There is growing consensus that we need a new paradigm if we are to solve the global problems that are the result of actions and policies stemming from prevailing paradigms or cognitive maps. Theories are cognitive maps. This article summarizes cultural transformation theory, which proposes that to solve our mounting global problems we need a clearer understanding of the self-organizing interaction of two basic movements in cultural evolution. The first consists of technological phase changes, including the most recent shift from industrial to electronic, nuclear, and biochemical technologies. The second consists of shifts in a system's orientation to what, based on three decades of transdisciplinary research, the author identifies as the socio-economic, gender, and cultural configurations characteristic of the dominator and partnership models. The article calls for a reassessment of earlier theories as the basis for effective action to accelerate the shift to a world orienting to the partnership rather than dominator model as a basis for a sustainable, equitable, and peaceful future.