Perceptual Classes Research Articles

Visitor Behaviour During the COVID-19 Pandemic in Kintamani Agroecotourism, Bali, Indonesia

The COVID-19 pandemic has hampered agro-ecotourism's economic, social, and environmental benefits. Previous studies have ignored visitor experiences, sustainability, and secondary data. A pandemic-era field assessment of Kintamani agro-ecotourism fills this gap. Purposive sampling was used to select 100 local visitors for the survey. Perceptual class intervals and WarpPLS 7.0 were used to analyze the data. Kintamani agro-ecotourism destination services and guest loyalty scored the highest. Attributes and service quality affected visitor satisfaction and loyalty, whereas the CHSE program measures did not. These findings include improving attributes and service quality, encouraging sustainability, collaborating with local communities and stakeholders, and developing innovative products and services for Kintamani agro ecotourism. Diverse market segments may be immersed in a region's culture and nature. Kintamani agro-ecotourism requires strong branding, marketing, and data-driven decision-making. Crisis management plans and sustainable infrastructure can help agro-ecotourism to survive unexpected disasters. Agro-ecotourism in Kintamani depends on the adaptation, innovation, and preservation of a region's natural and cultural legacy.

Using perceptual classes to dream policies in open-ended learning robotics

Achieving Lifelong Open-ended Learning Autonomy (LOLA) is a key challenge in the field of robotics to advance to a new level of intelligent response. Robots should be capable of discovering goals and learn skills in specific domains that permit achieving the general objectives the designer establishes for them. In addition, robots should reuse previously learnt knowledge in different domains to facilitate learning and adaptation in new ones. To this end, cognitive architectures have arisen which encompass different components to support LOLA. A key feature of these architectures is to implement a proper balance between deliberative and reactive processes that allows for efficient real time operation and knowledge acquisition, but this is still an open issue. First, objectives must be defined in a domain-independent representation that allows for the autonomous determination of domain-dependent goals. Second, as no explicit reward function is available, a method to determine expected utility must also be developed. Finally, policy learning may happen in an internal deliberative scale (dreaming), so it is necessary to provide an efficient way to infer relevant and reliable data for dreaming to be meaningful. The first two aspects have already been addressed in the realm of the e-MDB cognitive architecture. For the third one, this work proposes Perceptual Classes (P-nodes) as a metacognitive structure that permits generating relevant “dreamt” data points that allow creating “imagined” trajectories for deliberative policy learning in a very efficient way. The proposed structure has been tested by means of an experiment with a real robot in LOLA settings, where it has been shown how policy dreaming is possible in such a challenging realm.

Perceptual Generalization and Context in a Network Memory Inspired Long-Term Memory for Artificial Cognition

In the framework of open-ended learning cognitive architectures for robots, this paper deals with the design of a Long-Term Memory (LTM) structure that can accommodate the progressive acquisition of experience-based decision capabilities, or what different authors call "automation" of what is learnt, as a complementary system to more common prospective functions. The LTM proposed here provides for a relational storage of knowledge nuggets given the form of artificial neural networks (ANNs) that is representative of the contexts in which they are relevant in a configural associative structure. It also addresses the problem of continuous perceptual spaces and the task- and context-related generalization or categorization of perceptions in an autonomous manner within the embodied sensorimotor apparatus of the robot. These issues are analyzed and a solution is proposed through the introduction of two new types of knowledge nuggets: P-nodes representing perceptual classes and C-nodes representing contexts. The approach is studied and its performance evaluated through its implementation and application to a real robotic experiment.

A framework for computer-assisted sound design systems supported by modelling affective and perceptual properties of soundscape

ABSTRACTAutonomously generating artificial soundscapes for video games, virtual reality, and sound art presents several non-trivial challenges. We outline a system called Audio Metaphor that is built upon the notion that sound design for soundscape compositions is emotionally informed. We first define the problem space of generating soundscape compositions referencing the sound design and soundscape literature. Next, we survey the state-of-the-art soundscape generation systems and establish the characteristics and challenges for evaluating these types of systems. We then describe the Audio Metaphor system that aims to model the soundscape generation problem using a method of soundscape emotion recognition and segmentation based on perceptual classes, and an autonomous mixing engine utilising optimisation and prediction algorithms to generate a soundscape composition. We evaluate the soundscape compositions generated by Audio Metaphor by comparing them with those created by a human expert and also those generated randomly. Our analysis of the evaluation study reveals that the proposed soundscape generation model is human-competitive regarding semantic and emotion-based indicators.

Complete characterization of a class of privacy-preserving tracking problems

We examine the problem of target tracking whilst simultaneously preserving the target’s privacy as epitomized by the robotic panda-tracking scenario, which O’Kane introduced at the 2008 Workshop on the Algorithmic Foundations of Robotics to elegantly illustrate the utility of ignorance. The present paper reconsiders his formulation and the tracking strategy he proposed, along with its completeness. We explore how the capabilities of the robot and panda affect the feasibility of tracking with a privacy stipulation, uncovering intrinsic limits, no matter the strategy employed. This paper begins with a one-dimensional setting and, putting the trivially infeasible problems aside, analyzes the strategy space as a function of problem parameters. We show that it is not possible to actively track the target as well as protect its privacy for every non-trivial pair of tracking and privacy stipulations. Secondly, feasibility can be sensitive, in several cases, to the information available to the robot initially. Quite naturally in the one-dimensional model, one may quantify sensing power by the number of perceptual (or output) classes available to the robot. The robot’s power to achieve privacy-preserving tracking is bounded, converging asymptotically with increasing sensing power. We analyze the entire space of possible tracking problems, characterizing every instance as either achievable, constructively by giving a policy where one exists (some of which depend on the initial information), or proving that the instance is impossible. Finally, to relate some of the impossibility results in one dimension to their higher-dimensional counterparts, including the planar panda-tracking problem studied by O’Kane, we establish a connection between tracking dimensionality and the sensing power of a one-dimensional robot.

A Bio-Inspired Incremental Learning Architecture for Applied Perceptual Problems

We present a biologically inspired architecture for incremental learning that remains resource-efficient even in the face of very high data dimensionalities (>1000) that are typically associated with perceptual problems. In particular, we investigate how a new perceptual (object) class can be added to a trained architecture without retraining, while avoiding the well-known catastrophic forgetting effects typically associated with such scenarios. At the heart of the presented architecture lies a generative description of the perceptual space by a self-organized approach which at the same time approximates the neighborhood relations in this space on a two-dimensional plane. This approximation, which closely imitates the topographic organization of the visual cortex, allows an efficient local update rule for incremental learning even in the face of very high dimensionalities, which we demonstrate by tests on the well-known MNIST benchmark. We complement the model by adding a biologically plausible short-term memory system, allowing it to retain excellent classification accuracy even under incremental learning in progress. The short-term memory is additionally used to reinforce new data statistics by replaying previously stored samples during dedicated “sleep” phases.

De Novo Emergence of Odor Category Representations in the Human Brain.

How the human brain assigns novel odors to perceptual classes and categories is poorly understood. We combined an olfactory-visual paired-associates task with multivariate pattern-based fMRI approaches to investigate the de novo formation of odor category representations within the human brain. The identification of emergent odor category codes within the perirhinal, piriform, orbitofrontal, and insular cortices suggests that these regions can integrate multimodal sensory input to shape category-specific olfactory representations for novel odors, and may ultimately play an important role in assembling each individual's semantic knowledge base of the olfactory world.

Understanding the Odour Spaces: A Step towards Solving Olfactory Stimulus-Percept Problem.

Odours are highly complex, relying on hundreds of receptors, and people are known to disagree in their linguistic descriptions of smells. It is partly due to these facts that, it is very hard to map the domain of odour molecules or their structure to that of perceptual representations, a problem that has been referred to as the Structure-Odour-Relationship. We collected a number of diverse open domain databases of odour molecules having unorganised perceptual descriptors, and developed a graphical method to find the similarity between perceptual descriptors; which is intuitive and can be used to identify perceptual classes. We then separately projected the physico-chemical and perceptual features of these molecules in a non-linear dimension and clustered the similar molecules. We found a significant overlap between the spatial positioning of the clustered molecules in the physico-chemical and perceptual spaces. We also developed a statistical method of predicting the perceptual qualities of a novel molecule using its physico-chemical properties with high receiver operating characteristics(ROC).

Seeking Barriers to the Development of Knowledge Transgressivity Potential (KTP): Lessons from a Postgraduate Student Survey at The University of Johannesburg

Institutional mergers coupled with the distinction between teaching-focused 'comprehensives' and traditional, research-intensive universities are evidence of differentiation in action within South African higher education. Comprehensive institutions such as the University of Johannesburg (UJ) are relatively underresearched. A UJ-based survey of postgraduate students (n=300) suggests the possibility of knowledge transgressi vity within and outside of UJ. However, the development of a transdisciplinary platform (to fa cilitate the evolu tion of knowledge transgressivity potential (KTP)) between natural and social science-focused postgraduates, is likely limited by perceptual class and race barriers, with the former proving most influential. Moreover, inter institutional KTP between UJ, as a comprehensive, and WITS, as a traditional university, is present, but limited by material class barriers, such as fees differentials. Nevertheless, findings suggest that KTP could be developed at the junior postgraduate level if class perceptions and structural legacies are to be overcome. Comprehensives l ike UJ are capable of more than solely fulfilling an undergraduate teaching function as such, they should enjoy more research attention. While all South African universities contribute to transformation and competitiveness in distinct ways, the rigid demarcation, and potentially inadvertent 'privileging' of some South African universities, should be avoided. This is critical as such demarcation cannot lead to long-term institutional integration and increased potential for true knowledge transgressivity.

Seeking Barriers to the Development of Knowledge Transgressivity Potential (KTP): Lessons from a Postgraduate Student Survey at The University of Johannesburg

Institutional mergers coupled with the distinction between teaching-focused 'comprehensives' and traditional, research-intensive universities are evidence of differentiation in action within South African higher education. Comprehensive institutions such as the University of Johannesburg (UJ) are relatively underresearched. A UJ-based survey of postgraduate students (n=300) suggests the possibility of knowledge transgressi vity within and outside of UJ. However, the development of a transdisciplinary platform (to fa cilitate the evolu tion of knowledge transgressivity potential (KTP)) between natural and social science-focused postgraduates, is likely limited by perceptual class and race barriers, with the former proving most influential. Moreover, inter institutional KTP between UJ, as a comprehensive, and WITS, as a traditional university, is present, but limited by material class barriers, such as fees differentials. Nevertheless, findings suggest that KTP could be developed at the junior postgraduate level if class perceptions and structural legacies are to be overcome. Comprehensives l ike UJ are capable of more than solely fulfilling an undergraduate teaching function as such, they should enjoy more research attention. While all South African universities contribute to transformation and competitiveness in distinct ways, the rigid demarcation, and potentially inadvertent 'privileging' of some South African universities, should be avoided. This is critical as such demarcation cannot lead to long-term institutional integration and increased potential for true knowledge transgressivity.

Adults can be trained to acquire synesthetic experiences.

Synesthesia is a condition where presentation of one perceptual class consistently evokes additional experiences in different perceptual categories. Synesthesia is widely considered a congenital condition, although an alternative view is that it is underpinned by repeated exposure to combined perceptual features at key developmental stages. Here we explore the potential for repeated associative learning to shape and engender synesthetic experiences. Non-synesthetic adult participants engaged in an extensive training regime that involved adaptive memory and reading tasks, designed to reinforce 13 specific letter-color associations. Following training, subjects exhibited a range of standard behavioral and physiological markers for grapheme-color synesthesia; crucially, most also described perceiving color experiences for achromatic letters, inside and outside the lab, where such experiences are usually considered the hallmark of genuine synesthetes. Collectively our results are consistent with developmental accounts of synesthesia and illuminate a previously unsuspected potential for new learning to shape perceptual experience, even in adulthood.

Representation of temporal sound features in the human auditory cortex

Temporal information in acoustic signals is important for the perception of environmental sounds, including speech. This review focuses on several aspects of temporal processing within human auditory cortex and its relevance for the processing of speech sounds. Periodic non-speech sounds, such as trains of acoustic clicks and bursts of amplitude-modulated noise or tones, can elicit different percepts depending on the pulse repetition rate or modulation frequency. Such sounds provide convenient methodological tools to study representation of timing information in the auditory system. At low repetition rates of up to 8-10 Hz, each individual stimulus (a single click or a sinusoidal amplitude modulation cycle) within the sequence is perceived as a separate event. As repetition rates increase up to and above approximately 40 Hz, these events blend together, giving rise first to the percept of flutter and then to pitch. The extent to which neural responses of human auditory cortex encode temporal features of acoustic stimuli is discussed within the context of these perceptual classes of periodic stimuli and their relationship to speech sounds. Evidence for neural coding of temporal information at the level of the core auditory cortex in humans suggests possible physiological counterparts to perceptual categorical boundaries for periodic acoustic stimuli. Temporal coding is less evident in auditory cortical fields beyond the core. Finally, data suggest hemispheric asymmetry in temporal cortical processing.

The synthesis of complex categories from perceptual and equivalence classes: effects of training and testing parameters

Most real-world categories are complex since each contains some exemplars that resemble each other and others that are perceptually disparate. One example would be the many sounds of a persons’ voice when speaking and whispering, pictures of that person taken from different vantage points and in different degrees of focus, and the name of that person as written by different hands, and in different fonts. When all of these exemplars occasion the mutual selection of each other, and a function acquired by one class member generalizes to all other class members, all of the exemplars are acting as members of a complex category. A complex category can be formed by the merger of perceptual, fuzzy, and relational classes with equivalence classes. This presentation will consider how training and testing variables influence the likelihood of establishing a variety of complex categories such as linked perceptual classes, and fully elaborated generalized equivalence classes. These data provide a basis for understanding how complex categories are induced in natural settings.

Perceptually important acoustic features of environmental sounds.

Listeners were asked to indicate the sources of dozens of sound events presented over headphones. The sounds were environmental sounds made by solid objects, liquids, and/or air undergoing a variety of actions taken from the website www.auditorylab.org. Each listener gave a series of responses about possible sources for each sound so that a similarity matrix could be constructed. The results of data reduction point to a manageable set of perceptual classes of sound events that can be described with a small number of distinctive spectro‐temporal acoustic features. These features will be related to the attributes of the events that generated each class of sounds. Results for normal‐hearing listeners will be analyzed in detail and preliminary results from hearing‐impaired listeners will be previewed. [Work supported by NSF 0446955 and RI STAC.]

Optimizing linked perceptual class formation and transfer of function.

A linked perceptual class consists of two distinct perceptual classes, A' and B', the members of which have become related to each other. For example, a linked perceptual class might be composed of many pictures of a woman (one perceptual class) and the sounds of that woman's voice (the other perceptual class). In this case, any sound of the woman's voice would occasion the selection of any picture of the woman and vice versa. In addition, after learning to name the woman in the presence of one picture, that name would be uttered when presented with all of the images of the woman's face and all of the sounds of her voice. This study involved 15 participants and sought to (a) maximize the percentage of participants who formed linked perceptual classes, and (b) determine whether those classes acted as transfer networks, that is, whether the discriminative function of one class member would generalize to other members of the class and not to members of a different class. The rate of emergence of each linked perceptual class was maximized by establishing a single class-linking conditional relation between the clearest member of one class used as a sample stimulus and the most ambiguous member of the other class used as a comparison stimulus. Class formation was demonstrated using the serial and programmed presentation of A'-B' probes that consisted of untrained pairs of stimuli drawn from the A' and B' classes. Most participants showed immediate emergence of the two linked perceptual classes. The remaining participants showed delayed emergence following a second exposure to each originally error-producing probes. Once the linked perceptual classes had emerged, a differential response to a specific member of one perceptual class generalized mostly or completely to the other members of that linked class and rarely, if ever, to members of the other linked class. Thus, generalization did not depend on the specific class members that had been used for discrimination training.

Apprentissage de concepts perceptuels, associationnels et relationnels chez le pigeon

The study of concepts in cognitive psychology has generally been anthropocentric with respect to both content and theory. A broader comparative perspective on the various forms of concept learning would provide a more inclusive view of conceptual behavior. It would also provide a more objective perspective from which to identify underlying processes. Several of the major varieties of conceptual classes claimed for humans alone also appear to be represented in nonhuman animals and young children: perceptual classes involving classification according to the shared attributes of objects, associative classes or functional equivalences in which stimuli form a class based on common associations and relational classes, in which the conceptual relationship between stimuli defines the class.

The effects of differential training procedures on linked perceptual class formation.

When the stimuli in one perceptual class (A') become related to the stimuli in another perceptual class (B'), the two are functioning as a single linked perceptual class. A common linked perceptual class would be the sounds of a person's voice (class A') and the pictures of that person (class B'). Such classes are ubiquitous in real world settings. We describe the effects of a variety of training procedures on the formation of these classes. The results could account for the development of naturally occurring linked perceptual classes. Two perceptual classes (A' and B') were formed in Experiment 1. The endpoints of the A' class were called anchor (Aa) and boundary (Ab) stimuli. Likewise, the anchor and boundary stimuli in the B' class were represented as Ba and Bb. In Experiment 2, the A' and B' classes were linked by the establishment of one of four cross-class conditional discriminations: Aa-->Ba, Aa-->Bb, Ab-->Ba, or Ab-->Bb. Results were greatest after Aa-->Bb training, intermediate after Aa-->Ba and Ab-->Ba training, and lowest after Ab-->Bb training. Class formation was influenced by the interaction of the anchor/boundary values and the sample/comparison functions of the stimuli used in training. Experiment 3 determined whether class formation was influenced by different sets of two cross-class conditional discriminations: Aa-->Ba and Ab-->Bb, or Aa-->Bb and Ab-->Ba. Both conditions produced equivalent results. Similarities were attributable to the use of anchor stimuli as samples and boundary stimuli as comparisons in each training condition. Finally, the results afterjoint Aa-->Ba and Ab-->Bb training were much greater than those produced by summing the results of Aa-->Ba training alone and Ab-->Bb training alone. This same synergy was not observed after joint Aa-->Bb and Ab-->Ba training or either alone.

THE EFFECT OF TEST SCHEDULES ON THE FORMATION OF LINKED PERCEPTUAL CLASSES

After training conditional discriminations among selected stimuli from two perceptual classes, the emergence of novel relations involving other members of both classes was assessed using cross-class probes. The cross-class probes were presented using one of four different testing schedules. In the 2/9 test, nine different probes were presented in each of two test blocks. In the 6/3 test, three different probes were presented in each of six test blocks. In the 18/1-RND test, each of the 18 cross-class probes was presented in separate test blocks. In the 2/9 and 6/3 tests, the cross-class probes were presented in a randomized order within test block. In the 18/1-RND test, the cross-class probes were presented in a randomized sequence. In the 18/1-PRGM test, however, the cross-class probes were presented in a programmed order (i.e., the values of the stimuli in each cross-class probe were changed systematically in the succession of probe presentations). About 55% of the linked perceptual classes emerged during the 2/9, 6/3, and 18/1-RND tests. Thus the number of different probes in a test block did not influence the emergence of classes as long as the probes were presented in a random order. Virtually all classes emerged during the 18/1-PRGM test. Thus at least one ordered introduction of different cross probes resulted in the reliable emergence of linked perceptual classes. Mechanisms responsible for linked perceptual class formation are discussed along with the relation of these classes to other complex categories.

The formation of linked perceptual classes.

Multiple-exemplar training with stimuli in four domains induced two new fill-based (A1' and A2') and satellite-image-based (B1' and B2') perceptual classes. Conditional discriminations were established between the endpoints of the A1' and B1' classes as well as the A2' and B2' classes. The emergence of linked perceptual classes was evaluated by the performances occasioned by nine cross-class probes that contained fill variants as samples and satellite variants as comparisons, along with nine other cross-class probes that consisted of satellite variants as samples and fill variants as comparisons. The 18 probes were first presented serially and then concurrently. Class-consistent responding indicated the emergence of linked perceptual classes. Of the linked perceptual classes, 70% emerged during the initial serial test. An additional 20% of the linked perceptual classes emerged during the subsequently presented concurrent test block. Thus, linked perceptual classes emerged on an immediate or delayed basis. Linked perceptual classes, then, share structural and fuctional similarities with equivalence classes, generalized equivalence classes, cross-modal classes, and complex maturally occurring categories, and may clarify processes such as intersensory perception.

The formation of a generalized categorization repertoire: effect of training with multiple domains, samples, and comparisons.

The present experiment explored the effects of three variables on the spontaneous categorization of stimuli in perceptually distinct and novel domains. Each of six stimulus domains was created by morphing two images that were the domain endpoints. The endpoints of the domains were male and female faces, two abstract drawings, a car and a truck, two banded-elevation satellite land images, a tree and a cat, and two false-color satellite images. The stimulus variants at each end of a domain defined two potential perceptual classes. Training was conducted in a matching-to-sample format and used stimuli from one or two domains, one or three variants per class as samples, and one or three variants per class as comparisons. The spontaneous categorization of stimuli in the untrained stimulus domains showed the emergence of a generalized categorization repertoire. The proportion of spontaneously categorized stimuli in the new domains was positively related to the number of domains and samples used in training, and was inversely related to the number of comparisons used in training. Differential reaction times demonstrated the discriminability of the stimuli in the emergent classes. This study is among the first to provide an empirical basis for a behavior-analytic model of the development of generalized categorization repertoires in natural settings.