Perceptual States Research Articles

The positive evidence bias in perceptual confidence is unlikely post-decisional.

Confidence in a perceptual decision is a subjective estimate of the accuracy of one’s choice. As such, confidence is thought to be an important computation for a variety of cognitive and perceptual processes, and it features heavily in theorizing about conscious access to perceptual states. Recent experiments have revealed a “positive evidence bias” (PEB) in the computations underlying confidence reports. A PEB occurs when confidence, unlike objective choice, overweights the evidence for the correct (or chosen) option, relative to evidence against the correct (or chosen) option. Accordingly, in a perceptual task, appropriate stimulus conditions can be arranged that produce selective changes in confidence reports but no changes in accuracy. Although the PEB is generally assumed to reflect the observer’s perceptual and/or decision processes, post-decisional accounts have not been ruled out. We therefore asked whether the PEB persisted under novel conditions that addressed two possible post-decisional accounts: (i) post-decision evidence accumulation that contributes to a confidence report solicited after the perceptual choice and (ii) a memory bias that emerges in the delay between the stimulus offset and the confidence report. We found that even when the stimulus remained on the screen until observers responded, and when observers reported their choice and confidence simultaneously, the PEB still emerged. Signal detection-based modeling showed that the PEB was not associated with changes to metacognitive efficiency, but rather to confidence criteria. The data show that memory biases cannot explain the PEB and provide evidence against a post-decision evidence accumulation account, bolstering the idea that the PEB is perceptual or decisional in nature.

Sensible individuation

AbstractThere is a straightforward view of perception that has not received adequate consideration because it requires us to rethink basic assumptions about the objects of perception. In this paper, I develop a novel account of these objects—the sensible qualities—which makes room for the straightforward view. I defend two primary claims. First, I argue that qualities like color and shape are “ontologically flexible” kinds. That is, their real definitions allow for both physical objects and mental entities to be colored or shaped. Second, a single instance of these qualities can be attributed to more than one entity. Just as we attribute the same instance of a material property to a statue and to the clay that constitutes it, single instances of sensible qualities should be attributed both to the physical objects perceived and to the perceptual states that have those instances as their objects.

Philosophical Specification of Empathetic Ethical Artificial Intelligence

In order to construct an ethical artificial intelligence (AI) two complex problems must be overcome. Firstly, humans do not consistently agree on what is or is not ethical. Second, contemporary AI and machine learning methods tend to be blunt instruments which either search for solutions within the bounds of predefined rules, or mimic behaviour. An ethical AI must be capable of inferring unspoken rules, interpreting nuance and context, possess and be able to infer intent, and explain not just its actions but its intent. Using enactivism, semiotics, perceptual symbol systems and symbol emergence, we specify an agent that learns not just arbitrary relations between signs but their meaning in terms of the perceptual states of its sensorimotor system. Subsequently it can learn what is meant by a sentence and infer the intent of others in terms of its own experiences. It has malleable intent because the meaning of symbols changes as it learns, and its intent is represented symbolically as a goal. As such it may learn a concept of what is most likely to be considered ethical by the majority within a population of humans, which may then be used as a goal. The meaning of abstract symbols is expressed using perceptual symbols of raw sensorimotor stimuli as the weakest (consistent with Ockham's Razor) necessary and sufficient concept, an intensional definition learned from an ostensive definition, from which the extensional definition or category of all ethical decisions may be obtained. Because these abstract symbols are the same for both situation and response, the same symbol is used when either performing or observing an action. This is akin to mirror neurons in the human brain. Mirror symbols may allow the agent to empathise, because its own experiences are associated with the symbol, which is also associated with the observation of another agent experiencing something that symbol represents.

Sensorimotor Relationalism and Conscious Vision

AbstractI argue that the phenomenal properties of conscious visual experiences are properties of the mind-independent objects to which the subject is perceptually related, mediated by the subject's practical understanding of their sensorimotor relation to those properties. This position conjoins two existing strategies for explaining the phenomenal character of perceptual experiences: accounts appealing to perceivers’ limited, non-inferential access to the details of their sensory relation to the environment, and the relationalist conception of phenomenal properties. Bringing these two positions together by emphasizing their sensorimotor common ground allows each one to respond to damaging objections using the resources of the other. The resulting ‘sensorimotor relationalism’ about conscious vision provides a promising schema for explaining phenomenal properties of perceptual states, replacing ‘Hard’ questions with tractable ones about the perceptual relation and its sensorimotor underpinnings.

Introduction: the image between presence and absence

Dream images, anticipations of the future, memories of the past, perceptual distortions, delusional hallucinations, cognitions intoxicated by alcohol and drugs have always inhabited the visual representations of paintings, comics, films, television series, videogames and, more recently, virtual reality installations. We call them “altered states of consciousness”, meaning any perceptual state other than ordinary human perception

Taking non‐conceptualism back to Dharmakīrti

AbstractSome recent surveys of the modern philosophical debate over the existence of non‐conceptual perceptual content have concluded that the distinction between conceptual and non‐conceptual representations is largely terminological. To remedy this terminological impasse, Robert Hanna and Monima Chadha claim that non‐conceptualists must defend an essentialist view of non‐conceptual content, according to which perceptual states have representational content whose structure and psychological function are necessarily distinct from that of conceptual states. Hanna and Chadha additionally suggest that non‐conceptualists should go “back to Kant” to find the most defensible version of an essentialist content non‐conceptualism. I propose instead that non‐conceptualists go back even further to the seventh‐century Indian Buddhist philosopher Dharmakīrti, so that they may not only find historical precedent for an essentialist content view, but also some better arguments in its favor. This essay reconstructs Dharmakīrti's essentialist non‐conceptualism about the contents of conscious sensory representations and the refined theory of conceptualization that it presupposes. In particular, I examine his arguments from the proprietary phenomenology of sensory experience, the cognitive encapsulation of sensory processing, as well as the iconic format of sensory representations, and assess the strength of these arguments relative to their modern counterparts.

Conditioned Hallucinations and Prior Overweighting Are State-Sensitive Markers of Hallucination Susceptibility

BackgroundRecent advances in computational psychiatry have identified latent cognitive and perceptual states that predispose to psychotic symptoms. Behavioral data fit to Bayesian models have demonstrated an overreliance on priors (i.e., prior overweighting) during perception in select samples of individuals with hallucinations, corresponding to increased precision of prior expectations over incoming sensory evidence. However, the clinical utility of this observation depends on the extent to which it reflects static symptom risk or current symptom state. MethodsTo determine whether task performance and estimated prior weighting relate to specific elements of symptom expression, a large, heterogeneous, and deeply phenotyped sample of hallucinators (n = 249) and nonhallucinators (n = 209) performed the conditioned hallucination (CH) task. ResultsWe found that CH rates predicted stable measures of hallucination status (i.e., peak frequency). However, CH rates were more sensitive to hallucination state (i.e., recent frequency), significantly correlating with recent hallucination severity and driven by heightened reliance on past experiences (priors). To further test the sensitivity of CH rate and prior weighting to symptom severity, a subset of participants with hallucinations (n = 40) performed a repeated-measures version of the CH task. Changes in both CH frequency and prior weighting varied with changes in auditory hallucination frequency on follow-up. ConclusionsThese results indicate that CH rate and prior overweighting are state markers of hallucination status, potentially useful in tracking disease development and treatment response.

Do Chimpanzees Predict Others’ Behavior by Simulating Their Beliefs?

Recent studies have shown that great apes predict that other agents will search for objects of interest where the agents believe the objects are hidden. Little is understood about the cognitive process that apes undergo to make such predictions. According to prevailing models, great apes make such predictions by metarepresenting others’ beliefs or perceptual states. We investigated the simpler simulation model. In this model, apes predict where other agents will search for objects of interest by simulating believing what another agent believes about the location of the object. The simulation model predicts that simulating what another believes should manifest in altercentric biasing effects, such as behaving as if one shares another’s belief in cases where the other’s belief is false. We tested this by giving chimpanzees a novel search paradigm embedded in a change-of-location false-belief test and measured where they searched for a grape that they witnessed moved from its original location to a new location. In true-belief trials, chimpanzees were presented with an agent who knew (as they did) that the grape was hidden in the new location; in false-belief trials, the agent falsely believed the grape was still hidden in the original location while the chimpanzee knew it was hidden in the new location. As predicted by the simulation model, chimpanzees searched for the grape closer to its original location than to its new location in significantly more false-belief trials than true-belief trials. Results suggest that chimpanzees show a signature altercentric biasing effect of simulating believing what others believe and may use simulation, rather than metarepresentation, to predict where others will search for objects of interest.

Visual consciousness dynamics in adults with and without autism

Sensory differences between autism and neuro-typical populations are well-documented and have often been explained by either weak-central-coherence or excitation/inhibition-imbalance cortical theories. We tested these theories with perceptual multi-stability paradigms in which dissimilar images presented to each eye generate dynamic cyclopean percepts based on ongoing cortical grouping and suppression processes. We studied perceptual multi-stability with Interocular Grouping (IOG), which requires the simultaneous integration and suppression of image fragments from both eyes, and Conventional Binocular Rivalry (CBR), which only requires global suppression of either eye, in 17 autistic adults and 18 neurotypical participants. We used a Hidden-Markov-Model as tool to analyze the multistable dynamics of these processes. Overall, the dynamics of multi-stable perception were slower (i.e. there were longer durations and fewer transitions among perceptual states) in the autistic group compared to the neurotypical group for both IOG and CBR. The weighted Markovian transition distributions revealed key differences between both groups and paradigms. The results indicate overall lower levels of suppression and decreased levels of grouping in autistic than neurotypical participants, consistent with elements of excitation/inhibition imbalance and weak-central-coherence theories.

A practical guide to applying machine learning to infant EEG data

Electroencephalography (EEG) has been widely adopted by the developmental cognitive neuroscience community, but the application of machine learning (ML) in this domain lags behind adult EEG studies. Applying ML to infant data is particularly challenging due to the low number of trials, low signal-to-noise ratio, high inter-subject variability, and high inter-trial variability. Here, we provide a step-by-step tutorial on how to apply ML to classify cognitive states in infants. We describe the type of brain attributes that are widely used for EEG classification and also introduce a Riemannian geometry based approach for deriving connectivity estimates that account for inter-trial and inter-subject variability. We present pipelines for learning classifiers using trials from a single infant and from multiple infants, and demonstrate the application of these pipelines on a standard infant EEG dataset of forty 12-month-old infants collected under an auditory oddball paradigm. While we classify perceptual states induced by frequent versus rare stimuli, the presented pipelines can be easily adapted for other experimental designs and stimuli using the associated code that we have made publicly available.

Breaking Down a Rhythm: Dissecting the Mechanisms Underlying Task-Related Neural Oscillations.

A century worth of research has linked multiple cognitive, perceptual and behavioral states to various brain oscillations. However, the mechanistic roles and circuit underpinnings of these oscillations remain an area of active study. In this review, we argue that the advent of optogenetic and related systems neuroscience techniques has shifted the field from correlational to causal observations regarding the role of oscillations in brain function. As a result, studying brain rhythms associated with behavior can provide insight at different levels, such as decoding task-relevant information, mapping relevant circuits or determining key proteins involved in rhythmicity. We summarize recent advances in this field, highlighting the methods that are being used for this purpose, and discussing their relative strengths and limitations. We conclude with promising future approaches that will help unravel the functional role of brain rhythms in orchestrating the repertoire of complex behavior.

Perceptual Motivation for Action

In this paper we focus on a kind of perceptual states that we call perceptual motivations, that is, perceptual experiences that plausibly motivate us to act, such as itching, perceptual salience and pain. Itching seems to motivate you to scratch, perceiving a stimulus as salient seems to motivate you to attend to it and feeling a pain in your hand seems to motivate actions such as withdrawing from the painful stimulus. Five main accounts of perceptual motivation are available: Descriptive, Conative, Imperativist, Reflexive and Dual Content views. Some of these have been developed in detail and others are natural extensions of existing views. However, we argue that none provides a satisfactory account of the target perceptual states. Driven by the failings of each account, we identify three conditions that any satisfactory theory of perceptual motivation must meet: Direct Motivational Force, Non-Obligatory Force and Intention-Independent Influence. Then we offer an account that attempts to fulfil these conditions: the Affordance Model. This model of perceptual motivation is premised on the claim that each of the target states involves the perception of a specific affordance for action and the triggering of Automatic Motor Initiations (AMIs). We suggest that AMIs can explain the motivational force of these perceptual states.

Feeling Fit for Function: Haptic Touch and Aesthetic Experience

Abstract Traditionally, the sense of touch—alongside the senses of taste and smell—has been excluded from the aesthetic domain. These proximal modalities are thought to deliver only sensory pleasures, not the complex, world-directed perceptual states that characterize aesthetic experience. In this paper, I argue that this tradition fails to recognize the perceptual possibilities of haptic touch, which allows us to experience properties of the objects with which we make bodily contact, including their weight, shape, solidity, elasticity, and smoothness. These features, moreover, may be indicative of how well-suited an object is for its function, and in feeling them we can thus feel the positive aesthetic quality of functional beauty.

Seeing and visual reference

AbstractPerception is a central means by which we come to represent and be aware of particulars in the world. I argue that an adequate account of perception must distinguish between what one perceives and what one's perceptual experience is of or about. Through capacities for visual completion, one can be visually aware of particular parts of a scene that one nevertheless does not see. Seeing corresponds to a basic, but not exhaustive, way in which one can be visually aware of an item. I discuss how the relation between seeing and visual awareness should be explicated within a representational account of the mind. Visual awareness of an item involves a primitive kind of reference: one is visually aware of an item when one's visual perceptual state succeeds in referring to that particular item and functions to represent it accurately. Seeing, by contrast, requires more than successful visual reference. Seeing depends additionally on meta‐semantic facts about how visual reference happens to be fixed. The notions of seeing and of visual reference are both indispensable to an account of perception, but they are to be characterized at different levels of representational explanation.

Thomas J. Kiernan and Irish diplomatic responses to cold-war anticommunism in Australia, 1946-1951

Despite being a peripheral actor in the Cold War, Ireland in the immediate post-war period was attentive to cold war developments internationally, and the influence of the Catholic Church over state and society predominantly shaped the state's response to the conflict. Irish diplomats internationally sent home repo rts on communist activity in the countries in which they served. This article will discuss Thomas J. Kiernan, Ireland's Minister Plenipotentiary in Australia between 1946 and 1955, and his responses, views and perceptions of Australian anti-communism from his 1946 appointment to the 1951 plebiscite on banning the Communist Party of Australia, which ultimately failed. Through analysis of his reports in the National Archives of Ireland – including accounts of his interactions with politicians and clergy, the Australian press, parliamentary debates and other sources – it argues that his views were moulded by the dominant Irish conception of the Cold War, which was fundamentally shaped by Catholicism, and his overreliance on Catholic and print sources led him to sometimes exaggerate the communist threat. Nonetheless, his reports home to Dublin served to reinforce the Irish state's perception that communism was a worldwide malaise which the Catholic Church and Catholics internationally were at the forefront of combatting.

When perception is stronger than physics: Perceptual similarities rather than laws of physics govern the perception of interacting objects

When several multistable displays are viewed simultaneously, their perception is synchronized, as they tend to be in the same perceptual state. Here, we investigated the possibility that perception may reflect embedded statistical knowledge of physical interaction between objects for specific combinations of displays and layouts. We used a novel display with two ambiguously rotating gears and an ambiguous walker-on-a-ball display. Both stimuli produce a physically congruent perception when an interaction is possible (i.e., gears counterrotate, and the ball rolls under the walker’s feet). Next, we gradually manipulated the stimuli to either introduce abrupt changes to the potential physical interaction between objects or keep it constant despite changes in the visual stimulus. We characterized the data using four different models that assumed (1) independence of perception of the stimulus, (2) dependence on the stimulus’s properties, (3) dependence on physical configuration alone, and (4) an interaction between stimulus properties and a physical configuration. We observed that for the ambiguous gears, the perception was correlated with the stimulus changes rather than with the possibility of physical interaction. The perception of walker-on-a-ball was independent of the stimulus but depended instead on whether participants responded about a relative motion of two objects (perception was biased towards physically congruent motion) or the absolute motion of the walker alone (perception was independent of the rotation of the ball). None of the two experiments supported the idea of embedded knowledge of physical interaction.

Perceptual capacities, discrimination, and the senses

In this paper, I defend a new theory of the nature and individuation of perceptual capacities. I argue that we need a theory of perceptual capacities to explain modal facts about what sorts of perceptual phenomenal states one can be in. I defend my view by arguing for three adequacy constraints on a theory of perceptual capacities: perceptual capacities must be individuated at least partly in terms of their place in a hierarchy of capacities, where these capacities include the senses themselves; an adequate account of perceptual capacities must be sensitive to empirical considerations; and an adequate account should accommodate the nature of the capacity to perceive. I arrive at these constraints by considering how Schellenberg’s view fails, before defending and developing my alternative in line with the constraints. I defend a view on which there are few, coarse-grained perceptual capacities which can fulfil complex explanatory roles because they are evaluatively gradable on many axes. Finally, on my view, perceptual capacities bear a particularly close relation to the sensory modalities themselves.

Change not State: Perceptual coupling in multistable displays reflects transient bias induced by perceptual change

We investigated how changes in dynamic spatial context influence visual perception. Specifically, we reexamined the perceptual coupling phenomenon when two multistable displays viewed simultaneously tend to be in the same dominant state and switch in accord. Current models assume this interaction reflecting mutual bias produced by a dominant perceptual state. In contrast, we demonstrate that influence of spatial context is strongest when perception changes. First, we replicated earlier work using bistable kinetic-depth effect displays, then extended it by employing asynchronous presentation to show that perceptual coupling cannot be accounted for by the static context provided by perceptually dominant states. Next, we demonstrated that perceptual coupling reflects transient bias induced by perceptual change, both in ambiguous and disambiguated displays. We used a hierarchical Bayesian model to characterize its timing, demonstrating that the transient bias is induced 50–70 ms after the exogenous trigger event and decays within ~200–300 ms. Both endogenous and exogenous switches led to quantitatively and qualitatively similar perceptual consequences, activating similar perceptual reevaluation mechanisms within a spatial surround. We explain how they can be understood within a transient selective visual attention framework or using local lateral connections within sensory representations. We suggest that observed perceptual effects reflect general mechanisms of perceptual inference for dynamic visual scene perception.

Long-term stability of cortical ensembles.

Neuronal ensembles, coactive groups of neurons found in spontaneous and evoked cortical activity, are causally related to memories and perception, but it is still unknown how stable or flexible they are over time. We used two-photon multiplane calcium imaging to track over weeks the activity of the same pyramidal neurons in layer 2/3 of the visual cortex from awake mice and recorded their spontaneous and visually evoked responses. Less than half of the neurons remained active across any two imaging sessions. These stable neurons formed ensembles that lasted weeks, but some ensembles were also transient and appeared only in one single session. Stable ensembles preserved most of their neurons for up to 46 days, our longest imaged period, and these 'core' cells had stronger functional connectivity. Our results demonstrate that neuronal ensembles can last for weeks and could, in principle, serve as a substrate for long-lasting representation of perceptual states or memories.

Perceptual justification in the Bayesian brain: a foundherentist account

In this paper, I use the predictive processing (PP) theory of perception to tackle the question of how perceptual states can be rationally involved in cognition by justifying other mental states. I put forward two claims regarding the epistemological implications of PP. First, perceptual states can confer justification on other mental states because the perceptual states are themselves rationally acquired. Second, despite being inferentially justified rather than epistemically basic, perceptual states can still be epistemically responsive to the mind-independent world. My main goal is to elucidate the epistemology of perception already implicit in PP. But I also hope to show how it is possible to peacefully combine central tenets of foundationalist and coherentist accounts of the rational powers of perception while avoiding the well-recognized pitfalls of either.