Eye-contact perception in schizophrenia: relationship with symptoms and socioemotional functioning

Accurately perceiving self-referential social signals, particularly eye contact, is critical to social adaptation. Schizophrenia is often accompanied by deficits in social cognition, but it is unclear whether this includes gaze discrimination deficits. This study investigated whether eye-contact perception is preserved or impaired and if it is related to symptoms and broader socioemotional functioning in schizophrenia. Twenty-six participants with schizophrenia (SCZ) and 23 healthy controls (HC) made eye-contact judgments for faces in varying gaze direction (from averted to direct in ten 10% increments), head orientation (forward, 30° averted), and emotion (neutral, fearful). Psychophysical analyses for forward faces showed that SCZ began endorsing eye contact with weaker eye-contact signal and their eye-contact perception was less of a dichotomous function, as compared with HC. SCZ were more likely than HC to endorse eye contact when gaze was ambiguous, and this overperception of eye contact was modulated by head orientation and emotion. Overperception of eye contact was associated with more severe negative symptoms. Decreased categorical gaze perception explained variance of socioemotional deficits in schizophrenia after taking basic neurocognition into consideration, suggesting the relationship was not solely due to a general deficit problem. These results were discussed in relation to the nature of categorical gaze perception and its significance to clinical and functional presentations of schizophrenia.     

Changing grasp position on a wielded object provides self-training for the perception of length

Calibration of perception to environmental properties typically requires experiences in addition to the perceptual task, such as feedback about performance. Recently, it has been shown that such experiences need not come from an external source or from a different perceptual modality. Rather, in some cases, a given perceptual modality can train itself. In this study, we sought to expand on the range of experiences in which this can occur for perception of the length of a wielded occluded object. Specifically, in two experiments, we investigated whether the act of perceiving the length of a wielded object from a given grasp position could recalibrate the perception of length from a different grasp position. In both experiments, three groups of participants perceived the lengths of wielded rods in a pretest, practice, and a posttest. The practice included either (a) experimenter feedback, (b) changing the grasp position on the object (and again attempting to perceive length), or (c) no additional experiences. In Experiment 1, participants changed their grasp position from the middle to the end of each rod, and in Experiment 2, they did so from the end to the middle of each rod. In both experiments, the results showed that perceiving length from a different grasp position can recalibrate (i.e., provide self-training for) the perception of length.     

The motor theory of speech perception revisited

Galantucci, Fowler, and Turvey (2006) have claimed that perceiving speech is perceiving gestures and that the motor system is recruited for perceiving speech. We make the counter argument that perceiving speech is not perceiving gestures, that the motor system is not recruitedfor perceiving speech, and that speech perception can be adequately described by a prototypical pattern recognition model, the fuzzy logical model of perception (FLMP). Empirical evidence taken as support for gesture and motor theory is reconsidered in more detail and in the framework of the FLMR Additional theoretical and logical arguments are made to challenge gesture and motor theory.     

The attentional blink unveils the interplay between conscious perception,spatial attention and working memory encoding

Our ability to perceive two events in close temporal succession is severely limited, a phenomenon known as the attentional blink. While the blink has served as a popular tool to prevent conscious perception, there is less research on its causes, and in particular on the role of conscious perception of the first event in triggering it. In three experiments, we disentangled the roles of spatial attention, conscious perception and working memory (WM) in causing the blink. We show that while allocating spatial attention to T1 is neither necessary nor sufficient for eliciting a blink, consciously perceiving it is necessary but not sufficient. When T1 was task irrelevant, consciously perceiving it triggered a blink only when it matched the attentional set for T2. We conclude that consciously perceiving a task-relevant event causes the blink, possibly because it triggers encoding of this event into WM. We discuss the implications of these findings for the relationship between spatial attention, conscious perception and WM, as well as for the distinction between access and phenomenal consciousness.     

How many voices did you hear? Natural variability disrupts identity perception from unfamiliar voices

Our voices sound different depending on the context (laughing vs. talking to a child vs. giving a speech), making within‐person variability an inherent feature of human voices. When perceiving speaker identities, listeners therefore need to not only ‘tell people apart’ (perceiving exemplars from two different speakers as separate identities) but also ‘tell people together’ (perceiving different exemplars from the same speaker as a single identity). In the current study, we investigated how such natural within‐person variability affects voice identity perception. Using voices from a popular TV show, listeners, who were either familiar or unfamiliar with this show, sorted naturally varying voice clips from two speakers into clusters to represent perceived identities. Across three independent participant samples, unfamiliar listeners perceived more identities than familiar listeners and frequently mistook exemplars from the same speaker to be different identities. These findings point towards a selective failure in ‘telling people together’. Our study highlights within‐person variability as a key feature of voices that has striking effects on (unfamiliar) voice identity perception. Our findings not only open up a new line of enquiry in the field of voice perception but also call for a re‐evaluation of theoretical models to account for natural variability during identity perception.     

The perception of continuous curves in dot stimuli

Two categorisation experiments are reported in which the perceptual phenomenon that some simple arrays of discrete dots appear as a continuous curve whereas others are perceived as an angular contour or as consisting of separate groups of dots was investigated. Triplets of dots were presented in the first experiment, and complete or incomplete regular dot polygons (ie dots positioned on the vertices of imaginary regular polygons) in the second. In both experiments the perception of a curve versus an angle was determined mainly by the relative orientations of the dots, ie by the angles between successive virtual lines, whereas the lengths of the virtual lines had relatively little influence. In experiment 2 the number of displayed dots was shown to be a second independent factor for perceiving continuity. These results are in agreement with results from experiments on dipole textures discrimination, and suggest the psychological existence and importance of virtual lines in the visual processing of dot stimuli.     

Awareness of one's body as subject and object

Abstract

This paper rejects Hume's famous claim that we never perceive our selves, by arguing that, under conditions specified, our perception of our bodies is perception of our selves. It takes as its point of departure Quassim Cassam's defence of a position to a similar effect but puts a different interpretation on the distinction between perceiving the body as an object, having spatial attributes, and perceiving it as a self or subject of experiences.     

Contributions of facial expressions and body language to the rapid perception of dynamic emotions

Correctly perceiving emotions in others is a crucial part of social interactions. We constructed a set of dynamic stimuli to determine the relative contributions of the face and body to the accurate perception of basic emotions. We also manipulated the length of these dynamic stimuli in order to explore how much information is needed to identify emotions. The findings suggest that even a short exposure time of 250 milliseconds provided enough information to correctly identify an emotion above the chance level. Furthermore, we found that recognition patterns from the face alone and the body alone differed as a function of emotion. These findings highlight the role of the body in emotion perception and suggest an advantage for angry bodies, which, in contrast to all other emotions, were comparable to the recognition rates from the face and may be advantageous for perceiving imminent threat from a distance.     

Connecting the dots: Illusory pattern perception predicts belief in conspiracies and the supernatural

A common assumption is that belief in conspiracy theories and supernatural phenomena are grounded in illusory pattern perception. In the present research we systematically tested this assumption. Study 1 revealed that such irrational beliefs are related to perceiving patterns in randomly generated coin toss outcomes. In Study 2, pattern search instructions exerted an indirect effect on irrational beliefs through pattern perception. Study 3 revealed that perceiving patterns in chaotic but not in structured paintings predicted irrational beliefs. In Study 4, we found that agreement with texts supporting paranormal phenomena or conspiracy theories predicted pattern perception. In Study 5, we manipulated belief in a specific conspiracy theory. This manipulation influenced the extent to which people perceive patterns in world events, which in turn predicted unrelated irrational beliefs. We conclude that illusory pattern perception is a central cognitive mechanism accounting for conspiracy theories and supernatural beliefs.     

Perception of Object Length by Sound

Although hearing is classically considered a temporal sense, everyday listening suggests that subtle spatial properties constitute an important part of what people know about the world through sound. Typically neglected in psychoacoustics research, the ability to perceive the precise sizes of objects on the basis of sound was investigated during the routine event of dropping wooden dowels of different lengths onto a hard surface. In two experiments, the ordinal and metrical success of naive listeners was related to length but not to the simple acoustic variables (duration, amplitude, frequency) likely to be related to it. Additional analysis suggests the potential relevance of an object's inertia tensor in constraining perception of that object's length, analogous to the case that has been made for perceiving length by effortful touch.     

THE PERCEPTUAL THEORY OF PAIN: ANOTHER LOOK

The essential logical deficiency of the perceptual theory of pain, as I tried to show in my paper,¹ is that feeling pain cannot be perceiving anything. The conceptual framework that would make it possible for us to understand "feel" in this use to be a perception concept does not exist. The concept of a glimpse, which George Pitcher relies upon to supply this framework,²cannot begin to do so because it is a secondary perception concept entirely dependent upon that of seeing. This primary concept of visual perception is tied up with actions and supporting concepts like looking, glancing, gazing, glimpsing, watching, and the like. These are different ways in which one's visual perceiving may be characterized. Without the primary concept and the actions connected with it, there would be nothing to characterize. The word "feel" in contexts involving pain is not a perception concept and efforts to make it one are doomed to fail. The supporting actions and concepts do not exist.     

Routes to Actions and their Efficacy for Remembering

Four experiments focused on the influence that different controls of actions have on memory for these actions. A verbal-to-action task in which subjects had to perform actions on verbal command was distinguished from a movement-to-action task in which subjects had to perform the same action that a model had shown (imitation). We expected free recall to be worse for the imitation condition than for the enactment-on-command condition. The following rank order of recall performances was observed: verbal learning << perceiving the model = imitating the watched model < performing on command = performing on command in addition to perceiving the model. The less pronounced effect of imitation on memory is explained by the fact that subjects in this condition could directly use the information provided by perception for enactment without selection and detailed planning of motor actions. In contrast, subjects in the command-to-action condition had to look up the “motor program”. The inefficiency of using two modalities, i.e. perception and action, as compared to using only one is explained by the redundancy of encoded information in the visual and “motor” modality.     

Perceiving a calling and well-being: Motivation and access to opportunity as moderators

The current study examined moderator variables that may accentuate the effect of perceiving a calling on well-being amongst a large and diverse sample of working adults (N = 746). Drawing from Self Determination Theory (SDT; Deci & Ryan, 2000) and the Psychology of Working Theory (PWT: Duffy, Blustein, Diemer, & Autin, 2016), perceiving a calling was hypothesized to have greater effects on wellbeing for individuals with greater calling motivation and access to vocational opportunity, as assessed by income and work volition. Three moderated, multiple mediator models using structural equation modeling were run to test these hypotheses. Specifically, life meaning and living a calling were positioned as mediator variables in the relation of perceiving a calling to life satisfaction and the paths from perceiving a calling to the mediators were proposed to be significantly moderated. Calling motivation was found to be a significant moderator for both paths, supporting propositions of SDT. As the motivation to pursue one's calling increased, the direct effects on life meaning and living a calling and the indirect effects on life satisfaction were stronger. Income was also found to be a significant moderator, supporting propositions of the PWT, but only in the relation of perceiving a calling to living a calling. It was proposed that work volition—a variable related to the perception of vocational opportunity—may be better positioned as correlate of calling variables versus a moderator variable affecting the impact of having a calling. Practical implications are discussed.     

A counterexample to the rigidity assumption in the visual perception of structure from motion

It has been proposed that the human visual system prefers perceptions of objects that are rigid or undergo minimum form change. A counterexample is presented in which a rigid two-dimensional figure rotating in the frontal plane is perceived as a distorting three-dimensional shape. It is argued that this perception results from the stimulation of automatic processes for perceiving size change, and that these processes are not subject to a general rigidity assumption.     

Curvature affects haptic length perception

One possible way of haptically perceiving length is to trace a path with one’s index finger and estimate the distance traversed. Here, we present an experiment in which observers judge the lengths of paths across cylindrically curved surfaces. We found that convex and concave surfaces had qualitatively different effects: convex lengths were overestimated, whereas concave lengths were underestimated. In addition, we observed that the index finger moved more slowly across the convex surface than across the concave one. As a result, movement times for convex lengths were longer. The considerable correlation between movement times and length estimates suggests that observers take the duration of movement as their primary measure of perceived length, but disregard movement speeds. Several mechanisms that could underlie observers’ failure to account for speed differences are considered.     

Social cognition in simple action coordination: A case for direct perception

In this paper we sketch the outlines of an account of the kind of social cognition involved in simple action coordination that is based on direct social perception (DSP) rather than recursive mindreading. While we recognize the viability of a mindreading-based account such as e.g. Michael Tomasello’s, we present an alternative DSP account that (i) explains simple action coordination in a less cognitively demanding manner, (ii) is better able to explain flexibility and strategy-switching in coordination and crucially (iii) allows for formal modeling. This account of action coordination is based on the notion of an agent’s field of affordances. Coordination ensues, we argue, when, given a shared intention, the actions of and/or affordances for one agent shape the field of affordances for another agent. This a form of social perception since in particular perceiving affordances for another person involves seeing that person as an agent. It is a form of social perception since it involves perceiving affordances for another person and registering how another person’s actions influence one’s own perceived field of affordances.     

Developmental prosopagnosia: a study of three patients

We studied perception in three patients with prosopagnosia of childhood onset. All had trouble with other 'within-category' judgments. All were deficient on face matching tests and severely impaired on tests of perception of the spatial relations of facial features and abstract designs, indicating a deficit in the encoding of coordinate relationships, similar to adult-onset prosopagnosia with lesions of the fusiform face area. Two had difficulty perceiving feature colour, which correlated with reduced luminance sensitivity. In contrast to adult-onset patients, saturation discrimination was spared in two and spatial resolution impaired in two. Curvature discrimination was relatively spared. Contrast sensitivity showed variable reductions at different spatial frequencies. We conclude that developmental prosopagnosia is similar to the adult-onset form in encoding deficits for the spatial arrangement of facial elements. Deficits in luminance perception and spatial resolution are more associated with defective encoding for basic object-level recognition, as shown on tests of object and spatial perception.