Perceptual learning effect on decision and confidence thresholds

Practice can enhance of perceptual sensitivity, a well-known phenomenon called perceptual learning. However, the effect of practice on subjective perception has received little attention. We approach this problem from a visual psychophysics and computational modeling perspective. In a sequence of visual search experiments, subjects significantly increased the ability to detect a “trained target”. Before and after training, subjects performed two psychophysical protocols that parametrically vary the visibility of the “trained target”: an attentional blink and a visual masking task. We found that confidence increased after learning only in the attentional blink task. Despite large differences in some observables and task settings, we identify common mechanisms for decision-making and confidence. Specifically, our behavioral results and computational model suggest that perceptual ability is independent of processing time, indicating that changes in early cortical representations are effective, and learning changes decision criteria to convey choice and confidence.     

Feature Statistics Modulate the Activation of Meaning During Spoken Word Processing

Understanding spoken words involves a rapid mapping from speech to conceptual representations. One distributed feature‐based conceptual account assumes that the statistical characteristics of concepts’ features—the number of concepts they occur in (distinctiveness/sharedness) and likelihood of co‐occurrence (correlational strength)—determine conceptual activation. To test these claims, we investigated the role of distinctiveness/sharedness and correlational strength in speech‐to‐meaning mapping, using a lexical decision task and computational simulations. Responses were faster for concepts with higher sharedness, suggesting that shared features are facilitatory in tasks like lexical decision that require access to them. Correlational strength facilitated responses for slower participants, suggesting a time‐sensitive co‐occurrence‐driven settling mechanism. The computational simulation showed similar effects, with early effects of shared features and later effects of correlational strength. These results support a general‐to‐specific account of conceptual processing, whereby early activation of shared features is followed by the gradual emergence of a specific target representation.     

Epistemic perceptualism and neo-sentimentalist objections

Epistemic Perceptualists claim that emotions are sources of immediate defeasible justification for evaluative propositions that can (and do) sometimes ground undefeated immediately justified evaluative beliefs. For example, fear can constitute the justificatory ground for a belief that some object or event is dangerous. Despite its attractiveness, the view is apparently vulnerable to several objections. In this paper, I provide a limited defence of Epistemic Perceptualism by responding to a family of objections which all take as a premise a popular and attractive view in value theory – Neo-Sentimentalism – according to which values are analysed in terms of fitting emotions.     

The interaction between social saliency and perceptual saliency

The ability to select visual targets in hierarchical stimuli can be affected by both perceptual saliency and social saliency. However, the functional relations between the effects are not understood. Here we examined whether these two factors interact or combine in an additive way. Participants first learnt to associate geometric shapes with three people (e.g., triangle–self, square–stranger). After learning the associations, participants were presented with compound stimuli (e.g., a global triangle formed by a set of local squares) and had to select a target at the global or local level. In Experiment 1 the task was to identify the person associated with the local or global shape. In Experiment 2 the task was simply to identify the shape. We manipulated perceptual saliency by blurring local elements to form perceptually global salient stimuli or by contrasting the colours of neighbouring local elements (red vs. white) to form perceptually local salient stimuli. In Experiment 1 (person discrimination) there was a strong effect of saliency on local targets (there were faster and more accurate responses to high than to low saliency targets) when social and perceptual saliency occurred at same level. However, both perceptual and social saliency effects were eliminated when the effect of saliency at one level competed with that at the other level. In Experiment 2 (shape discrimination), there were only effects of perceptual saliency. The data indicate that social saliency interacts with perceptual saliency when explicit social categorizations are made, consistent with both factors modulating a common process of visual selection.     

The objects of visuospatial short-term memory: Perceptual organization and change detection

We used a colour change-detection paradigm where participants were required to remember colours of six equally spaced circles. Items were superimposed on a background so as to perceptually group them within (a) an intact ring-shaped object, (b) a physically segmented but perceptually completed ring-shaped object, or (c) a corresponding background segmented into three arc-shaped objects. A nonpredictive cue at the location of one of the circles was followed by the memory items, which in turn were followed by a test display containing a probe indicating the circle to be judged same/different. Reaction times for correct responses revealed a same-object advantage; correct responses were faster to probes on the same object as the cue than to equidistant probes on a segmented object. This same-object advantage was identical for physically and perceptually completed objects, but was only evident in reaction times, and not in accuracy measures. Not only, therefore, is it important to consider object-level perceptual organization of stimulus elements when assessing the influence of a range of factors (e.g., number and complexity of elements) in visuospatial short-term memory, but a more detailed picture of the structure of information in memory may be revealed by measuring speed as well as accuracy.     

工程设计的伦理意蕴

工程设计不是单独的个人行为,而是富有文化意蕴的社会性的系统行动。它以生态保护为基本伦理原则,以以人为本为主要评价标准。工程设计伦理的主要特征是科学精神与人文精神的有机结合,价值理性挑战工具理性的集中体现,环境伦理、技术伦理与社会伦理的融合统一。     

Rowing together: Interpersonal coordination dynamics with and without mechanical coupling

Although most research on interpersonal coordination focuses on perceptual forms of interaction, many interpersonal actions also involve interactions of mechanical nature. We examined the effect of mechanical coupling in a rowing task from a coupled oscillator perspective: 16 pairs of rowers rowed on ergometers that were physically connected through slides (mechanical coupling condition) or on separate ergometers (no mechanical coupling condition). They rowed in two patterns (in- and antiphase) and at two movement frequencies (20 and 30 strokes per minute). Seven out of sixteen pairs showed one or more coordinative breakdowns, which only occurred in the antiphase condition. The occurrence of these breakdowns was not affected by mechanical coupling, nor by movement frequency. For the other nine pairs, variability of steady state coordination was substantially lower in the mechanical coupling condition. Together, these results show that the increase in coupling strength through mechanical coupling stabilizes coordination, even more so for antiphase coordination.     

Gender and appearance accuracy: Women’s advantage over men is restricted to dress items

Which aspects of people’s appearance do women remember better than men? Women were predicted to remember the dress-related items but not the physical characteristics of targets more accurately than men, given that the former might be a more female-relevant domain of interest among perceivers. Participants watched a videotaped target and then completed a surprise test of their memory for her/his appearance. Men were as accurate as women at remembering the target’s physical features but less accurate than woman at recalling what the target was wearing. Discussion focuses on the implications of these findings for eyewitness accuracy.     

Spatial But Not Oculomotor Information Biases Perceptual Memory: Evidence From Face Perception and Cognitive Modeling

Recent research put forward the hypothesis that eye movements are integrated in memory representations and are reactivated when later recalled. However, “looking back to nothing” during recall might be a consequence of spatial memory retrieval. Here, we aimed at distinguishing between the effect of spatial and oculomotor information on perceptual memory. Participants’ task was to judge whether a morph looked rather like the first or second previously presented face. Crucially, faces and morphs were presented in a way that the morph reactivated oculomotor and/or spatial information associated with one of the previously encoded faces. Perceptual face memory was largely influenced by these manipulations. We considered a simple computational model with an excellent match (4.3% error) that expresses these biases as a linear combination of recency, saccade, and location. Surprisingly, saccades did not play a role. The results suggest that spatial and temporal rather than oculomotor information biases perceptual face memory.     

Is positivity a cue or a response option? Warm glow vs evaluative matching in the familiarity for attractive and not-so-attractive faces

Monin (2003) showed that the attractiveness of a face increases its perceived familiarity regardless of prior exposure, and suggested that this beautiful-is-familiar effect was due to the misattribution to familiarity of the positive affect (or “warm glow”) elicited by attractive faces. This research tests the alternative interpretation that an evaluative match between a positive stimulus (an attractive face) and a positive response (“familiar”) accounts for this effect in the absence of any misattribution. In a face recognition task, participants were led to signal their sense of familiarity with previously seen and unseen faces by selecting either a pleasant (affectively congruent) or unpleasant (affectively incongruent) image. Consistent with the warm glow heuristic, higher false alarm rates were obtained for more attractive distracters, and this effect survived (and was, if anything, stronger) when an affectively incongruent response format was used. These findings are discussed in the context of current face memory and perceptual fluency models.