Preference for Facial Symmetry Depends on Study Design

Facial symmetry is purportedly attractive, though methods for measuring preference for facial symmetry vary between studies. Some studies have used a two-alternative forced choice (2AFC) task, while others have used a ratings task. How researchers manipulate facial symmetry also varies; some studies have used faces manipulated to be more (or perfectly) symmetrical, while others have used faces manipulated to be more asymmetrical. Here, across three studies, we evaluate and compare these different methods. In Studies 1 and 2 (N = 340 and 256, respectively), we compare facial symmetry preferences as measured by the 2AFC and ratings tasks. Across both studies, we consistently found a significant preference for facial symmetry when using the 2AFC task, but not with the ratings task. Additionally, correlations between facial symmetry preferences as measured by the two tasks were weak or showed no association. In Study 3, 159 participants rated the attractiveness of faces manipulated to be either symmetrical or more asymmetrical. The asymmetrical faces were rated as significantly less attractive compared to the original faces, while the difference in attractiveness ratings between the original and symmetrical versions was comparatively much smaller. These studies suggest that preference for facial symmetry depends greatly on the study design.

Pre-training RNNs on ecologically relevant tasks explains sub-optimal behavioral reset

When faced with a new task, animals′ cognitive capabilities are determined both by individual experience and by structural priors evolved to leverage the statistics of natural environments. Rats can quickly learn to capitalize on the trial sequence correlations of two-alternative forced choice (2AFC) tasks after correct trials, but consistently deviate from optimal behavior after error trials, when they waive the accumulated evidence. To understand this outcome-dependent gating, we first show that Recurrent Neural Networks (RNNs) trained in the same 2AFC task outperform animals as they can readily learn to use previous trials′ information both after correct and error trials. We hypothesize that, while RNNs can optimize their behavior in the 2AFC task without a priori restrictions, rats′ strategy is constrained by a structural prior adapted to a natural environment in which rewarded and non-rewarded actions provide largely asymmetric information. When pre-training RNNs in a more ecological task with more than two possible choices, networks develop a strategy by which they gate off the across-trial evidence after errors, mimicking rats′ behavior. Our results suggest that the observed suboptimal behavior reflects the influence of a structural prior that, adaptive in a natural multi-choice environment, constrains performance in a 2AFC laboratory task.

Classical Rondos and Sonatas as Stylistic Categories

Sonata and rondo movements are often defined in terms of large-scale form, yet in the classical era, rondos were also identified according to their lively, cheerful character. We hypothesized that sonatas and rondos could be categorized based on stylistic features, and that rondos would involve more acoustic cues for happiness (e.g., higher average pitch height and higher average attack rate). In a corpus analysis, we examined paired movement openings from 180 instrumental works, composed between 1770 and 1799. Rondos had significantly higher pitch height and attack rate, as predicted, and there were also significant differences related to dynamics, meter, and cadences. We then conducted an experiment involving participants with at least 5 years of formal music training or less than 6 months of formal music training. Participants listened to 120 15-second audio clips, taken from the beginnings of movements in our corpus. After a training phase, they attempted to categorize the excerpts (2AFC task). D-prime scores were significantly higher than chance levels for both groups, and in post-experiment questionnaires, participants without music training reported that rondos sounded happier than sonatas. Overall, these results suggest that classical formal types have distinct stylistic and affective conventions.

Listeners integrate pitch and durational cues to prosodic structure in word categorization

In this study we investigate how listeners perceive vowel duration as a cue to voicing based on changes in pitch height, using a 2AFC task in which they categorized a target word from a vowel duration continuum as “coat” or “code”. We consider this issue in light of (1) psychoacoustic perceptual interactions between pitch and duration and (2) compensatory effects for prosodically driven patterning of pitch and duration in the accentual/prominence-marking system of English. In two experiments we found that listeners’ interpretation of pitch as a psychoacoustic, or prosodic event is dependent on continuum step size and range. In Experiment 1 listeners exemplified the expected psychoacoustic pattern in categorization. In Experiment 2, we altered the duration continuum in an attempt to highlight pitch as a language-specific prosodic property and found that listeners do indeed compensate for prosodically driven patterning of pitch and duration. The results thus highlight flexibility in listeners’ interpretation of these acoustic dimensions. We argue that, in the right circumstances, prosodic patterns influence listeners’ interpretation of pitch and expectations about vowel duration in the perception of isolated words. Results are discussed in terms of more general implications for listeners’ perception of prosodic and segmental cues, and possibilities for cross-linguistic extension.

Non-conscious Perception of Facial Expression with Continuous Flash Suppression: A Signal Detection Analysis

The aim of this study was to explore if a conservative response criterion is responsible for non-conscious perception of facial expressions during continuous flash suppression (CFS). We hypothesized that participants’ sensitivity in a detection task would be significantly lower than their sensitivity in a 2-alternative forced-choice (2AFC) task while using CFS. After rendering images of faces with different facial expression (fearful vs. neutral) invisible for 500 milliseconds (ms) and 700 ms using CFS, participants judged the presence/absence of the faces with a detection task and the emotion of faces with a 2AFC task. When we rendered the face stimuli invisible for 500 ms, participants discriminated the signal (fearful face) from noise (neutral face) by having a higher sensitivity in the 2AFC task compared to the detection task. When we rendered the face stimuli invisible for 700 ms, the difference between participants’ sensitivities in the two tasks disappeared.

Testing alternative theoretical accounts of code-switching: Insights from comparative judgments of adjective–noun order

Objectives: Spanish and English contrast in adjective–noun word order: for example, brown dress (English) vs. vestido marrón (‘dress brown’, Spanish). According to the Matrix Language model ( MLF) word order in code-switched sentences must be compatible with the word order of the matrix language, but working within the minimalist program (MP), Cantone and MacSwan arrived at the descriptive generalization that the position of the noun phrase relative to the adjective is determined by the adjective’s language. Our aim is to evaluate the predictions derived from these two models regarding adjective–noun order in Spanish–English code-switched sentences. Methodology: We contrasted the predictions from both models regarding the acceptability of code-switched sentences with different adjective–noun orders that were compatible with the MP, the MLF, both, or none. Acceptability was assessed in Experiment 1 with a 5-point Likert and in Experiment 2 with a 2-Alternative Forced Choice (2AFC) task. Data and analysis: Data from both experiments were subjected to linear mixed model analyses. Results from the 2AFC task were also analyzed using Thurstone’s law of comparative judgment. Conclusions: We found an additive effect in which both the language of the verb and the language of the adjective determine word order. Originality: Both experiments examine adjective–noun word order in English–Spanish code-switched sentences. Experiment 2 represents a novel application of Thurstone’s law of comparative judgements to the study of linguistic acceptability which yielded clearer results than Likert scales. We found convincing evidence that neither the MLF nor the MP can fully account for the acceptability of adjective–noun switches. Implications: We suggest that advances in our understanding of grammaticality in code-switching will be achieved by combining the insights of the two frameworks instead of considering them in isolation, or by espousing a probabilistic model of code-switching.

Pitch discrimination performance of ferrets and humans on a go/no-go task

ABSTRACTAnimal models are widely used to examine the neurophysiological basis of human pitch perception, and it is therefore important to understand the similarities and differences in pitch processing across species. Pitch discrimination performance is usually measured using two-alternative forced choice (2AFC) procedures in humans and go/no-go tasks in animals, potentially confounding human-to-animal comparisons. We have previously shown that pitch discrimination thresholds of ferrets on a 2AFC task are markedly poorer than those reported for go/no-go tasks in other non-human species (Walker et al., 2009). To better compare the pitch discrimination performance of ferret with other species, here we measure pitch change detection thresholds of ferrets and humans on a common, appetitive go/no-go task design. We found that ferrets’ pitch thresholds were ~10 times larger than that of humans on the go/no-go task, and were within the range of thresholds reported in other non-human species. Interestingly, ferrets’ thresholds were 100 times larger than human thresholds on a 2AFC pitch discrimination task using the same stimuli. These results emphasize that sensory discrimination thresholds can differ across tasks, particularly for non-human animals. Performance on our go/no-go task is likely to reflect different neurobiological processes than that on our 2AFC task, as the former required the subjects only to detect a pitch change while the latter required them to label the direction of the pitch change.ABBREVIATIONS2AFC2-Alternative Forced ChoiceF0Fundamental FrequencyHIGHLIGHTSPitch discrimination thresholds of ferrets were 10 times larger than those of humans on a go/no-go taskFerrets’ pitch thresholds are similar to those reported for a range of other mammalsPitch thresholds of ferrets, but not humans, were drastically better on the go/no-go task than a 2AFC task using the same stimuli

Do Not Judge According to Appearance: Patients— Preference of a Doctor's Face Does Not Influence Their Assessment of the Patient–doctor Relationship

Objectives The aim of this study was to investigate whether a patient's preference for a doctor's face is associated with better assessments of relational empathy in the patient–doctor relationship after the first clinical consultation. Methods A total of 110 patients enrolled in a traditional Korean medical clinic participated in the study. Patients’ preference for doctors’ faces was assessed by a two alternative forced choice (2AFC) task, with 60 different pairs of six different Asian male doctors’ faces. One of the six doctors then carried out the initial clinical consultation for these patients. The patient–doctor relationship was assessed using the Consultation and Relational Empathy (CARE) measure. Results The data of all patients’ simulated preferences for a doctor's face and their assessment values of a doctor's relational empathy was compared, and no significant correlation was found between both values (r=−0.024, p>0.809). Conclusions These findings suggest that the perceived empathy in the patient–doctor relationship is not influenced by the patient's preference for a certain doctor's face. The first impression of a doctor is often determined by his appearance and look. However, whether or not the patient particularly prefers a doctor's face does not seem to matter in developing a good patient–doctor relationship.