A validation of Amazon Mechanical Turk for the collection of acceptability judgments in linguistic theory

Amazon’s Mechanical Turk (AMT) is a Web application that provides instant access to thousands of potential participants for survey-based psychology experiments, such as the acceptability judgment task used extensively in syntactic theory. Because AMT is a Web-based system, syntacticians may worry that the move out of the experimenter-controlled environment of the laboratory and onto the user-controlled environment of AMT could adversely affect the quality of the judgment data collected. This article reports a quantitative comparison of two identical acceptability judgment experiments, each with 176 participants (352 total): one conducted in the laboratory, and one conducted on AMT. Crucial indicators of data quality—such as participant rejection rates, statistical power, and the shape of the distributions of the judgments for each sentence type—are compared between the two samples. The results suggest that aside from slightly higher participant rejection rates, AMT data are almost indistinguishable from laboratory data.     

Objective Bayesianism,Bayesian conditionalisation and voluntarism

Objective Bayesianism has been criticised on the grounds that objective Bayesian updating, which on a finite outcome space appeals to the maximum entropy principle, differs from Bayesian conditionalisation. The main task of this paper is to show that this objection backfires: the difference between the two forms of updating reflects negatively on Bayesian conditionalisation rather than on objective Bayesian updating. The paper also reviews some existing criticisms and justifications of conditionalisation, arguing in particular that the diachronic Dutch book justification fails because diachronic Dutch book arguments are subject to a reductio: in certain circumstances one can Dutch book an agent however she changes her degrees of belief. One may also criticise objective Bayesianism on the grounds that its norms are not compulsory but voluntary, the result of a stance. It is argued that this second objection also misses the mark, since objective Bayesian norms are tied up in the very notion of degrees of belief.     

Anti-Luck Epistemologies and Necessary Truths

That believing truly as a matter of luck does not generally constitute knowing has become epistemic commonplace. Accounts of knowledge incorporating this anti-luck idea frequently rely on one or another of a safety or sensitivity condition. Sensitivity-based accounts of knowledge have a well-known problem with necessary truths, to wit, that any believed necessary truth trivially counts as knowledge on such accounts. In this paper, we argue that safety-based accounts similarly trivialize knowledge of necessary truths and that two ways of responding to this problem for safety, issuing from work by Williamson and Pritchard, are of dubious success.     

Risks and realities: dyadic interaction between 6-month-old infants and their mothers in opioid maintenance treatment

A number of studies point to methadone exposure in utero as a possible risk factor in the developing mother–infant relationship in the first year of life. This study is part of a larger, national follow-up of 38 infants prenatally exposed to methadone or buprenorphine and 36 comparison, low-risk infants. The aim of the present paper is to assess the quality of mother–infant relationship when the infants are 6 months old. Videotaped mother–infant interactions were rated in a global scale (NICHD). Maternal and infant contributions collapsed into the variables “infant style” and “maternal style” showed that the only factor making significant contribution to the outcome measure “dyadic mutuality” was maternal style. The importance of group membership (exposed versus non-exposed), was reduced when controlling for maternal drug use prior to opioid maintenance treatment (OMT), maternal depression and parenting stress as well as infants’ developmental status and sensory-integrative functions. This suggests that prediction of dyadic mutuality should be based on individual characteristics rather than group characteristics. These results support previous research findings that methadone and buprenorphine use per se does not have direct influence on the quality of early mother–infant relationship, but tailored follow-up procedures targeting drug-free pregnancies and parenting support are beneficial for women in OMT and their children.     

Recognition of own- and other-race faces in autism spectrum disorders

Empirical data regarding the extent of face recognition abnormalities in autism spectrum disorder (ASD) is inconsistent. Here, 27 ASD and 47 typically developing (TD) children completed an immediate two-alternative forced-choice identity matching task. We contrasted recognition of own- and other-race faces, and, counter to prediction, we found a typical advantage for recognizing own- over other-race faces in both the ASD and TD groups. In addition, ASD and TD groups responded similarly to stimulus manipulations (use of identical or different photographs for identity matching and cropping stimuli to remove hair information). However, age-standardized scores varied widely within the ASD sample, and a subgroup of ASD participants with impaired face recognition did not exhibit a significant own-race recognition advantage. An explanation regarding early experience with faces is considered, and implications for research of individual variation within ASD are discussed.     

The integration of stimulus dimensions in the perception of music

A central aim of cognitive psychology is to explain how we integrate stimulus dimensions into a unified percept, but how the dimensions of pitch and time combine in the perception of music remains a largely unresolved issue. The goal of this study was to test the effect of varying the degree of conformity to dimensional structure in pitch and time (specifically, tonality and metre) on goodness ratings and classifications of melodies. The pitches and durations of melodies were either presented in their original order, as a reordered sequence, or replaced with random elements. Musically trained and untrained participants (24 each) rated melodic goodness, attending selectively to the dimensions of pitch, time, or both. Also, 24 trained participants classified whether or not the melodies were tonal, metric, or both. Pitch and temporal manipulations always influenced responses, but participants successfully emphasized either dimension in accordance with instructions. Effects of pitch and time were mostly independent for selective attention conditions, but more interactive when evaluating both dimensions. When interactions occurred, the effect of either dimension increased as the other dimension conformed more to its original structure. Relative main effect sizes (| pitch η(2) - time η(2) |) predicted the strength of pitch-time interactions (pitch?×?time η(2)); interactions were stronger when main effect sizes were more evenly matched. These results have implications for dimensional integration in several domains. Relative main effect size could serve as an indicator of dimensional salience, such that interactions are more likely when dimensions are equally salient.     

The role of pitch and temporal diversity in the perception and production of musical sequences

In two experiments we explored how the dimensions of pitch and time contribute to the perception and production of musical sequences. We tested how dimensional diversity (the number of unique categories in each dimension) affects how pitch and time combine. In Experiment 1, 18 musically trained participants rated the complexity of sequences varying only in their diversity in pitch or time; a separate group of 18 pianists reproduced these sequences after listening to them without practice. Overall, sequences with more diversity were perceived as more complex, but pitch diversity influenced ratings more strongly than temporal diversity. Further, although participants perceived sequences with high levels of pitch diversity as more complex, errors were more common in the sequences with higher diversity in time. Sequences in Experiment 2 exhibited diversity in both pitch and time; diversity levels were a subset of those tested in Experiment 1. Again diversity affected complexity ratings and errors, but there were no statistical interactions between dimensions. Nonetheless, pitch diversity was the primary factor in determining perceived complexity, and again temporal errors occurred more often than pitch errors. Additionally, diversity in one dimension influenced error rates in the other dimension in that both error types were more frequent relative to Experiment 1. These results suggest that although pitch and time do not interact directly, they are nevertheless not processed in an informationally encapsulated manner. The findings also align with a dimensional salience hypothesis, in which pitch is prioritised in the processing of typical Western musical sequences.     

On keeping your enemies close: powerful leaders seek proximity to ingroup power threats

Throughout history, humans have had to detect and deflect myriad threats from their social and physical environment in order to survive and flourish. When people detect a threat, the most common response is avoidance. In the present research, the authors provide evidence that ingroup power threats elicit a very different response. Three experiments supported the hypothesis that dominant leaders seek proximity to ingroup members who pose a threat to their power, as a way to control and downregulate the threat that those members pose. In each experiment, leaders high (but not low) in dominance motivation sought proximity to an ingroup member who threatened their power. Consistent with the hypothesis that increased proximity was designed to help leaders protect their own power, the proximity effect was apparent only under conditions of unstable power (not stable power), only in the absence of intergroup competition (not when a rival outgroup was present), and only toward a threatening group member (not a neutral group member). Moreover, the effect was mediated by perceptions of threat (Experiment 1) and the desire to monitor the threatening group member (Experiment 3). These results shed new light on one key strategy through which dominant leaders try to maintain control over valuable yet potentially threatening group members. Findings have implications for theories of power, leadership, and group behavior.     

Examining a brief suicide screening tool in older adults engaging in risky alcohol use

Alcohol misuse increases risk of suicidal behavior in older adults. The Depressive Symptom Inventory‐Suicidality Subscale (DSI‐SS; Metalsky & Joiner, 1997) and its relation to suicide attempt history was examined to see if it differed for older adults as a function of their alcohol use. Structural equation modeling was used in a sample (N = 1,061) of older adult outpatients to examine the scale’s measurement invariance and population heterogeneity and its relation to suicide attempt history. Analyses supported the equivalence of the DSI‐SS in risky and nonrisky drinkers. The DSI‐SS significantly predicted past suicide attempts. Findings support the viability of the DSI‐SS as suicide screening tool for older adults.     

40,000 memories in young teenagers: psychometric properties of the Autobiographical Memory Test in a UK cohort study

Although the Autobiographical Memory Test (AMT) is widely used its psychometric properties have rarely been investigated. This paper utilises data gathered from a 10-item written version of the AMT, completed by 5792 adolescents participating in the Avon Longitudinal Study of Parents and Children, to examine the psychometric properties of the measure. The results show that the scale derived from responses to the AMT operates well over a wide range of scores, consistent with the aim of deriving a continuous measure of over-general memory. There was strong evidence of group differences in terms of gender, low negative mood, and IQ, and these were in agreement when comparing an item response theory (IRT) approach with that based on a sum score. One advantage of the IRT model is the ability to assess and consequently allow for differential item functioning. This additional analysis showed evidence of response bias for both gender and mood, resulting in attenuation in the mean differences in AMT across these groups. Implications of the findings for the use of the AMT measure in different samples are discussed.