The DalHouses: 100 new photographs of houses with ratings of typicality, familiarity, and degree of similarity to faces.

Houses have often been used as comparison stimuli in face-processing studies because of the many attributes they share with faces (e.g., distinct members of a basic category, consistent internal features, mono-orientation, and relative familiarity). Despite this, no large, well-controlled databases of photographs of houses that have been developed for research use currently exist. To address this gap, we photographed 100 houses and carefully edited these images. We then asked 41 undergraduate students (18 to 31 years of age) to rate each house on three dimensions: typicality, likeability, and face-likeness. The ratings had a high degree of face validity, and analyses revealed a significant positive correlation between typicality and likeability. We anticipate that this stimulus set (i.e., the DalHouses) and the associated ratings will prove useful to face-processing researchers by minimizing the effort required to acquire stimuli and allowing for easier replication and extension of studies. The photographs of all 100 houses and their ratings data can be obtained at http://dx.doi.org/10.6084/m9.figshare.1279430.

Craving and emotional responses to trauma and cannabis cues in trauma-exposed cannabis users: Influence of PTSD symptom severity.

Conditioned craving to trauma cues and avoidance learning have both been implicated in the high concurrence of trauma-related distress and substance misuse. Using a cue-exposure paradigm involving personalized trauma, cannabis, and neutral cues, we examined if conditioned craving and/or elevated negative affect to trauma cues are mechanisms linking PTSD and cannabis use disorder. Fifty-one trauma-exposed cannabis users were randomly presented the three cue types. Craving and emotional responses were evaluated after each cue using the Marijuana Craving Questionnaire-Short Form (Heishman et al., 2001) and the Positive and Negative Affect Schedule (Watson et al., 1988). Relief cannabis craving (compulsivity and emotionality) was significantly higher after trauma than cannabis and neutral cues (p's < 0.001) and was also higher among those with more severe PTSD symptoms (p's < 0.05). The relationship between PTSD symptom severity and cannabis craving was stronger after trauma than cannabis cues for the compulsivity component of craving (p < .05). Relief craving was also higher after the cannabis cue than after the neutral cue (expectancy and purposefulness; p < .001). Negative affect was significantly higher: after trauma than cannabis and neutral cues (p's < 0.001); and among those with more severe PTSD symptoms (p < . 005). Positive affect was significantly lower after trauma than cannabis cues (p < .05). Trauma cue exposure might promote cannabis misuse through conditioned craving as well as the desire to relieve negative affect. Conditioned cannabis craving involving an uncontrollable compulsion to use cannabis in response to trauma reminders appears particularly likely among cannabis users with more severe PTSD symptoms.

Modeling the integration of expectations in visual search with centre-surround neural fields.

Centre-Surround Neural Field (CSNF) models were used to explain a possible mechanism by which information from different sources may be integrated into target likelihood maps that are then used to direct eye saccades. The CSNF model is a dynamic model in which each region in network excites near-by location and inhibits distant locations, thereby modeling competition for eye movements (saccades). The CSNF model was tested in a number of conditions analogous to a naturalistic search task in which the target was either (1) present in the expected location, (2) present in the unexpected location, or (3) absent. Simulations showed that the model predicted a pattern of accuracy results similar to those obtained by [Eckstein, M. P., Drescher, B. A., & Shimozaki, S. S. (2006). Attentional cues in real scenes, saccadic targeting, and Bayesian priors. Psychological Science, 17(11), 973-980] from human participants. However, the model predicts different saccadic latencies between conditions where Eckstein, Drescher, and Shimozaki (2006) found no significant differences. These discrepancies between model predictions and behavioural results are discussed. Additional simulations indicated that these models can also capture the qualitative flavor of eye movements in conditions with multiple targets as compared to [Findlay, J. M. (1997). Saccade target selection during visual search. Vision Research, 37(5), 617-631].

Luck, come here! Automatic approach tendencies toward gambling cues in moderate- to high-risk gamblers.

BACKGROUND AND AIMS: Similar to substance addictions, reward-related cognitive motivational processes, such as selective attention and positive memory biases, have been found in disordered gambling. Despite findings that individuals with substance use problems are biased to approach substance-related cues automatically, no study has yet focused on automatic approach tendencies for motivationally salient gambling cues in problem gamblers. We tested if moderate- to high-risk gamblers show a gambling approach bias and whether this bias was related prospectively to gambling behaviour and problems. DESIGN: Cross-sectional assessment study evaluating the concurrent and longitudinal correlates of gambling approach bias in moderate- to high-risk gamblers compared with non-problem gamblers. SETTING: Online study throughout the Netherlands. PARTICIPANTS: Twenty-six non-treatment-seeking moderate- to high-risk gamblers and 26 non-problem gamblers community-recruited via the internet. MEASUREMENTS: Two online assessment sessions 6 months apart, including self-report measures of gambling problems and behaviour (frequency, duration and expenditure) and the gambling approach avoidance task, with stimuli tailored to individual gambling habits. FINDINGS: Relative to non-problem gamblers, moderate- to high-risk gamblers revealed a stronger approach bias towards gambling-related stimuli than neutral stimuli (P = 0.03). Gambling approach bias was correlated positively with past-month gambling expenditure at baseline (P = 0.03) and with monthly frequency of gambling at follow-up (P = 0.02). In multiple hierarchical regressions, baseline gambling approach bias predicted monthly frequency positively (P = 0.03) and total duration of gambling episodes (P = 0.01) 6 months later, but not gambling problems or expenditure. CONCLUSIONS: In the Netherlands, relative to non-problem gamblers, moderate- to high-risk gamblers appear to have a stronger tendency to approach rather than to avoid gambling-related pictures compared with neutral ones. This gambling approach bias is associated concurrently with past-month gambling expenditure and duration of gambling and has been found to predict persistence in gambling behaviour over time.

Methods for validating chronometry of computerized tests.

Determining the speed at which a task is performed (i.e., reaction time) can be a valuable tool in both research and clinical assessments. However, standard computer hardware employed for measuring reaction times (e.g., computer monitor, keyboard, or mouse) can add nonrepresentative noise to the data, potentially compromising the accuracy of measurements and the conclusions drawn from the data. Therefore, an assessment of the accuracy and precision of measurement should be included along with the development of computerized tests and assessment batteries that rely on reaction times as the dependent variable. This manuscript outlines three methods for assessing the temporal accuracy of reaction time data (one employing external chronometry). Using example data collected from the Dalhousie Computerized Attention Battery (DalCAB) we discuss the detection, measurement, and correction of nonrepresentative noise in reaction time measurement. The details presented in this manuscript should act as a cautionary tale to any researchers or clinicians gathering reaction time data, but who have not yet considered methods for verifying the internal chronometry of the software and or hardware being used.

Measuring the components of attention using the Dalhousie Computerized Attention Battery (DalCAB).

Using experimentally validated tests to measure the vigilance/alerting, orienting and executive control attention networks, we have developed a novel, theoretically driven battery for measuring attentional abilities, called the Dalhousie Computerized Attention Battery (DalCAB). The current study sought to examine the factor structure of the DalCAB as preliminary evidence for its validation as an assessment tool for the above-named attention networks. One hundred young, healthy adult participants (18 to 31 years) completed the DalCAB (simple reaction time, choice reaction time, dual task, go/no-go, visual search, vertical flanker, and item memory tasks). Exploratory factor analysis of task performance with promax rotation highlighted a 9-factor model, accounting for 54.66% of the shared variance. Factors 1, 2, and 5 are associated with measures reflecting the vigilance/alerting network (response speed, maintenance/preparation and consistency, respectively), Factor 3 is associated with the orienting network (searching measures). Factors 4, 6, 7, and 8 are associated with different aspects of the executive control network including: inhibition, working memory, filtering, and switching. The final factor is associated with vigilance/alerting (fatigue) and executive control (proactive interference). Our model provides preliminary evidence for the validation of our interpretation of the DalCAB as a measure of vigilance/alerting, orienting, and executive control attentional abilities, and contributes to the previously reported evidence for the validation of these tasks for measuring different aspects of attention. We also demonstrate the importance of each of the specific measures derived from the DalCAB tasks, and our results provide further behavioral evidence of the existence of multiple attention-related networks.

Photographs of manipulable objects are named more quickly than the same objects depicted as line-drawings: Evidence that photographs engage embodiment more than line-drawings.

Previous research has shown that photographs of manipulable objects (i.e., those that can be grasped for use with one hand) are named more quickly than non-manipulable objects when they have been matched for object familiarity and age of acquisition. The current study tested the hypothesis that the amount of visual detail present in object depictions moderates these "manipulability" effects on object naming. The same objects were presented as photographs and line-drawings during a speeded naming task. Forty-six participants named 222 objects depicted in both formats. A significant object depiction (photographs versus line drawing) by manipulability interaction confirmed our hypothesis that manipulable objects are identified more quickly when shown as photographs; whereas, non-manipulable objects are identified equally quickly when shown as photographs versus line-drawings. These results indicate that factors such as surface detail and texture moderate the role of "action" and/or "manipulability" effects during object identification tasks, and suggest that photographs of manipulable objects are associated with more embodied representations of those objects than when they are depicted as line-drawings.