Direct measurement of the system latency of gaze-contingent displays

Gaze-contingent displays combine a display device with an eyetracking system to rapidly update an image on the basis of the measured eye position. All such systems have a delay, the system latency, between a change in gaze location and the related change in the display. The system latency is the result of the delays contributed by the eyetracker, the display computer, and the display, and it is affected by the properties of each component, which may include variability. We present a direct, simple, and low-cost method to measure the system latency. The technique uses a device to briefly blind the eyetracker system (e.g., for video-based eyetrackers, a device with infrared light-emitting diodes (LED)), creating an eyetracker event that triggers a change to the display monitor. The time between these two events, as captured by a relatively low-cost consumer camera with high-speed video capability (1,000 Hz), is an accurate measurement of the system latency. With multiple measurements, the distribution of system latencies can be characterized. The same approach can be used to synchronize the eye position time series and a video recording of the visual stimuli that would be displayed in a particular gaze-contingent experiment. We present system latency assessments for several popular types of displays and discuss what values are acceptable for different applications, as well as how system latencies might be improved.     

Validation of the Ambivalent and Purposeful Engagement – Trait Measure

The Ambivalent and Purposeful Engagement-Trait Measure (APE-TM) was developed to assess two ways that people may react to stressful social interactions: ambivalent engagement (AE: counterproductive attempts to avoid thoughts and feelings) and purposeful engagement (PE: effortfully approaching and working through thoughts and feelings). We carried out three studies in undergraduate and clinical populations to (i) test the robustness of previous psychometric findings and (ii) determine whether AE and PE are specific to social anxiety. Across three studies, our results indicate that the APE-TM is a psychometrically valid measure of ambivalent and purposeful engagement. However, PE appeared less specific to social anxiety and may represent a more general tendency toward adaptive coping. In contrast, AE was specific to social anxiety in both undergraduate samples and clinical samples of individuals with a variety of anxiety disorders and depression.     

Adapted digital music players for individuals with severe impairments

Portable music production devices, such as radios, cassette players, and MP3 players, have characteristics that make them less than ideal for teaching the cause‐and‐effect relationships that would enable children and adults with severe impairments to control them independently and appropriately. Even when adapted for control with adaptive switches, the relationship between switch closure and on–off operation results in contingency characteristics that can inhibit learning. Some solutions to these problems are described, and for those individuals who can learn with complex contingencies, some promising products are reviewed. Copyright © 2011 John Wiley & Sons, Ltd.     

On the conjunction fallacy and the meaning of and, yet again: a reply to Hertwig, Benz, and Krauss (2008)

In this paper we question the theoretical tenability of Hertwig, Benz, and Krauss's (2008) (HBK) argument that responses commonly taken as manifestations of the conjunction fallacy should be instead considered as reflecting "reasonable pragmatic and semantic inferences" because the meaning of and does not always coincide with that of the logical operator ∧. We also question the relevance of the experimental evidence that HBK provide in support of their argument as well as their account of the pertinent literature. Finally, we report two novel experiments in which we employed HBK's procedure to control for the interpretation of and. The results obtained overtly contradict HBK's data and claims. We conclude with a discussion on the alleged feebleness of the conjunction fallacy, and suggest directions that future research on this topic might pursue.     

Testing the effects of social anxiety disorder on friendship quality across gender and ethnicity

Previous research suggests that social anxiety disorder (SAD) has a specific relationship with impairment in friendship quality; however, potential moderators of this relationship have not been tested. The current study examines whether the specific effect of SAD on friendship quality is stable or varies across gender and ethnicity in a large epidemiological dataset. Results indicate that the underlying construct of friendship quality differed slightly but significantly between men and women; as a result, effects of SAD were tested in men and women separately. After partially constraining friendship quality across ethnic groups, our results indicated that the relationship between SAD and friendship quality remained robust in all groups. In addition to replicating the finding that SAD specifically relates to perceived friendship quality, the current study highlights the need to test whether underlying constructs such as friendship quality are consistent across the groups that make up heterogeneous samples.     

Reading aloud: The cumulative lexical interference effect

Picture naming shows a cumulative semantic interference effect: Latency for naming a target picture increases as a function of the number of pictures semantically similar to the target that have previously been named (Howard, Nickels, Coltheart, & Cole-Virtue, Cognition 100:464-482, 2006). Howard and colleagues, and also Oppenheim, Dell, and Schwartz (Cognition 114:227-252, 2010), argued that this occurs because of the joint presence in the picture-naming system of three critical properties: shared activation, priming, and competition. They also discussed the possibility that whenever any cognitive system possesses these three properties, a cumulative similarity-based interference effect from repeated use of that cognitive system will occur. We investigated this possibility by looking for a cumulative lexical interference effect when the task is reading aloud: Will the latency of reading a target word aloud increase as a function of the number of words orthographically/phonologically similar to the target that have previously been read aloud? We found that this was so. This supports the general idea that cumulative similarity-based interference effects will arise whenever any cognitive system that possesses the three key properties of shared activation, priming, and competition is repeatedly used.     

Differential effects of m1 and m2 receptor antagonists in perirhinal cortex on visual recognition memory in monkeys

Microinfusions of the nonselective muscarinic antagonist scopolamine into perirhinal cortex impairs performance on visual recognition tasks, indicating that muscarinic receptors in this region play a pivotal role in recognition memory. To assess the mnemonic effects of selective blockade in perirhinal cortex of muscarinic receptor subtypes, we locally infused either the m1-selective antagonist pirenzepine or the m2-selective antagonist methoctramine in animals performing one-trial visual recognition, and compared these scores with those following infusions of equivalent volumes of saline. Compared to these control infusions, injections of pirenzepine, but not of methoctramine, significantly impaired recognition accuracy. Further, similar doses of scopolamine and pirenzepine yielded similar deficits, suggesting that the deficits obtained earlier with scopolamine were due mainly, if not exclusively, to blockade of m1 receptors. The present findings indicate that m1 and m2 receptors have functionally dissociable roles, and that the formation of new visual memories is critically dependent on the cholinergic activation of m1 receptors located on perirhinal cells.