Stress-Induced Drinking in Parents of Boys with Attention-Deficit-Hyperactivity Disorder: Heterogeneous Groups in an Experimental Study of Adult-Child Interactions

Research on whether parents of children with externalizing disorders are at elevated risk for alcohol problems is equivocal. To reduce this ambiguity, we examined how individual differences in stress reactivity might moderate the drinking behavior of such parents. Parents (119 mothers, 44 fathers) of ADHD sons interacted with different child confederates during each of two counter-balanced sessions. In one, the confederate portrayed a friendly, cooperative, “normal” boy; in the other, the confederate portrayed a “deviant” boy who exhibited behavior characteristic of externalizing disorders. Following each interaction, parents were given an opportunity for ad lib consumption of alcohol while anticipating a second interaction. Latent class analysis identified three subgroups of parents using distress scores and alcohol consumption: minimal stress reactivity; reacts to child deviance with increased distress, but not increased drinking; marked stress-induced drinking. Decisions about the nature and proper treatment of parents raising children with ADHD may be compromised by failure to attend to individual differences in stress reactivity and inclinations to use drinking to cope.     

Conditioned suppression/avoidance as a procedure for testing hearing in birds: The domestic pigeon (Columba livia)

Although the domestic pigeon is commonly used in learning experiments, it is a notoriously difficult subject in auditory psychophysical experiments, even those in which it need only respond when it detects a sound. This is because pigeons tend to respond in the absence of sound—that is, they have a high false-positive rate—which makes it difficult to determine a pigeon’s audiogram. However, false positives are easily controlled in the method of conditioned suppression/avoidance, in which a pigeon is trained to peck a key to obtain food and to stop pecking whenever it detects a sound that signals impending electric shock. Here, we describe how to determine psychophysical thresholds in pigeons using a method of conditioned suppression in which avoidable shock is delivered through a bead chain wrapped around the base of a pigeon’s wings. The resulting audiogram spans the range from 2 to 8000 Hz; it falls approximately in the middle of the distribution of previous pigeon audiograms and supports the finding of Kreithen and Quine (Journal of Comparative Physiology 129:1–4, 1979) that pigeons hear infrasound.     

Beyond the Grand Illusion: What Change Blindness Really Teaches Us About Vision

Experiments on scene perception and change blindness suggest that the visual system does not construct detailed internal models of a scene. These experiments therefore call into doubt the traditional view that vision is a process in which detailed representations of the environment must be constructed. The non-existence of such detailed representations, however, does not entail that we do not perceive the detailed environment. The “grand illusion hypothesis” that our visual world is an illusion rests on (1) a problematic “reconstructionist” conception of vision, and (2) a misconception about the character of perceptual experience.     

Motion influences gaze direction discrimination and disambiguates contradictory luminance cues

In two experiments, we investigated the role of apparent motion in discriminating left/right gaze deviation judgments. We demonstrated that discrimination accuracy and response confidence was significantly higher when the eyes were moved to the left or right, compared to when the eyes were presented in their final shifted position (static images). To dissociate the role of motion signals from luminance signals, gaze stimuli were also presented in reverse contrast. Replicating past studies polarity reversal had a profound and detrimental effect on gaze discrimination in static images, although, intriguingly, while response confidence remained low, participant performance improved as gaze angle increased. In striking contrast to these data, polarity reversal had no negative effect on performance when the eyes were moved. We discuss these findings in the context of a multiple-cue account of gaze perception.     

What is Essential About Indexicals?

Philosophical Studies -