Probability effects on stimulus evaluation and response processes.

This study investigated the effects of probability information on response preparation and stimulus evaluation. Eight subjects responded with one hand to the target letter H and with the other to the target letter S. The target letter was surrounded by noise letters that were either the same as or different from the target letter. In 2 conditions, the targets were preceded by a warning stimulus unrelated to the target letter. In 2 other conditions, a warning letter predicted that the same letter or the opposite letter would appear as the imperative stimulus with .80 probability. Correct reaction times were faster and error rates were lower when imperative stimuli confirmed the predictions of the warning stimulus. Probability information affected (a) the preparation of motor responses during the foreperiod, (b) the development of expectancies for a particular target letter, and (c) a process sensitive to the identities of letter stimuli but not to their locations.     

Functional Neuroimaging in the Examination of Effects of Prenatal Alcohol Exposure

Functional neuroimaging offers the opportunity to understand the effect of prenatal alcohol exposure on the activities of the brain as well as providing a window into the relationship between neural activation and the behavioral outcomes that have been described in affected individuals. Several different methodologies have been used to examine the neurophysiological signal changes associated with different brain functions in prenatally exposed individuals and those diagnosed with fetal alcohol syndrome (FAS) or other fetal alcohol spectrum disorders (FASD). These include electroencephalography (EEG), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and functional magnetic resonance imaging (fMRI). These studies demonstrate that it is feasible to use these technologies with this clinical population and that the damage to the central nervous system associated with prenatal alcohol exposure has widespread functional implications; however, currently, the literature in these areas is limited and unsystematic. Functional MRI with this clinical population has just begun to explore the implications of prenatal alcohol exposure with the first paper published in 2005. Other methodologies are similarly limited in scope. Nonetheless, these functional neuroimaging studies suggest that prenatal alcohol exposure, or a diagnosis of FAS, may lead to restrictions in neural efficiency or a global decrement in processing resources.     

Elucidating the Relation of Hoarding to Obsessive Compulsive Disorder and Impulse Control Disorders

Hoarding has historically been conceptualized as a symptom of Obsessive Compulsive Disorder (OCD); however, data demonstrate important differences between hoarding and OC symptoms (for discussion, see Grisham et al. Anxiety Disorders, 19, 767‑779. 2005). Hoarding has also been observed in disorders besides OCD, including specific Impulse Control Disorders (ICDs; e.g., kleptomania, trichotillomania, pathological gambling, compulsive buying). Therefore, the current study tested the hypothesis that hoarding would be as strongly related to symptoms of ICDs as it is to OCD and that these relationships would be medium to strong in magnitude. Results from an undergraduate sample showed hoarding behaviors were strongly related to symptoms of OCD, moderately related to symptoms of compulsive buying, and more modestly related to symptoms of pathological gambling, trichotillomania, and kleptomania. Finally, findings suggest indecisiveness may be a particularly important underlying feature in hoarding behaviors. These results support the consideration of hoarding outside the confines of OCD.

Cry analysis detects subclinical effects of prenatal alcohol exposure in newborn infants

The threshold, latency, and peak fundamental frequency (basic pitch) of crying were sensitive to the subclinical effects of prenatal alcohol exposure through the first month of postnatal life. Whereas infants with prenatal alcohol exposure showed a lower cry pitch and higher cry threshold at 2 days of age, higher pitched cries, typical of nervous system insult, were evident at 14 and 28 days. A longer latency was also evident at 14 days.     

Expression recognition and behavioural problems in early adolescence

The processing of emotional expressions is fundamental for normal socialisation and social interaction. Fifty-five children (aged 11–14 years) in mainstream education participated in this study. They were presented with a standardised set of pictures of facial expressions and asked to name one of the six emotions illustrated (sadness, happiness, anger, disgust, fear, and surprise). Following experimental testing, their behaviour was rated by two independent teachers on the Psychopathy Screening Device (PSD). The PSD assesses two dimensions of behavioral problems: affective-interpersonal disturbance and impulsive behaviour/conduct problems. The results showed that the ability to recognise sad and fearful expressions (but not happy, angry, disgusted, or surprised expressions) was inversely related to both level of affective-interpersonal disturbance and impulsive/conduct problems. These results are interpreted with reference to current models of empathy and its disorders.