Behavioral Characteristics of DSM-IV ADHD Subtypes in a School-Based Population

From an ethnically diverse sample of 2,744 school children, 221 attention deficit hyperactivity disorder (ADHD) [123 (4.5%) predominantly inattentive (IA), 47 (1.7%) predominantly hyperactive/impulsive (HI), and 51 (1.9%) combined type (C)] were identified using teacher ratings on a Diagnostic and Statistical Manual of Mental Disorders (4th ed.) (DSM-IV) symptom checklist. Subjects were compared to 221 controls on teacher ratings of behavioral, academic, and social functioning. The results revealed relatively independent areas of impairment for each diagnostic group. The IA children were impaired in all areas, but were rated as displaying more appropriate behavior and fewer externalizing problems than HI or C children. The HI group displayed externalizing and social problems, but was rated as no different than controls in learning or internalizing problems. The C group demonstrated severe and pervasive difficulties across domains. These findings support the validity of the DSM-IV ADHD subtypes; all ADHD groups demonstrated impairment relative to controls, but show different patterns of behavioral characteristics.     

Demonstration of a socially transmitted taste aversion in the rat

Observer rats were allowed to interact for 15 min with 2 conspecific demonstrators, 1 that had been fed a cocoa-flavored diet and 1 that had been fed a cinnamon-flavored diet. One of the demonstrators had been made ill immediately following ingestion of its diet. The observer rats were then presented with the cocoa-flavored and cinnamon-flavored diets for 22 h. The observer rats consumed significantly less of the ill demonstrator’s diet than of the healthy demonstrator’s diet. This finding suggests that, under some conditions, rats can acquire a socially transmitted taste aversion.     

Separation anxiety in mothers of latency-age fearful children

The hypothesis that mothers of children who have symptoms indicative of separation anxiety are themselves separation-anxious was tested by scoring mothers' TAT themes for separation concerns. The stories of 15 mothers of fearful children were compared to the stories of 26 mothers of children manifesting behavior disorders and 21 mothers of children having had no psychiatric contact. Different kinds of separation concerns were found to differentiate the groups of mothers. The stories of mothers of fearful children expressed significantly more concerns about abandonment and rejection and more often expressed a desire to stay near the loved one; the mothers of children with behavior disorders were found to tell significantly more stories with nurturance-succorance themes. The results lend support to the theory of anxious attachment in that mothers of fearful children seem to share the same concerns that have been ascribed to their children. On the other hand, it seems that separation anxiety may not be a unidimensional construct as different components seem to be more relevant to some symptom clusters than to others.     

The role of motion in children's categorization of objects.

Perceptual cues play a fundamental role in early categorization of objects. What is meant by perceptual cues in the literature, however, is not always clear. It is fair to say that they are typically understood to be static shape cues. A number of recent studies have suggested that dynamic perceptual cues, such as motion, may also be important in early categorization. The study presented here explored the role that motion plays in children's categorization of animal and non-animal kinds, such as geometric figures. Motion was directly pitted against shape as a cue for categorization. Results showed that 4-year-old children, confronted with a choice between shape and motion, significantly used motion cues over shape cues to categorize objects, regardless of whether they were animals or geometric figures. Seven-year-olds also tended to use motion more often to categorize animals but not when dealing with geometric figures. Older children, who have been found to have a clearer natural kind/artifact distinction, seem to appreciate the uniqueness of movement to animals and see motion as more relevant to their categorization but relatively less so to categorize geometric figures. This developmental shift in the categorization of animals and geometric figures based on motion was further confirmed by testing adults on the same tasks. Adults were found to base their judgements significantly more often on motion for animals but not for geometric figures. These findings support the view that children are initially guided by motion in object categorization, suggesting that motion plays an overriding role that is central in the process of concept acquisition and in the mechanisms by which concepts are later structured.     

Somatization, psychiatric disorder, and stress in utilization of ambulatory medical services

Examined the prediction from Mechanic's (1972) attribution theory of somatization that somatizers who are under stress will overuse ambulatory medical services. Two hundred fourteen volunteer patients from university ambulatory care clinics completed the Diagnostic Interview Schedule and the Life Experiences Inventory. We examined somatization, psychiatric diagnoses, and life stress-and the interaction of these factors-in predicting frequency of medical visits during the preceding year, after controlling for need (active medical problems) and predisposing factors. As hypothesized, life stress interacted with somatization in predicting number of medical visits; somatizers who were under stress made more visits to the clinics than did nonsomatizers or somatizers who were not under stress. Although stress affected somatizers most, stress was predictive of increased medical utilization for all patients. These results suggest that psychological services intended to reduce overutilization of outpatient medical services might best focus on stress reduction and be most beneficial to somatizers.     

Attentional capture and inhibition (of return): the effect on perceptual sensitivity

The present study was designed to determine the spatial distribution of attention in displays in which an irrelevant color singleton was present. The results show that at the location of an irrelevant singleton, there is, first, an increased sensitivity (d'), followed later by a reduced sensitivity. The increased sensitivity implies that, first, the irrelevant singleton captured spatial attention, producing an increased sensory gain for input at the irrelevant distractor location. The later-occurring, reduced sensitivity implies the operation of inhibitory processes, possibly related to inhibition of return.     

Lexicality and phonological similarity: a challenge for the retrieval-based account of serial recall?

The retrieval-based account of serial recall (Saint-Aubin & Poirier, 2000) attributes lexicality, phonological similarity, and articulatory suppression effects to a process where long-term representations are used to reconstruct degraded phonological traces. Two experiments tested this assumption by manipulating these factors in the recall of four- and five-item lists of words and non-words. Lexicality enhanced item recall (IR), but only affected position accuracy (PA) for five-item lists under suppression. Phonological similarity influenced both words and non-words, and produced impaired PA in silent and suppressed conditions. Consistent with the retrieval-based account, words and non-words of high word-likeness appear subject to redintegration. However, some findings, like suppression not reducing the phonological similarity impairment in suppressed conditions, present challenges for the retrieval-based account and other models of serial recall.     

Contributions of linguistic,quantitative, and spatial attention skills to young children's math versus reading: Same,different, or both?

The study used Bayesian and Frequentist methods to investigate whether the roles of linguistic, quantitative, and spatial attention skills are distinct in children's acquisition of reading and math. A sample of 175 Chinese kindergarteners was tested with measures of linguistic skills (phonological awareness and phonological memory), quantitative knowledge (number line task, symbolic digit comparison, and non-symbolic number estimation), spatial attention skills (visual span, mental rotation, and visual search), word reading, and calculation. After statistically controlling for age and nonverbal intelligence, phonological awareness and digit comparison performance explained unique variance in both math and reading. Moreover, number line estimation was specifically important for math, while phonological memory was specifically essential for reading. These findings highlight the possibility of developing early screening tools with different cognitive measures for children at risk of learning disabilities in reading and/or math.