The contribution of familiarity to within- and between-domain associative recognition memory: Use of a modified remember/know procedure

The purpose of the present study was to determine the extent to which familiarity can support associative recognition memory as a function of whether the associations are within- or between-domain. Standard recognition and familiarity only performance were compared in different participants, using a new adaptation of the remember/know procedure. The results indicated that within-domain (face–face) associative recognition was mainly supported by familiarity. In contrast, familiarity provided relatively poor support to between-domain (face–name) associative recognition for which optimal performance required a major recollection contribution. These findings suggest that familiarity can support associative recognition memory, particularly for within-domain associations, and contrast with the widely held view that associative recognition depends largely on recollection.     

Cross-Sectional Age Analysis of Sleep Problems in 2 to 17 Year Olds with ADHD Combined,ADHD Inattentive,or Autism

Sleep problems are common in autism and ADHD. No study has compared sleep problems by age in 2 to 17 year olds with autism versus ADHD-Combined versus ADHD-Inattentive type. Mothers rated 1415 youth with autism and 1041 with ADHD on 10 Pediatric Behavior Scale sleep items. Nighttime sleep problems were most severe in autism, followed by ADHD-Combined, and then ADHD-Inattentive. Difficulty falling asleep, restless during sleep, and waking during the night were the most common problems. Adolescents slept more at night than other age groups, and youth who slept more at night were sleepier during the day. Sleep problems declined with age, but correlations were small. In adolescence, 63% with autism, 53% with ADHD-Combined, and 57% with ADHD-Inattentive had difficulty falling asleep. Given that the majority of children in all age groups had one or more sleep problem, developmentally appropriate interventions are needed to address sleep difficulties and limit their adverse effects.

     

Effects of level of retrieval success on recall-related frontal and medial temporal lobe activations

Brain dedicated single photon emission computed tomography (SPECT) was used to compare the neuroactivation produced by the cued recall of response words in a set of studied word pairs with that produced by the cued retrieval of words semantically related to unstudied stimulus words. Six of the 12 subjects scanned were extensively trained so as to have good memory of the studied pairs and the remaining six were minimally trained so as to have poor memory. When comparing episodic with semantic retrieval, the well-trained subjects showed significant left medial temporal lobe activation, which was also significantly greater than that shown by the poorly trained subjects, who failed to show significant medial temporal lobe activation. In contrast, the poorly trained subjects showed significant bilateral frontal lobe activation, which was significantly greater than that shown by the well-trained subjects who failed to show significant frontal lobe activation. The frontal activations occurred mainly in the dorsolateral region, but extended into the ventrolateral and, to a lesser extent, the frontal polar regions. It is argued that whereas the medial temporal lobe activation increased as the proportion of response words successfully recalled increased, the bilateral frontal lobe activation increased in proportion to retrieval effort, which was greater when learning had been less good.     

Evidence for a boundary effect in roll vection

Large circular displays rotating around the line of sight produce an illusion in which the seen orientation of the true vertical is shifted in a direction opposite to the display’s motion. Two experiments were performed to determine whether the magnitude of this illusory tilt is a function of the area of display elements, of their boundary length, or of their spatial frequency. In Experiment 1, 12 subjects viewed each of nine displays across which the number and area of the circular elements were independently varied. Three of the displays were equated for the area of their elements. The results suggested that tilt magnitude and onset latency could be explained by a boundary length effect. A second experiment tested eight subjects on two displays, equated for element boundary length but differing in the spatial frequency of the elements. The displays produced closely similar illusory trite corroborating the view that, within broad limits, element boundary length—and not spatial frequency or area—determines the size and onset latency of illusory tilt. A third experiment confirmed previous research in finding greater tilt and more rapid onset with more peripherally projected displays.     

A visual object stimulus database with standardized similarity information

Although many visual stimulus databases exist, none has data on item similarity levels for multiple items of each kind of stimulus. We present such data for 50 sets of grayscale object photographs. Similarity measures between pictures in each set (e.g., 25 different buttons) were collected using a similarity-sorting method (Goldstone, Behavior Research Methods Instruments & Computers, 26(4):381–386, 1994). A validation experiment used data from 1 picture set and compared responses from standard pairwise measures. This showed close agreement. The similarity-sorting measures were then standardized across picture sets, using pairwise ratings. Finally, the standardized similarity distances were validated in a recognition memory experiment; false alarms increased when targets and foils were more similar. These data will facilitate memory and perception research that needs to make comparisons between stimuli with a range of known target–foil similarities.     

Development of neural systems for processing social exclusion from childhood to adolescence

Adolescence is a period of development in which peer relationships become especially important. A computer-based game (Cyberball) has been used to explore the effects of social exclusion in adolescents and adults. The current functional magnetic resonance imaging (fMRI) study used Cyberball to extend prior work to the cross-sectional study of younger children and adolescents (7 to 17 years), identifying age-related changes in the neural correlates of social exclusion across the important transition from middle childhood into adolescence. Additionally, a control task illustrated the specificity of these age-related changes for social exclusion as distinct from expectancy violation more generally. During exclusion, activation in and functional connectivity between ventrolateral prefrontal cortex and ventral anterior cingulate cortex increased with age. These effects were specific to social exclusion and did not exist for expectancy violation. Our results illustrate developmental changes from middle childhood through adolescence in both affective and regulatory brain regions during social exclusion.     

Learning,Attention, Writing,and Processing Speed in Typical Children and Children with ADHD,Autism, Anxiety,Depression, and Oppositional-Defiant Disorder

Learning, attention, graphomotor, and processing speed scores were analyzed in 149 typical control children and 886 clinical children with normal intelligence. Nonsignificant differences were found between control children and children with anxiety, depression, and oppositional-defiant disorder. Control children performed better than children with ADHD and autism in all areas. Children with ADHD and autism did not differ, except that children with ADHD had greater learning problems. Attention, graphomotor, and speed weaknesses were likely to coexist, the majority of children with autism and ADHD had weaknesses in all three areas, and these scores contributed significantly to the prediction of academic achievement.