Amygdala and periaqueductal gray lesions only partially attenuate unconditional defensive responses in rats exposed to a cat

Defensive responses to a cat were observed in rats given excitotoxic lesions of the central nucleus of the amygdala (ACe), dorsolateral periaqueductal gray (dlPAG), ventral periaqueductal gray (vPAG), or sham lesions. Rats were placed adjacent to a compartment containing a cat. Sham-lesioned rats avoided the area nearest the cat and preferred the area furthest away from the cat. They also exhibited numerous defensive responses including, climbing, escape from the apparatus, and freezing. Rats with lesions of the ACe reacted like the sham lesioned rats by preferring the area of the apparatus furthest from the cat, however they climbed and escaped significantly less than sham lesioned rats. Avoidance of the area adjacent to the cat was attenuated in rats with lesions of the vPAG. Climbing along the walls of the apparatus was also attenuated in rats with lesions of the vPAG. Escapes from the apparatus were not significantly reduced by lesions of the vPAG and dlPAG. Thus, ACe lesions attenuated climbing and eliminated escapes, but did not impair locomotion of the rat away from the cat.     

The aftereffects of ventriloquism: are they sound-frequency specific?

Exposing different sense modalities (like sight, hearing or touch) to repeated simultaneous but spatially discordant stimulations generally causes recalibration of localization processes in one or both of the involved modalities, which is manifested through aftereffects. These provide opportunities for determining the extent of the changes induced by the exposure. Taking the so-called ventriloquism situation, in which synchronized sounds and light flashes are delivered in different locations, we examine if auditory recalibration produced by exposing tones of one frequency to attraction by discordant light flashes generalizes to different frequencies. Contrary to an earlier report, generalization was obtained across two octaves. This result did not depend on which modality attention was forced on through catch trials during exposure. Implications concerning the functional site of recalibration are briefly discussed.     

Measuring the multidimensional self-concept and global self-worth of 6- to 8-year-olds

A downward extension of a Dutch version of Harter's Self-Perception Profile for Children (SPPC) was tested in a Flemish sample of 880 1st to 3rd graders (Mage = 7.18 years, SD = 0.80). In 2nd and 3rd graders, 5 SPPC factors were identified; in 1st graders only 4 were identified. Support was found for the equivalence of structure and measurement for 2nd and 3rd grades and for boys and girls. Most scales possessed reasonable to good internal consistency for these groups. The results support the multidimensionality of self-concept responses for young children and the improving of the distinctiveness of SPPC factors with age. Young children seem to have an ability to verbalize concepts of their global self-worth that can be tapped by self-report measures.     

Treating boys with low school achievement and behavior problems: comparison of two kinds of intervention

Children with low school achievement frequently have behavior problems and interpersonal difficulties that pose a risk for psychosocial maladjustment. 39 boys were assessed and randomly assigned to one of two group treatment conditions: (a) interpersonal cognitive problem-solving for whom training was provided through oral and written language activities that met children's social and academic needs and (b) a language workshop, during which only academic difficulties were treated. Parents of children in both groups received group attention. Posttreatment assessments indicated that boys in both conditions showed significant improvements on school achievement and behavior problems, as they were measured by behavior scales reported by mothers and by an academic achievement test. Children in the problem-solving group improved significantly more than the other group on most measures. These results suggest that work with interpersonal cognitive problem-solving skills combined with reading and writing activities is a useful means to produce improvements in child behavior and school achievement.     

Age differences in working memory— The roles of storage and selective access

Twenty-four young (23 years) and 24 old (71 years) adults performed arithmetic tasks with working memory loads ranging from 1 to 4. Age groups were equivalent in mean accuracy and speed of arithmetic operations under minimal working memory load, but old adults were slower than young with memory demands >1. Access to a new object in working memory as the basis of computation required additional time. This object-switching cost increased with increases in memory demand, but was unaffected by age, indicating that old adults have no deficit in selective access to working memory.     

It takes two to mimic: behavioral consequences of self-construals

The present studies demonstrated the moderation of self-construal orientation on mimicry. Recent research has indicated that an interdependent self-construal is associated with assimilation of the other to the self whereas an independent self-construal is associated with minimizing the influence of others on the self (H. R. Markus & S. Kitayama, 1991; D. Stapel & W. Koomen, 2001). Therefore, the authors hypothesized that an interdependent self-construal would be associated with more mimicry than an independent self-construal. When self-construal orientations were experimentally primed, as in Studies 1 and 2, independent self-construals produced less nonconscious mimicry than interdependent self-construals. When self-construals were examined as cultural differences with either a chronically dominant independent (Americans) or interdependent (Japanese) construal of the self, these results were replicated.     

Nonparametric IRT: Testing the bi-isotonicity of isotonic probabilistic models (ISOP)

Nonparametric tests for testing the validity of polytomous ISOP-models (unidimensional ordinal probabilistic polytomous IRT-models) are presented. Since the ISOP-model is a very general nonparametric unidimensional rating scale model the test statistics apply to a great multitude of latent trait models. A test for the comonotonicity of item sets of two or more items is suggested. Procedures for testing the comonotonicity of two item sets and for item selection are developed. The tests are based on Goodman-Kruskal's gamma index of ordinal association and are generalizations thereof. It is an essential advantage of polytomous ISOP-models within probabilistic IRT-models that the tests of validity of the model can be performed before and without the model being fitted to the data. The new test statistics have the further advantage that no prior order of items or subjects needs to be known.     

How normal is grammatical development in the right hemisphere following hemispherectomy? The root infinitive stage and beyond

We examined the morphosyntax of eight left hemispherectomized children at two different stages and compared it to MLU-matched normals. We found that the language of the hemispherectomies paralleled that of their MLU matches with respect to the specific morphosyntactic characteristics of each stage. Our findings provide strong evidence for the presence of functional categories in all early grammars and demonstrate that grammatical development, regardless of its neural substrate, is highly constrained by UG and follows a narrowly determined course. We discuss our findings within a neurobiological framework in which etiology defines the integrity of the remaining hemisphere, which in turn, determines its potential for linguistic reorganization and/or acquisition.     

Face processing in adolescents with autistic disorder: the inversion and composite effects

Two experiments with upright and inverted face and object images were carried out to investigate whether face processing in autism is more feature-based than in individuals with typical development. Participants were 17 high-ability adolescents with autistic disorder (16-24 years), 24 typically developing children (9-10 years) and 16 adults (18-33 years). In Experiment 1, a normal inversion effect was found for the adolescents with autism in a standard face recognition paradigm with reduced memory demands, except for a subgroup with low social intelligence who were not better in recognizing upright relative to inverted photographs of faces. In Experiment 2, the group with autism did not show the composite effect like the adult group did: they recognized face halves as well in aligned composite faces as in non-aligned composite faces. The results on the inversion task suggest that most adolescents with autism form a normal configuration-based face representation, but the absence of the composite effect indicates that they are less prone to use the contextual information of the face in a visual-search task.     

Velocity dependence of the interocular transfer of dynamic motion aftereffects

It is well established that motion aftereffects (MAEs) can show interocular transfer (IOT); that is, motion adaptation in one eye can give a MAE in the other eye. Different quantification methods and different test stimuli have been shown to give different IOT magnitudes, varying from no to almost full IOT. In this study, we examine to what extent IOT of the dynamic MAE (dMAE), that is the MAE seen with a dynamic noise test pattern, varies with velocity of the adaptation stimulus. We measured strength of dMAE by a nulling method. The aftereffect induced by adaptation to a moving random-pixel array was compensated (nulled), during a brief dynamic test period, by the same kind of motion stimulus of variable luminance signal-to-noise ratio (LSNR). The LSNR nulling value was determined in a Quest-staircase procedure. We found that velocity has a strong effect on the magnitude of IOT for the dMAE. For increasing speeds from 1.5 deg s(-1) to 24 deg s(-1) average IOT values increased about linearly from 18% to 63% or from 32% to 83%, depending on IOT definition. The finding that dMAEs transfer to an increasing extent as speed increases, suggests that binocular cells play a more dominant role at higher speeds.