A comparison of cognitive and behavioral patterns in learning‐disabled children: Subtype and sex differences

Ventral Frontal Cortex Morphology in Adult Males with Isolated Orofacial Clefts: Relationship to Abnormalities in Social Function

Objective

In a previous magnetic resonance imaging (MRI) study, men with nonsyndromic clefts of the lip and/or palate (NSCLP) were found to have abnormalities in the structure of the frontal lobe of the brain. Moreover, many subjects with nonsyndromic clefts of the lip and/or palate have been described as being socially inhibited. A subregion of the frontal lobe, the ventral frontal cortex (VFC), has been shown to be related to social function. This study was designed to evaluate the morphology of the ventral frontal cortex in men with nonsyndromic clefts of the lip and/or palate, and the morphology's relationship to social function.

Methods

Subjects were 46 men with nonsyndromic clefts of the lip and/or palate and 46 sex matched controls. Social function was assessed using a standardized scale. The morphology of the ventral frontal cortex (composed of the orbitofrontal cortex [OFC] and the straight gyrus [SG]) was obtained from magnetic resonance imaging scans using the software BRAINS.

Results

After controlling for frontal lobe gray matter, the patient group had significant reductions in orbitofrontal cortex volume and area. The straight gyrus was not morphologically abnormal. Measures of orbitofrontal cortex morphology were significantly correlated to measures of social function—the greater the structural abnormality, the greater the social dysfunction.

Conclusion

Compared with healthy controls, subjects with nonsyndromic clefts of the lip and/or palate showed morphologic abnormalities in the cortical surface anatomy of a brain region known to govern social function, the orbitofrontal cortex. Moreover, the structural abnormality in this brain region was directly correlated with social function.

Impulsivity, intelligence, and discriminating reinforcement contingencies in a fixed-ratio 3 schedule

Research conducted in academic contexts suggests a moderating effect of impulsive behavior on the relationship between aptitude and achievement. According to these studies, intelligence scores being equal, higher levels of impulsivity have an adverse effect on achievement (Helmers, Young, & Pihl, 1995; Vigil-Colet & Morales-Vives, 2005; Zeidner, 1995). The present study aims to contrast the aforementioned moderator effect in the context of a discriminant learning task, carried out under a fixed-ratio 3 reinforcement schedule. To that end, an impulsive behavioral pattern was identified in a sample of 1,600 participants' task execution based on response rate and latency. Said pattern was consistent and stable across several trials and can be ascribed to subjects' interactive style (Hernández, 2000). The observed interaction effect supports the hypothesis that impulsivity has a moderating effect on the aptitude-achievement relationship, highlighting how it impacts achievement differentially depending on the subject's level of aptitude.