Vocational maturity of Arab and American high school students

The vocational maturity of Arab and American ninth- and eleventh-grade students were compared. Arab students were found to have lower maturity scores than American students. Eleventh graders of both nationalities were more vocationally mature than ninth graders. The possibility that the overall difference found between Arab and American students can be attributed to cultural differences was supported by the response trend of discriminating items as revealed by an item analysis.     

CT scan and neuropsychological correlates of Alzheimer's disease and Huntington's disease

"Cortical" and "subcortical" dementia syndromes differ in areas of primary neuropathology and clinical characteristics. Conventional CT scan interpretation, visual inspection of pictures, has not been useful in studying dementia. Recent studies of the digitally stored CT attenuation values have found systematic variations with normal aging and aphasia subtypes. In this study of numerical CT scan information in four Alzheimer's Disease and two Huntington's Disease patients, a double dissociation of frontal and temporal lobe density values was found, and a significant correlation was found between left temporal lobe density and verbal ability measures in the Alzheimer's Disease patients.     

Very long term memory for tacit knowledge

Very long term memory for abstract materials was examined by recalling subjects who had served in a synthetic grammar learning experiment two years earlier. In that study (Reber & Allen, 1978) we differentiated among several cognitive modes of acquisition, their resultant memorial representations, and their associated decision processes. Two years later and without any opportunity for rehearsal or relearning, subjects still retain knowledge of these grammars to a remarkable degree. Although some differences have become blurred with the passage of time, the form and structure of that knowledge and the manner in which it is put to use remain strikingly similar to the original. That is, differences traceable to acquisition mode and conditions of initial training can still be observed. As in the original study, these results are discussed within the general context of a functionalist approach to complex cognitive processes.     

The development of grapheme-phoneme correspondence in normal and dyslexic readers

The present experiment was concerned with the development of grapheme-phoneme conversion ability in normal and reading-age matched dyslexic readers. The use of grapheme-phoneme correspondences was observed in a recognition memory task for pronounceable nonwords. The nonwords were presented in either the visual or auditory modality and had to be recognized immediately from the converse modality, thus necessitating decoding of stimuli across modalities. The use of grapheme-phoneme correspondences increased with reading age in the normal readers but not in the dyslexics. It was postulated that dyslexics have a specific difficulty in grapheme-phoneme conversion. For them an increase in reading age is attributable mainly to an increase in size of sight vocabulary.     

Event-related potentials in neuropsychological studies of language

Experiments are described in which event-related potentials (ERPs) are employed to study the specialization of functions between and within the cerebral hemispheres during the performance of language and nonlanguage tasks by normal adults. Similar studies of deaf subjects suggest that the functional organization of the brain may be altered after different early language and sensory experiences. Studies of patients with alexia without agraphia suggest that the ERP may be a valuable tool with which to study cerebral reorganization after brain damage.     

Hemispheric asymmetries in the perception of musical intervals as a function of musical experience and family handedness background

This study examines the effect of musical experience and family handedness background on the categorization of musical intervals (two-note chords). Right-handed subjects, who were divided into four groups on the basis of musical training and presence (or absence) of left-handed family members, categorized musical intervals which were monaurally presented to left or right ear. The results, based on consistency and discreteness of categorization, showed: (1) Musicians' performance is superior to nonmusicians'; (2) musicians and nonmusicians differ significantly on their ear of preference; (3) family handedness background significantly affects ear of preference among musicians but not among nonmusicians.     

Developmental stuttering and the role of the supplementary motor cortex

Developmental stuttering is a frequent neurodevelopmental disorder with a complex neurobiological basis. Robust neural markers of stuttering include imbalanced activity of speech and motor related brain regions, and their impaired structural connectivity. The dynamic interaction of cortical regions is regulated by the cortico-basal ganglia-thalamo-cortical system with the supplementary motor area constituting a crucial cortical site. The SMA integrates information from different neural circuits, and manages information about motor programs such as self-initiated movements, motor sequences, and motor learning. Abnormal functioning of SMA is increasingly reported in stuttering, and has been recently indicated as an additional “neural marker” of DS: anatomical and functional data have documented abnormal structure and activity of the SMA, especially in motor and speech networks. Its connectivity is often impaired, especially when considering networks of the left hemisphere. Compatibly, recent data suggest that, in DS, SMA is part of a poorly synchronized neural network, thus resulting in a likely substrate for the appearance of DS symptoms. However, as evident when considering neural models of stuttering, the role of SMA has not been fully clarified. Herein, the available evidence is reviewed, which highlights the role of the SMA in DS as a neural “hub”, receiving and conveying altered information, thus “gating” the release of correct or abnormal motor plans.     

The tendency to overestimate what is visible in a planar mirror amongst adults and children

Adults hold several mistaken beliefs about simple mechanical and optical phenomena. In particular, many adults believe that they would be able to see their own image in a mirror before they are in front of it. Similarly, they expect objects to become visible in mirrors before they actually do. This overestimation of what is visible is known as the early error (Bertamini, Spooner, & Hecht, 2003). It has been suggested that incorrect models about mechanics, and therefore erroneous beliefs, develop over time, as evidenced by good performance in young children (Kaiser, McCloskey, & Proffitt, 1986). With respect to knowledge about what is visible in mirrors we report the first developmental data. We confirmed an effect for prospective University students but found no evidence of any early error in children between the age of 5 and 11. This erroneous belief about mirrors develops during the later school years when people develop a system of beliefs based on experience.