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Salvage excavations of a nearly complete and remarkably well-preserved skeleton of an American mastodont (Mammut americanum) in Licking County, Ohio, yielded a discrete, cylindrical mass of plant material found in association with articulated vertebrae and associated ribs. This material is interpreted as intestinal contents of the mastodont and paleobotanical analyses indicate that the mastodont diet included significant amounts of low, herbaceous vegetation. Enteric bacteria (Enterobacter cloacae), isolated from a sample of this material, are believed to represent survivors or descendants of the intestinal microflora of the mastodont. This is the first report of the isolation of bacteria associated with late Pleistocene megafauna.
Synaptic development and elimination are normal neurodevelopmental processes, which if altered could contribute to various neuropsychiatric disorders. 31P-1H magnetic resonance spectroscopic imaging (MRSI) and structural magnetic resonance imaging (MRI) exams were conducted on 105 healthy children ages 6–18 years old to identify neuromolecular indices of synaptic development and elimination. Over the age range studied, age-related changes in high-energy phosphate (phosphocreatine), membrane phospholipid metabolism (precursors and breakdown products), and percent gray matter volume were found. These neuromolecular and structural indices of synaptic development and elimination are associated with development of several cognitive domains. Monitoring of these molecular markers is essential for devising treatment strategies for neurodevelopmental disorders. (JINS, 2009, 15, 671–683.)
A neuropsychological investigation of 21 Persian Gulf veterans and 38 demographically matched controls was conducted in order to make a preliminary determination concerning presence of neuropsychological deficits associated with the Persian Gulf War experience. The neuropsychological test battery consisted of measures of complex attention, memory, and motor skills previously shown to be sensitive to exposure to environmental toxins. It was found that the Persian Gulf veteran group did not demonstrate substantial impairment, but an impairment index derived from 14 test variables was statistically significantly different from controls in the direction of poorer performance. (JINS, 1996, 2, 368–371.)
Clinical neuropsychologists have often commented that sometimes a memory problem is not a problem with memory. The implication of this remark is that what appears to be a difficulty with remembering is actually the result of a deficit in some other domain of cognitive functioning, influencing memory only indirectly. Our studies of the profile of neuropsychological functioning in autism have provided evidence of multiple primary coexisting deficits with one of the affected cognitive processes being memory (Minshew, Goldstein & Siegel, 1997; Williams, Goldstein & Minshew, 2006a). Over the past fifteen years, we have performed comprehensive studies of memory functioning in over 100 children, adolescents and adults, all of whom met Autism Diagnostic Interview (ADI & ADI-Revised, Le Couteur et al., 1989; Lord, Rutter & Le Couteur, 1994), Autism Diagnostic Observation Schedule (ADOS; Lord et al., 1989, 1999), and expert opinion criteria for autistic disorder (AD), including onset prior to age 3 years. The lower limit of Full-Scale and Verbal IQ scores varied between 70 and 80 depending on the study. The results of this research have led us to conclude that the memory impairment is universal across participants with high-functioning autism (HFA), but is selective in that it does not involve all aspects of memory functioning. The memory processes in HFA are differentially affected by domain, demands of the memory task, and the cognitive abilities of the individual.
Neuropsychological deficits are considered by many to be core features of schizophrenia. However, about 20% of patients with schizophrenia appear to have normal neuropsychological function. This study investigates this subgroup by comparing a “neuropsychologically normal” schizophrenia group to a non-schizophrenic, non-brain damaged patient comparison (PC) sample, and to patients with definitive brain damage who performed normally on neuropsychological testing. All patients completed the Halstead-Reitan Neuropsychological Test Battery and were classified as neuropsychologically normal or impaired using the Average Impairment Rating (AIR). In a sample of 113 patients with schizophrenia, 19.5% were classified as neuropsychologically normal. The brain damaged neuropsychologically normal group (BD-NN) consisted of 14.3% of 124 subjects. These groups were compared with a patient non-schizophrenic, non-brain damaged group who were selected on the basis of having an Average Impairment Rating in the neuropsychologically normal range. The neuropsychologically normal schizophrenic group performed less well than the non-brain damaged, non-schizophrenic patient comparison group on a number of tests, indicating that patients in this group may not be completely neuropsychologically normal, and would be better characterized as “high-functioning” or near normal. The results are discussed in regard to possible neurobiological differences between neuropsychologically impaired and intact schizophrenic patients, and implications for course and outcome. (JINS, 2003, 9, 56–63.)
A battery of tests of auditory and visual memory was used to investigate memory function in 52 high-functioning adolescents and young adults with autism and 40 group-matched normal controls. It was hypothesized that memory dysfunction is present in autism but is not modality specific and is produced by poor utilization of organizing strategies. It was therefore hypothesized that memory impairment in autism would become more prominent as task complexity was increased. The participants with autism performed as well as controls on short-term memory and paired-associate learning tasks, but performed significantly less well than controls on a list learning task. They also performed significantly more poorly on immediate and delayed recall of a story and of a complex geometric figure. On a maze learning task, their performance became progressively worse relative to controls as the complexity of the maze increased. On a series of span tasks, they did not differ from controls on letter span, but did significantly worse on word span and sentences of increasing complexity. These findings indicate a lack of modality specificity and a failure to initiate organizing strategies as evidenced by inefficiency in new learning, poor utilization of contextual cues in story and complex pattern recall, and greater impairment with increasing complexity of the material.
A cluster analytic solution based upon a battery
of tests consisting of the Halstead Category and Tactual
Performance Tests, the Trail Making Test, and the Wisconsin
Card Sorting Test was compared with a solution based on
the subtests of the Wechsler intelligence scales, utilizing
a sample of 221 schizophrenic patients. Both analyses permitted
four-cluster solutions, and we found a weak but significant
degree of association between solutions. Examination of
external validity of the two solutions revealed stronger
associations with clinical variables for the Wechsler-scale-based
solution. The major conclusions were that the existence
of cognitive heterogeneity in schizophrenia exists across
a broad range of abilities, and appears to reflect a combination
of continuity of ability level and existence of possible
subtypes requiring further neuropsychological and neurobiological
verification. (JINS, 1998, 4, 353–362.)
Neurobehavioral theories of autism have hypothesized
core deficits in sensory input or perception, basic attentional
abilities or generalized attention to extrapersonal space,
anterograde memory, auditory information processing, higher
order memory abilities, conceptual reasoning abilities,
executive function, control mechanisms of attention, and
higher order abilities across domains. A neuropsychologic
battery designed to investigate these hypotheses was administered
to 33 rigorously diagnosed autistic individuals with IQ
scores greater than 80, and 33 individually matched normal
controls. Stepwise discriminant function was used to define
the profile of neuropsychologic functioning across domains.
The neuropsychologic profile in these autistic individuals
was defined by impairments in skilled motor, complex memory,
complex language, and reasoning domains, and by intact
or superior performance in the attention, simple memory,
simple language, and visual–spatial domains. This
profile is not consistent with mental retardation or with
a general deficit syndrome, but rather with a selective
impairment in complex information processing that does
not involve visual–spatial processing. This profile
is not consistent with a single primary deficit, but with
a multiple primary deficit model in which the deficit pattern
within and across domains is reflective of the complexity
of the information processing demands. This neuropsychologic
profile is furthermore consistent with the neurophysiologic
characterization of autism as a late information processing
disorder with sparing of early information processing.
(JINS, 1997, 3, 303–316)