The organization of arithmetic facts in memory: evidence from a brain-damaged patient

We report a single case study of a brain-damaged patient with impaired arithmetic performance. Three principal findings are presented: First, in a task involving production of answers to simple arithmetic problems, the patient's performance was far better for subtraction than for addition or multiplication. Second, in all arithmetic operations performance was generally much better for problems potentially solvable by rule (e.g., 5 + 0) than for problems requiring retrieval of specific facts (e.g., 5 + 3). Third, the dissociation between subtraction and the other arithmetic operations obtained in the production task was not observed in a verification task. The implications of these findings for claims concerning the organization of stored arithmetic facts are discussed.     

The representation of arithmetic facts in memory: results from retraining a brain-damaged patient

This single case study was designed to gather evidence regarding whether the mental representations mediating multiplication fact retrieval make use of single or multiple codes. MC is a brain-damaged volunteer whose numerical processing impairments were limited to multiplication fact retrieval. He relearned three sets of multiplication facts. Each set was relearned in one of three input formats: Arabic, written verbal, or spoken verbal. Following training all facts were tested in all input formats. MC's posttraining performance was virtually error free and showed no effects of input format. However, reaction-time data showed fact retrieval was fastest when the training format matched the test format. Results are discussed in relation to single- and multiple-code models of multiplication fact retrieval.     

Electrodermal base level, tonic arousal, and adaptation in chronic schizophrenics.

Electrodermal arousal was studied at rest and during repetitive stimulation in chronic schizophrenics who were rated at either extreme of the Montrose Rating scale (MRS), either receiving a phenothiazine or no drugs, and in a control normal sample. Resting base level was significantly higher among Hi than Lo MRS, and among Nondrug than Drug patients: no patient sample was reliably below Control level. Nondrug patients showed no impairment in tonic arousal relative to Controls, even when such patients showed impaired phasic response (though the drug was seemingly associated with diminished tonic response). Considerable independence was demonstrated between phasic and tonic electrodermal functions. Unlike Controls (or Drug patients), Nondrug patients showed a general heightening of electrodermal arousal during repetitive innocuous stimulation. A vigilance hypothesis was offered suggesting that sensitivity to the general demands of the environment remains high among chronic patients, even where there may be a reduction in the input of specific items of information from that environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodermal activity as a prodromal sign in schizophrenia

To simplify the quality control procedure used to determine the efficiency and consistency of bedside leukoreduction, a counting protocol using prefiltration and postfiltration aliquots fixed in 10% formaldehyde was designed. To assess the reliability of the values obtained by counting the formalin-fixed samples, a parallel study was performed using our standard protocol of counting fresh propidium iodide-stained samples in a Nageotte chamber under a fluorescent microscope. A total of 30 single-donor platelet concentrates and 30 units of packed red blood cells were analyzed in parallel using the standard and formalin-fixation methods. Furthermore, the aliquots fixed in formaldehyde were split and counted at 1, 3, and 30 days. The results showed no significant quantitative difference between the two methods. Of note is that the counts in formaldehyde-fixed samples at 1, 3, and 30 days were consistent among themselves. The formaldehyde fixation of samples obtained for quality control of leukoreduction allows blood collection and storage at 4 degrees C and batch counting when and where convenient.     

Lack of asymmetry of middle cerebral artery blood velocity in unilateral migraine

BACKGROUND AND PURPOSE: A recent transcranial Doppler study found reduced blood velocity in seven patients during migraine attacks in the middle cerebral artery at the headache side. This would implicate vasodilation of the middle cerebral artery in the pathogenesis of headache in migraine. We attempted to confirm this finding. METHODS: We determined blood velocity with transcranial Doppler ultrasonography in the middle cerebral arteries of 51 migraine patients with unilateral headache (5 with aura, 46 without aura) and of 14 patients with bilateral headache, during and outside attacks. During attacks, median time from onset of attack to transcranial Doppler examination was 6 hours (range, 1 to 35 hours). RESULTS: We found no difference between blood velocity at the headache and nonheadache sides nor between blood velocity during and outside attacks. Similar results were obtained in a subgroup of 11 patients who were investigated in the first 4 hours of an attack. There were also no differences between attacks with unilateral or bilateral headache. CONCLUSIONS: We cannot support the hypothesis that migraine is associated with vasodilation of the middle cerebral artery ipsilateral to the headache.     

Ventilation in the patient with unilateral lung disease

Severe ULD presents a challenge in ventilator management because of the marked asymmetry in the mechanics of the two lungs. The asymmetry may result from significant decreases or increases in the compliance of the involved lung. Traditional ventilator support may fail to produce adequate gas exchange in these situations and has the potential to cause further deterioration. Fortunately, conventional techniques can be safely and effectively applied in the majority of cases without having to resort to less familiar and potentially hazardous forms of support. In those circumstances when conventional ventilation is unsuccessful in restoring adequate gas exchange, lateral positioning and ILV have proved effective at improving and maintaining gas exchange. Controlled trials to guide clinical decision making are lacking. In patients who have processes associated with decreased compliance in the involved lung, lateral positioning may be a simple method of improving gas exchange but is associated with many practical limitations. ILV in these patients is frequently successful when differential PEEP is applied with the higher pressure to the involved lung. In patients in whom the pathology results in distribution of ventilation favoring the involved lung, particularly BPF, ILV can be used to supply adequate support while minimizing flow through the fistula and allowing it to close. The application of these techniques should be undertaken with an understanding of the pathophysiology of the underlying process; the reported experience with these techniques, including indications and successfully applied methods; and the potential problems encountered with their use. Fortunately, these modalities are infrequently required, but they provide a critical means of support when conventional techniques fail.     

Electrodermal measures in experimental amnesia.

14 Ss equated with respect to hypnotizability were subjected to electrodermal orienting response (OR) adaptation to tone stimulation. ? the Ss were hypnotized, ? were not. Adaptation of the OR was conducted under hypnosis, with suggestion of amnesia both under hypnosis and as a posthypnotic suggestion. The control group yielded progressive adaptation curves, while "amnesia" produced a lifting of the adaptation. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cranial asymmetry secondary to unilateral hemispheric damage during late childhood. Case report

Skull abnormalities such as unilateral hypertrophy of skull thickness, enlarged sinuses, and elevated petrous ridge with contralateral body hemiatrophy are commonly associated with hemispheric damage that occurs during infancy. The present case emphasizes that such changes may be associated with cortical damage during late childhood.     

Electrodermal activity as a predictor of social functioning in female schizophrenics

Twenty-nine female schizophrenics and 20 female controls were presented with a series of moderately intense tones in a standard orienting habituation paradigm while skin conductance was monitored. Premorbid adjustment and symptoms were also rated, and the schizophrenics were observed 2 years later. The total schizophrenic group was divided into a good-outcome group and a poor-outcome group. Good social functioning outcome required both self-supporting ability in the job market and at least a minimal social life. The poor-outcome group had a significantly higher skin-conductance level and frequency of spontaneous skin-conductance fluctuations than the control group, whereas the few patients with good outcome did not differ from controls. These results are contrary to previous findings with a group of schizophrenic men in which poor social functioning was associated with low electrodermal activity. This discrepancy is discussed in terms of sex differences in schizophrenic disorder.     

Reduced Electrodermal Activity in Psychopathy-Prone Adolescents.

This study tests the hypothesis that psychopathy-prone adolescents show reduced anticipatory skin conductance responding. Electrodermal activity was recorded while participants anticipated and responded to a 105dB signaled or unsignaled white-noise burst. Using an extreme groups design, the authors used Child Psychopathy Scale (D. R. Lynam, 1997) scores from a community sample of 335 male adolescents (age 16) to form control (n=65) and psychopathy-prone (n=65) groups. Significantly more psychopathy-prone participants were nonresponders in the signaled anticipatory (p=.014), signaled responsivity (p=.037), and unsignaled responsivity (p=.003) conditions compared with controls. Anticipatory hyporesponsivity of psychopathy-prone adolescents similar to the electrodermal hyporesponsivity found in psychopathic adults suggests that this autonomic impairment is present by adolescence and may predispose individuals to adult psychopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Excessively high prolactin level in a patient with a nonprolactin-secreting adenoma. Case report

The urachus can present a partial or complete obliteration defect. If the defect is situated in its vesical extremity, it then forms a diverticulum. The authors report a case of diverticulum of the urachus in a young adult, responsible for recurrent febrile urinary tract infections since the beginning of adolescence. The diagnosis was suggested by ultrasonography and magnetic resonance imaging and confirmed by cystoscopy and histological examination. Treatment consisted of complete surgical resection via a suprapubic incision.     

Auditory evoked potentials in a patient with a unilateral lesion of the inferior colliculus and medial geniculate body

To reveal any association between the histological type and grade of intraductal breast neoplasms and the manner of accumulation of gene alterations, eight types of gene alterations, i.e., loss of heterozygosity (LOH) on chromosomal arms 16p, 16q, 17p, 17q, and 18q, amplification of the c-erbB-2 and hst-1/int-2 genes, and mutation of the p53 gene, were examined by Southern blot analysis or single-strand conformation polymorphism analysis in a total of 60 cases of intraductal breast cancer and 18 nonmalignant proliferative lesions. Among the histological types and three histological grade groups of intraductal carcinomas, the gene alterations which occurred most frequently were LOH on 16q alone in non-comedo type and Grade 1, alterations of c-erbB-2, 17p, and 16q in comedo type and Grade 2, and alterations of 17q and p53 as well as those of 16q, 17p, and c-erbB-2 in Grade 3. LOH on 16q and 18q was frequent in intraductal carcinoma of the intracystic papillary type, whereas LOH on 18q alone was detected in 27% of papillomas. Among intraductal carcinomas, the mean number of gene alterations was largest in comedo type and Grade 3, whereas it was smallest in non-comedo type and Grade 1. It was possible that LOH on 18q and 16q was involved frequently in papillary tumori-genesis and acquisition of malignant phenotype, respectively, whereas most of the other gene alterations were involved in acquisition of aggressive biological properties by intraductal carcinoma cells. It was also possible that the phenotype of breast neoplasms was determined by the combination of gene alterations at a relatively early developmental stage.     

Cartilage degeneration in relation to repetitive pressure: case study of a unilateral hip hemiarthroplasty patient

The mitochondrial, inner-membrane-associated, reversible NADPH-->NAD transhydrogenase of adult Hymenolepis diminuta physiologically couples matrix-localized, NADP-specific "malic" enzyme with NADH-dependent anaerobic electron transport. Employing submitochondrial particles (SMP) as the source of enzyme activity and both spectrophotometric and fluorometric assessments, the present study made evident that in its catalysis of transhydrogenation between NADPH and NAD, the cestode enzyme engages in the concomitant transmembrane translocation of protons. As assessed spectrophotometrically, the catalysis of NADPH-dependent NAD reduction by H. diminuta SMP was stimulated significantly by carbonyl cyanide 3-chlorophenylhydrazone (CCCP), carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), as well as by the protonophoric anthelmintic, niclosamide. In addition, N,N'-dicyclohexylcarbodiimide (DCCD) markedly diminished SMP-catalyzed hydride ion transfer between NADPH and NAD. The catalysis by SMP of concomitant, transhydrogenase-mediated proton translocation was evaluated more directly via fluorometric assays using 8-anilino-1-napthalenesulfonic acid (ANS) as the probe. These latter evaluations revealed a transhydrogenase-dependent enhancement of ANS fluorescence in accord with an intravesicular accumulation of protons. ANS fluorescence was quenched rapidly when the assay system was supplemented with CCCP, FCCP, or niclosamide. Consistent with the helminth transhydrogenase acting as a proton pump, transhydrogenase-mediated enhanced fluorescence also was inhibited by DCCD. Considered collectively, these data indicated, apparently for the first time for any invertebrate system, that the transhydrogenase, in catalyzing the NADPH-->NAD reaction, acts in the translocation of protons from the matrix to the intermembrane space mitochondrial compartment.     

Electrodermal activity and obstetric complications in schizophrenia.

The pregnancy and birth records of 79 schizophrenic patients, from whom adult electrodermal data were available, were systematically evaluated for obstetric complications using 34 criteria of nonoptimality in pregnancy, delivery, and postpartum periods. Patients with many obstetric complications had lower levels of electrodermal activity. For frequency of skin conductance responses and spontaneous fluctuations in skin conductance, the association was more evident for women than for men. However, the ratio of stimulus-elicited to spontaneous skin conductance responses showed a reliable association with obstetric complications without any gender differences. The relationship between obstetric complications and electrodermal activity was interpreted in terms of neurodevelopmental insults resulting in structural brain abnormalities interfering with orienting and electrodermal activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodermal activity in schizophrenics: Further considerations.

Discusses a number of reports that challenge the generality of the conclusions of a recent review by R. A. DePue and D. C. Fowles (see record 1973-21232-001) that schizophrenics show both slower habituation than normal Ss for electrodermal activity and a greater frequency of spontaneous electrodermal responses. More generally, there is evidence of abnormally low electrodermal activity and responsiveness among some schizophrenics, and evidence of systematic trends in the behavior of such patients paralleling their physiological abnormalities. It appears that theories of schizophrenia need to account for the occurrence of hyperelectrodermal, hypoelectrodermal, and "paradoxical" electrodermal reactivity and tonic activity in connection with the disorder. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodermal lability in delusional schizophrenics following personalized stimuli.

Presented a series of phrases to 10 male hospitalized paranoid schizophrenics and 10 male alcoholic controls while their electrodermal responses were recorded. The topics of the phrases were delusion-related, alcohol-related, or neutral. No main effect difference between the groups was found. However, the topic of the phrases affected the groups differently: Delusion-related and neutral stimuli produced greater lability in schizophrenics than in alcoholics. Results suggest that these schizophrenics responded to significant stimuli much like nonschizophrenics but differed from nonschizophrenics as to which stimuli they found significant. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrodermal activity and clinical status in chronic schizophrenia.

Investigated the association between electrodermal nonresponsiveness and clinical state in schizophrenia. 63 patients with a Diagnostic and Statistical Manual of Mental Disorders-III (DSM-III) diagnosis of chronic schizophrenia served as Ss. Clinical status was assessed using multiple measures, including age of onset, symptom severity, illness duration, hospitalization history, global functioning, and occupational functioning. Electrodermal hypoactivity was found to be associated with poorer functioning and a more severe form of illness. In addition, hyporesponsive patients displayed more conceptual disorganization and alogia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification with a brain-damaged parent: Theoretical considerations on a case of self-mutilation.

Presents a case of a female patient in her 20's with a history of repeated hospitalization for self-mutilation. Countertransference clues prompted reexamination of the S's symptoms and suggested an identification with an aphasic, hemiparetic parent. The case focuses theoretical attention on the interaction between processes of pathological identification and neuropsychological dysfunction. A proposal is made to broaden the concept of identification to include potential variations in neurological, somatosensory, and intellectual function as they interact with changes in affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sedimentation level in acute intracerebral hematoma in a patient receiving anticoagulation therapy: an autopsy study

OBJECTIVE: To evaluate the clinical usefulness of genomic HLA typing during the first two years of established giant cell arteritis (GCA). METHODS: HLA typing was performed by PCR-SSO in 41 selected white patients with GCA confirmed by biopsy. Patient data were compared with those of a control group of 384 bone marrow donors (relative risk, p value and chi 2 test for each allele). Clinical features at onset and response to treatment over a two year period were evaluated in relation to the genetic pattern. RESULTS: DRB1*04 was significantly increased in the GCA group (frequency of 48.78% compared with 19.79% in controls, p < 0.001). The distribution of the DRB1*04 subtypes in the GCA group was similar to that in controls. No clinical or biological differences were found in association with HLA at the time of diagnosis. Over the two year follow up, nine patients presented resistance to corticosteroid treatment and eight of these (88.88%) had DRB1*04 (p < 0.001). CONCLUSIONS: GCA seems to be associated with HLA DRB1*04 (regardless of the subtype) and this association appears to be accompanied by corticosteroid resistance, suggesting that genomic typing may be useful to identify patients eligible for early alternative treatment to corticosteroid drugs.