Biomedical subjects

A Cienfuegos

Publications and source records attributed to A Cienfuegos.

6 recordsLinked to original sources

PubMed2001

Auditory distraction and thought disorder in chronic schizophrenic inpatients. Evidence for separate contributions by incapacity and poor allocation and a subsyndrome related to the allocation deficit.

This study investigated auditory attentional processes associated with schizophrenic thought disorder. Thirty-five chronically schizophrenic, state hospital inpatients were assessed for thought disorder using the Thought, Language, and Communication Disorders Scale (TLC) and tested in an attentional task. Two measures of attention were derived from the Digit Span Distraction Test (DSDT) (Oltmannns, T.F., Neale, J.M., 1975. Schizophrenic performance when distractors are present: attentional deficit or differential task difficulty. J. Abnorm. Psychol. 84, 205-209), a digit recall task in which distractor digits were interspersed with target digits. The two measures were Distractibility -- the overall inaccuracy of recall -- which measured attentional incapacity, and Distractible Intrusion -- the number of irrelevant digits recalled -- which was developed in this study to separately measure the inability to allocate attentional resources. These two measures predicted thought disorder strongly and independently. Distractibility did not significantly correlate with any TLC subscale. In contrast, Distractible Intrusions correlated with the TLC subscales Distractible Speech, Incoherence, Loss of Goal, and Word Approximations. The present findings suggest that these subtypes may comprise a distinct subsyndrome of thought disorder, characterized by a dysfunctionally low threshold for selecting appropriate speech information, and that an attentional allocation deficit is related to this language dysfunction.

Adult↗

PubMed2001

Adjunctive high-dose glycine in the treatment of schizophrenia.

Glycine is an agonist at brain N-methyl-D-aspartate receptors and crosses the blood-brain barrier following high-dose oral administration. In a previous study, significant improvements in negative and cognitive symptoms were observed in a group of 21 schizophrenic patients receiving high-dose glycine in addition to antipsychotic treatment. This study evaluated the degree to which symptom improvements might be related to alterations in antipsychotic drug levels in an additional group of 12 subjects. Glycine treatment was associated with an 8-fold increase in serum glycine levels, similar to that observed previously. A significant 34% reduction in negative symptoms was observed during glycine treatment. Serum antipsychotic levels were not significantly altered. Significant clinical effects were observed despite the fact that the majority of subjects were receiving atypical antipsychotics (clozapine or olanzapine). As in earlier studies, improvement persisted following glycine discontinuation.

Adult↗

PubMed1999

Impaired categorical perception of synthetic speech sounds in schizophrenia.

BACKGROUND: Simple speech sounds such as /ba/ and /da/ differ in the frequency composition of their underlying formants. Normal volunteers asked to identify intermediate phonemes along the /ba/ to /da/ continuum abruptly switch from perceiving "ba" to perceiving "da". The present study investigates precision of phonemic processing in schizophrenia. METHODS: Categorical perception of speech sounds was evaluated in 15 schizophrenic and 14 control subjects, using a forced-choice phonemic discrimination paradigm. RESULTS: Patients and controls were equally able to recognize endpoint forms of both phonemes, but differed significantly in their perception of intermediate forms near the center of the continuum. Patients also showed a significantly shallower response curve, suggesting an impairment in boundary definition. Despite their impairment in categorical perception, schizophrenic subjects showed normal adaptation of response when test stimuli were preceded by a series of /ba/ or /da/ stimuli from the endpoints of the continuum. CONCLUSIONS: The present results suggest that precision of phonemic processing is impaired in schizophrenia. This categorical perception deficit may represent upward generalization of impaired memory-dependent acoustic processing. Deficits in the precision of cortical processing may contribute significantly to cognitive dysfunction in schizophrenia.

Adaptation, Psychological↗

PubMed1999

Normal time course of auditory recognition in schizophrenia, despite impaired precision of the auditory sensory ("echoic") memory code.

Prior studies have demonstrated impaired precision of processing within the auditory sensory memory (ASM) system in schizophrenia. This study used auditory backward masking to evaluate the degree to which such deficits resulted from impaired overall precision versus premature decay of information within the short-term auditory store. ASM performance was evaluated in 14 schizophrenic participants and 16 controls. Schizophrenic participants were severely impaired in their ability to match tones following delay. However, when no-mask performance was equated across participants, schizophrenic participants were no more susceptible to the effects of backward maskers than were controls. Thus, despite impaired precision of ASM performance, schizophrenic participants showed no deficits in the time course over which short-term representations could be used within the ASM system.

Acoustic Stimulation↗

PubMed1999

Panmodal processing imprecision as a basis for dysfunction of transient memory storage systems in schizophrenia.

Schizophrenia is a severe mental disorder associated with cognitive disturbances that may reflect underlying deficits in the functioning of brain transient memory storage systems. This study investigates performance in three distinct tasks that require transient memory storage: (1) tone discrimination, (2) object weight discrimination, and (3) "AX"-type visual continuous performance task. The tests used were chosen to investigate the degree to which a similar pattern of performance deficit could be observed across multiple sensory and cognitive domains in schizophrenia. In each of the paradigms, a similar pattern emerged: subjects with schizophrenia showed severe performance deficits whenever performance depended on functioning of transient memory systems. The deficits were apparent at both short and long interstimulus intervals (ISI), however, and schizophrenia subjects were no more affected by increasing ISI than were controls. Moreover, when short ISI performance was matched across groups by manipulating task difficulty, subsequent decay in performance was equivalent across groups. Thus, although schizophrenia subjects show severe performance deficits in memory-dependent tasks, the deficits do not appear to reflect impaired transient memory per se. Rather, they appear to reflect impaired precision of operation of such systems, irrespective of the duration over which representations must be maintained. The severe deficits in processing precision, despite the relatively preserved maintenance of representation, may be relevant to pathophysiological models of schizophrenia.

Adult↗

PubMed1996

A naturalistic outcome study of risperidone treatment among hospital patients.

Risperidone, an atypical antipsychotic, was introduced into clinical use in New York State facilities in April 1994. In this chart review study, records were reviewed for the first 63 patients started on risperidone at the Bronx Psychiatric Center during 1994. Sixty percent of patients treated with risperidone had a positive outcome, indicated by clinical improvement either at discharge or in the hospital. Twenty-two percent required termination of risperidone treatment within the initial three months. Risperidone appeared to be associated with favorable outcome among chronic state hospital patients, including those not discharged within the first three months of treatment.

Adult↗