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Biomedical subjects

N J Cohen

Publications and source records attributed to N J Cohen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Language, social cognitive processing, and behavioral characteristics of psychiatrically disturbed children with previously identified and unsuspected language impairments.

This study examined characteristics of social cognitive processing, psychiatric disorder, and behavioral ratings of 380 children aged 7 to 14 years who had been referred consecutively for child psychiatric services with identified and unsuspected language impairments and with normally developing language. The results indicated that children with language impairments generally exhibited greater deficits in social cognitive processing, and particularly emotion decoding and social problem solving, than children who have language that is developing normally. Differences in psychiatric diagnosis and behavior problems were observed only between children with previously identified language impairments and children with normally developing language; children with previously identified language impairments were more likely to be diagnosed as having Attention Deficit Hyperactivity Disorder (ADHD) and to be rated by both parents and teachers as having more severe attentional problems. In addition, teachers rated them as more socially withdrawn. The results suggest that it is important to incorporate measures of both social cognition and language functioning routinely into clinical assessment, something that currently is rarely done.

Adolescent↗
PubMed1998

Language, achievement, and cognitive processing in psychiatrically disturbed children with previously identified and unsuspected language impairments.

This study examined the language, achievement, and cognitive characteristics of 380 children, aged 7 to 14 years, consecutively referred to child psychiatric services. Among those children referred solely for psychiatric problems, 40% had a language impairment that had never been suspected. Children with previously identified and unsuspected language impairments were similar with respect to receptive and expressive language and on measures of cognitive processing. Although both groups of children with language impairments exhibited poorer academic achievement than children with normal language, children with previously identified language impairments had the lowest achievement. The milder achievement problems of children with unsuspected language impairment may explain why their problems had not been suspected. Both the clinical and theoretical implications of the findings are discussed. Heightened awareness concerning the high frequency of language impairment and other cognitive processing problems in children referred for psychiatric assessment and treatment should lead to more systematic examination of language functioning and evaluation of the impact of language and communication functioning on therapeutic outcomes.

Adolescent↗
PubMed1996

Parents' sense of "entitlement" in adoptive and nonadoptive families.

The literature suggests that problems with developing a sense of entitlement are unique to adoptive families, but this assumption has not been examined empirically. In this study, a questionnaire was constructed to define operationally those characteristics associated with the construct of entitlement, and was administered to adoptive and nonadoptive families with children averaging 11.5 years in age who presented either for mental health service or were recruited as a comparison-control sample. Factor analysis yielded four factors on which the four groups of subjects were compared. Results indicated that problems with entitlement are not specific to adoptive families. Instead, differences in sense of entitlement occurred primarily between clinic and nonclinic control families, regardless of whether the target child had been adopted. Findings are discussed in terms of methodological shortcomings in the adoption research literature and how problems in entitlement may be associated with other family characteristics.

Adolescent↗
PubMed1993

Unsuspected language impairment in psychiatrically disturbed children: prevalence and language and behavioral characteristics.

OBJECTIVE: This study examined the prevalence of unsuspected language impairments in 4-12-year-old psychiatric outpatients. METHOD: Children (N = 399) were routinely screened with standardized language tests, and parents and teachers completed behavioral checklists. RESULTS: Results indicated that of 288 children referred solely for a psychiatric disorder, 99 (34.4%) had a language impairment that had not been suspected previously. These children had more subtle language impairments than did the 111 children referred with previously identified language impairments. Both children with unsuspected and previously identified language impairments had symptoms associated with attention-deficit hyperactivity disorder. Children with unsuspected language impairments had the most serious externalizing behavioral problems. CONCLUSIONS: Attention needs to be paid to screening children for language impairments and to helping adults understand how language disabilities impact on communication and behavior.

Attention Deficit Disorder with Hyperactivity↗
PubMed1993

Adopted and biological children in the clinic: family, parental and child characteristics.

Adopted children are overrepresented in referrals to mental health facilities. Research has described child symptomatology but has rarely described family characteristics or how adoptive and biological families presenting a child for treatment differ. This study took a systemic approach carrying out a multilevel assessment of families of adopted and biological children presented for treatment with adopted and biological nonclinical comparison groups. The results from this study of 88 parents of 7-17-year-old children suggest that adoptive families have greater social and psychological resources that can be relied on in treatment. However, adopted children are perceived to have more problems and their families are more likely to consider removal of the child as a solution to problems. Therapists' failure to appreciate these unique strengths and vulnerabilities of adoptive families can lead to treatment failure.

Adolescent↗
PubMed1991

Cognitive representations and processes in arithmetic: inferences from the performance of brain-damaged subjects.

In this article, we present data from two brain-damaged patients with calculation impairments in support of claims about the cognitive mechanisms underlying simple arithmetic performance. We first present a model of the functional architecture of the cognitive calculation system based on previous research. We then elaborate this architecture through detailed examination of the patterns of spared and impaired performance of the two patients. From the patients' performance we make the following theoretical claims: that some arithmetic facts are stored in the form of individual fact representations (e.g., 9 x 4 = 36), whereas other facts are stored in the form of a general rule (e.g., 0 x N = 0); that arithmetic fact retrieval is mediated by abstract internal representations that are independent of the form in which problems are presented or responses are given; that arithmetic facts and calculation procedures are functionally independent; and that calculation algorithms may include special-case procedures that function to increase the speed or efficiency of problem solving. We conclude with a discussion of several more general issues relevant to the reported research.

Brain Damage, Chronic↗
PubMed1990

Relation of global ratings of functioning with behaviour and development in delayed and disturbed preschoolers.

Ratings on the Global Assessment Scale for Children (GASC) were assessed in relation to a battery of objective developmental and behavioural measures. Children aged three to six years (N = 55) attending a day treatment program for developmental delays, language disorders, and behavioural and emotional problems comprised the sample. A battery of tests was administered to the children. Parents and teachers completed standardized questionnaires to measure developmental, behavioural and emotional problems. The results indicated that the GASC score correlated significantly with child developmental level, impulse control, and with teacher ratings of social withdrawal. The GASC was unrelated to ratings of behavioural problems. Ratings on the GASC also were highly consistent over time. These results are discussed with respect to the strengths and limitations of using global ratings with preschool children.

Affective Symptoms↗
PubMed1989

Sex differences in child psychiatric outpatients: cognitive, personality, and behavioral characteristics.

This paper describes sex differences in a clinically referred sample on direct measures of child competence and ratings of psychopathology. The sample comprised 117 6-12 year-old boys and 63 girls referred to a psychiatric outpatient service. The results indicated that although boys and girls did not differ in overall problems or on externalizing problems, girls had significantly more internalizing problems and were more impaired as measured by both individual and composite measures of competence.

Child↗
PubMed1989

Further studies of hippocampal representation during odor discrimination learning.

The contribution of hippocampal and nonhippocampal memory processing to simultaneous-cue odor discrimination learning was assessed. In this task, rats with hippocampal system damage consequent to fornix lesions (fornix rats) were severely and persistently impaired in discrimination learning, acquisition of learning set, and concurrent discrimination, although they occasionally solved some problems at a normal rate. By using those problems on which fornix rats succeeded, to permit comparisons of performance strategies with normal rats, differences between groups were shown on response latency measures and on probe trials involving the novel pairing of familiar odors. Normal rats had a bimodal distribution of response latencies, and their latency depended on where the S+ was presented. Fornix rats had short response latencies and responded equally quickly wherever the S+ was presented. Furthermore, when the representation of familiar S+ and S- odor pairs was challenged in probe trials, normal rats responded appropriately to the correct stimulus, whereas fornix rats behaved as if presented with a new odor pair. These data provide support for the view that the hippocampus participates in the representation of relations among odor (and other) stimuli and among other experiences and that it permits the flexible use of these representations in new contexts. In contrast, memory processing outside the hippocampal system can represent only the significance of individual stimuli and can be revealed only in a repetition of the original learning event.

Animals↗
PubMed1989

Prevalence of unsuspected language disorders in a child psychiatric population.

Nonretarded 5- to 12-year-old consecutive referrals to a child psychiatric outpatient clinic underwent a routine systematic language assessment. The assessment battery comprised standardized measures of the receptive and expressive components of syntax, semantics, and phonology. Standardized behavior rating scales also were completed by parents. Of the children referred solely for a psychiatric problem, 28% had a moderate or severe language disorder that previously had not been suspected or diagnosed. These children differed from a comparison group of children with both psychiatric and language disorders in that they were younger and more likely to have an externalizing behavioral problem. The findings indicate that there is a sizeable proportion of children whose language disorders are overlooked possibly because of their disruptive behavior. This suggests the need for routine screening of language in child psychiatric populations.

Child↗
PubMed1989

The organization of spatial coding in the hippocampus: a study of neural ensemble activity.

Neural activity was recorded from local groups of hippocampal single units in rats performing a spatial-memory task. The organization of functional correlates in these neural ensembles was investigated by examining the spatial relationships among the place fields of single units in each ensemble. The distance and overlap between place fields were determined together with the tuning of cellular activity to behavioral variables, including direction, speed, and turning angle during movements within place fields. The place fields of recorded neural ensembles were significantly clustered: closer in space and considerably more overlapped than chance when compared statistically with Monte Carlo simulations. Just as single units often have significant firing in more than one distinct location in the environment (subfields), the ensembles had multiple and distinct clusters of overlapping subfields. In addition, proximity and overlap between place fields were significantly, but weakly, correlated with similarity in optimal movement tuning parameters. These results suggest that the hippocampus maintains a local organization with respect to place fields despite having no apparent large-scale isomorphism with the spatial environment. The organization of multiple, clustered place fields with correlated movement tuning properties in small neural ensembles suggests the existence of functional neural ensembles serving to encode multiple sensory and behavioral aspects of a place or event. Such an organization is similar to that observed for neocortical association areas afferent to the hippocampal system.

Animals↗
PubMed1988

The impaired learning of semantic knowledge following bilateral medial temporal-lobe resection.

The integrity of several aspects of semantic memory (including knowledge of the meaning, lexical status, perception, and pronunciation of words and famous names) was examined in H.M., a patient with anterograde amnesia following bilateral medial temporal-lobe excision. Despite normal memory for such semantic knowledge acquired prior to the onset of his amnesia in 1953, H.M. showed a severe deficit in memory for semantic information encountered subsequently. In combination with the previously reported impairments in new learning shown by H.M., the deficits observed here point to an association between semantic and episodic memory, and do not lend support to a distinction between them. The acquisition of semantic and episodic information, therefore, appears to depend upon a common memory system that requires the intact functioning of medial temporal-lobe structures.

Aged↗
PubMed1988

Hippocampal system dysfunction and odor discrimination learning in rats: impairment or facilitation depending on representational demands.

The performance of normal rats and that of rats with hippocampal system damage were compared on acquisition of different versions of the same two-odor discrimination task that placed different encoding and representational demands on memory. Rats with fornix lesions were impaired when explicit comparisons among multiple odor cues and differential response choices were encouraged. However, when odor-cue comparison was hindered and explicit cues for response choice were eliminated, rats with fornix lesions out performed normal animals. The results support an hypothesis that the hippocampal system is critical to a memory representation based on encoding relations among multiple percepts, and other brain systems support performance adaptations based on encodings of stimuli individually.

Animals↗