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N J Cohen

Publications and source records attributed to N J Cohen.

At least 19 recordsLinked to original sources
PubMed2000

Prefrontal regions play a predominant role in imposing an attentional 'set': evidence from fMRI.

fMRI was used to determine whether prefrontal regions play a predominant role in imposing an attentional 'set' that drives selection of task-relevant information. While monitoring for an atypical item, individuals viewed Stroop stimuli that were either colored words or colored objects. Attentional demands were varied, being greater when the stimuli contained two distinct and incongruent sources of information about the task-relevant attribute (e.g., when attending to color, seeing the word 'blue' in red ink) as compared to only one source (e.g., seeing the word 'late' in red ink). Prefrontal but not anterior cingulate regions exhibited greater activation on incongruent than neutral trials, suggesting that prefrontal cortex has a major role in imposing an attentional 'set'. In addition, we found that prefrontal activation is most likely to occur when that attentional set is difficult to impose.

Attention↗
PubMed2000

Amnesia is a deficit in relational memory.

Eye movements were monitored to assess memory for scenes indirectly (implicitly). Two eye movement-based memory phenomena were observed: (a) the repetition effect, a decrease in sampling of previously viewed scenes compared with new scenes, reflecting memory for those scenes, and (b) the relational manipulation effect, an increase in viewing of the regions where manipulations of relations among scene elements had occurred. In normal control subjects, the relational manipulation effect was expressed only in the absence of explicit awareness of the scene manipulations. Thus, memory representations of scenes contain information about relations among elements of the scenes, at least some of which is not accessible to verbal report. But amnesic patients with severe memory impairment failed to show the relational manipulation effect. Their failure to show any demonstrable memory for relations among the constituent elements of scenes suggests that amnesia involves a fundamental deficit in relational (declarative) memory processing.

Adult↗
PubMed2000

fMri studies of Stroop tasks reveal unique roles of anterior and posterior brain systems in attentional selection.

The brain's attentional system identifies and selects information that is task-relevant while ignoring information that is task-irrelevant. In two experiments using functional magnetic resonance imaging, we examined the effects of varying task-relevant information compared to task-irrelevant information. In the first experiment, we compared patterns of activation as attentional demands were increased for two Stroop tasks that differed in the task-relevant information, but not the task-irrelevant information: a color-word task and a spatial-word task. Distinct subdivisions of dorsolateral prefrontal cortex and the precuneus became activated for each task, indicating differential sensitivity of these regions to task-relevant information (e.g., spatial information vs. color). In the second experiment, we compared patterns of activation with increased attentional demands for two Stroop tasks that differed in task-irrelevant information, but not task-relevant information: a color-word task and color-object task. Little differentiation in activation for dorsolateral prefrontal and precuneus regions was observed, indicating a relative insensitivity of these regions to task-irrelevant information. However, we observed a differentiation in the pattern of activity for posterior regions. There were unique areas of activation in parietal regions for the color-word task and in occipitotemporal regions for the color-object task. No increase in activation was observed in regions responsible for processing the perceptual attribute of color. The results of this second experiment indicate that attentional selection in tasks such as the Stroop task, which contain multiple potential sources of relevant information (e.g., the word vs. its ink color), acts more by modulating the processing of task-irrelevant information than by modulating processing of task-relevant information.

Adult↗
PubMed2000

WAIS-III and WMS-III profiles of mildly to severely brain-injured patients.

Wechsler Adult Intelligence Scale-III (WAIS-III) and Wechsler Memory Scale-III (WMS-III; The Psychological Corporation, 1997) scores of patients with mild traumatic brain injury (MTBI, n = 23) to moderate-severe traumatic brain injury (M-S TBI, n = 22) were compared to those of 45 matched normal control patients. WAIS-III results revealed that IQ and index scores of MTBI patients did not significantly differ from those of controls, whereas M-S TBI patients received significantly lower mean scores on all measures. All M-S TBI patients' WMS-III index scores also revealed significantly lower scores in comparison to those of control participants, with the exception of Delayed Auditory Recognition. MTBI patients showed significantly lower mean index scores compared to normal controls on measures of immediate and delayed auditory memory, immediate memory, visual delayed memory, and general memory. Eta-squared analyses revealed that WMS-III visual indexes and WAIS-III processing speed showed particularly large effect sizes. These results suggest that symptomatic MTBI patients obtain some low WMS-III test scores comparable to those of more severely injured patients.

Adolescent↗
PubMed2000

The interface between ADHD and language impairment: an examination of language, achievement, and cognitive processing.

Language impairments are commonly observed among children referred for psychiatric services. The most frequent psychiatric diagnosis of children with language impairment (LI) is Attention Deficit Hyperactivity Disorder (ADHD). It is not clear whether there are differences between children with ADHD and comorbid LI and children with other psychiatric disorders who are also comorbid for LI. In the present study the language, achievement, and cognitive processing characteristics of 166 psychiatrically referred 7-14-year-old children were examined using a 2 x 2 (ADHD, LI) design to examine four groups: children with ADHD + LI, children with ADHD who have normally developing language, children with psychiatric diagnoses other than ADHD with a language impairment (OPD + LI) or without a LI (OPD). Results indicated that children with LI were at the most disadvantage regardless of the nature of the psychiatric diagnosis. Contrary to prediction, working memory measures, used to tap the core cognitive deficit of ADHD in executive functions, were more closely associated with LI than with ADHD. It was concluded that caution must be exercised in attributing to children with ADHD what might be a reflection of problems for children with language impairment generally. As most therapies are verbally based it is notable that language competence is rarely evaluated systematically before such therapies are undertaken.

Achievement↗
PubMed1999

Adhesive capsulitis: a sticky issue.

The shoulder is a very complex joint that is crucial to many activities of daily living. Decreased shoulder mobility is a serious clinical finding. A global decrease in shoulder range of motion is called adhesive capsulitis, referring to the actual adherence of the shoulder capsule to the humeral head. Adhesive capsulitis is a syndrome defined as idiopathic restriction of shoulder movement that is usually painful at onset. Secondary causes include alteration of the supporting structures of and around the shoulder, and autoimmune, endocrine or other systemic diseases. The three defined stages of this condition are the painful stage, the adhesive stage and the recovery stage. Although recovery is usually spontaneous, treatment with intra-articular corticosteroids and gentle but persistent physical therapy may provide a better outcome, resulting in little functional compromise.

Bursitis↗
PubMed1999

Hippocampal system and declarative (relational) memory: summarizing the data from functional neuroimaging studies.

In the last several years there have been impressive strides in the ability to explore the nature of hippocampal system functioning in humans by employing functional neuroimaging methods, permitting such methods to be used in conjunction with neuropsychological methods to better understand the role of the hippocampal system in memory. In this paper, we review the literature on functional imaging studies of the hippocampal system, summarizing the data and testing these data against a number of theories or explanatory accounts of hippocampal function. We consider five alternative explanatory accounts of, or ideas about, hippocampal function- some from already existing work, for which the functional imaging data can provide a new test, and others that have emerged directly from the functional imaging work, and that have yet to be tested for their fit of data from neuropsychological methods. We conclude that the relational (declarative) memory account, in which it is proposed that the hippocampal system plays a critical role in binding together multiple inputs to permit representations of the relations among the constituent elements of scenes or events, can better accommodate the full range of imaging (and other existing) data than any other explanatory account of hippocampal function.

Brain Mapping↗
PubMed1999

The relationship between skill learning and repetition priming: experimental and computational analyses.

Skill learning and repetition priming are considered by some to be supported by separate memory systems. The authors examined the relationship between skill learning and priming in 3 experiments using a digit entering task, in which participants were presented with unique and repeated 5-digit strings with controlled sequential structure. Both skill learning and priming were observed across a wide range of skill levels. Performance reflected the effects of learning at 3 different levels of stimulus structure, calling into question a binary dichotomy between item-specific priming and general skill learning. Two computational models were developed which demonstrated that previous dissociations between skill learning and priming can occur within a single memory system. The experimental and computational results are interpreted as suggesting that skill learning and priming should be viewed as 2 aspects of a single incremental learning mechanism.

Adult↗
PubMed1999

Eye-movement-based memory effect: a reprocessing effect in face perception.

An eye-movement-based memory effect was demonstrated in 2 experiments showing different patterns of eye movements elicited to famous versus nonfamous faces, across a range of different processing tasks. The effects of prior exposure emerged early in viewing, within the first 5 fixations, and were observed on multiple measures of eye-movement behavior, reflecting a change in viewers' sampling behavior to the famous faces. Accordingly, the eye-movement-based memory effect can be seen as a change in the nature of processing of novel versus repeated items, with implications for other effects of prior exposure such as those seen in examples of repetition priming. The authors argue that the eye-movement-based memory effect is an obligatory consequence of previous exposure--a reprocessing effect caused by re-engaging the visual pattern analyzers and face processing machinery of the brain.

Brain↗
PubMed1999

Discourse deficits associated with psychiatric disorders and with language impairments in children.

The purpose of the current study was to examine whether types of discourse deficits were associated differentially with psychiatric disorders (PD) and with language impairments (LI) in children. Discourse analyses examining the occurrence of different types of discourse deficits in language structure, information structure, and flow of information were performed on the spoken narratives of 111 children aged 7 to 12 years who comprised 4 groups: (1) psychiatrically referred children with LI (PD + LI), (2) psychiatrically referred children with normally developing language (PD), (3) nonreferred children with language impairments (LI), and (4) nonreferred children with normally developing language (controls). Discourse deficits in language and information structure characterized children with LI, whereas disruptions in the flow of discourse characterized children with PD. Children with the comorbid condition exhibited deficits associated with both LI and PD; in addition, they displayed distinct deficits related to pronominal reference and causal cohesion. The findings provide a preliminary understanding of the associations among language, discourse, and psychopathology in children.

Affective Symptoms↗
PubMed1998

Hemispheric specialization in human dorsal frontal cortex and medial temporal lobe for verbal and nonverbal memory encoding.

The involvement of dorsal frontal and medial temporal regions during the encoding of words, namable line-drawn objects, and unfamiliar faces was examined using functional magnetic resonance imaging (fMRI). Robust dorsal frontal activations were observed in each instance, but lateralization was strongly dependent on the materials being encoded. Encoding of words produced left-lateralized dorsal frontal activation, whereas encoding of unfamiliar faces produced homologous right-lateralized activation. Encoding of namable objects, which are amenable to both verbal and nonverbal encoding, yielded bilateral dorsal frontal activation. A similar pattern of results was observed in the medial temporal lobe. These results indicate that regions in both hemispheres underlie human long-term memory encoding, and these regions can be engaged differentially according to the nature of the material being encoded.

Adolescent↗
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↗