Mary H. Kosmidis

The verbal fluency task in the Greek population: Normative data, and clustering and switching strategies

We assessed 300 healthy adults in Greece on measures of semantic and phonemic verbal fluency in order to develop norms for the Greek population. We also evaluated the strategies that the participants used spontaneously in order to maximize word production, namely clustering and switching techniques. Our tasks comprised three semantic and three phonemic categories. Consistent with previous investigations of English-speaking samples, we found a contribution of demographic variables to word fluency. Specifically, level of education contributed to total word production, number of switches, and number of repetitive responses on both semantic and phonemic tasks, and the average cluster size only on the phonemic task. Age contributed to total word production and cluster size on the semantic task, and to number of switches on both semantic and phonemic tasks. Sex contributed only to total word production on the semantic task. In our sample, clustering and switching strategies were related to total word production on both tasks, suggesting that these strategies were used effectively. We present tables of normative data stratified by age and level of education. We have also included detailed guidelines for scoring clusters relevant to the Greek population.

Relationship of affect recognition with psychopathology and cognitive performance in schizophrenia.

The purpose of the present study was to explore the relationship between emotion perception and both psychopathology and cognitive functioning in a group of Greek patients with schizophrenia. Thirty-five patients with schizophrenia were assessed with computerized tests of emotion perception, using visual faces (Kinneys Affect Matching Test, KAMT), prosody (Affective Prosody Test, APT), and visual everyday scenarios (Fanties Cartoon Test, FCT), as well as a facial recognition test (Kinneys Identity Matching Test, KIMT). The patients were also evaluated with the symptoms dimensions derived from the PANSS (positive, negative, cognitive, depression, and excitement) and a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and visual scanning/psychomotor speed. The three emotion perception and face recognition tests correlated significantly with each other. The KAMT was significantly related to the cognitive symptoms dimension of the PANSS and executive functions. The FCT was significantly related to level of education and attention. Finally, the APT was significantly related to the cognitive symptoms dimension, executive functions, and attention. Our findings regarding the significant relationships of affect perception, both facial and vocal, as well as in everyday scenarios, with several cognitive abilities support the notion that deficits in decoding affective information in schizophrenia could be attributed to impairment in more basic neurocognitive domains.

Neurocognitive outcome after coronary artery bypass surgery using minimal versus conventional extracorporeal circulation: a randomised controlled pilot study

Objective Neurocognitive impairment can be a debilitating complication after cardiac surgery. The aim of this study was to assess the effect of minimal extracorporeal circulation (MECC) versus conventional extracorporeal circulation (CECC) on neurocognitive function after elective coronary artery bypass grafting (CABG) and whether this can be attributed to improved cerebral perfusion intraoperatively. Methods and results 64 patients scheduled for elective CABG surgery were prospectively randomly assigned to surgical revascularisation with MECC versus CECC. All patients were continuously monitored for changes in cerebral oxygenation with near-infrared spectroscopy during the procedure. Neurocognitive assessment was performed before surgery, on the day of discharge and at 3 months postoperatively using a battery of standardised neurocognitive tests. Both groups were comparable in terms of demographic and clinical data. MECC was associated with improved cerebral perfusion during cardiopulmonary bypass (CPB). Eleven patients operated on with MECC and 17 with CECC experienced at least one episode of cerebral desaturation (38% vs 55%, p=0.04) with similar duration (10 vs 12.3 min, p=0.1). At discharge patients operated on with MECC showed a significantly improved performance on complex scanning, visual tracking, focused attention and long-term memory. At 3 months significantly improved performance was also evident on visuospatial perception, executive function, verbal working memory and short-term memory. Patients operated on with MECC experienced a significantly lower risk of early cognitive decline both at discharge (41% vs 65%, p=0.03) and at 3-month evaluation (21% vs 61%, p<0.01). Conclusions Use of MECC attenuates early postoperative neurocognitive impairment after coronary surgery compared with conventional CPB. This finding may have important implications on the surgical management strategy for coronary artery disease. Clinical trial registration number The study is registered at ClinicalTrials.gov, number NCT01213511.

Disproportionate impairment in semantic verbal fluency in schizophrenia: differential deficit in clustering

The purpose of the current study was to investigate whether patients with schizophrenia present disproportionate impairment in semantic, relative to phonemic, fluency. Specifically, we explored whether this impairment could be explained by differential deficits in clustering or switching strategies. The Greek Verbal Fluency Test was administered to 119 patients with schizophrenia and 150 age-, education-, and gender-matched healthy controls. We calculated the total number of words generated, the number of cluster related words, and the number of switches on the semantic and phonological fluency tasks separately. Patients with schizophrenia generated fewer total words, cluster related words and switches than healthy controls on both fluency tasks. When controlling for the total number of words produced, however, the differences between the two groups in the number of cluster related words and switches disappeared. We found a disproportionate impairment in semantic, compared with phonemic, fluency in schizophrenia for total word production and the number of cluster related words, but not for the number of switches. In conclusion, patients with schizophrenia used the same strategies as healthy controls to perform on a word fluency test, but they used them less effectively. Disproportionate impairment in semantic fluency in schizophrenia resulted from a differential deficit only in clustering. Therefore, disproportionately impaired category fluency in schizophrenia may be primarily due to disorganization and not to inefficient access to and retrieval from semantic store.

Studying social cognition in patients with schizophrenia and patients with frontotemporal dementia: theory of mind and the perception of sarcasm.

We investigated social cognition and theory of mind in patients with schizophrenia and in patients with frontotemporal dementia in order to elucidate the cognitive mechanisms involved in the breakdown of these skills in psychiatric and neurological patients. Our tasks included videotaped scenarios of social interactions depicting sincere, sarcastic and paradoxical remarks, as well as lies. We found impaired performance of the schizophrenia group on all theory of mind conditions despite their intact understanding of sincere statements. In contrast, the FTD group performed poorly only when they had to rely on paralinguistic cues indicating sarcasm or lies, and not on paradoxical remarks or sarcasm when given additional verbal cues. Our findings suggest that, while current deficits in social and interpersonal functioning in patients with FTD may reflect a decrement in previously acquired skills, similar deficits in patients with schizophrenia may reflect an altogether inadequately learned process.

Semantic and phonological processing in illiteracy.

Researchers of cognitive processing in illiteracy have proposed that the acquisition of literacy modifies the functional organization of the brain. They have suggested that, while illiterate individuals have access only to innate semantic processing skills, those who have learned the correspondence between graphemes and phonemes have several mechanisms available to them through which to process oral language. We conducted 2 experiments to verify that suggestion with respect to language processing, and to elucidate further the differences between literate and illiterate individuals in the cognitive strategies used to process oral language, as well as hemispheric specialization for these processes. Our findings suggest that semantic processing strategies are qualitatively the same in literates and illiterates, despite the fact that overall performance is augmented by increased education. In contrast, explicit processing of oral information based on phonological characteristics appears to be qualitatively different between literates and illiterates: effective strategies in the processing of phonological information depend upon having had a formal education, regardless of the level of education. We also confirmed the differential abilities needed for the processing of semantic and phonological information and related them to hemisphere-specific processing.

Community dysfunction in schizophrenia: rate-limiting factors.

The purpose of the present study was to investigate the impact of cognitive functioning, psychopathology, and severity of extrapyramidal side effects on community outcome in a group of Greek outpatients with schizophrenia. Participants were 40 outpatients with schizophrenia (25 men). Social adjustment was assessed with the Quality of Life Scale (QLS). Severity of symptoms of schizophrenia was measured with the Positive and Negative Syndrome Scale (PANNS), and extrapyramidal symptoms with the Extrapyramidal Symptom Rating Scale (ESRS). Finally, a battery of neuropsychological tests was administered in order to assess the following cognitive domains: executive functioning/set shifting, executive functioning/inhibition, fluency, verbal memory, visual memory, working memory, attention, visuospatial ability, and psychomotor speed/visual scanning. Total scores on the QLS were significantly correlated with negative symptoms, parkinsonism, and performance on the fluency tasks. Interpersonal relations subscale was significantly related with negative symptoms and fluency. No significant relationship was found between the Instrumental Role Functioning subscale and the PANSS, ESRS, or any cognitive domain. Scores on the Intrapsychic Foundation subscale were significantly correlated with negative symptoms and fluency. Finally, scores on the Common Objects and Activities subscale were significantly related with severity of negative symptoms, parkinsonism and visual memory. Our findings suggest that severity of negative symptoms, cognitive dysfunction, especially performance on fluency tasks and visual memory, as well as parkinsonism, are important determinants of functional outcome in schizophrenia.

Impaired emotion perception in schizophrenia: A differential deficit

We investigated previously reported contradictory findings regarding the nature of deficits in emotion perception among patients with schizophrenia. Some studies have concluded that such deficits are due to a generalized impairment in visual processing of faces, while others have found it to be restricted to facial emotional expressions. We examined 37 patients and 32 healthy controls, matched on age and education, using three computerized tests: matching facial identity, matching facial emotional expressions, and discrimination of subtle differences in the valence of facial emotional expressions. Our results showed impaired matching of emotions in patients with schizophrenia. This impairment did not manifest on tasks that depended on perceiving the identity of faces or cues of the relative valence of facial emotional expressions. Our findings support the differential deficit hypothesis of emotion perception in schizophrenia.

Assessment of memory skills in illiterates: strategy differences or test artifact?

Previous studies have reported that illiterates perform more poorly than literates on a variety of neuropsychological measures. We investigated the hypothesis that putative memory deficits in illiterates are an artifact of the assessment tools used rather than a reflection of an ‘underdeveloped’ ability. In order to accomplish this, we designed two tests, a word list learning test and an object learning test. The illiterate group performed more poorly than semiliterate and literate groups on most variables of the word list learning test, but only on delayed recall and semantic clustering on the object learning test. Our findings suggest that poor memory performance among illiterates can be attributed both to the nature of the task, as well as to the use of different cognitive mechanisms to recall learned information. Presumably, formal education may enhance the innate ability of learning through training individuals in efficient learning and retrieval strategies. We emphasize the importance of developing and using ecologically valid neuropsychological tests to assess illiterate individuals.

Deficits in sustained attention in schizophrenia but not in bipolar disorder

The aim of the present study was to investigate sustained attention in remitted patients with bipolar disorder and in patients with schizophrenia, as compared to each other and to healthy controls; a secondary aim was to investigate the correlations of different symptom dimensions with performance on sustained attention in the two patient groups. Participants were 29 (18 men) outpatients with schizophrenia (SZ), 19 (8 men) patients with bipolar disorder I (BP) in remission, and 30 (15 men) healthy controls (HC); all three groups were matched on age, sex ratio, and level of education. Symptom severity (positive symptoms, negative symptoms, and general psychopathology) of patients with SZ were assessed with the Greek version of the Positive and Negative Syndrome Scale (PANSS); residual affective symptoms of patients with BP were assessed with the Young Mania Rating Scale (YMRS) and the Montgomery-Asberg Depression Rating Scale (MADRS). Sustained attention was measured by means of the Penn Continuous Performance Test (PCPT). The three groups differed significantly on the PCPT scores. Patients with SZ performed more poorly than both the BP and HC groups, whereas patients with BP did not differ significantly from HC. Performance on the PCPT did not correlate significantly with scores on the YMRS and MADRS in patients with BP. Also, scores on the PCPT did not correlate significantly with scores on any of the three subscales of the PANSS. Outpatients with schizophrenia presented deficits in sustained attention, whereas patients with bipolar disorder I in remission did not manifest such impairment. These results imply that impaired sustained attention might be a more enduring deficit in schizophrenia than it appears to be in bipolar disorder.