scholarly journals Semantic Search in Psychosis: Modeling Local Exploitation and Global Exploration

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Nancy B Lundin ◽  
Peter M Todd ◽  
Michael N Jones ◽  
Johnathan E Avery ◽  
Brian F O’Donnell ◽  
...  
Keyword(s):  
Processing Speed ◽  
Verbal Fluency ◽  
Semantic Space ◽  
Preliminary Evidence ◽  
Similar Amount ◽  
Schizotypal Personality ◽  
Verbal Fluency Task ◽  
Cue Salience ◽  
Fluency Task ◽  
Selection Of

Abstract Impairments in category verbal fluency task (VFT) performance have been widely documented in psychosis. These deficits may be due to disturbed “cognitive foraging” in semantic space, in terms of altered salience of cues that influence individuals to search locally within a subcategory of semantically related responses (“clustering”) or globally between subcategories (“switching”). To test this, we conducted a study in which individuals with schizophrenia (n = 21), schizotypal personality traits (n = 25), and healthy controls (n = 40) performed VFT with “animals” as the category. Distributional semantic model Word2Vec computed cosine-based similarities between words according to their statistical usage in a large text corpus. We then applied a validated foraging-based search model to these similarity values to obtain salience indices of frequency-based global search cues and similarity-based local cues. Analyses examined whether diagnosis predicted VFT performance, search strategies, cue salience, and the time taken to switch between vs search within clusters. Compared to control and schizotypal groups, individuals with schizophrenia produced fewer words, switched less, and exhibited higher global cue salience, indicating a selection of more common words when switching to new clusters. Global cue salience negatively associated with vocabulary ability in controls and processing speed in schizophrenia. Lastly, individuals with schizophrenia took a similar amount of time to switch to new clusters compared to control and schizotypal groups but took longer to transition between words within clusters. Findings of altered local exploitation and global exploration through semantic memory provide preliminary evidence of aberrant cognitive foraging in schizophrenia.

scholarly journals EXPRESS: Attention in Post-Lexical Processes of Utterance Production: Dual-Task Cost in Younger and Older Adults

2021 ◽  
pp. 174702182110341
Author(s):  
Maryll Fournet ◽  
Michaela Pernon ◽  
Sabina Catalano Chiuvé ◽  
Ursula Lopez ◽  
Marina Laganaro
Keyword(s):  
Older Adults ◽  
Dual Task ◽  
Verbal Fluency ◽  
Verbal Task ◽  
Lexical Selection ◽  
Speech Task ◽  
Verbal Fluency Task ◽  
Dual Task Cost ◽  
Lexical Processes ◽  
Fluency Task

There is a general agreement that speaking requires attention at least for conceptual and lexical processes of utterance production. However, conflicting results have been obtained with dual-task paradigms using either repetition tasks or more generally tasks involving limited loading of lexical selection. This study aimed to investigate whether post-lexical processes recruit attentional resources. We used a new dual-task paradigm in a set of experiments where a continuous verbal production task involved either high or low demand on lexical selection processes. Experiment 1 evaluates lexical and post-lexical processes with a semantic verbal fluency task, whereas experiments 2 and 3 focus on post-lexical processes with a non-propositional speech task. In each experiment, two types of non-verbal secondary tasks were used: processing speed (simple manual reaction times) or inhibition (Go/No-go). In Experiment 1, a dual-task cost was observed on the semantic verbal fluency task and each non-verbal task. In Experiment 2, a dual-task cost appeared on the non-verbal tasks but not on the speech task. The same paradigm was used with older adults (Experiment 3), as increased effort in post-lexical processes has been associated with ageing. For older adults, a dual-task cost was also observed on the non-propositional verbal task when speech was produced with the inhibition non-verbal task. The results suggest an attentional cost on post-lexical processes and strategic effects in the resolution of the dual-task.

scholarly journals Effects of dual task demanding manual dexterity and sit-to-stand in Parkinson disease individuals

2021 ◽  
Vol 15 (2) ◽  
pp. 137-148
Author(s):  
Tatiana B. Freitas ◽  
José Eduardo Pompeu ◽  
Briana R. B. Moraes ◽  
Sandra M. A. A. Pompeu ◽  
Keyte G. Silva ◽  
...  
Keyword(s):  
Dual Task ◽  
Verbal Fluency ◽  
Manual Dexterity ◽  
Dual Tasks ◽  
Verbal Fluency Task ◽  
Sit To Stand ◽  
Yahr Scale ◽  
Task Conditions ◽  
The Cost ◽  
Fluency Task

BACKGROUND: Parkinson's disease (PD) causes loss of automaticity and impairment in dual task (DT) performance. AIM: To investigate the performance and pattern of prioritization of individuals with PD in motor and cognitive DT. METHOD: An observational, transversal, comparative study assessed 20 individuals with PD between stages 1.5 to 3 of the modified Hoehn and Yahr scale. Performance was assessed during the execution of manual dexterity and sit-to-stand tasks, in a single task or in association with a verbal fluency task. RESULTS: There was a loss of performance in both dual task conditions. The cost of verbal fluency was higher than the cost of manual dexterity function. CONCLUSION: Individuals with PD showed worse DT performance and prioritized the manual dexterity task. There was no prioritization between sit-to-stand and verbal fluency. These findings suggest that the nature of tasks can influence the prioritization of dual tasks.

Action (verb) fluency: Test–retest reliability, normative standards, and construct validity

2005 ◽  
Vol 11 (4) ◽  
pp. 408-415 ◽  
Author(s):  
STEVEN PAUL WOODS ◽  
J. COBB SCOTT ◽  
DANIELLE A. SIRES ◽  
IGOR GRANT ◽  
ROBERT K. HEATON ◽  
...  
Keyword(s):  
Construct Validity ◽  
Verbal Fluency ◽  
Normative Data ◽  
Verbal Working Memory ◽  
Information Processing Speed ◽  
Verbal Fluency Task ◽  
Action Verb ◽  
Test Retest Reliability ◽  
Fluency Task ◽  
Fluency Test

Action (verb) fluency is a newly developed verbal fluency task that requires the examinee to rapidly generate as many verbs (i.e., “things that people do”) as possible within 1 min. Existing literature indicates that action fluency may be more sensitive to frontal–basal ganglia loop pathophysiology than traditional noun fluency tasks (e.g., animal fluency), which is consistent with the hypothesized neural dissociation between noun and verb retrieval. In the current study, a series of analyses were undertaken to examine the psychometric properties of action fluency in a sample of 174 younger healthy participants. The first set of analyses describes the development of demographically adjusted normative data for action fluency. Next, a group of hypothesis-driven correlational analyses reveals significant associations between action fluency and putative tests of executive functions, verbal working memory, verbal fluency, and information processing speed, but not between action fluency and tests of learning or constructional praxis. The final set of analyses demonstrates the test–retest stability of the action fluency test and provides standards for determining statistically reliable changes in performance. In sum, this study enhances the potential clinical applicability of action fluency by providing demographically adjusted normative data and demonstrating evidence for its reliability and construct validity. (JINS, 2005,11, 408–415.)

scholarly journals Shifting Gear in the Study of the Bilingual Advantage: Language Switching Examined as a Possible Moderator

2019 ◽  
Vol 9 (8) ◽  
pp. 86 ◽  
Author(s):  
Evy Woumans ◽  
Shauni Van Herck ◽  
Esli Struys
Keyword(s):  
Executive Functions ◽  
Verbal Fluency ◽  
Specific Aspect ◽  
Language Switching ◽  
Verbal Fluency Task ◽  
Bilingual Advantage ◽  
Switching Behaviour ◽  
Switching Task ◽  
Determining Factor ◽  
Fluency Task

The bilingual advantage is a heavily debated topic in research on bilingualism. The current study further investigated one specific aspect of bilingualism proposed to be a determining factor for the bilingual advantage, namely language switching behaviour. We investigated whether a bilingual advantage can be detected in the executive functions of inhibition and shifting by comparing monolingual and bilingual participants on a Simon task and a colour–shape switching task. Furthermore, we examined the relation between these executive functions and language switching proficiency, as measured by a semantic verbal fluency task. In addition, the current study set out to investigate the convergence of self-reported language switching estimates and actual language switching proficiency. Results revealed a bilingual advantage for shifting, but not for inhibition. However, this bilingual advantage for shifting was not related to language switching behaviour. Additionally, we were unable to identify a relation between objective and subjective measures of switching abilities. These findings seem to confirm the existence of a bilingual advantage, but also once again validate its elusiveness, as demonstrated by the absence of bilingual benefits on our measure of inhibition. It furthermore questions the validity of switching measures employed in previous studies.

Verbal and design fluency in patients with frontal lobe lesions

2001 ◽  
Vol 7 (5) ◽  
pp. 586-596 ◽  
Author(s):  
JULIANA V. BALDO ◽  
ARTHUR P. SHIMAMURA ◽  
DEAN C. DELIS ◽  
JOEL KRAMER ◽  
EDITH KAPLAN
Keyword(s):  
Frontal Cortex ◽  
Frontal Lobe ◽  
Verbal Fluency ◽  
Right Hemisphere ◽  
Verbal Fluency Task ◽  
Frontal Lobe Lesions ◽  
Design Fluency ◽  
The Right ◽  
Frontal Lesions ◽  
Fluency Task

The ability to generate items belonging to categories in verbal fluency tasks has been attributed to frontal cortex. Nonverbal fluency (e.g., design fluency) has been assessed separately and found to rely on the right hemisphere or right frontal cortex. The current study assessed both verbal and nonverbal fluency in a single group of patients with focal, frontal lobe lesions and age- and education-matched control participants. In the verbal fluency task, participants generated items belonging to both letter cues (F, A, and S) and category cues (animals and boys' names). In the design fluency task, participants generated novel designs by connecting dot arrays with 4 straight lines. A switching condition was included in both verbal and design fluency tasks and required participants to switch back and forth between different sets (e.g., between naming fruits and furniture). As a group, patients with frontal lobe lesions were impaired, compared to control participants, on both verbal and design fluency tasks. Patients with left frontal lesions performed worse than patients with right frontal lesions on the verbal fluency task, but the 2 groups performed comparably on the design fluency task. Both patients and control participants were impacted similarly by the switching conditions. These results suggest that verbal fluency is more dependent on left frontal cortex, while nonverbal fluency tasks, such as design fluency, recruit both right and left frontal processes. (JINS, 2001, 7, 586–596.)

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