Disruption of order information by irrelevant items: A serial recognition paradigm

irrelevant speech effect (ISE) is defined as a decrement in visually presented digit-list short-term memory performance due to exposure to irrelevant auditory material. Perhaps the most successful theoretical explanation of the effect is the changing state hypothesis. This hypothesis explains the effect in terms of confusion between amodal serial order cues, and represents a view based on the interference caused by the processing of similar order information of the visual and auditory materials. An alternative view suggests that the interference occurs as a consequence of the similarity between the visual and auditory contents of the stimuli. An important argument for the former view is the observation that ISE is almost exclusively observed in tasks that require memory for serial order. However, most short-term memory tasks require that both item and order information be retained in memory. An ideal task to investigate the sensitivity of maintenance of serial order to irrelevant speech would be one that calls upon order information but not item information. One task that is particularly suited to address this issue is serial recognition. In a typical serial recognition task, a list of items is presented and then probed by the same list in which the order of two adjacent items has been transposed. Due to the re-presentation of the encoding string, serial recognition requires primarily the serial order to be maintained while the content of the presented items is deemphasized. In demonstrating a highly significant ISE of changing versus steady-state auditory items in a serial recognition task, the present finding lends support for and extends previous empirical findings suggesting that irrelevant speech has the potential to interfere with the coding of the order of the items to be memorized. (c) 2006 Elsevier B.V. All rights reserved

Interaction between a verbal working memory network and the medial temporal lobe

The irrelevant speech effect illustrates that sounds that are irrelevant to a visually presented short-term memory task still interfere with neuronal function. In the present study we explore the functional and effective connectivity of such interference. The functional connectivity analysis suggested an interaction between the level of irrelevant speech and the correlation between in particular the left superior temporal region, associated with verbal working memory, and the left medial temporal lobe. Based on this psycho-physiological interaction, and to broaden the understanding of this result, we performed a network analysis, using a simple network model for verbal working memory, to analyze its interaction with the medial temporal lobe memory system. The results showed dissociations in terms of network interactions between frontal as well as parietal and temporal areas in relation to the medial temporal lobe. The results of the present study suggest that a transition from phonological loop processing towards an engagement of episodic processing might take place during the processing of interfering irrelevant sounds. We speculate that, in response to the irrelevant sounds, this reflects a dynamic shift in processing as suggested by a closer interaction between a verbal working memory system and the medial temporal lobe memory system. (c) 2006 Elsevier Inc. All rights reserved.info:eu-repo/semantics/publishedVersio

The relationship of verbal learning and verbal fluency with written story production implications for social functioning in first episode psychosis

Background: Impairments in speech, communication and Theory of Mind are common in schizophrenia, and compromise social functioning. Some of these impairments may already be present pre-morbidly. This study aimed to investigate verbal functions in relation to written story production and social functioning in people experiencing a first episode of psychosis (FEP). Method: Two groups of participants: FEP (N = 31) and healthy controls (HC, N = 31), completed measures of clinical status, social functioning, a series of neuropsychological tests targeting verbal functioning, and the “Frog Where Are You?” story production task. Results: Story results showed reduced efficiency (words per minute) and self-monitoring (corrections per minute) for FEP compared with HC groups (p < 0.01). The FEP group performed significantly poorer than the HC group on most indices of verbal learning and verbal fluency. Story production was positively associated with verbal learning and verbal fluency for the FEP group only (p < 0.05). Premorbid function decline was associated with impaired verbal learning and memory for the FEP group. Conclusion: Individuals with FEP show a childhood history of reduced social and academic performance that is associated with skills essential for daily social interactions, as evidenced by the findings for story production, verbal learning and verbal fluency