The phonological loop model of working memory: An ERP study of irrelevant speech and phonological similarity effects

Abstract

The phonological loop model for retention of auditory verbal material in working memory, developed by Baddeley,assumes that irrelevant speech and phonological similarity influence only one and the same element of the system-that is, the phonological short-term store. Wetested this idea by recording eventrelated potentials (ERPs) to auditorily presented letters that were phonologically similar or dissimilar and were to be memorized in the presence of more or less disturbing irrelevant speech. Irrelevant speech and phonological similarity caused ERP effects with clearly different scalp topographies, indicating that these factors influence different brain systems and hence probably different cognitive elements. Moreover, ERPs indicated that the phonological similarity effect might involve processes at the level of phonological analysis. Our data also support recent suggestions that the irrelevant speech effect is not based on the phonological similarity between relevant and irrelevant material, but on the phonological variability within the irrelevant stream, 471Baddeley's model of working memory proposes the existence ofan attentional control system (the central executive) and two slave systems. These slave systems are the visuospatial sketch pad for visual images and the phonological loop for speech-based information (Baddeley, 1986(Baddeley, , 1990(Baddeley, , 1992b(Baddeley, , 1992c. The phonological loop is assumed to be composed of two subsystems or elements: a phonological short-term store to hold acoustic or speech-based information, and an articulatory control process, analogous to inner speech, used to maintain material within the phonological store. The articulatory control process is also used to transfer visually presented verbal material into the phonological store by subvocalization, whereas auditorily presented verbal material gains direct and obligatory access to the phonological shortterm store. Evidence for this description of the phonological loop has come from many studies (e.g

The irrelevant speech effect: a PET study

“…ERP data indicate that irrelevant speech influences brain activity despite the absence of a corresponding performance effect (Martin-Loeches, Schweinberger & Sommer, 1997). Also, according to Lavie's law of attention (Lavie, 1995) supported by recent neuroimaging data (Rees, Frith, & Lavie, 1997; Rees, Frith, & Lavie, 2001), participants' intention to ignore irrelevant distractors is not sufficient to avoid processing them, in other words, distractors are always processed whenever there is capacity available for processing.…”

Disruption of immediate memory and brain processes: an auditory ERP protocol

“…Working memory is the capacity to maintain and manipulate information temporarily in memory, typically in the service of some particular goal or task, and the influence of these tasks on human brain processes has been investigated using electroencephalogram (EEG) [26] and event-related potentials (ERPs), [41][42][43].…”

“…The irrelevant sound effect is characterized by an increase in the mean probability of an error scored with this criterion as a consequence of the auditory stimulation. The size of the effect depends on the makeup of the sequence of task irrelevant auditory stimuli presented during the retention interval [5,[7][8][9][10]13,22,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]52,53,[59][60][61][62].…”

Neural modeling and imaging of the cortical interactions underlying syllable production

“…Examples include functional magnetic resonance imaging (IMRI) studies (e.g., Ackermann, Wildgruber, Daum, & Grodd, 1998;Baciu, Abry, & Segebarth, 2000;Binder, 1997a;1997b;Binder et al, 1995;1996;Buchsbaum, Hickok, & Humphries, 2001;Buckner, Raichle, & Petersen, 1995;Buckner, Raichle, Miezin, & Petersen, 1996;Hashimoto & Sakai, 2003;Lotze, Seggewies, Erb, Grodd, & Birbaumer, 2000b;Riecker, Ackennarm, Wildgruber, Dogil, & Grodd, 2000;Rueckert et al, 1994;Urban et al, 2003;Wildgruber, Ackermann, & Grodd, 2001), positron emission tomography (PET) studies (e.g., Demone! et al, 1992;Demone!, Price, Wise, & Frackowiak, 1994;Etard et al, 2000;Fiez, Raichle, Balota, Tallal, & Petersen, 1996;Hirano et al, 1996;1997b;1997a;Mazoyer et al, 1993;Mellet, Tzourio, Denis, & Mazoyer, 1998;Papathanassiou et al, 2000;Petersen, Fox, Posner, Mintun, & Raichle, 1988;Petersen, Fox, Snyder, & Raichle, 1990;Wise, Boussaoud, Johnson, & Caminiti, 1997;Wise, Greene, Buche!, & Scott, 1999;Zatorre, Evans, Meyer, & Gjedde, 1992;Zatorre, Meyer, Gjedde, & Evans, 1996), electroencephalography (EEG) studies (e.g., Martin-Leeches, Schweinberger, & Sommer, 1997;Mills, Coffeycorina, & Neville, 1993;Neville, Coffey, Holcomb, & Tallal, 1993;van Turem10ut, Hagoort, & Brown, 1997), and magnetoencephalography (M...…”