Development of rehearsal in short‐term memory: Differences between pictorial and spoken stimuli

Abstract

Two experiments on the development of subvocal rehearsal in short-term memory (STM) are reported in this study. According to the articulatory loop model of adult performance, rehearsing the names of visually presented stimuli involves extra mental operations compared with rehearsing items that are heard. We used this analysis to predict that rehearsal will appear later in the development of STM for pictured objects than for spoken words. To provide an indication of rehearsal, we manipulated the word length of these two types of stimuli. Experiment 1 tested children's ability to recall sequences of fixed length, while Expt 2 used a memory span procedure. The results supported our prediction in that STM for spoken words was sensitive to word length at all ages from 4 years upwards, while STM for pictured objects showed equivalent effects only in children aged over 8 years.Subsidiary analysis of the relation between recall of spoken words and speech rate confirmed previous evidence that the capacity of the articulatory loop remains approximately constant during development. We conclude that this rehearsal system is present from an early age, and that development involves a broadening of the range of stimuli which can gain access to it.It is widely accepted that very young children do not rehearse in STM tasks and that the development of rehearsal strategies contributes to the increase in performance with age (see Kail, 1984). One line of evidence comes from studies of lip movements. Using namable pictorial stimuli, Flavell, Beach & Chinsky (1966) found that rehearsal was regularly present only in children aged 7 years or over. A less direct method is to examine the development of speech-based coding by testing for the phonemic similarity effect. This effect is well established in adult subjects and is the tendency for short-term recall to be poorer for phonemically similar items (e.g. Baddeley, 1966). In an influential study, Conrad (1971) found that introducing phonemic similarity among the names of pictorial stimuli had no effect on STM in children aged under about 6 years. Thus there is some convergence between different kinds of evidence about the development of rehearsal.A further method is to study the development of the word length effect: the tendency for adult subjects to be able to recall fewer long words than short words *Requests for reprints.

Memory development in Libyan and Dutch school children

“…In the case of words of different length, differences in recall were closely related to the rate at which they could be spoken. Other researchers have reported similar results (e.g., Hitch, Halliday, Dodd, & Littler, 1989a;Hitch, Halliday, & Littler, 1989b;Hitch, Halliday, Schaafstal, & Heffernan, 1991).…”

Le développement de la mémoire de travail : perspectives dans le cadre du modèle de partage temporel des ressources

“…Ces âges ont été choisis parce que de nombreuses études ont montré qu'avant l'âge de sept ans, les enfants n'ont pas spontanément recours à des stratégies de maintien (comme la répétition subvocale) dans les tâches de mémoire à court terme, (Gathercole & Hitch, 1993 ;Gathercole, Adams, & Hitch, 1994 ;Hitch, Halliday, Dodd, & Littler, 1989). Dans cette expérience, nous avons modifié notre paradigme de tâche d'empan complexe afin de l'adapter à des enfants si jeunes.…”

Phonological, visual, and semantic coding strategies and children's short-term picture memory span

“…In previous research, pictures have typically been presented in a fixed horizontal row, turning each card face down in turn (Hitch et al, 1988;Hitch, Halliday et al, 1989;1991;Longoni & Scalisi, 1994). This provides the potential for spatial cues to assist performance, so cards were always presented in the same spatial location (Henry, 2008) to make the task comparable to verbal span tasks.…”

“…spoken duration or differences in phonological complexity -see Hulme, Neath, Stuart, Shostak, Surprenant & Brown, 2006;Lewandowsky & Oberauer, 2008;Mueller, Seymour, Kieras & Meyer, 2003;Romani, McAlpine, Olson, Tsouknida & Martin, 2005). Word length effects in picture span tasks emerge at 7-9 years (Halliday et al, 1990;Henry, Turner, Smith & Leather, 2000;Hitch, Halliday, Dodd & Littler, 1989;Hitch et al, 1991), although there is debate about the precise cognitive processes responsible for this development in relation to verbal rehearsal and verbal output (Cowan, Day, Saults, Keller, Johnson & Flores, 1992;Henry, 1991;Henry et al, 2000;Yuzawa, 2001). Others doubt that word length effects require articulatory processes (e.g.…”