The effects of the word length effect and articulatory suppression on short term memory
SJPS5002
Experimental Methods and Statistical Analysis
An investigation into word length effect and articulatory suppression and how they affect recall in working memory
Sarah Messenger
0801595
Title
An investigation into word length effect and articulatory suppression and how they affect recall in working memory.
Abstract
In light of research carried out by Baddeley, Thomson and Buchanan (1975), a study was carried out using a related design to investigate whether word length and articulatory suppression affects memory recall. The study used an opportunity sample of 32 participants, who were asked to recall words from four lists of twenty words (either short or long) either with or without articulatory suppression. The hypothesis of the study predicted that participants will recall significantly more words than short words, participants will recall significantly more words in the ‘no suppression’ condition than the ‘suppression’ condition and that participants will recall significantly more short words in the ‘no suppression’ condition compared to the long words with ‘suppression’. A two way ANOVA was carried out to analyse the results. The findings showed that participants recalled significantly more words with ‘no suppression’ than with ‘suppression’; that participants recalled significantly more short than long words and that participants recalled significantly more short words with ‘no suppression’ than long words with ‘suppression’. The findings support WLE and indicate that AS has a detrimental effect on memory recall.
Introduction
The working memory (WM) was introduced by Salame and Baddeley (1982, cited in Pring and Walker, 1994). One component WM, the phonological loop (PL) consists of two components (cited in Baddeley, Garthercole & Papagno, 1998). One component, the phonological store, is a short-term store with auditory memory traces that are subject to rapid decay. The second component, the articulatory control system, allows for sub vocal rehearsal of the information stored in the phonological store, and can revive the memory traces.
Empirical support WM and in particular the PL stems from research into the effects of articulatory suppression (AS) and word length effect (WLE).
The present study investigates dual task logic that when a person tries to carry out two tasks simultaneously that use the same perceptual domain, performance is less efficient than when performing the tasks individually, (Simon and Sussman, 1987). This study focuses on the WM and the effects of AS and WLE on an immediate serial recall task.
WLE (Baddeley et al, 1975, cited in Cowan, 2005: 27) refers to the ability to reproduce a sequence of short words better than long words. This suggests that the capacity of the PL is determined by temporal duration and that memory span is determined by the rate of rehearsal. It is suggested that words with more syllables that take longer to speak, are more difficult to retain and recall than words with fewer or one syllable than can be more spoken rapidly (Berman, 2003).
Support for WLE stems from an investigation looking at the effect of word length on recall and on a recognition test in which the stimulus was presented auditorily, where output delay was controlled. The result of this investigation indicated that immediate serial recall for word sequences decreased systematically with the number of syllables within the words (Baddeley, Chincotta, Stafford & Turk, 2002).
AS involves the articulation of an irrelevant sound during the presentation of stimulus that is required to be retained and recalled. It is suggested that AS impairs recall as the irrelevant sound is assumed to block the articulatory rehearsal process, thereby the memory traces in the PL are left to decay, (Richardson and Baddeley, 1975).
Empirical support for the effects of AS stems from a study investigating the effects of articulatory suppression on a recall task. The results of the study indicated that AS reduces immediate serial recall substantially when taking part in memory recall tasks (Baddeley, 1990; Levy, 1971, cited in Coye, Divin & James, 2001). Conclusions of this study lead to the suggestion that suppression engages the capacity of the PL, thus disrupting rehearsal, therefore making the ability to retain and recall the information more difficult.
A study carried out by Baddeley, Thomson and Buchanan (1975) investigated the WLE and the effect of AS on immediate memory recall. There findings indicated that words with fewer syllables are recalled more effectively than words with numerous syllables. The results of this study indicated further that when participants were exposed to AS, recall was detrimentally affected.
This study partly replicates the research carried out by Baddeley, Thomson & Buchanan (1975) in order to validate their findings with regards to the WLE and the effects of AS. The study aims to investigate whether WM is involved in cognitive tasks, looking specifically at the effects of AS and the WLE on short-term memory. This leads to a one-tailed hypothesis that participants will recall significantly more words than short words, participants will recall significantly more words in the ‘no suppression’ condition than the ‘suppression’ condition and that participants will recall significantly more short words with ‘no suppression’ condition compared to the long words with ‘suppression’.
Methodology
Design
The current experiment used a related design. There were two independent variables. The first variable; the suppression of the words presented, was manipulated so that the words were presented with ‘suppression’ or ‘no suppression’. AS was created by asking participants to utter the word ‘the’ repeatedly while the word lists were presented to them. The second variable; the length of the words, was manipulated so that they were either ‘short’ (one syllable) or ‘long’ (numerous syllables). The dependant variable was the number of words recalled by the participants out of the four lists of 20 words.
Participants
An opportunity sample of students from a psychology class was used in the experiment. There were a total of 32 participants; a ratio of 5 males-27 females. Participants were aged between 19 and 50 years.
Apparatus
Participants were exposed to four lists of words. Each list contained twenty words which randomly generated by the experimenter and were presented to participants auditorily. (See Appendix One for the word list. Paper and pens were used by participants to recall words, and a stopwatch was used to time the task.
Procedure
The procedure was carried out using standardised instructions. (See Appendix Two for standardised instructions).
