Relationship between intraindividual variability and level of performance in visuospatial memory: the role of task difficulty

Poster

Reference

Relationship between intraindividual variability and level of performance in visuospatial memory: the role of task difficulty

GOLAY, Philippe, LECERF, Thierry

GOLAY, Philippe, LECERF, Thierry. Relationship between intraindividual variability and level of performance in visuospatial memory: the role of task difficulty. In: 16th European Society for Cognitive Psychology Conference, Krakow, 2nd-5th September 2009, 2009

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http://archive-ouverte.unige.ch/unige:29485

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Maximum Value of iSD

Average proportion of correct answers

INTRODUCTION

METHOD

CONCLUSIONS RESULTS

Contact: Philippe.Golay@unige.ch

ESCoP 2009, XVI Conference | Krakow, Poland, 2nd – 5th September, 2009 Supported by the Swiss National Science Foundation Grant N°100011-107764

Relationship between intraindividual variability and level of performance in visuospatial memory: the role of task difficulty

Philippe Golay

& Thierry Lecerf

Faculty of Psychology and Educational Sciences, ^*University of Geneva, Switzerland ^#University of Lausanne, Switzerland

• Relationships between intraindividual variability (IIV) and level of performance in memory tasks (accuracy measures) show a negative correlation between intraindividual Standard Deviation (iSD) and mean score;

• In contrast to reaction times, accuracy measures are constrained between two finite bounds (0 to 100%)

• The negative correlation between level of performance and IIV was consistent with the literature;

• The magnitude of this negative correlation is strongly related to the task difficulty. This is a direct consequence of the quadratic relationship between Mean and Maximum Variance ( ²) for accuracy measures;

• Results were consistent within and across the three age groups : tasks with a very high correct response ratio can lead to artefactual results because mean score and IIV share a very large amount of variance;

 It’s necessary to adjust tasks difficulty to rule out ceiling/floor effects, and to avoid merging mean score and IIV into a single source of variance;

• This could be applied to both across trial IIV and across occasions IIV experiments.

• Free recall of black cells (computerized task)

• Simultaneous presentation (presentation time = number of black cells x 1 sec)

THE MATRIX TASK





levels 4 & 5

ADAPTATIVE PROCEDURE

• Span Level determination (ascending procedure)

• 10 items at level N (span level)

• 10 items at level N+1 (supra-span level)

ANALYSES

201 children (9-12 years)

137 young adults (18-35 years) 122 old adults (≥60 years)

32 groups (Age x Span x Level)

Group size : M = 28.5, SD = 16.8, min = 7, max = 53

Group 1 : children, Span = 2, Level = N Group 2 : children, Span = 2, Level = N+1

Group 3 : children, Span = 3, Level = N ...

Group 32 : old adults, Span = 7, Level = N+1

SAMPLE DESCRIPTION

• High correlation between task difficulty (average iM) and the magnitude of R (iM X iSD within groups)

• Participants were divided into 32 groups;

• Calculation of the correlation (R) between individual Mean (iM) and intraindividual Standard Deviation (iSD) within each group;

• Analyses of the relationship between average iM and R across the 32 groups.

OBJECTIVE

Maximum score : 100%

of correct answers for all trial. IIV necessarily equal to zero

Regular Pattern :

participant correctly recalled 50% of information on each trial. IIV is null

& mean score is .50 Oscillating Pattern :

participant failed half of the trials (0%) and succeed the other half (100%). IIV is maximum & mean

score is .50 Same level of

performance but different IIV

Results for the 32 groups Limit of possible values (spectrum of

possible measurements)

• Evaluation of the contribution of the task difficulty on the magnitude of the correlation between IIV and level of performance in a visuospatial working memory task

• Across all 32 groups (N & N+1) : R = -.722, p < 0.01

• N Level (16 groups) : R = -.724, p<.01

• N+1 Level (16 groups) : R = -.745, p<.01

• Children (12 groups) : R = -.520, n.s

• Young Adults (10 groups) : R = -.150, n.s

• Old Adults (10 groups) : R = -.740, p<.05

• The same trend can be observed within the three age groups

(less evident for young adults because of high homogeneity across theses groups)

• Task difficulty alone accounts for more than 50% of the relationship between IIV and level of performance

• Quadratic relationship between Mean and Maximum Variance ( ²)

• When the proportion of correct responses is very low or very high, potential variability is strongly limited (and tends to zero)

 It may artificially and strongly increase the linear dependency between IIV and mean performance when the average proportion of correct answer is very high (or very low).

R² = 0.5209

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Correlation between iM and iSD (R)

Proportion of cells correctly recalled

Children (N & N+1)

Young Adults (N & N+1) Old Adults (N & N+1)