Development of Time Knowledge in children (6 to 11 years)

Florence Labrell and Georges Dellatolas

Inserm U669 Univ. Reims, Paris Sud, Paris Descartes

•  Time Knowledge: –  Accurate representation and use of time units

•  Accurate Perception of time intervals (?)

Short time intervals (msec, sec, few min.): reproduction tasks, bisection tasks, … Long time intervals: verbal « code »: numbers, time units

Content of a Time Knowledge Inventory

•  Orientation (OR) Present time awareness

•  Sequences (SEQ) (e.g,, order of months, seasons)

•  Time units (TU) (relations between TU)

•  Clock Reading (CR) (analogue CR)

•  Representation of TU (RT) (what is possible to do in a given time)

•  Life span (LS) (Aristotle’s score)

•  Birthday (B) •  Interview duration (ID)

The 127 typically developing children. School Grade, age, and gender

Age group

Grade N % girls Age m SD range

1 PreSchool 22 54 5.9 0.1 5.7 – 6.1

2 Grade 1 21 48 6.9 0.1 6.7 – 7.1

3 Grade 2 21 48 7.8 0.3 7.2 – 8.1

4 Grade 3 19 53 8.6 0.3 8.2 – 9.0

5 Grade 4 24 79 9.7 0.2 9.2 – 10.0

6 Grade 5 20 65 10.8 0.3 10.2 – 11.1

Interview Duration

Interview Duration Score

Interview duration (ID): (1) For how much time are we here together? « Real » Duration : Q2=15 min, Q3 –Q1: 14 – 21 min, Range: 5 – 42 Scoring based on the difference The age effect may be due to: (1) a better perception of the time interval (2) a better « verbal coding » of the time interval

Life Span (Aristotle’s Score)

WHAT IS TIME ? A moving picture of the motionless Eternity (Plato) The number of movement according to the former and the later (Aristotle) is the number of years from one stage to the next

movement =change number = number of units (exception : code) if time is a number, the units must be time units (e.g., years)

(1)* Could these pictures be of the same person or are they from different persons? Why? (2)* Is it possible for this old man to become a baby? Why?* How long does it takes: (3) for a baby (here) to become a child (here)? (4) for a child (here) to become an young adult (here)? (5) for a young adult to become an old man ?

School grade Age (y ; m)

PS 5;7 – 6;1

GR1 6;7 – 7;1

GR2 7;2 – 8;1

GR3 8;2 – 9;0

GR4 9;2 – 10;0

GR5 10;2 – 11;1

« Same » (%) 18 57 62 89 62 100

Irreversibility (%) 100 100 100 100 100 95

How long does it takes: (3) for a baby (here) to become a child (here)? (4) for a child (here) to become an young adult (here)? (5) for a young adult to become an old man ?

PS Grade 1 Grade 2 Grade 3 Grade 4 Grade 5

From baby to child [adults (n=20): median=6, range= 4 – 10 years] Don’t know (%)

54.5 23.8 0 0 0 0

Median 2 4 3.5 4 4 6 Q3 –Q1 4.2 – 0.5 5.5 – 2.0 5 – 1 6 – 2 5.7 – 3.2 8.7 – 4.0 Range <0.001 - 5 0.75 - 20 0.08 - 10 0.16 - 10 1 - 9 3 - 10

From child to adult [adults (n=20): median=22, range= 15 – 30 years] Don’t know (%)

50.0 19.0 0 0 0 0

Median 7.0 18.0 7.0 14 15 13 Q3 –Q1 33 - <.001 20 – 8 12 – 2 20 – 8 20 – 10 16.5 -10 Range 80 - <.001 90 - 4 20 - .66 30 - .33 30 - 2 20 - 10

From adult to elderly (3) [adults (n=20): median=35, range= 20 – 55 years] Don’t know (%)

63.6 23.8 4.8 5.3 0 0

Median 2 15 10 35 23 28 Q3 –Q1 23 - .21 55 – 3 31.5 – 3 60 - 20 45 – 12.5 40 – 20 Range 80 - <.001 100 - 1 80 - .66 90 - .5 60 - 3 60 - 5

How long does it takes:

Scoring : for each of the three intervals adult range: 2 points borderline: 1 point dont know or outside the above: 0

max=0

Aristotle’s Score

Birthday

•  1)How old are you? –  All correct (error<1year)

•  (2)When is your birthday? –  PS: 27% correct, Gr 1&2: 76%, Gr 3-5: near 100% correct

•  (3) How long ago was your birthday? –  Score 0 (DN or error>12m), 1 (>3m), 2 (>1m), 3 (error<1m)

•  (4) How much time is left to your next birthday? –  Score 0 (DN or error>12m), 1 (>3m), 2 (>1m), 3 (error<1m)

Birthday Score

Representation of Time Units •  (1) If you have 1 hour left, do you have enough time for:

–  (a) learning to play a new musical instrument that you have in hands for the first time;

–  (b) give a look at a comics book; –  (c) make a drawing

•  (2) If you have 3 hours left, do you have enough time: –  (a) to go from home to the North Pole by plane; –  (b) to read a book with 100 pages; –  (c) to go for a bike ride

•  (3) A baby is just born. How long time is needed for this baby to become a father or a mother (to have his/her own children)? –  (a) 10 years; (b) 20 years; (c) 90 years

•  (4) Are 6 months sufficient for: –  (a) a little girl to become a young woman; –  (b) a 1 year old baby to learn how to walk well ; –  (c) a baby to become a grand father or a grand mother

Representation of Time Units School grade PS Grade

1 Grade

2 Grade

3 Grade

4 Grade

5 Age 5;7 – 6;1 6;7 – 7;1 7;2 – 8;1 8;2 – 9;0 9;2 – 10;0 10;2-11;1

N 22 21 21 19 24 20 Representation of durations (RD) 1 hour 3 hours New-born’s baby 6 months Mean % correct (SD)

52 73 54 71

62 (17)

60 94 65 81

75 (14)

65 95 81 86

82 (9)

84 89 68 86

82 (10)

86 94 92 92

91 (8)

93 92 85 95

91 (7)

•  Orientation (OR): (1) What day is it today? (2) What hour is it? (3) In what month are we?(4) In what year are we? (5) In what season are we ?

•  Sequences (SEQ): (1) What month comes after march? (2) Could you tell me the months of the year in order? (3) Could you tell me the seasons of the year in order?

•  Time units (TU): (1) Is a minute shorter or longer than a second? (2) Is a week longer or shorter than a month? (3) Is a month shorter or longer than a year? (4) How many hours does a day have, from one day’s morning to the next day’s morning?

•  Clock Reading (CR) (Six figures of a clock): (1) Show me 2 o’clock (2) Show me ten to three (3) Show me a quarter past height (4) Show me ten past eleven (5) Look at this clock. How many minutes are still left to two o’clock ?

School grade PS Grade 1 Grade 2 Grade 3 Grade 4 Grade 5

Age 5;7 – 6;1 6;7 – 7;1 7;2 – 8;1 8;2 – 9;0 9;2 – 10;0 10;2-11;1

N 22 21 21 19 24 20

Orientation (OR) Day (% correct) Hour Month Year Season Mean % correct (SD)

73 9

41 32 50

41 (28)

95 19 90 52 86

69 (23)

100 76 95

100 81

90 (10)

94 84

100 100 95

95 (9)

96 87

100 96

100 96 (10)

100 90

100 100 100

98 (6)

Sequences (SEQ) Month after march Months of the year Seasons of the year Mean % correct (SD)

5 0 0

1.5 (7)

76 33 38

49 (33)

90 62 38

63 (31)

100 89 74

88 (21)

100 96 67

87 (16)

95 85 60

80 (23)

Time Units (TU) Minute/second Week/month Month/year Nb of hours/day Mean % correct (SD)

36 36 36 0

27 (19)

38 81 71 19

52 (26)

71 86 86 43

71 (31)

74 95 94 89

88 (21)

79

100 96 79

88 (18)

90

100 100 95

96 (10)

Clock (CL) Two hours Ten to three A quarter past eight Ten past eleven Nb of min until two Mean % correct (SD)

27 36 36 14 0

23 (18)

52 48 48 57 0

41 (22)

48 62 86 67 24

57 (26)

89 79 79 79 68

79 (23)

96 87 92 96 54

85 (21)

100 55

100 95 80

86 (15)

Correlations and partial (age-adjusted) correlations SEQ TU CL RTU LS BIR ID

OR .69 .44

.60

.23 .66 .33

.53

.18 .53 .14

.71

.45 .50 .17

SEQ .66 .35

.65

.32 .61 .32

.58

.24 .62 .30

.54

.24 TU .71

.40 .56 .21

.61

.26 .64 .30

.58

.28 CL .57

.20 .60 .24

.63

.26 .56 .25

RTU .45 .06

.48

.08 .46 .14

LS .57 .21

.51

.20 BIR .49

.15

P<0.001 for r>0.30 ; p<0.01 for r>.22 ; p<0.05 for r>0.17 alpha=.90 age-adjusted alpha=.72

Total Score School grade PS Grade

1 Grade

2 Grade

3 Grade

4 Grade

5 Age 5;7 – 6;1 6;7 – 7;1 7;2 – 8;1 8;2 – 9;0 9;2 – 10;0 10;2-11;1 N 22 21 21 19 24 20

TOTAL Score (% correct) Mean SD Q3 median Q1 P10 Range (min – max)

24.5 9.1 32 24 15 14

11 - 38

48.8 13.6 56 46 39 34

25 - 76

67.0 15.0 73 64 56 50

43 - 98

82.0 13.4 92 84 78 65

39 - 96

85.4 10.2 94 86 80 71

63 - 99

87.4 7.4 93 90 80 77

73 - 98

PS < Grade 1 < Grade 2 < Grade 3 - 5

Children with Dyslexia No Dyslexia Dyslexia p

(t test) p

(Wilcoxon test)

N 44 24

Age: Mean (SD) 10.2 (0.6) 10.4 (0.6) .19

Orientation 96.8 (8.6) 81.7 (25.0) .008 .001 Sequences 84.1 (19.7) 36.1 (27.7) .0001 .0001 Time Units 92.0 (15.0) 83.3 (15.9) .03 .01 Clock 85.5 (18.5) 56.7 (28.7) .0001 .0001 Representation of TU

91.1 (7.3) 91.0 (7.7) .95 .76 Life span 73.1 (28.6) 61.8 (33.9) .15 .05 Birthday 86.7 (18.2) 57.6 (29.1) .0001 .0001 Interview duration 77.3 (28.4) 58.3(29.3) .01 .003 Total 85.8 (9.2) 65.8 (13.1) .0001 .0001

Children with Dyslexia (n=24)

FSIQ VCI PRI WMI PSI Reading

Orientation .22 .02 .15 .23 .24 .40*

Sequences -.12 .03 -.29 .03 -.14 .28

Time Units .26 ;06 .37 .30 .11 - ;05

Clock .40* .10 .15 .50* .44* -.04

Representation of TU .25 .29 .28 .35 -.26 .09

Life span .08 -.05 .14 .22 .22 -.13

Birthday .08 -.19 .04 .25 .40* -.02

Interview duration .29 .03 .44* .20 -.22 .22*

Total .31 -.01 .24 .49** .34 .36

FSIQ – Full Scale IQ ; VCI - Verbal Comprehension Index; PRI – Perceptual Reas. Index, WMI - Working Memory Index and PSI - Processing Speed Index. (WISC IV)

Time and number Children with Dyslexia aged 9-11.5 (1)

All Children with Dyslexia

aged 9-13 (2)

Typically developing

children aged 9-11.5

(3)

P (1)/(3) P (2)/(3)

34 49 117

Counting Dots 5.0 (1.1) 5.0 (1.1) 5.4 (0.8) 0.04 .03 Counting Backwards 2.4 (1.5) 2.7 (1.4) 3.2 (1.0) .003 .02 Dictation (numbers) 10.4 (4.4) 11.6 (4.2) 14.8 (2.1) .001 .001 Mental Calculation 17.9 (10.4) 21.3 (11.9) 32.2 (7.3) .001 .001 Reading (numbers) 12.5 (4.3) 13.4 (3.8) 15.3 (1.6) .001 .001 Number positionning 17.4 (3.6) 18.1 (3.3) 17.4 (3.9) .94 .26 Number comparison (o) 12.6 (2.5) 13.0 (2.3) 13.7 (2.3) .02 .06 Visual Estimation 3.8 (3.4) 4.0 (1.1) 4.0 (1.0) .36 .78 Contextual estimation 5.9 (1.9) 6.7 (2.1) 7.2 (2.7) .008 .19 Problems 9.1 (2.5) 9.4 (2.3) 8.2 (3.0) .11 .01* Number comparison (w) 9.6 (0.6) 9.6 (0.8) 9.8 (0.6) .34 .20 Total 106.7 (24.8) 114.7 (25.4) 131.3 (15.6) .001 .001

100

0

100

0

100

0

17 59 83

Contextual estimation of quantities

Is it few?, median?, a lot ? •  Two clouds in the sky •  Forty-six children in a classroom •  Two children in a family •  …

Time and number Correlations (n=49)

Total Time Score (r) Counting Dots .005 Counting Backwards .49*** Dictation (numbers) .64*** Mental Calculation .67*** Reading (numbers) .60*** Number positionning .64*** Number comparison (o) .53*** Visual Estimation .23 Contextual estimation .55*** Problems .45** Number comparison (w) -.08 Total ZAREKI .76 FSIQ .35* IMT .51**

Factors related to « time knowledge » performance Selected variables

•  In typically developing chuildren: – Mental calculation – Number comparison (oral presentaion) – Contextual estimation

•  In children with dyslexia – Reading « arabic » numbers – Number positioning – Working memory (WISC-IV)

Conclusion

•  Time knowledge and time perception ? •  Associated cognitive factors and special

groups of children ? •  International comparisons ?