7. Right Hand (Tapping Alone) Left Hand (Tapping Alone)
Right Hand (Tapping & Reading) Left Hand (Tapping & Reading)
8. Whose woods these are I think I know.
His house is in the village, though;
He will not see me stopping here
To watch his woods fill up with snow.
My little horse must think it queer
To stop without a farmhouse near
Between the woods and frozen lake
The darkest evening of the year.
He gives his harness bells a shake
To ask if there is some mistake.
The only other sound's the sweep
Of easy wind and downy flake.
The woods are lovely, dark, and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep. Robert Frost
9. Right Hand (Tapping Alone) Left Hand (Tapping Alone)
Total number of Taps = Total number of Taps =
Right Hand (Tapping & Reading) Left Hand (Tapping & Reading)
Total number of Taps = Total number of Taps =
11. Tapping Task
• Base rate of how many times a person can
tap their index finger within a specified time is
taken for each hand, one at a time
• Measurements taken again –
Tapping & Talking
• The tapping while simultaneously-talking-rate
is compared to base rate
12. Tapping Task
• usually found that for most right handers talking
decreases the tapping rate of the right hand
more than left
(Hellige & Longstreth, 1981)
• greater interference when two activities are
carried out within the same hemisphere
• greater right- than-left-hand interference
indicates left hemisphere language dominance
15. BalancingTask
• Base rate – length of time each hand can
balance a dowel rod - alone
• Then, balancing in conjunction with reading
The balancing while simultaneously-reading-
rate is compared to base rate for each hand
16. BalancingTask
• usually found that reading decreases the
length of time for balancing of the right
hand more than left
• greater right- than-left-hand interference
indicates left hemisphere language
dominance
20. Tachistoscopic Presentation
Right Visual Field Advantage (RVFA)
usually found for language
i.e., greater accuracy or faster Reaction Time
for verbal stimuli presented in the right
visual field
25. Dichotic Listening
Broadbent (1954)
• Initially used to study attention
• The aim was to purposely divide the
attention
• To provide information regarding
processing capacity/limitations
26. Dichotic Listening
In Broadbent’s early studies
• participants heard 6 digits, 3 to each ear in simultaneous
pairs:
Right Ear Left Ear
6 9
7 5
2 4
• Recall
1. pair by pair (6 9, 7 5, 2 4) or
2. ear by ear (672, 954)
Ear by ear recall was found to be easier & more accurate
27. Dichotic Listening
Broadbent’s early studies
• Broadbent concluded the ears act as separate
channels, to which the person can only attend to
one at a time
• But participants do recall some items from the
other ear
Concluded that there is a buffer zone in which items
are held until the person can get to them
37. Hand Preference and Cerebral Asymmetry
Right handers
- most left hemisphere dominant for language
Left handers
- c. 75% left hemisphere dominant for language
- remainder have a bilateral organization
38. Handedness & Cerebral Asymmetry
Right Handers Left Handers
Lateralization of Bilateral Organization
Language of Language
43. EDINBURGH HANDEDNESS INVENTORY (Oldfield, 1971)
Please indicate your preferences in the use of hands in the following activitie by putting + in the appropriate column.
Where the preference is so strong that you would never try to use the other hand unless absolutely forced to, put ++. If
in any case you are really indifferent put + in both columns.
Some of the activities require both hands. In these cases the part of the task, or object, for which hand preference is wanted is
indicated in brackets.
Left Right
1 Writing
2 Drawing
3 Throwing
4 Scissors
5 Toothbrush
6 Knife (without fork)
7 Spoon
8 Broom (upper hand)
9 Striking match (match)
10 Opening box (lid)
44. Edinburgh Handedness Inventory (EHI)
(Oldfield, 1971)
EHI Scoring
The laterality Quotient for the EHI is derived in the following way:
• Add the number of +’s getting a total for each column
• Subtract the sum for the left hand column from that for the right hand
column
• Divide the obtained difference by the sum of both columns
• Multiply the resulting ratio by 100
Right Column – Left Column X 100 = Laterality Quotient
R Col + L Col
• The EHI provides a score which ranges from
+100 to -100
(Right handed (Left handed
for all items) for all items)
45. Edinburgh Handedness Inventory (EHI)
• Measures degree of hand preference
• Provides a hand preference score
• EHI scores range from
+100 (Strongly Right Handed)
to
-100 (Strongly Left Handed)
46. Degree of Handedness
Strong Left Strong Right
Handers Handers
Weak Left Weak Right
Handers Handers
-100 -50 0 +50 +100
47. Hand Preference Measurement
• Other Hand Preference Measures
(e.g., Annett’s Hand Preference Measure)
• Carry out tasks
48. Degree of Hand Preference
• Forced to use right hand
• Handicap – broken arm
• Family Handedness
• Genetics – biologically related
49. Handedness & Cerebral Asymmetry
Strong Left & Weak Left &
Right Handers Right Handers
Lateralization of Bilateral Organization
Language of Language
52. Cerebral Asymmetry Worksheet
1. Define cerebral asymmetry
2. Name 3 behavioural techniques used to measure cerebral asymmetry
3. Briefly describe the rationale behind one of these techniques
4. What are the advantages of a behavioural technique over other types of
techniques?
5. Calculate your direction and degree of hand preference using the
Edinburgh Handedness Inventory (Oldfield, 1971).
EHI = R column – L column X 100 =
Rc + Lc
direction =
degree =
6. Is a strong hand preference associated with:
-Weak brain lateralization
-Strong brain lateralization
-No cerebral lateralization
