Stim u l

3.1 A. 1.2.1

Vertical to Horizontal

Stimuli were identical to those used in experiments 2 and 3. The numbers "1", "2",

"3", "4" and "5" appeared at progressively higher vertical locations. These stimulus-

response mappings parallel those used by pianists when reading music, in which responses

made at progressively m ore right-ward locations on the piano keyboard are specified by

notes presented at progressively higher locations on the musical stave. A possible sequence

o f stimulus presentations occurring for a single congruent trial is shown in Figure 3-1 la.

Incongruent trials differed from those used in experiments 2 and 3. The stimuli

comprising incongruent trials in this experiment exhibited the opposite num ber/location

relationship to those used in the congruent trials: the numbers "1", "2", "3" , "4", "5"

would appear at progressively lower vertical locations. These stimulus-response mappings

are the opposite to those used by pianists when reading music. A possible sequence o f

stimulus presentations occurring for a single incongruent trial is shown in Figure 3-1 lb .

Baseline trials consisted o f the consecutive presentation o f 5 stimuli in which the num ber

was always presented in the middle box. In these trials, the spatial location at which the

num ber appeared provided no information regarding the specified response. A possible

sequence o f stimulus presentations occurring for a single baseline trial is shown in Figure

3 -llc .

3.1.4.1.2.2

Horizontal to Horizontal

Stimuli were identical to those used in experiments 2 and 3. The numbers "1", "2",

"3", "4" and "5" would appear at horizontal locations which corresponded with the

would appear at progressively more right-ward locations and would specify progressively

m ore right-ward responses. A possible sequence o f stimulus presentations occurring for a

single baseline trial is shown in Figure 3-l id . This spatial stimulus-response

correspondence is maximally compatible, both for pianists and for non-musicians.

Incongruent trials differed from those used in experiments 2 and 3. The stimuli

comprising incongruent trials exhibited the opposite num ber/location relationship to

those used in the congruent trials: the numbers "1", "2", "3" , "4", "5" would appear at

progressively more left-ward locations, specifying progressively m ore right-ward responses.

A possible sequence o f stimulus presentations occurring for a single incongruent trial is

shown in Figure 3-1 le. Baseline trials consisted o f the consecutive presentation o f 5

stimuli in which the num ber was always presented in the middle box. A possible sequence

3 b) 3 c) 1 4 2 8 8

d) .

Figure 3-11. D evelopm ent o f a V ertical to H orizontal M apping - Stim uli.

Exam ple o f a set o f m otorieally m atched trials (congruent/incongruent/baseline) from the vertical to horizontal task (upper) and the horizontal to horizontal task (low er). Each trial consisted o f 5 stim uli w hich specified a sequence o f 5 different keypresses. The task w as to m ake a keypress based on the num ber presented, ignoring the spatial location at w hich the num ber appeared. Each task consisted o f congruent trials (a;d), incongruent rule based trials (b;e) and baseline trials (c;f). Stimuli appeared consecutively, triggered by a keypress response to the previous stim ulus. Each task com prised 24 such trials.

3.1.4.1.3

Task Procedure and Sta tistical A nalysis

These were identical to those described in experiment 2 (section 3.1.2.1.3 and

3.1.2.1.4).

3.1.4.2

Predictions

Pianists were predicted to be faster overall compared to non-musicians. Pianists

were predicted to show an effect of congruence on the vertical to horizontal task as well as

the horizontal to horizontal task. Non-musicians were predicted to show an effect of

congruence on the horizontal to horizontal task but not the vertical to horizontal task.

interference on congruent and incongruent trials respectively, relative to baseline. Thus a

main effect of group (pianists faster) was predicted. An interaction o f task x congruence

alone (effect of congruence on horizontal to horizontal task only) was predicted for the

non-musicians alone, as well as a task x congruence x group interaction.

3.1.4.3

Results

3.1.4.3.1

Errors

The number o f errors made on the vertical to horizontal and the horizontal to

horizontal interierence task can be seen for both groups (pianists, non-musicians) in Figure

3-12. Friedman Tests revealed that pianists showed no significant effect o f congruence on

the number of errors made for either task while non-musicians showed a significant effect

o f congruence for both tasks: vertical to horizontal [Chi-Square = 11.60; df = 3; p < 0.001]

and horizontal to horizontal [Chi-Square = 20.34; df = 3; p < 0.001].

i

I

I

H z / H z H z / H z H z / H z V t / H z V t / H z V t / H z B C Ir B C Ir Pianists H z / H z H z / H z H z / H z V t / H z V t / H z V t / H z B C Ir B 0 Ir Non-m usicians Figure 3-12. D eveloping the V ertical to H orizontal Interference T ask - Errors.

N um ber o f errors m ade on baseline, congruent and incongruent rule based trials, for horizontal to horizontal (H z/H z) and vertical to horizontal tasks (V t/H z). B - baseline, C - congruent, Ir = incongruent rule based.

In document Neurocognitive studies of music reading (Page 133-137)