TEORÍA SOBRE LAS ESTRATEGIAS DEL APRENDIZAJE.

The self-attribution task was set up using the participant’s own photograph at the time of data collection. The data collection procedures for setting up the task included taking photograph of the participant, creating the image sequences and setting up the task. All the procedures were completed in a single session.

Photograph: A front facing portrait of each participant was taken using a Nikon D3000 camera, Nikon DX (AF-S Nikkor) 18-55 mm (1:3.5-5.6 G) lens, and Nikon SB-400 flash. The camera was placed on a tripod at an approximate height of 90 cm and participants seated approximately 215 cm away. The flash was turned 45o upwards facing the white ceiling, to provide soft/diffused lighting by bouncing light on to the subject. All other lightings were controlled. A full-face portrait taken, devoid of any make up or face tattoos and with a neutral expression (no expression), was used to set up the task.

Stimuli creation: The portraits taken in the first phase of the study were used to set up the self-attribution task. The portraits were cropped and rotated to present the correct pupil alignment along the transverse plane, to minimise differences due to posture or angle of the head. Portraits were cropped using Microsoft Photo Editor. Head rotation correction was done by aligning the midpoint of the eyes (iris) to the

same temporal plane at 0o _{angle. These were then warped towards a pair of sex-} congruent composite faces with high neuroticism and emotionally stable traits, respectively. Warping is a process of gradual change of the internal reference points of an individual face towards the respective reference points on the composite faces, as explained later. The composite face pairs of neuroticism were adopted from the study detailed in Chapter 4. The composites had accuracy of 69% for female pair and 77% for male pair, which was significantly better than chance.

Warping participant’s photograph towards sex-congruent composite face pairs created the image sequences for the task. This was done using JPsychomorph (J. Chen & Tiddeman, 2010). In this process, 139 landmarks were identified on each

photograph and then warped 100% towards the emotionally stable and the neurotic face composites, also accounting for their shape, colour and texture, to create 19 images. In the resultant Neurotic Face Scale, the original face was the mid-point of the scale and gradually changed with increasing emotionally stable facial appearance towards one end and neurotic facial appearance towards the other. The scores on the 19-point scale were from -9 (least neurotic) through 0 (original face) to +9 (most neurotic). Figure C.1 shows the graphical illustration of the warping process and the image sequences on the 19-point neurotic face scale. This is an implicit task because the participants were not aware of the underlying neurotic appearance of the scale.

Presentation: In the self-attribution task, the participant’s own face images were presented using Matlab. The task presented with eight blocks (questions: ideal, actual, happy, emotionally stable, attractive, unhappy, anxious and least attractive) x 1 trial (self face) x 19 images (face warps). The blocks (questions) were randomly selected per presentation. The order of images (19 face warps) in the trial was

randomly selected in each block. The 19 images (self-face warps) were presented (500x500 pixels) one at a time in the middle of a computer screen with instructions at the top, as shown in Figure 5.1. The images were presented one at a time in order of the sequence of the 19-point face scale and looped back and forth through the sequence to provide seamless increase and decrease of neurotic traits.

The instructions were to choose their actual (‘Choose your actual face’), ideal (‘Choose your ideal face’), positive self and negative self. There were three positive and negative self-attributions. The instructions for positive-self were, ‘Make the face look most happy and content’, ‘Make the face look calm, stable and well-balanced’ and ‘Make the face look most attractive’. The instructions for negative-self were, ‘Make the face look unhappy and least content’, ‘Make the face look anxious and emotionally unstable’ and ‘Make the face look least attractive’.

The first image per presentation was randomly selected from the 19 images. When participants pressed either the right or left arrow keys, the images changed through a looped sequence in their order on the implicit neurotic face scale. This gave the impression of the presented face changing, as controlled by the participant. The presentation of looped sequence of images made it difficult for the observer to understand the lateral representation of the scale, and therefore its end points. Participants selected one image for each instruction by pressing spacebar. This task was not timed.

Figure 5.1. An illustration of a trial from the self and social attribution task as presented on a computer

screen and viewed by the participants. When they press either the right or left arrow keys the presented face will appear to be changing. By continued pressing of either of the keys, will present the 19 images in a continuous looped sequence. Without a lateral representation, the end points of the scale were not obvious to the participants.