Abstract
Purpose: We investigated the effect of spatial attention on contrast sensitivity for face recognition using Posner spatial cueing method1. The aims were to explore whether an attention effect occurs for a recognition task of face images, and in a further experiment, to investigate the effect of a ‘distracter face’ on the complex task. Methods: Contrast thresholds at which a face was correctly recognised were measured in a 4AFC procedure. Subjects were extensively pre-trained in recognising the four synthetic face images2. The stimulus image was presented on either the left side or the right side of the fixation point. Contrast sensitivity was measured for 79% correct responses. Posner cueing was used to direct spatial attention. An arrow cue pointing left or right preceded the stimulus for 100ms. The signal display was presented for 60 ms. The cue validity was either 100% (always pointed at the upcoming stimulus location) or 50% (pointed randomly on the same or different side as the stimulus). In the first experiment, only the ‘face image’ was presented. In the second experiment, subjects were required to ignore a ‘distracter face’ in the location not occupied by the stimulus. The set size for the divided attention task was limited to two because of the high memory load. Results: In the first experiment, contrast sensitivity for face recognition increased in the range of 5% to 8% with accurate cueing of spatial location. In the presence of the distractor face, contrast sensitivity increased significantly in the range of 32% to 67% when the location was accurately cued. Discussion: Results revealed that valid cueing of the spatial location of the stimulus increased contrast sensitivity for face recognition. The benefits for spatial cueing increased significantly in the presence of a distracter face. Data are discussed in terms of existing data with simpler stimuli and to existing models of attention.
1. J Exp Psychol, 109(2), 160–174
2. Vis Res, 39: 3824–3833