Attention PERTEMUAN 3 3.1 Attention • Auditory attention • Cherry (1953),cocktail party phenomenon – that is, the ability of normal people to attend to a single conversation against a background of numerous conversations taking place in parallel 3.2 The role of attention in perception Attentional glue • On one level, stimuli are presented to the visual system as sets of features, on another level they are perceived as coherent objects in the world. • Treisman and Schmidt (1982), the role of attention is to act as perceptual glue which binds the sets of features that we process together into coherent percepts of objects. • Feature Integration Theory, or FIT. – features are assembled in appropriate relationships to form percepts of objects as we attend to those objects. – feature integration depends upon use of spatial relationships, depth cues and principal axes. 3.3 Automaticity Shiffrin and Schneider's theory • automatic processing as processing which is not capacity limited; that is, not • affected by the limitations of short-term or working memory, and not dependent upon attention. 3.4 The spotlight model of visual attention • Posner (1978), two stage model of attention: – First stage, automatic process, fast, and involuntary • presentation of a stimulus initially makes contact with its internal representation – The second stage, conscious and slower. • result in the generation of expectancies based on the information contained in priming stimuli. • Visual orienting – defined as the shifting of visual attention to various spatial locations. 3.5 Prosopagnosia • Prosopagnosia is an inability to recognise faces that cannot be explained by sensory impairment. • Severely prosopagnosic individuals are often unable to recognise members of their immediate family (husbands/wives, children, etc.) and sometimes do not recognise their own reflection. The case of the unknown sheep: a case study in prosopagnosia • McNeil and Warrington (1993) – the case of WJ,51 yo male, suffered from strokes Deficits in the perception of specific facial expressions • Ekman and colleagues identified a set of universal facial expressions (happiness, surprise, fear, sadness, disgust and anger)which they argued were recognised in all cultures (Ekman, 1982). – identification of a facial expression is a categorical process, with any expression always being recognised as one of these six. – This gives rise to the possibility that – a deficit in expression analysis might be specific to one particular expression.