Attention and some varieties of blindness

Martin Davies

Abstract: This talk begins from two points about visual attention. First, attention plays a role in binding together visual features (e.g. colour, shape, orientation, and motion) as belonging to a single object. The notion of binding can be extended to binding or grouping the components of a shape (e.g. the three line segments that make up a triangle), but the attentional requirements of this ‘form binding’ are low. Even the attentional requirements of feature binding can sometimes be reduced and, in a multi-stage model of binding, it is only the final stage that is attention-dependent. What is the cognitive role of attention in this late stage of feature binding? The second point about attention is that people often fail to notice an object or event right in front of their eyes, when their attention is otherwise engaged: this is inattentional blindness. Other varieties of blindness involve data limitations (e.g. visual masking) or resource limitations (e.g. change blindness). This talk will consider, in contrast to all these varieties of blindness, a phenomenon in which limitations of data and resources do not play a role and yet stimuli to which attention is directed disappear. Investigating this ‘attentional’ (rather than inattentional) variety of blindness suggests an answer to the question about the cognitive role of attention in feature binding.