Attention Lecture Part 2

Study Notes

Visual attention plays a crucial role in object perception, acting like a spotlight that focuses on objects
Feature Integration Theory (Treisman & Gelade, 1980) differentiates processing object features (e.g., color, shape) from object perception
- Stage 1: Pre-attentive stage - individual features of all visible objects are processed in parallel and not yet associated
- Stage 2: Focussed Attention Stage - attend to objects with features matching the one being searched for, binding the features into one integrated percept

Treisman and Schmidt's (1982) experiment: participants saw displays with two numbers and four shapes for 1/5 of a second
- Results: illusory conjunctions (e.g., yellow triangle) on nearly 20% of trials
Research on Patient R.M. (Robertson et al., 1997): unable to focus visual attention, resulting in illusory conjunctions

Distractions can impact task performance: McEvoy et al. (2006) found 6% of drivers attributed crashes to external distractions
Lavie's Perceptual Load Theory (1995, 2010) explains how likely we are to be impacted by distractions during focussed attention tasks
- Low perceptual load tasks: distractions may be processed, potentially impairing primary task performance
- High perceptual load tasks: few or no attentional resources left over to process distractions

Failure to notice unexpected salient objects or events when viewing a scene due to divided attention
Simons and Chabris's (1999) gorilla study: 42% of participants did not notice the gorilla
Inattentional blindness can occur in real-world situations, such as radiologists examining lung X-rays (Drew et al., 2013)

Unexpected object/task similarity
Perceptual Load: Lavie suggested inattentional blindness is most likely to occur during high perceptual load tasks
Evidence: Cartwright-Finch and Lavie (2007), Murphy and Greene (2016, 2017)

Studied via the dual-task paradigm, comparing performance in focussed attention and divided attention conditions
Modality of stimuli and response modality can impact divided attention performance (Treisman & Davies, 1973; McLeod, 1977)
Practice improves divided attention/dual-task performance (Spelke et al., 1976)
Aging affects divided attention, with older adults showing slower processing speeds but similar accuracy (Verhaeghen et al., 2001)

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