2111 Attention L2.pptx
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Selective Attention 2 (PS2111) Dr. Doug Barrett e-mail:[email protected] Selective Attention Recap: Selective attention biases perceptual and post-perceptual processing at cued locations Attention can be oriented by: – Exogenous (bottom-up) – Endogenous (top-down) – A combination of exogenous and endog...
Selective Attention 2 (PS2111) Dr. Doug Barrett e-mail:[email protected] Selective Attention Recap: Selective attention biases perceptual and post-perceptual processing at cued locations Attention can be oriented by: – Exogenous (bottom-up) – Endogenous (top-down) – A combination of exogenous and endogenous effects PS2111 Selective Attention PS2111 Selective Attention Locations Features (colour, contrast, orientation) Objects (single and groups) PS2111 Selective Attention Object-based Attention – Features – Objects Models of Attention – Spotlight – Feature Integration Theory (FIT) – Integrated Competition Hypothesis PS2111 Object-based Attention Valid Cue Invalid cues separated by the same spatial distance Egly et al. (1994) PS2111 Invalid Same Object Invalid Differen t Object Object Based Attention Invalid Same Object PS2111 Invalid Different Object Object-based Attention Moore et al. (1998) Object Based Attention PS2111 Object Based Attention Cue Valid Intra Inter Object-based Attention Spatial attention is constrained by object boundaries Object boundaries delineated by perceptual processes (e.g., amodal completion) “Where” is affected by “what” Is selection ever guided by non-spatial cues? – What happens if we are searching for something without knowing where it is? – Does “what” affect “where”? PS2111 Feature-based Attention Martinez-Trujillo & Treue (2004) PS2111 Feature-based Attention Task irrelevant probe Attend red / Ignore green Zhang & Luck (2008) PS2111 Feature-based Attention ERPs to (irrelevant) probe stimuli were modulated by selective attention towards colour P1 amplitude attend colour > ignored colour Attention modulated perceptual input from The Emotional Superiority Effect PS2111 Maratos et al. (2008) Cognition and Emotion , 22, 1340-1352. The Emotional Superiority Effect PS2111 Maratos et al. (2008) Cognition and Emotion , 22, 1340-1352. Emotional Superiority (top-down attentional bias) Salience (Prioritisation) Map PS2111 Visual Scene Feature- & Object-based Attention Selective attention enhances perceptual processing at locations Enhancement is constrained by perceptual information that governs object recognition Attention can be directed towards nonspatial features (i.e., colour or emotional valance) Feature- and object-based attention focus perceptual resources upon relevant items across visual field PS2111 Models of Attention Treisman and colleagues (1980; 1998) developed an influential model of attention called “Feature integration theory” (FIT) Attention was conceptualised as the glue that binds visual features encoded by separate anatomical modules Based on behavioural evidence of a qualitative distinction in performance in visual search tasks PS2111 Visual Search T Find L L L L L L T L L L L L L L L L Visual Search T Find T L L T T L T L L T T T T L L T Visual Search PS2111 Feature Integration Theory Unique Feature (pre-attentive) Master Map of Locations Colour Shape L L T PS2111 L Orientation Feature Integration Theory Serial Master Map of Locations Colour Shape T T T PS2111 L Orientation Feature Integration Theory FIT accounts for the difference between feature and conjunction searches Qualitative or quantitative distinction? Not all conjunction searches are slower than feature searches Feature-based attention appears to be global (reciprocal connections between what and where) Is search ever pre-attentive? PS2011 Two types of attention? Joseph, Chun & Nakayama (1997) Biased Competition Model Selection is the result of competitive interactions between objects Stimuli presented within a receptive field generate strongest competition Competition can be biased by bottom-up and top-down processes – Feature contrasts and transients – observer’s goals and intentions (template) Competition coordinates activity in distributed cortical regions PS2111 Salience PS2111 Task Cellular Recording Chelazzi et al (1993) PS2111 Display onset Attenuation of distractor Saccade PS2111 Attention Goals, intentions, relevance Computational Resource Summary Attention is not a unitary construct Neural / cognitive mechanisms for prioritising (selecting) information Competition for representation resolved via reciprocal links between bottom-up and top-down processes Protects capacity limits in perceptual, post-perceptual and action systems PS2111 So what? – from lab to life Top-down suppression of bottom-up saliency Can you think of other examples? PS2111 Further reading: Any cognitive text book that includes a chapter on attention References in the lecture: 1. Egly, R., et al. (1994). Journal of Experimental Psychology: General, 123(2): 161-177. 2. Moore, C.M., et al (1998). Psychological Science, 9(2): 104-110. 3. He, Z., et al. (2004). Journal of Cognitive Neuroscience, 16(6): 1085-1097. 4. Martinea-Trujillo, J.C., & Treue, S. (2004). Current Biology, 14: 744-751. 5. Zhang, W., & Luck, S.J. (2008). Nature Neuroscience, 12: 12-24. 6. Treisman, A., & Gelade, G. (2012). Cognitive Psychology, 12: 97136. 7. Joseph, J.S., Chun, M.M., & Nakayama, K. (1997). Nature, 387, 805-807. 8. Chelazzi, L., et al. (1993). Nature, 363: 345-347. PS2011
