1. Cognitive Psychology Spring 2005 -Discussion Section-

2. Cognitive functions Perception Memory Attention Decision-making Reasoning, problem-solving Imagery Language Emotion Motivation Action Attention Perception

3. Level of Analysis

4. Explaining (and predicting) human behavior in terms of constructs like Attention, Memory, etc. Processes that are not directly observable, but defined in terms of their effects. The lawful nature of behavior allows it‘s prediction Since this is slightly tautological, Cognitive Neuroscience has been on the rise, adding a physiological and structural level of analysis. Functional:

5. Electronics “Electricity is an invisible force that we know about only through the effects it produces. The exact nature of electricity is not known but the laws governing electrical phenomena are clearly understood and defined. We do know that electricity is a form of energy resulting from the existence and motion of charged particles”

6. Drawbacks: Simple fundamentals vs. “irreducible” complexity Inherent variability of the phenomena (low vs. high) Reliability of measurements Possible level of invasiveness (technical, ethical) …

7. Electronics  We have to work even harder. However, to predict the behavior of a specific circuit, no one gains much by a quantum mechanic analysis of electronics. So no one does that. Measuring Voltages, Resistances and Currents is enough.  Similarly, in order to predict a specific behavior it’s not necessary to invoke the activity pattern of neural populations. But it ultimately helps in understanding the nature of the phenomena.

8. From the lecture

9. Double dissociation

10. Shiffrar

11. Attention

12. Attention as Selection

13. Change blindness Demos

14. Change blindness The way to do it? They confuse demo and study...

15. Logothetis (2003)

16. Popout - Idea Some stimuli need attention to process, others don´t. The ones that do not need attention in visual search „pop out“. They are building blocks of perception, basic features. These supposedly have a representation in an early brain area.

17. Basics

18. But (Pomerantz et al.)

19. There are all kinds of slopes for different stimulus configurations. Popout-Reality Sometimes, complex stimuli also pop out. Basic features? Not really. Not in early brain area, either. To date, Popout doesn´t explain anything. Needs to be explained itself. No a priori prediction of popout possible.

20. Indispensible for coordinated and goal-directed action. Hard to study, theoretically complex. Summary Many models have been proposed, all of them are imperfect at this point.

21. Perception

22. What we perceive is NOT a exact copy of the external world, it is a selective RECONSTRUCTION. It is a MENTAL REPRESENTATION. (of aspects of the external world)

23. Implications: 1) Things that we perceive might not be actually present in the environment. 2) Things that are actually present in the environment might not be perceived (see: Attention examples of last time). 3) Changes in the environment might not result in changes in perception (example: Thresholds). 4) Changes in perception might not result from changes in the environment. 4 fundamental non-correspondences

24. Perception 4) Shepards tables 1) Kanisza triangle

26. Perception This allows us to study the assumptions, the PROCESSING by looking at illusions and how people perceive them.

27. Perception A huge brain machinery is devoted to process visual information alone. At least 30% of the brain. Together with other perceptual information: Easily 50%. This explains how we can act efficiently on impoverished input (assumptions).  Perception appears effortless.

28. Mary Potter Looks innocent, but raises many issues.

29. Eye movements

30. Retina

31. Saccadic suppression Assignment: Look in the mirror and follow your eyes as they move around.

32. QALMRI Q: A L M R I P