1. Cognitive processes Jakub Jura Jakub.jura@fs.cvut.cz
Engineering Psychology
Cognitive processes
perception – sensation – attention – thinking – imagination – memory – creativity – problem solving
Jakub Jura

2. What is Cognitive? From latin cognoscere = getting to know
Distinguish emotional and rational
Descarte’s „Cogito ergo sum“.
Mental processes mediate between stimulus and response.

3. Cognitive processes Base Cognitive processes:
Perception
Sensation
Attention
Thinking
Imagination
Memory
Learning
Advanced Cognitive processes
Creativity
Problem solving

4. Sensation
Sensation is about sense organ and basic processes on this level.
Perception is about creating whole percept.

5. Sensation Perception Percept Sence Organ Visual Perception Image Eye
Auditive Perception
Sound
Ear
Gustatory Perception
Taste
Taste Buds
Olfactory Perception
Smell
Nose
Haptic Perception
Touch on skin
Nociceptors
Proprioception
Body position
Proprioceptor
Human Feromon
Affection / antipathy
Vomero-Nasal Organ
Magnetoception
Impression of north
Unknown

6. Lateral Inhibition Efect
Sensation Delusions
Lateral Inhibition Efect
Mach’s Strips

7. Negative afterimage

8. Perception Perception is perception of diference. Sensuals limits
Gestalt law
Multistable figures
Invariance in perception
Weber–Fechner law

9. Perception Delusionss
Which of these circles is bigger?

10. Perception Delusionss
Effect of Contrast
Lighter
Darker

11. Perception Delusionss

13. Is anything here?

14. Gestalt Laws Proximity Similarity Closure
We tend to group nearby objects.
Similarity
We tend to group objects with similar properties
Closure
We are so accustomed to seeing closure that we sometimes close things that aren't.

15. Gestalt Laws Good Continuation Pregnantz
We tend to assign objects to an entity that is defined by smooth lines or curves
Pregnantz
We tend to good shape

16. Experiment 2

17. Multistable perception
Mind separate figure and backgroun.
Unstably between two or more alternative interpretations.
Since you see both, you can’t see both.
Changing may be under control only partially.

18. Invariance in perception
Objects are recognized independent of rotation, translation, scale, elastic deformations, different lighting, and different component features.

19. Neisser's cycle of perception Cognitive Ecology
Actual world
Object
available
information
Samples
Modify
Schema
of environment
Exploration
Locomotion and action
Cognitive map
Directs

20. Psychophysics Ernest Heinrich Weber (1795–1878)
Gustav Theodor Fechner (1801–1887)
Stimulus  Percept
Stimulus  Sensation  Percept

21. Weber law
Ernest Heinrich Weber  (1795–1878)
Experiment with weight difference
Just noticeable difference (jnd) between two weights was approximately proportional to the mass of the weights
I = kw* I
I … Base intensity (Total weight)
I … Discrimination threshold (Weight difference)
kw Constatnt (Weber Fraction)
We can‘t perceive the intensity of stimulus directly, but in relation to the reference value.

22. Fechner law Gustav Theodor Fechner (1801–1887)
Dependence of sense impression on the intensity of stimulus is logarithm.
P = k * ln (S)
P … percept
k … constant
S … stimulus

23. Experiment 1
Dependence of sense impression on the intensity of stimulus
Sound
Light
Procedure:
Set intensity to basic level (L)
Increase intensity up to one degree (L+1)
Remember this degree and set intensity up to L+2, L+3, … L+n
Impresion
Sensum

24. Fechner law

25. Weber–Fechner Law P = k * (S/S) dP = k * dS/S, P = k * ln (S/S0)
P … percept
k … constant
S … stimulus
S0 … lower possible stimulus

26. Weber-Fechner law Weber-Fechner principle in the acoustics:
LI=10 log (I/I0)
Lp=20 log (pe/pe0)
L … Level of intensity
I … Intensity
P … Aacoustic pressure
I0, pe0 ... Minimal perceived value