Perception and Action

Question 1

What are the 3 behaviours that improve chances of survival?

Answer 1

1. Find food
2. Reproduce
3. Avoid predation

Question 2

In order to produce actions, animals need cognition. In what way(s) do animals perceive useful information for cognition and movement?

Answer 2

Proprioception (are my muscles moving?), vestibular organs (am I moving?), vision/audition/olfaction (what is out there?)

Question 3

Visual information travels from the back of the eye, to the LGN, then to the primary visual cortex (V1), with everything still laid out as it was on the back of the eye. What occurs between V2 and V4?

Answer 3

Form and colour is picked out from the stimuli. The information then passes to the inferotemporal, prefrontal, and premotor cortices, before travelling to the motor cortex and brainstem.

Question 4

Receptors + Brain + Central pathways = ?

Answer 4

Perceptual System

Question 5

What are the four types of energy?

Answer 5

• Chemical (taste/smell)
• Heat/Tactile (skin)
• Waves of Air (audition)
• Body Motion (vestibular system)

Question 6

What is filtration?

Answer 6

Preventing overload of information to the brain by selectively remove irrelevant information e.g. the evolution of the human eye to perceive the visible spectrum and not other wavelengths. Unchanging information is usually not threatening and is therefore filtered out.

Question 7

What are the benefits of sound (echolocation) over light information for some animals?

Answer 7

• Travels further and faster in water

- No need to rely on external energy source (the sun) so can hunt at night and therefore avoid predators

Question 8

What is sampling?

Answer 8

An active process involving looking for specific information and searching for useful information e.g. eye movements.

Question 9

What are the six single eye movements or ‘ductions’?

Answer 9

Abduction, Adduction, Intorsion (up and in), Extorsion (up and out), Supraduction and Infraduction.

Question 10

What are the six ‘versions’?

Answer 10

Dextroversion (gaze to right), Laeversion (gaze to left), Supraversion, Infraversion, Dextrocycloversion (upper cornea moves to right), Laeocycloversion (upper cornea moves to left).

Question 11

What is divergence?

Answer 11

Both eyes returning to primary position from convergence (both eyes adducted). These are disconjugate eye movements.

Question 12

What is the annulus of zin?

Answer 12

Fibrous tissue surrounding optic nerve where extraocular muscles converge.

Question 13

What is a yoke muscle?

Answer 13

The muscle in the opposite eye that accomplishes a given version. e.g. medial rectus in left eye and lateral rectus in right eye for dextroversion.

Question 14

When the eye is in line with the front of the orbit (i.e. abducted by 23 degrees), which are the main elevators and depressors?

Answer 14

Superior and inferior rectus. When eye is adducted, these muscles are used in intorsion and extorsion, and the main elevators and depressors are superior and inferior oblique.

Question 15

What are some characteristics of eye movements?

Answer 15

They reflect the task (e.g. flick between two points to determine relationship), the more information contained in an object, the longer the eyes stay on it, and there is voluntary and involuntary focus on information.

Question 16

Saccades, smooth pursuit, fixation, and the vestibulo-ocular reflex are all examples of…?

Answer 16

Conjugate eye movements

Question 17

What is a saccade?

Answer 17

A rapid, ballistic movement of the eye of short duration (15-100ms). Often followed by a catch up saccade to let information fall on fovea.

Question 18

Why is useful information not obtained during a saccade?

Answer 18

We are blind during saccades- visual information is ignored as it would just be a blur. This is called saccadic suppression. Useful information is obtained in the period of fixation following a saccade.

Question 19

What is the Troxler effect?

Answer 19

Fading of peripheral information during fixation. This is counteracted by microsaccades: ocular drifts to prevent fatigue of photoreceptors and keep image clear.

Question 20

In order to sample high quality information from a moving target/while we are moving, which eye movement is used?

Answer 20

Smooth pursuit. Predictions must be made about the target movements.

Question 21

What is the vestibulo-ocular reflex?

Answer 21

The interaction between muscles of the eye and the vestibular system. Information from vestibular organs signals to move eyes in opposite direction, allowing you to fixate on an object while your head moves.

Question 22

Optokinetic nystagmus is a combination of which two conjugate eye movements?

Answer 22

Smooth pursuit and saccade.

Question 23

What are disconjugate eye movements used for?

Answer 23

Approaching objects, and gauging distance.

Question 24

What is Sherrington’s Law?

Answer 24

Increased innervation to one muscle is accompanied by decreased innervation to its antagonist.

Question 25

According to Yarbus (1967), what do eye movements allow us to do?

Answer 25

Locate, direct, guide and check. This allows us to carry out actions towards and upon objects.

Question 26

What does this equation represent? Posterior= (likelihood x prior) / marginal likelihood

Answer 26

Bayes Theorem.

Question 27

What is the Bayesian Brain Hypothesis?

Answer 27

The brain uses probabilities to make predictions about the world and survive in a noisy and uncertain environment.

Question 28

Who provided a formal and quantifiable definition of information, and what was it?

Answer 28

Claude Shannon: H = - Σ p(x) log2[p(x)]

Question 29

Which of these is not true regarding logarithms? A: They were first described by Shannon (1948) B: They make large numbers more manageable C: They replace multiplication of large numbers with addition of small ones D: They make straight line graphs

Answer 29

A- Logarithms were first described by Napier.

Question 30

What is Weber's law?

Answer 30

Weber's (Fechner's) law states that the just-noticable difference (subjective sensation) between two stimuli is proportional to the magnitude of the stimuli (logarithm of stimulus intensity).

Question 31

What qualities of the definition were essential for information theory?

Answer 31

Information had to be a continuous function, behave in a lawful manner, and provide the same total information regardless of how it is split.

Question 32

Which of these gives more information? A: Revealing the result of rolling a fair six sided die B: Revealing the result of a two-tailed coin toss C: Revealing the result of a fair coin toss

Answer 32

A. When there are 2 possible outcomes, most information is given when probability is 0.5 (log2(0.5)=1). A coin with both sides tails means 0 bits of information are imparted as the probability of getting tails is 1. However, when there are more than 2 possible outcomes, there is increased uncertainty (decreased probability) and so more information can be gained.

Question 33

Who suggested that the development of the sensorimotor system was essential in order to develop higher cognitive abilities?

Answer 33

Piaget, e.g. learning numbers through physical interaction.

Question 34

Carmen suggests there are two systems in the human brain for cognition, a fast and a slow. What are these now considered to be related to/the same as?

Answer 34

``` Fast= sensorimotor system (gut reactions, highly emotional and unconscious) Slow= offline cognition (recently evolved, analytical and rational) ```

Question 35

What is Phylogeny?

Answer 35

Considering something within the history of our species.

Question 36

What is CAIT?

Answer 36

Cognition Action Interaction Theory- two systems in brain should be considered separately, but it must be understood that offline cognition is underpinned by sensorimotor system (as shown in evolution and suggested by Piaget) and they interact. (Embodied cognition)

Question 37

What is modified weak fusion?

Answer 37

MWF suggests that cues interact only by promoting each other to provide information to the system.

Question 38

What is the difference between strong and weak fusion?

Answer 38

Weak fusion said that averages of all cues (sources of information) are used to accurately represent the world, whereas strong fusion said that the nervous system selects the most probable interpretation.

Question 39

``` Which of these is not a type of interneuron in the visual system? A: amacrine B: horizontal C: bipolar D: apocrine ```

Answer 39

D: Apocrine.

Question 40

Which pathway responds better to colour change: A: Magnocellular B: Parvocellular

Answer 40

B: Parvocellular pathway responds well to colour change, high spatial frequency and luminance contrast, and low temporal frequency.

Question 41

How many layers of cells are in the lateral geniculate nucleus?

Answer 41

6: 2 magnocellular and 4 parvocellular.

Question 42

What is another name for the striate cortex?

Answer 42

Primary Visual Cortex, V1, Occipital Cortex.