Chapter 2: Fathoming unconscious depths

Question 1

Who are notable figures in study of unconscious?

Answer 1

Hipocrates (epilepsy description)

Galen (walking + breathing without attention)

Alhazen (visual perception)

Augustine, Thomas Aquinas, Descartes, Spinoza, Leibniz (human actions are driven by broad mechanisms, inaccessible to introspection)

Marshall Hall (reflex arc)

John Hughlings Jackson (hierarchy of nervous system)

Ribot (practical knowledge - action memory)

Gabriel Tarde (unconscious imitation)

Pierre Janet (subconscious goals in childhood impact personality)

William James (humans often do incongruent things unaware of it)

Question 2

What is cortex hypothesis of consciousness?

Answer 2

• information reaching cortex must be conscious
• because it is responsible for attention, planning and speaking
• unconscious processing took place in subcortical regions

Question 3

What is hemisphere hypothesis of consciousness?

Answer 3

left hemisphere = language center = could report what is happening = conscious

Question 4

What is ventral hypothesis of consciousness?

Answer 4

• some cortical circuits are conscious, while others are not
• ventral route = image recognition = conscious
• dorsal route = images used to guide action = unconscious

Question 5

What kind of unconscious memory demonstrate amnesia patients?

Answer 5

Unconscious emotional memory due to fast fear circuits leading to quick appraisals.
If patients encounter the other day a doctor with a pin in their hand, then later they are relcutant to shake the doctor hand.

Question 6

What type of symptoms are associated with blindsight patients?

Answer 6

They experience lesions to primary visual cortex.
People with blindsight consistently deny awareness of items in front of them, but they are capable of pointing and omiting objects while walking.

Some initial ideas was that visual information travels to superior colliculus, but this information was still able to activate the cortex (+thalamus and other higher visual areas)

Question 7

What can you say about patient D.F. who suffered from visual form agnosia?

Answer 7

Patient D.F. suffered from carbon monoxide poisoning. She struggled with recognition of presented objects, however, she was able to perform motor actions (such as posting in slot task)

Question 8

What happens when there is lesion to the right hemisphere, typically in the vicinity of the inferior parietal lobe?

Answer 8

Patients sffers from spatial neglect in which they are prevented from attending to the left side of space.

However, patients are not blind per in left visual field (retina + visual cortex FUNCTONAL). Higher level lension prevents them from attending information and registering it on a conscious level.

However, unattended information is somewhat processed -
> house situation (house on the left on fire, house on the right not) -> patients claim both houses look the same, but still they would prefer to live in the right house

-> brain-imaging studies ⇒ ventral visual cortex still shows activation when seeing faces/houses in unattended field

Question 9

How far can masked picture travel in the brain?

Answer 9

subliminal priming -> prior presentation of a word, even unconsciously, speeds up its processing when the same word reappears consciously (subliminal repetition priming = as effective, regardless of the case letter)

→ ventral visual cortex can be activated unconsciously (fusiform gyrus - shape recognition - abstract identity processing)
-> so hypohtesis that ventral stream is only conscious was proven wrong

Question 10

Can visual binding (creating coherent picture) occur unconsciously?

Answer 10

Yes, as subliminal processing is sensitive to how the letters are arranged (range vs anger are the same letters, but range is better at priming for RANGE)

Question 11

Can you play chess unconsciously?

Answer 11

Yes! If you are experienced chess player.
Research proves that a single glance is enough for any grand master to evaluate a chessboard and to remember its configuration in full detail.
It is attributed to the parsing + chunking of information

Question 12

Can multisensory information (=watching a movie) be bounded unconsciously?

Answer 12

McGurk effect illusion - person saying da da da - when you close your eyes, you realise she is actually saying ba ba ba → visually person moves her mouth to say ga - confict situation → fusing both information together - the syllable da, a compromise between the auditory ba and the visual ga

Question 13

Can any information be assembled unconsciously?

Answer 13

probably not, however in case of vision, speech recognition and expert chess → all of them are extremely automatic and overlearned

Question 14

What is routine binding?

Answer 14

dedicated neurons committed to specific combinations of sensory inputs

Question 15

What is nonroutine binding?

Answer 15

creation of unforeseen combinations—and they may be mediated by a more conscious state of brain synchrony

Question 16

What is cocktail party effect?

Answer 16

people can focus their attention on listening to only one person talking in a social setting, but they hear their name if it is spoken nearby → suggesting that unattended information is processed

Question 17

How does priming connect to meaning selection?

Answer 17

Marcel’s semantic priming

• bank → river’s edge vs financial institution
• conscious: context effect → river-bank-water (bank primes water) vs save-bank-money (bank primes money)
• unconscous: joint activity in both cases

Question 18

How did Greenwald measure unconscious arithmetic processing?

Answer 18

• experiment: flashing numbers 1,4,6 and 9 preceded and followed by string of random letters (making numbers invisible), afterwards second number, clearly visible has been displayed
• participants needed to say if number is larger or smaller than 5
• invisible numbers → semantic priming → congruent trials (both numbers under/over 5) → quicker response
• results independent of number form → both four and 4 work equally well (abstract meaning)

“number sense” regions of the brain, in the left and right parietal lobes, were influenced by the unseen number - repetition suppression - if the same number was shown twice, regions became less active (neurons recognize the number!)

number priming was strongest for the same numbers (four-4), less strong for nearby numbers (three-4), smaller for numbers at distance of 2(two-4) etc

Question 19

What is N400 component?

Answer 19

It is negative component which appears 400 ms after the target. It assesses how well words fit within sentence’s context. Unexpected words cause larger peaks.

Question 20

How did van Gaal check whether unexpected invisible words also cause N400?

Answer 20

• words appearing in succession (masked below awareness threshold) → unique combinations of positive and negative meaning
• • not happy, very happy, not sad, very sad
• immediately afterwards, participants saw either positive or negative word
• N400 in incongruous trials (effect modulated by presence of not and very)
• N400 has the same size regardless whether words are seen or not - consciousness is irrelevant to semantics?

Question 21

Is it possible to cause selective attention without consciousness?

Answer 21

→ flashing stimulus in corner of an eye may attract the attention and make responses to stimuli presented in the same place quicker (unconsciously)

• conversely, a hidden picture may slow you down when its content is irrelevant to the task at hand → bigger effect when it is unconscious (conscious distractor is easier to ignore)

Question 22

How can unconscious incentives affect our motivations?

Answer 22

Participants were asked to squeeze a handle as strongly as they could to gain money.
When a flashed picture suggested higher monetary gain, people exerted stronger force. They did it even when image was masked.

The reward circuits in the brain were unconsciously pre-activated (hands sweating in anticipation of gain)

Other experiment: a game in which subjects needed to either press a button or withhold the response. They did it accordingly to masked images (“go” vs “withold”)

Question 23

What is Hadmard mathematical discovery dissection?

Answer 23

1. Initiation → conscious problem exploration
2. Incubation → unconscious brewing period mind is vaguely preoccupied with the problem, but you don’t consciously work on it
3. Illumination → solution appears with its glory
4. Verification

Question 24

How does Iowa Gambling Task relate to mathematical discovery thesis ?

Answer 24

Iowa Gambling Task assumes that participants can choose from 4 decks of cards. They have a loan of $2 000. 2 decks of cards are disadvantegous and 2 decks of cards are advantegous in the long term.

Players strategy: at first playing at random, then getting the idea what decks are more advantegous (pre-hunch phase → incubation phase - picking disadvantegous deck to test the theory causes drop in skin conductance due to sweat - brain already registers risk).

Where does alarm signal arise? ventromedial prefrontal cortex → unconscious valuation

• lesions in ventromedial prefrontal cortex → no anticipatory skin conductance

Question 25

What other studies illustrate support for unconscious incubation period?

Answer 25

Brand choice
Participants required to choose from 4 car brands -> - half of participants could consciously deliberate, the other half was distracted
- distracted group made better choice!

• replicated in real-life scenarios: IKEA - more conscious effort, less satisfaction
• conscious processes → place exaggerated weight on one or two features without seeing the bigger picture
• unconscious processes excel in assigning values to many items and averaging them to reach a decision

Question 26

Can you perform mathematical operations in your sleep?

Answer 26

• participants were faced with math task, they could have omitted effort of complicated computations if they realized the pattern
• initial test: most of them failed to notice the rule
• after sleeping, a lot of them noticed the rule!
• sleep = consolidation of knowledge
• neurons in hippocampus and cortex are active during sleep! (they replay the same sequences of activity that ocurred during waking hourse)

Question 27

Can executive functions operate unconsciously?

Answer 27

Executive functions focus among others on inhibiting automatic responses.
They can be investigated in the repetitive task - like pressing the button - unless you see stop signal.

Subliminal stop makes participants responses slower or even stops the responses