Theoretical psychology

week 1

Basic law of associationism/law of continguity

Basic law of associationism/law of continguity

If two things repeatedly occur simultaneously, the presence of one of them will remind us of the other

Aristotle - Associationism

= mental processes proceed by way of associations

• tabula rasa: the mind lacks content at birth

• the mind is filled by perception: the mind uses smell, touch, hearing, taste, and sight to create the common sense

• in common sense associations are formed between domain specific images (sensory images), e.g. shape and taste of an apple

Locke

• blank slate

• sensoristic

• atomistic

• associative

empiricism

all knowledge is obtained via the senses

nativism

mental abilities and knowledge are innate

Long-term potentiation

• neural basis of the law of contiguity

• Hebb’s law: if two nerve cells are simultaneously stimulated for a period of time, the synapse binding them is strengthened

• long-term potentiation: prolonged rise in efficiency of a synapse resulting form a change in the neuronal structure

• discovered in 1973 in hippocampus of rabbits

Connectionism

• modern form of associationism

• also involved computer simulations

horizontal faculties

• mental faculties, learning, memory, attention, perception, and will, are domain general, so they work the same for different content domains

Vertical faculties

• idea: functions are domain-specific

• phrenology: the study of the size and shape of people's heads in the belief that you can find out about their characters and abilities from this

→ functions are localised in the brain (localisationism)

→ when a function is well developed it occupies more space in the brain

→ bumps on skull reflect a faculty, e.g., language, arithmetic

• double sided: each function exists once in each hemisphere

Physiognomy

• Person’s character is reflected by features of the face

• Lombroso’s “criminal type”: criminals have certain facial features in common, e.g., high forehead

Mesmerism

• Mesmer: there are magnetic forces that work at a distance and hypnosis & magnets can cure mental disorders

Mental healing

• Phineas Parkhurst Quimbly: believe mental illnesses may be cured by establishing correct, positive thinking

Spiritualism

• William James: people called “mediums” may establish contact with spirits of the dead

• alternative explanation by James Randi: The medium does not get answers from the spirits of the dead, but actually from you, by asking you many questions → “cold reading” also used by police

Flourens

perception and memory don’t have specific regions, but are distributed across the whole cerebral cortex (holism)

Gall

• localizationism

• phrenology: bumps on skull reflect mental faculties

• domain-specific (vertical) faculties are bilaterally localised in the brain

Broca

• Broca’s area: left frontal lobe; speech production

• The brain of Leborgne (Mr. Tan): speech production deficit due to left frontal lobe damage; could only say “tan”

• evidence for localization

Wernicke’s language model

• Wernicke’s area: left superior temporal gyrus; speech comprehension

• association theory of language: Wernicke’s area stores auditory images of words, Broca’s area stores motor images of words

• concept images: sensory images of the object that the word refers to, e.g., images of an apple’s shape, taste, & color

• embodied cognition: view that concepts are represented in terms of sensory images

• aphasia: language impairment after brain damage

brain damage to connection between Broca’s and Wernicke’s area

• repetition of words is impaired, but production and comprehension are relatively spared

Johannes Müller

the speed of nerve conduction is infinitely fast, and can therefore not be measured

Helmholtz

• conduction of nerve impulses is not infinitely fast, but takes time

• experiment with frog → speed from stimulation to muscle contraction is about 30 m per second in humans and frogs

Donder’s

• mental processes take time

• subtraction method: determining duration of mental processes;

→ Task A: simple reaction, e.g., press button when faces are shown; involves perception and action

→ Task B: choice reaction, e.g., press left button for person A and right button for person B; involves perception, recognition, choice, and action

→ Task C: go/no-go, e.g., press button for person A, but not for person B; involves perception, recognition, and action

→ B - C = choice duration

→ C - A = recognition duration

Sternberg’s additive factors method

• aim: identify stages of processing

• clarity (low vs. high) and number (2 vs. 4) of persons on the pictures influence the duration of different stages

Psychophysics: Weber

• quantifies the perception of change in a given stimulus as the constant ratio

• Weber’s law: ΔR/R = C

→ C = constant

→ R = Rights, indicates the first weight

• example: if you lift a weight of 5 kg (R) you only notice a change in lifting it when > 0.5 kg are added (ΔR); so: 0.5/5.0 = 0.1 (C), which is the same for 2 kg and 0.2 kg added and increases/decreases with R, so it is constant

Psychophysics: Fechner

• Fechner’s law: S = k log R

• logarithm (log): if k^S = R, then S = k log R; the exponent to which a base must be raised to yield a given number

→ The sensation (S) increases as the logarithm of stimulus intensity (R)

→ k = constant

→ in terms of the previous example: 0.5 ^5.0 = stimulus intensity (S); Stimulus intensity (S) = 0.5 log 5.0

• so: the difference between 30g and 60g is physically the same (30g difference), but psychologically different (difference between 30g and 60g corresponds to 30 delta a (= 1g for 30g), whereas difference between 60g and 90g corresponds to 15 * delta a (= 2g for 60g)

Jerry Fodor

• human mind consists of localised modules and holistic central systems (combined localisationism and holism)

• modules: localised, domain specific (vertical faculties)

• central systems: distributed, domain general (horizontal faculties); connected to Front-parietal cortex

• input modules: e.g., speech perception, face perception, etc.

• output modules: manual actions, e.g., articulation of speech

• Central systems: recognition, choice

• Donda: modules mediate perception and action; central systems mediate recognition and choice

9 properties of modules

• domain-specific (e..g, process faces but nothing else)

• mandatory (e.g., triggered by any stimulus that looks like a face)

• limited central access (e.g., can not access the intermediate stages that precede the immediate perception of the face)

• fast

• informationally encapsulated (e.g., module only has knowledge about the shape of faces)

• shallow outputs (e.g., representation of the properties of a face, but not about who it is)

• fixed neural architecture (e.g., located in the fusiform gyrus in right hemisphere)

• specific breakdown patterns

• characteristic development

→ central systems are domain-general and contain none of these properties

mental reflex parroting

in Wernicke’s model you go directly from speech perception to articulation

prosopagnosia

• face blindness

• damage to face perception module or its connection to the central systems

Oliver Sacks’ blindness

• damage to connection between face perception module and central system → could distinguish faces from other objects, but not identify people by their face

• face perception module is responsible for what (perception)

• central system is responsible for who (identification)

Nancy kanwisher

• modules in the brain are present for the perception of places, faces, visual words, body parts, and for the assignment of thoughts to others

• autism: impairment of the module for the assignment of thoughts to others and the face perception module