Thinking

• Textbook overview– Directed versus undirected thinking– thinking and disorders of thinking

• An alternative perspective– Regulatory function of thinking

Integrating language, thinking and emotion

Groome:

A. Thinking: "Self-controlled symbolic mental activity"

Textbook overview

How can we observe thinking?

Thinking and Action

Planning

Execution

How do we know that John is thinking?

We can observe the outcome

or we can monitor his brain

Thinking and Action - areas of the brain involved in planning and execution

Left cortex Right cortexMedial cortexFront Rear Rear Front

Textbook overviewGroome:

A. Thinking: "Self-controlled symbolic mental activity"

(Goal) directed1. Problem solving

– Gestalt theory– Information processing theory

2. Reasoning

Inductive, deductive, statistical, everyday

Un-directed

Creativity, imagery, dreaming, etc.

Emotion ??

Groome (continued):

B. Disorders of Thinking: Dysexecutive Syndrome– no loss of ability, rationality, or intelligence– loss of regulatory function

Not inability to think!

Textbook overview

An alternative perspective• Regulatory function of thinking

System to represent previous experience, monitor ongoing behaviour and potential new information

• Evidence– Psychiatry (Barkley's theory of ADHD)

• Thinking subserves the executive function

• Self-regulation of behaviour and emotion

– Phylogeny (evolution of the human species)• Thinking is a substitute for action (Pinker, Darwin)

– Ontogeny (child development)• Thinking is internalized language (Vygotsky)

Vygotsky's theory of language

• Language is self-controlled symbolic mental activity used for communication and behavioural regulation of others

• Thinking is fully internalized silent inner speech• Developmental stages

– External speech– Private speech

• ego-centric language used for self-regulation

• elliptical, telegraphic

• not whispering, but link between overt and covert speech

– Inner speech– Verbal thought

Evolutionary perspective (Pinker 1997)

• Thinking is an internalized substitute for trial and error behaviour– allows testing possible future events without suffering the

consequences– allows our species to outsmart objects, plants, animals, and

each other– evolves more rapidly than defenses of other organisms

• Humans occupy a "cognitive niche" in the biological arms race

Psychiatry (Barkley, 1997)

Executive function of cognition

– biological basis is operation of inhibitory neural circuits that control overt behaviour

– behavioural inhibition makes it possible to internalize repertoirs that become mental strategies

– strategies are basis for cognitive abilities – require working memory to operate

E.g: Attention deficit / hyperactivity disorder (ADHD) is a deficit in behavioural inhibition resulting from malfunction of norepinephrine and / or dopamine circuits (but not an acquired disorder)

Barkley's model of the executive function

Behaviour repertoir

Sensing Speech Affect Play inhibition

Mental strategy

Holding events in mind

Internalization of speech

Self-regulation of affect

Analysis and synthesis of action

Cognitive ability

Bridge time Reflect upon and describe events

Motivate oneself and delay reward

Creativity, diversity, re-organization

Cognitive process Working memory

References

• Barkley, R.A. (1997) ADHD and the Nature of Self Control. Guilford Press.

• Pinker, S. (1997) The Language Instinct. Penguin Books.

• Vygotsky, L. S. (1962) Thought and Language.MIT Press.

Goal-directed thinking (Groome)

1. Problem solving"A problem exists when a person has a goal and does not

know how to reach it" (Duncker, 1945)

– Well-defined versus ill-defined problems

– Gestalt theory– Information processing theory

2. Reasoning– Inductive– Deductive– Statistical– Everyday

Problem SolvingA. Gestalt Theory

A problem exists because of the way it is represented or perceived.

– InsightRestructuring or spontaneous reorganization shows that solution

is a necessary part of the problem

– Reproductive thinkingRote application of previously rewarded responses

Novelty arises only from random trial-and-error

– Productive thinkingRe-structuring of problem situation produces novel solutions

– Obstacles to achieving insight Mental set, functional fixedness, previous experience,

over-confidence

–Problem spaceinitial state, goal state, constraints, rules, instructions, etc. that define the problem

–Well-defined problemsRepresentation of problem space

Operators to create new states

imPlementation of operators

Evaluation of current state w.r.t. goal

• Information Processing TheoryProblem solving is a search through problem space

– Analysis into parts (not Gestalt)knowledge states

operators that transform these

application of these makes paths that link states

Problem Solving

Ill-defined problems

lack one or more of these

state-action tree

• Information Processing (continued)– Obstacles

Problem definition, size of problem space, mental capacity, knowledge, time

– Strategies (ways of solving)Random trial & error

fails when many loops

Algorithmsrecipes for problem solution

never fail

Heuristicsshort-cut strategies using limited resources

success not guaranteed

Change goalfails in well-defined problems

and adversary problems

Problem Solving

Examples of well-defined problems

• Chess

– 10120 possible states

(estimated age of solar system is only 1018 seconds)

• Tower of Hanoi

– shortest solution in 2n-1 moves

2 disks 3 moves

3 disks 7 moves

5 disks 31 moves

64 disks ??? moves Shortest solution in 8,446,744,073,709,551,616 moves

Would require 584,942,417,355 years at rate of one move per second - ie. 580 billion years (estimated age of the universe is 14 billion years)

• Role of knowledge in problem solving

– analogy

– previous experience

– expertise

– mental set

– functional fixedness

• Heuristics

Problem reduction

– Means-end analysis

select sub-goals that are nearer to main goal

fails when move away from goal required

– Difference reduction (hill climbing)

fails when there are local minima or maxima

– Working backwards

create sequence of sub-goals from main goal

fails when too many paths towards goal

State-action tree: Tower of Hanoi, 3-disks

initial state

goal state

possible sub-goal

"clear largedisk"

loop

Reasoning

Thinking with rules, not content

E.g: Given that a) No students are stupid

b) No stupid people eat pizza

What do you conclude?"No students eat pizza"

Not valid

"Nothing"

Is valid

Formal logic

How people connect propositions and draw conclusions

• Pragmatic reasoning– schema bound (scripts, obligations)

– content based (derived from experience)

– incomplete (experience is limited)

– expressed in natural language

– validity equates with truth

– probabilistic conclusions (not certain)

• Formal logic– bound by normative rules

– abstract, not based on content

– complete, closed system, all information given

– expressed in formal language

– validity does not equate with truth but with logical necessity

• validity is independent of truth of the propositions

• if the reasoning is valid and the propositions are true, then the truth of the conclusion is a logical certainty

Reasoning

E.g. Inductive reasoning

E.g. Deductive reasoning

Reasoning

A. InductiveFrom particular to particular, or particular to general

Accumulation of confirmatory evidence leads to general propositions that are probably true

Empirical generalizations that are more uncertain than instances of them

B. DeductiveFrom general to general, or general to particular

Finding a conclusion that necessarily follows by rules of formal logic from what is given (premises)

– Syllogisms• Drawing conclusions about category membership of items, or

relations between items given in pairs of premises

– Conditional reasoning• Inference from propositions about antecedents and

consequences

Reasoning (continued)

C. Hypothetico-deductive reasoningCertainty by falsification

Basis of scientific method, legal argument, forensic investigation

Empirically testing truth of theories

Combines inductive with deductive logic for greater certainty• By induction, formulate a general hypothesis,or a rule • Deduce a particular proposition from this• Obtain empirical evidence

a) The hypothesis is probably true if all evidence is consistent with it

b) The hypothesis is certainly false if any contradictory evidence is found

Hypothetico-deductive (continued)

Examples of laboratory studiesWason four-card problem

Bruner concept attainment task

Many people tested show confirmation bias, fail to consider potentially falsifying evidence

Research for the way in which people tackle particular problems has led to questions about the diversity of strategies employed by people

StatisticsTaming chance to reconcile

Fortuna and Sapientia

Reasoning (continued)

D. Statistical reasoningManaging risk

Algorithms

Probability calculations make statistically independent events predictable in the long run

• use mathematical models based on all possible outcomes

HeuristicsWhen reasoning about future events we evaluate the likelihood by constructing mental models that are representative of the present. The availability of such models in terms of imaginability and retrievability does not reflect the likelihood of such scenarios in reality, and hence our estimates are biased (Kahneman & Tversky)

a) Availability• judge likelihood on basis of what is remembered

– memory is selective: significant events noted, insignificant events ignored– overestimate likelihood of significant events

Reasoning (continued)

Heuristics (continued)

b) Representativeness• judge likelihood on basis of similarity to a mental model

– typical instances are judged more likely than untypical ones– bias due to limited experience of what is typical

Example: Lottery Phenomenon Most people are irrational, because they voluntarily participate in a game with a

negative expected outcome - odds of losing are greater than odds of winning (Hill & Williamson, 1998)

• Availability: Media favour winners - millions of losers never shown

• Representativeness"Keep playing and you'll win sooner or later" (Gambler's fallacy) Long

sequence of losses believed to be untypical, but losing and winning balance only in the very long run

"Choose an even spread", "avoid adjacent numbers", "study pattern of previous draws", but random events have no pattern

B. Disorders of Thinking

Dysexecutive Syndrome– no loss of ability, rationality, or intelligence– loss of regulatory function

Textbook overview (continued)

1. Cognitive deficits

2. Working memory and forebrain

3. Supervisory attentional system

Neuropsychology of Freud's personality theory

Original 1933 diagram(colour added)

Functions mappedaccording to Solms (2004)

Disorders of thinkingResult of frontal lobe lesions1. Cognitive deficitsAny or all of the following

Attention

Abstraction

Estimation

Strategy formation

Everyday planning

• Inability to direct and sustain attention

• Distractibility

• Utilization behaviour

• Inability to suppress most salient response

• Perseveration

• Inability to utilize feedback

• Inability to suppress previously incorrect response

• Disinhibition

• Think of bizarre hypotheses, but do not disconfirm

• Generate intentions (markers) but not spontaneously reactivated later

Personality changeDeficits in emotional and social decision makingDe-regulation of affect

Frontal lobe syndrome

Disorders of thinking

2. Working memory and the forebrain – Baddeley's theorySensory information (visual, auditory) is held online

Associated actions are planned and released at appropriate time

– Goldman-RakicPre-frontal lesions in monkeys produce selective impairment of

delayed working memory task

– Object permanence in young infantsImmature frontal lobes (1 year)

Delayed-response deficits and perseveration

Disorders of thinking

Supervisory attentional system (SAS)Two cognitive modes monitored by SAS

• Routine, automatic, schema-driven

• Novel, difficult or dangerous, error monitoring, decision making

Deficits result in behaviour dominated by schemas that are triggered by irrelevant sensory input

The End

Deductive reasoning examples

• Valid SyllogismIF given: All men are mortal

and: Socrates is a man

Therefore: Socrates is mortal

• Valid conditional If P then QAffirm: P

Therefore: Q

Affirm: Not Q

Therefore: Not P

• Invalid SyllogismIF given: All men are mortal

and: All women are mortal

Therefore: All men are women

• Invalid Conditional If P then QAffirm: Not P

Therefore: Not Q

Affirm: Q

Therefore: P

Deductive reasoning: Using mental models

Consider all possible worlds. If a contrary example can be found then the conclusion cannot be a logical necessity

E.G. Constructing circle (Venn) diagrams

students stupid

eat pizza

No students are stupid

No stupid people eat pizza

Therefore no students eat pizza

All professors are pianists

All the pianists are athletes

Therefore all the professors are athletes

athletes

pianists

prof.

stupideat pizza

students

A B

No alternative is possible