Lecture 1: What is Cognition?

Question 1

What is classical cognition?

Answer 1

human cognition reflects the manipulation of symbols according to specified rules for combining those symbols (syntax) – given this, the ‘programme’ for a human mind could be implemented in a computer, just as it is implemented in a biological brain.

Question 2

What is the Turing test?

Answer 2

> which a human interrogator attempts to distinguish between the (text-based) responses of a computer and a human to his/her (text based) questions > The Turing Test equates cognition with disembodied linguistic output.

Question 3

How can the Turing test be passed?

Answer 3

For a machine to pass a strong version of the Turing test its programme would need to encode all of the knowledge a human has acquired over a lifetime and it would need to have a procedure for matching any text input with an appropriate stored response.

Question 4

What is cognition?

Answer 4

> Cognition is the activity of acquiring, organising and using information to enable adaptive, goal-directed behaviour - The study of information processing - Includes mental processes such as learning, memory, attention, language, reasoning, decision making. “The mind is a system that creates representations of the world so that we can act within it to achieve our goals” (Goldstein, page 5)

Question 5

What is information?

Answer 5

We can define information (loosely) as the detectable changes in stimuli that enable us to (1) categorise the entities and events that we encounter, and (2) infer the relationships between them.

Question 6

How does the mind created mental representations of the world?

Answer 6

ATTENTION to behaviourally relevant aspects of the environment (i.e., selective attention) results in the development of a CONCEPTUAL STRUCTURE (i.e., mental model of the world) that enables the organism to RECOGNISE salient objects and events and to respond adaptively to them based on KNOWLEDGE acquired from past experiences with similar objects or events.

Question 7

Cognitive scientists are particularly interested in ….

Answer 7

understanding how knowledge is mentally represented in the nervous systems and brains of humans (and other animals) and how this knowledge is used to guide behaviour.

Question 8

What do cognitive agents do?

Answer 8

> sense and act on the environment - detect and affect changes in the environment & gain information

> Construct mental models to represent the causal structure of their environment

> Adapt their mental models in response to feedback from their behaviour

> Use mental models to guide future behaviour

Question 9

Is Aplysia a cognitive agent?

Answer 9

> Aplysia’s simple nervous system (approximately 20,000 neurons – 1millionth the number of the neurons in our own brains), and the unusually large size of its neurons, has made it a useful biological model for exploring how learned behaviours are encoded at the level of single cells and defined signaling pathways.

> While cognitive terms such as “thinking” and “believing” may be somewhat overstated when referring to the mental life of Aplysia, even such a relatively simple animal represents it’s experience in the connections of its nervous system, and these representations come to influence it’s future behaviour

Question 10

How is Aplysia’s knowledge represented?

Answer 10

> Aplysia’s knowledge is represented **implicitly ** (non-declaratively) within its nervous system - it has no explicit (declarative) representation of its knowledge.

> That is, Aplysia does not ‘know what it knows’ and cannot consciously consider it’s own knowledge in the way that we humans reflect explicitly on our beliefs and desires.

Question 11

Why study Aplysia?

Answer 11

Evolutionarily ancient animals like Aplysia provide an insight into the precursors of our own cognitive processes.

Question 12

what is the computational metaphor of classical cognition?

Answer 12

> Cognition as a flow of information through processing devices that encode, store and retrieve symbolic representations of knowledge
–The brain is the hardware
–The mind is the software (programme)
> Cognition analogous to the operations of a digital computer

Question 13

Describe a typical classical information processing model.

Answer 13

Three stages - Environmental input, Short-term memory, and Long-term Memory.

> stimuli are first encoded in sensory memory

> aspects of the input that are attended are then transformed into a mental code that is sent on to short term memory (or working memory), which serves as a metaphorical “workbench”, where information can be examined, evaluated, and compared to other information from long-term memory.

> Short-term/working memory receives input from long-term memory, relating to previous experiences that bring meaning to a stimulus.

> Rehearsal increases the chances of storage in long-term memory.

> Long-term memory (LTM) is assumed to store large amounts of information for an indefinite amount of time. LTM has a number of different components representing information in a variety of formats including declarative (episodic, semantic, and linguistic knowledge) and non-declarative forms (conditioned learning, procedural skills, priming).

Question 14

The Classical view of cognition tends to focus on ….

Answer 14

…pure, disembodied, thought processes that are expressed in a symbolic “language of thought” or “mentalese”.

Question 15

In Classical cognition what do though processes refelct?

Answer 15

mental manipulation of symbols according to syntactic rules for combining those symbols.

Question 16

What do symbols represent in classical cognition?

Answer 16

Symbols represent our knowledge of things and events (concepts) and our knowledge of the way concepts can relate to one another.

–Words and numerals are examples of symbols

• Concepts <dog></dog>
• Properties and relationships <in> <has> <not> <and> <or></or></and></not></has></in>
• 1,2,3

Question 17

What are syntactic rules in classical cognition?

Answer 17

Syntactic rules are the ‘program’ of the mind expressed in “mentalese” – the language of thought.

Natural languages translate mentalese into a publically expressible format.

Question 18

What is the role of natural language in classical cognition?

Answer 18

Under the Classical view, the mind is a rule-following device, analogous to a digital computer, where the mind is the software and the brain is the hardware – thoughts are based on symbolic representations of things and/or events that are combined and manipulated according to a set of rules (syntax).

From this perspective, natural languages (like English, Spanish, Cantonese, etc.) merely translate this abstract inner mental language into a publically expressible format.

Cognition is conceived of as a flow of information through information processing devices that encode, store and retrieve symbolic representations of knowledge.

Question 19

How can classical cognition be used to model intelligent behaviour?

Answer 19

> The steps we go through to solve a problem can be represented in an explicit symbolic code.
–A series of “If…..then….” commands

Question 20

What are the adv and disadv of classical models?

Answer 20

• Good for formal problems and logical reasoning
• Bad for perception, action, recognising patterns
• Tends to assume knowledge, rather than explain the learning process

Question 21

What are different types of symoblic representation?

Answer 21

> propositional representation > Semantic network

> Analogue representation - mental imagery and mental rotations

Question 22

what is a propositional representation?

Answer 22

A symbolic code to express the meaning underlying a particular relationship among concepts e.g. “The cat is under the table”

Question 23

what does the propositional represention provide?

Answer 23

> basic building block for symbolically represented mental models of knowledge and compherension processes

Question 24

The advantage of the propositional approach is that….

Answer 24

….the propositional framework can be used to represent the relationships among semantic elements independently of the specific surface details of a specific utterance, written sentence, or the specific perceptual details of a witnessed event.

propositional framework provides a means to represent the underlying meaning structures, independent of the specific details of the surface structure – and this is said to provide an approximation to the “language of thought” itself

Question 25

How can the same propositional frame/schema express many different surface forms?

Answer 25

Gave (agent, object, recipient)

> John gave Mary the book

Gave (John, book, Mary)

> The book was given to Mary by John

Gave (John, book, Mary)

> Kevin gave Julia a kiss

Gave (Kevin, kiss, Julia)

> Propositions can be combined to represent more complex relationships

Question 26

What are semantic networks?

Answer 26

> model of the organisation of conceptual knowledge in the semantic memory system

> concepts are coded in propositional form expressing relationships and properties such as “is-a” or “has” or “can” (e.g., a canary “is-a” bird; a canary “has” wings; a canary “can” sing).

> but cosider categorisation…(later lectures)

Question 27

What are analogue represnetations?

Answer 27

The data provide compelling evidence that at least some of our cognitive processes are carried out using analogue representations (based on images that are analogous to the thing they represent), rather than abstract symbols.

> Mental images are analogous to what they represent
> We “manipulate” mental images in our minds in a manner analogous to the way in which we might physically manipulate a real object.

Mental Imagery and Mental Rotation - Shepard and Metzler (1971)

Question 28

What idea did Shepard and Metzler’s experiment challenge?

Answer 28

> challenged the idea that thought processes depend entirely upon language-like symbolic processes

Question 29

How is cognition dynamic?

Answer 29

1. Unfolds over time and space
2. Cognition inseparable from sensing, thinking, acting in real time

Question 30

how is cognition emobodied?

Answer 30

• Our embodied interactions with the world provide the basis for higher level thought processes.
• Knowledge grounded in physical interactions with the world.
• Metaphors
• – e.g., to solve a problem in our minds we search through a mental problem space, as if searching a physical environment.
• Justice = balance; Love = warmth.

Question 31

how is cognition situated?

Answer 31

We structure the physical environment to support our cognitive processes.

• E.g., We lay things out in physical space to help us think about how to organise our ideas.
• Use lists to prompt memory, etc.

Question 32

what does the emobodied approach to cognition empahsise?

Answer 32

role of development, social interactions and emotions in supporting higher level cognitive processes.

Question 33

How do (Spivey & Dale, 2006) describe cognition? Why?

Answer 33

real time cognition = continuously changing pattern of neuronal activity not a sequence of logical operations

> mental activity is constructed btwn seemingly discrete thoughts

> Experiment = used real-time mouse-tracking to demonstrate categorical decision-making (identification) unfolding “dynamically” (i.e., over time) and inseparably from the perceptual and motor processes that accompanied it

Question 34

describe spivey and dale 2006 experiment.

Answer 34

trajectory of the participants responses as they moved the mouse towards the target image “carrot” in the context of a phonologically similar competitor “carriage” provided as a distracter. As the sound of the target item unfolded over time (“c_a –rr_o_t”), the participant’s response shows a diversion towards carriage before settling on a beeline for carrot.

Question 35

What do Rodney Brooks robots do?

Answer 35

• modelled on insects ‘mobots’

They sense their world and adapt to changes in their environments

Rather than having central programming to guide behaviour Brooks starts with basic sensory and motor systems, coupled with some sensitivity to social and emotional cues (such as tone of voice and facial expression) as a means to drive ongoing learning in real time

Question 36

How does Leonardo the social robot work?

Answer 36

• Object appraisal mechanism tags object as novel
• Triggers mild anxiety response and expressions
• Promotes a human response to emotion
• Attentional system monitors human facial expressions and looks back to object – sharing attention
• Picks up signals from tone of voice
• Empathic mechanism mirrors human facial expressions to simulate emotion in itself
• Change in emotional state triggers long-term memory response for object, tagged with socially referenced emotional information

Question 37

What is symbol grounding?

Answer 37

• Conceptual abstract knowledge must be grounded in our perceptions and interactions with the world.
• There is a fundamental relationship between cognition, sensation, perception and emotion - I feel/sense, therefore I think.

Question 38

what is one of the strongest criticisms of the classical view?

Answer 38

• it provides no account for how symbols are learned

Question 39

what is conceptual knowledge grounded in?

Answer 39

Conceptual knowledge is grounded in”

• bodily interactions with the world
• perceptions – things that cause us to feel (sense and perceive).
• developmental, bodily (sensory-motor), and social interactions.

Question 40

How do mental representations form a hierarchy?

Answer 40

• representations become increasingly independent from the environmental stimuli they represent
• Symbolic representations of knowledge are “grounded” in the more fundamental sensory, perceptual and emotional levels representations derived from experience with the world.
• We need not postulate either/or in relation to representations, but can find a way to accommodate abstract symbols that have their grounding in more basic dynamic, embodied and situated experiences.