LECTURE 8 - Spatial Memory and Language

Question 1

what is the cognitive map theory?

Answer 1

• idea that the hippocampus constructs a map of the environment
• this map provides the basis for spatial memory and navigation
• supports the ability to form mental images of scenes

Question 2

how do our cells help create a cognitive map?

Answer 2

• single cell recordings in hippocampus have revealed place cells that fire when an animal is in a certain environmental location
• single cell recordings in entorhinal cortex show grid cells that fire when animal moves around in space (track movement and position)
• animal’s movement and position are represented in a 2D grid, different grid cells fire depending on where we are along this 2D grid in space

Question 3

when does the parahippocampal place area fire?

Answer 3

• when people are viewing scenes
• when visualizing 2D route
• taxi drivers have larger hippocampi than non-taxi drivers

Question 4

what are spatial frameworks?

Answer 4

• ways in which people conceptualize and describe the spatial relationships between objects in their environment
• spatial framework can either be…
• egocentric: knowing the spatial relation of other objects with self
• allocentric: encoding and knowing the spatial relation of other objects with each other

Question 5

what brain areas are responsible for egocentric and allocentric spatial frameworks?

Answer 5

• hippocampus encodes space in an allocentric manner
• hippocampal place cells represent the rat’s location in a constant way, regardless of which direction the rat is facing
• parietal cortex (and other brain areas) encode space egocentrically
• head-direction cells in parietal cortex encode the direction of the rat’s head

Question 6

what are the most important qualities of language that need to be part of any theory?

Answer 6

• language is communicative
• language is referential and meaningful
• language is structured
• language is creative

Question 7

is body language actually classified as language?

Answer 7

communicative function is important but not an element that is sufficient for something to qualify as a language

Question 8

are animals able to communicate with language?

Answer 8

• Koko (gorilla): trained to respond to English words and use American Sign Language.
• critics argue Koko’s word use was a learned response for rewards, not true language understanding
• Kanzi (bonobo): learned by observing an older bonobo being trained, but lacks language flexibility and creativity, cannot comprehend complex sentences
• animals have rich communication systems but these systems are not considered language

Question 9

what does it mean when we say that language is referential and meaningful? what is our mental lexicon?

Answer 9

• most words we use refer to real-world objects, events, concepts, or relationships
• language is a direct expression of how we represent the world in our minds
• library of words we use and their links to real-world representations are called our mental lexicon

Question 10

how can we access our mental lexicon?

Answer 10

• mental lexicon exists in a representation of spoken and written language
• phonologically: via sound
• orthographically: in written form
• different access roots can help us understand language impairments

Question 11

what is acquired (pure) dyslexia?

Answer 11

• difficulties in orthographic processing but not phonological processing in adults who were previously literate
• damage to left occipitotemporal cortex, which includes the visual word form area
• an area that specializes in identifying written words and letters and processing of word meanings

Question 12

what is the spreading activation model?

Answer 12

• words in the mental lexicon are linked by their meaning
• exposure to one word (prime word) activates the corresponding node in a network, an activation spreads along the web

Question 13

how do we determine how word meanings are organized within the mental lexicon?

Answer 13

• lexical decision task has been designed to investigate this
• participants make rapid judgements about strings of letters that are presented to them (is it a word or not?)
• word frequency effect: people are faster to respond to high-frequency words than to low-frequency words
• because they can be accessed more easily in mental lexicon (more interconnected with other words, linked to stronger nodes)
• another version of the lexical decision task: presented with two words in each trial, a target word and a preceding prime word
• people answer faster about the target word if the prime word is related

Question 14

what are semantic and affective priming?

Answer 14

• semantic priming: exposure to a word that is related in meaning influences a response to a subsequent stimulus
• affective priming: exposure to a word that has the same emotional quality influences a response to a subsequent stimulus

Question 15

what does it mean to say that language is structured?

Answer 15

• sentences have underlying structures that are processed separately from their semantics or meaning of a word or phrase
• even when all the words in a sentence have meaning, the sentence might still be incoherent and incomprehensible if the words are not combined properly

Question 16

what are important aspects of language structure?

Answer 16

• syntax: rules about how to structure sentences and combine words (nouns, verbs, adjectives) into phrases
• grammar: broader set of rules that constrain language

Question 17

what does it mean to say that language is creative?

Answer 17

• productivity: ability to produce/understand completely new sentences, sentences that are unique and have never been produced before
• productivity shows that we have internalized a system of rules for how to combine elements into new meanings
• recursion: enables us to embed structures of language inside other structures, such as sentences within sentences, making the length of sentences unlimited
• “Haley is witty.” => “Olga thinks that Haley is witty.” => “Giorgia knows that Olga thinks that Haley is witty.”

Question 18

what is chomsky’s contribution to our understanding of language?

Answer 18

• main argument against behaviourist principles: language is acquired quickly in the real world and without much prior exposure, children also acquire language when parents make errors
• poverty of stimulus: there is a lack of information in the environment about correct language use
• children do not receive negative feedback for ungrammatical sentences
• children tend to overgeneralize grammatical rules, mistakes they don’t hear from parents
• believed that every human language involves rules that are universal in one way….
  they enable mental representations to be translated into a structured expression of those mental representations (universal grammar)
• children are born with a language acquisition device, instinct to seek out and master the rules that define their native tongue