Forelesning - Mental imagery and visual representations PDF

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Dette er forelesningsnotater som handler om mental imagery og visual representations. ...

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Mental imagery and visual representations -

Mental representation of stimuli when they are not physically present It is analogical – it is alike when we perceive real physical objects Propositional – abstract representations  Same brain activity when viewing physical objects and imagining them

Imagery – size and shape  

Judgments about small and large images - Compare rabbit and elephant, then ask questions like “does a rabbit have eyelashes?” (Kosslyn, 1975) Judge the angle between various hands on a mental clock (Paivio, 1978)

Interference effects  

Visual image interferes with visual perception Motor movement interferes with motor imagery

Ambiguous figures  

It is impossible or too hard to switch in-between interpretations in your head This is evidence for propositional representation

Neuroscience research on visual imagery   

Primary visual cortex – visual imagery. Where and what pathways play a role in imagery Auditory cortex – auditory imagery Motor cortex and cerebellum – motor imagery

Cognitive maps            

A mental representation of the external environment that surrounds us Route map (actions plans) vs. survey maps Anterior regions and motor cortex vs. parietal cortex and hippocampus Egocentric (we are acting ourselves in the environment in route) vs. allocentric (birds eye perspective, does not correspond to a specific point) representations Distance Number of intervening cities – makes distances seem longer Semantic categories – group places with their content. Places that have same content seem closer to eachother even though they are not Landmarks vs. nonlandmarks – Distances seem shorter if we go towards landmarks and vice versa. Shape Angles – we prefer 90 degree heuristic, we tidy up our maps Curves – symmetry heuristic, we tend to straighten the curves up, so the maps become more structured and symmetric. We remember things as more vertical or horizontal Relative position Rotation heuristic – Alignment heuristic – makes maps more aligned, more straight Verbal descriptions

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Verbal descriptions of scenes, 5 objects mentioned in relation observe. Turn to face a different object, and given the task to describe where the others are Spatial framework model Vertical dimension (above-below) – comes from gravity and our body symmetry. Front-back dimension – symmetry in our bodies, we handle things differently dependent on where it comes from. Left-right dimension – not as important as the other ones. We are symmetrical to the sides. We are programmed to assume left and right as similar. Whether it comes from left or right doesn’t matter

London taxi drivers Maguire et al. (1997)   

11 taxi drivers with 14 years experience When describing the route from one place to another there was significant activation in the right hippocampus This activation was not seen when recalling famous London landmarks or sequences from famous films

Piaget’s stage of development 1. 2. 3. 4.

Sensory-motor stage – age 0-2 Preoperational stage – age 2-7 Concrete operational stage – age 7-11 Formal operational stage – age 11-adult

Cognitive development  

Increased mental capacity – both working memory development and increased speed of neural processing Increased knowledge – both of specific facts and of strategies for performing tasks

Individual differences in cognitive ability 

The focus has traditionally been on a theoretical understanding of individual differences in cognitive ability, but today the focus has shifted towards explaining why individuals develop differently

Components of ability a) b) c) d) -

Task specific knowledge and skills Physical Performance Emotional abilities Thought processes When we want to explore general mental abilities, we need to find tasks that minimize the involvement of knowledge and rehearsed skills

Spearman’s theory  

Primitive tasks Administered to a small sample of school children

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Data were factoranalyzed Found one general factor affecting performance on all tasks Named this factor “g” for general ability Correlations between tasks show positive manifold

Thurstone’s theory     

56 psychological tasks Administered to 200 university students Was factoranalyzed Found almost 12 factors Named these factors primary mental abilities

Explanations    

The samples Time-limited administrations Number of tasks Basis for factor analysis

Hierarchical models of cognitive abilities    

When we consider hierarchical models of abilities, the conflict between spearman’s and Thurstone’s theories disappear Thurstone’s factors can be correlated We perform several factor analyses, until no more groups appear or there is just one factor remaining. We usually discover the g-factor the third time around (third-order factor)

Gustafsson (1981)       

Administered 20 tasks distributed over 10 PMAs (factors) The factors were correlated, so he performed an additional factor analysis Found 3 factors in the second round GF – fluid intelligence GC = crystallized intelligence GV = visualization These factors were correlated as well, so he performed one last factor analysis and found G.

Known facts about individual differences 1) An individuals scores on different cognitive tasks are positively correlated and the gfactor usually explains at least 40% of the total variance 2) In addition to general variance, each test shows a specific variance of about 20-50% of the total variance (both error variance and systematic variance) 3) Tests with similar contents show stronger positive correlations, since we have strengths and weaknesses in our individual abilities In the brain  

Dorsolateral prefrontal cortex Parietal lobe

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ACC – anterior cingulate cortex Specific regions in the temporal and occipital lobes Reviewed brain imaging research and concluded that a network of brain areas is responsible for individual differences in intelligence Called parieto-frontal integration theory of intelligence – P-FIT

Stanovich – 3 systems

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 Autonomous system - system 1  Algorithmic system – system 2  Reflective system – system 2 According to Stanovich, only the algorithmic system is measured by intelligence tests. But the task of discovering when we should switch from using system 1 to using system 2, in order to reason logically, falls on the reflective system. Smartness may belong to the reflective system Creativity may belong to the autonomous system...