Reasoning and mental representation

Four experiments exploring the effects of the coherence of a mental representation of material on reasoning performance are presented. Each employs a simple task that allows most subjects at some stage to solve the problem. We postulate that the crucial factor influencing performance is a unified representation of the material. In Experiment 1 we use an authorization of a kind familiar in daily life, and in Experiments 2, 3 and 4 we use sentences describing simple objects in different ways. In each case performance was enhanced when the material could be given a unified representation.     

The mental representation of countries

Three studies were conducted to describe adults' knowledge of the countries of the world. Undergraduates from a selective liberal arts college recognised nearly two-thirds of nations, and about one-third were produced in a free-recall task. The use of information related to countries' locations was an important determinant of order of recall. Contiguity in free-recall output, responses in a free-association task, and the prediction of recall from recognition also provided evidence of other relations between countries, including semantic and phonetic links and membership in groups of countries. The number of times a country was mentioned in the news was a consistent predictor of recognition and recall. The relative prosperity, population density, and geographic area of countries also influenced recall.     

Medieval theories of mental representation

Throughout most of the Middle ages, it was generally held that stored mental representations of perceived objects or events preserved the forms or species of such objects. This belief was consistent with a metaphor used by Plato. It was also consistent with the medieval belief that a number of cognitive processes took place in the ventricles of the brain and with the phenomenology of afterimages and imagination itself. In the 14th century, William of Ockham challenged this belief by claiming that mental representations are not stored but instead constructed in the basis of past learned experiences.     

The mental representation of countries

Three studies were conducted to describe adults’ knowledge of the countries of the world. Undergraduates from a selective liberal arts college recognised nearly two-thirds of nations, and about one-third were produced in a free-recall task. The use of information related to countries’ locations was an important determinant of order of recall. Contiguity in free-recall output, responses in a free-association task, and the prediction of recall from recognition also provided evidence of other relations between countries, including semantic and phonetic links and membership in groups of countries. The number of times a country was mentioned in the news was a consistent predictor of recognition and recall. The relative prosperity, population density, and geographic area of countries also influenced recall.     

Crossmodal interaction between the mental number line and peripersonal haptic space representation in sighted and blind individuals

Humans tend to represent numbers in the form of a mental number line. Here we show that the mental number line can modulate the representation of peripersonal haptic space in a crossmodal fashion and that this interaction is not visually mediated. Sighted and early-blind participants were asked to haptically explore rods of different lengths and to indicate midpoints of those rods. During each trial, either a small (2) or a large (8) number was presented in the auditory modality. When no numbers were presented, participants tended to bisect the rods to the left of the actual midpoint, consistent with the notion of pseudoneglect. In both groups, this bias was significantly increased by the presentation of a small number and was significantly reduced by the presentation of a large number. Hence, spatial shifts of attention induced by number processing are not limited to visual space or embodied responses but extend to haptic peripersonal space and occur crossmodally without requiring the activation of a visuospatial representation.     

Cogmic space for narrative-based world representation

Representing a world or a physical/social environment in an agent’s cognitive system is essential for creating human-like artificial intelligence. This study takes a story-centered approach to this issue. In this context, a story refers to an internal representation involving a narrative structure, which is assumed to be a common form of organizing past, present, future, and fictional events and situations. In the artificial intelligence field, a story or narrative is traditionally treated as a symbolic representation. However, a symbolic story representation is limited in its representational power to construct a rich world. For example, a symbolic story representation is unfit to handle the sensory/bodily dimension of a world. In search of a computational theory for narrative-based world representation, this study proposes the conceptual framework of a Cogmic Space for a comic strip-like representation of a world. In the proposed framework, a story is positioned as a mid-level representation, in which the conceptual and sensory/bodily dimensions of a world are unified. The events and their background situations that constitute a story are unified into a sequence of panels. Based on this structure, a representation (i.e., a story) and the represented environment are connected via an isomorphism of their temporal, spatial, and relational structures. Furthermore, the framework of a Cogmic Space is associated with the generative aspect of representations, which is conceptualized in terms of unconscious- and conscious-level processes/representations. Finally, a proof-of-concept implementation is presented to provide a concrete account of the proposed framework.     

Sleep-associated changes in the mental representation of spoken words

The integration of a newly learned spoken word form with existing knowledge in the mental lexicon is characterized by the word form's ability to compete with similar-sounding entries during auditory word recognition. Here we show that although the mere acquisition of a spoken form is swift, its engagement in lexical competition requires an incubation-like period that is crucially associated with sleep. Words learned at 8 p.m. do not induce (inhibitory) competition effects immediately, but do so after a 12-hr interval including a night's sleep, and continue to induce such effects after 24 hr. In contrast, words learned at 8 a.m. do not show such effects immediately or after 12 hr of wakefulness, but show the effects only after 24 hr, after sleep has occurred. This time-course dissociation is best accommodated by connectionist and neural models of learning in which sleep provides an opportunity for hippocampal information to be fed into long-term neocortical memory.     

Improved representation of metallic bonding in atomistic simulations

Previous use of the Sutton-Chen glue potential to model deformation processes in aluminium showed marked deviation from the results of an ab initio simulation prior to yield. The origin of this problem is identified, and a revised scheme is suggested and tested. It is based on the fact that the atomic volume is a key quantity in the metallic bonding of sp bonded elements, and our idea should therefore have wide applicability to interatomic bonding models. The scheme uses a new approximate but rapidly computable formula for the local atomic volume in an inhomogeneous system.     

Cognitive representation of auditory space in blind football experts

ObjectivesWe compared the mental representation of sound directions in blind football players, blind non-athletes and sighted individuals.DesignStanding blindfolded in the middle of a circle with 16 loudspeakers, participants judged whether the directions of two subsequently presented sounds were similar or not.MethodStructure dimensional analysis (SDA) was applied to reveal mean cluster solutions for the groups.ResultsHierarchical cluster analysis via SDA resulted in distinct representation structures of sound directions. The blind football players' mean cluster solution consisted of pairs of neighboring directions. The blind non-athletes also clustered the directions in pairs, but included non-adjacent directions. In the sighted participants' structure, frontal directions were clustered pairwise, the absolute back was singled out, and the side regions accounted for more directions.ConclusionsOur results suggest that the mental representation of egocentric auditory space is influenced by sight and by the level of expertise in auditory-based orientation and navigation.     

Systematic angular biases in the representation of visual space

Representing spatial information is one of our most foundational abilities. Yet in the present work we find that even the simplest possible spatial tasks reveal surprising, systematic misrepresentations of space—such as biases wherein objects are perceived and remembered as being nearer to the centers of their surrounding quadrants. We employed both a placement task (in which observers see two differently sized shapes, one of which has a dot in it, and then must place a second dot in the other shape so that their relative locations are equated) and a matching task (in which observers see two dots, each inside a separate shape, and must simply report whether their relative locations are matched). Some of the resulting biases were shape specific. For example, when dots appeared in a triangle during the placement task, the dots placed by observers were biased away from certain parts of the symmetry axes. But other systematic biases were not shape specific, and seemed instead to reflect differences in the grain of resolution for different regions of space. For example, with both a circle and even a shapeless configuration (with only a central landmark) in the matching task, observers were better at discriminating angular differences (when a dot changed positions around the circle, as opposed to inward/outward changes) in cardinal versus oblique sectors. These data reveal a powerful angular spatial bias, and highlight how the resolution of spatial representation differs for different regions and dimensions of space itself.

     

Gaze orientation interferes with mental numerical representation

Number comparison tasks are characterized by distance and size effects. The distance effect reveals that the higher the distance is between two numbers, the easier their magnitude comparison is. Accordingly, people are thought to represent numbers on a spatial dimension, the mental number line, on which any given number corresponds to a location on the line. The size effect, instead, states that at any given distance, comparing two small numbers is easier than comparing two large numbers, thus suggesting that larger numbers are more vaguely represented than smaller ones. In the present work we first tested whether the participants were adopting a spatial strategy to solve a very simple numbers comparison task, by assessing the presence of the distance and the magnitude effect. Secondarily, we focused on the influence of gaze position on their performance. The present results provide evidence that gaze direction interferes with number comparisons, worsening the vague representation of larger numbers and further supporting the hypothesis of the overlapping between physical and mental spaces.     

The mental representation of knowledge acquired from maps

Recognition priming and distance estimation were used to investigate the mental representation of knowledge acquired from maps. In Experiment 1, recognition priming showed that cities close in route distance primed each other more than cities far in route distance, even when Euclidean distance was equated. Experiment 2 showed that this finding was robust and not an artifact of the way subjects learned the maps. Distance estimations in Experiment 1 supported the priming results. These results indicated that psychological distance in cognitive maps is primarily dependent on route distance rather than Euclidean distance.     

Reliable misrepresentation and tracking theories of mental representation

It is a live possibility that certain of our experiences reliably misrepresent the world around us. I argue that tracking theories of mental representation (e.g. those of Dretske, Fodor, and Millikan) have difficulty allowing for this possibility, and that this is a major consideration against them.     

Surface construal and the mental representation of scenes

What distinguishes scenes from nonscenes? Photographs of objects on both naturalistic and blank backgrounds yielded boundary extension (BE: memory for unseen spatial expanse outside the picture's boundaries). However, line-drawn objects on blank backgrounds did not (Experiment 1). Perhaps the blank background was construed as depicting a real-world surface in the photograph condition but was construed as depicting nothing in the line-drawn condition. To change background construal, the authors used objects cut out of photographs; these were placed on blank backgrounds while viewers watched (Experiments 2 and 3). BE was eliminated. The authors propose that amodal continuation is a fundamental aspect of scene perception. However, not all pictures are scenes--only pictures construed as depicting a truncated view of a continuous world.