Findings

Intel Inside

Kevin Lewis

February 20, 2011

Facilitate Insight by Non-Invasive Brain Stimulation

Richard Chi & Allan Snyder
PLoS ONE, February 2011, e16655

Abstract:
Our experiences can blind us. Once we have learned to solve problems by one method, we often have difficulties in generating solutions involving a different kind of insight. Yet there is evidence that people with brain lesions are sometimes more resistant to this so-called mental set effect. This inspired us to investigate whether the mental set effect can be reduced by non-invasive brain stimulation. 60 healthy right-handed participants were asked to take an insight problem solving task while receiving transcranial direct current stimulation (tDCS) to the anterior temporal lobes (ATL). Only 20% of participants solved an insight problem with sham stimulation (control), whereas 3 times as many participants did so (p = 0.011) with cathodal stimulation (decreased excitability) of the left ATL together with anodal stimulation (increased excitability) of the right ATL. We found hemispheric differences in that a stimulation montage involving the opposite polarities did not facilitate performance. Our findings are consistent with the theory that inhibition to the left ATL can lead to a cognitive style that is less influenced by mental templates and that the right ATL may be associated with insight or novel meaning. Further studies including neurophysiological imaging are needed to elucidate the specific mechanisms leading to the enhancement.

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Decisions for Others Are More Creative Than Decisions for the Self

Evan Polman & Kyle Emich
Personality and Social Psychology Bulletin, forthcoming

Abstract:
Four studies investigate whether decisions for others produce more creative solutions than do decisions for the self and if construal level explains this relation. In Study 1, participants carried out a structured imagination task by drawing an alien for a story that they would write, or alternatively for a story that someone else would write. As expected, drawing an alien for someone else produced a more creative alien. In Studies 2a and 2b, construal level (i.e., psychological distance) was independently manipulated. Participants generated more creative ideas on behalf of distant others than on behalf of either close others or themselves. Finally, in Study 3, a classic insight problem was investigated. Participants deciding for others were more likely to solve the problem; furthermore, this result was mediated by psychological distance. These findings demonstrate that people are more creative for others than for themselves and shed light on differences in self-other decision making.

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Brain Structure in Young and Old East Asians and Westerners: Comparisons of Structural Volume and Cortical Thickness

Michael Wei Liang Chee et al.
Journal of Cognitive Neuroscience, May 2011, Pages 1065-1079

Abstract:
There is an emergent literature suggesting that East Asians and Westerners differ in cognitive processes because of cultural biases to process information holistically (East Asians) or analytically (Westerners). To evaluate the possibility that such differences are accompanied by differences in brain structure, we conducted a large comparative study on cognitively matched young and old adults from two cultural/ethnic groups-Chinese Singaporeans and non-Asian Americans-that involved a total of 140 persons. Young predominantly White American adults were found to have higher cortical thickness in frontal, parietal, and medial-temporal polymodal association areas in both hemispheres. These findings were replicated using voxel-based morphometry applied to the same data set. Differences in cortical thickness observed between young volunteers were not significant in older subjects as a whole. However, group differences were evident when high-performing old were compared. Although the observed differences in gray matter may be rooted in strategic differences in cognition arising from ethnic/cultural differences, alternative explanations involving genetic heritage and environmental factors are also considered.

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Chimpanzees know that others make inferences

Martin Schmelz, Josep Call & Michael Tomasello
Proceedings of the National Academy of Sciences, 15 February 2011, Pages 3077-3079

Abstract:
If chimpanzees are faced with two opaque boards on a table, in the context of searching for a single piece of food, they do not choose the board lying flat (because if food was under there it would not be lying flat) but, rather, they choose the slanted one - presumably inferring that some unperceived food underneath is causing the slant. Here we demonstrate that chimpanzees know that other chimpanzees in the same situation will make a similar inference. In a back-and-forth foraging game, when their competitor had chosen before them, chimpanzees tended to avoid the slanted board on the assumption that the competitor had already chosen it. Chimpanzees can determine the inferences that a conspecific is likely to make and then adjust their competitive strategies accordingly.

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Predicting Individuals' Learning Success from Patterns of Pre-Learning MRI Activity

Loan Vo et al.
PLoS ONE, January 2011, e16093

Abstract:
Performance in most complex cognitive and psychomotor tasks improves with training, yet the extent of improvement varies among individuals. Is it possible to forecast the benefit that a person might reap from training? Several behavioral measures have been used to predict individual differences in task improvement, but their predictive power is limited. Here we show that individual differences in patterns of time-averaged T2*-weighted MRI images in the dorsal striatum recorded at the initial stage of training predict subsequent learning success in a complex video game with high accuracy. These predictions explained more than half of the variance in learning success among individuals, suggesting that individual differences in neuroanatomy or persistent physiology predict whether and to what extent people will benefit from training in a complex task. Surprisingly, predictions from white matter were highly accurate, while voxels in the gray matter of the dorsal striatum did not contain any information about future training success. Prediction accuracy was higher in the anterior than the posterior half of the dorsal striatum. The link between trainability and the time-averaged T2*-weighted signal in the dorsal striatum reaffirms the role of this part of the basal ganglia in learning and executive functions, such as task-switching and task coordination processes. The ability to predict who will benefit from training by using neuroimaging data collected in the early training phase may have far-reaching implications for the assessment of candidates for specific training programs as well as the study of populations that show deficiencies in learning new skills.

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The Likelihood of Cognitive Enhancement

Gary Lynch, Linda Palmer & Christine Gall
Pharmacology Biochemistry and Behavior, forthcoming

Abstract:
Whether drugs that enhance cognition in healthy individuals will appear in the near future has become a topic of considerable interest. We address this possibility using a three variable system (psychological effect, neurobiological mechanism, efficiency vs. capabilities) for classifying candidates. Ritalin and modafinil, two currently available compounds, operate on primary psychological states that in turn affect cognitive operations (attention, memory), but there is little evidence that these effects translate into improvements in complex cognitive processing. A second category of potential enhancers includes agents that improve memory encoding, generally without large changes in primary psychological states. Unfortunately, there is little information on how these compounds affect cognitive performance in standard psychological tests. Recent experiments have identified a number of sites at which memory drugs could, in principle, manipulate the cell biological systems underlying the learning-related long-term potentiation (LTP) effect; this may explain the remarkable diversity of memory promoting compounds. Indeed, many of these agents are known to have positive effects on LTP. A possible third category of enhancement drugs directed specifically at integrated cognitive operations is nearly empty. From a neurobiological perspective, two plausible candidate classes have emerged that both target the fast excitatory transmission responsible for communication within cortical networks. One acts on nicotinic receptors (alpha7, alpha4) that regulate release of the neurotransmitter glutamate while the other (‘ampakines') allosterically modulates the glutamate receptors mediating the post-synaptic response (EPSCs). Brain imaging in primates has shown that ampakines expand cortical networks engaged by a complex task; coupled with behavioral data, these findings provide evidence for the possibility of generating new cognitive capabilities. Finally, we suggest that continuing advances in behavioral sciences provide new opportunities for translational work, and that discussions of the social impact of cognitive enhancers have failed to consider the distinction between effects on efficiency vs. new capabilities.

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The Nature of Gestures' Beneficial Role in Spatial Problem Solving

Mingyuan Chu & Sotaro Kita
Journal of Experimental Psychology: General, February 2011, Pages 102-116

Abstract:
Co-thought gestures are hand movements produced in silent, noncommunicative, problem-solving situations. In the study, we investigated whether and how such gestures enhance performance in spatial visualization tasks such as a mental rotation task and a paper folding task. We found that participants gestured more often when they had difficulties solving mental rotation problems (Experiment 1). The gesture-encouraged group solved more mental rotation problems correctly than did the gesture-allowed and gesture-prohibited groups (Experiment 2). Gestures produced by the gesture-encouraged group enhanced performance in the very trials in which they were produced (Experiments 2 & 3). Furthermore, gesture frequency decreased as the participants in the gesture-encouraged group solved more problems (Experiments 2 & 3). In addition, the advantage of the gesture-encouraged group persisted into subsequent spatial visualization problems in which gesturing was prohibited: another mental rotation block (Experiment 2) and a newly introduced paper folding task (Experiment 3). The results indicate that when people have difficulty in solving spatial visualization problems, they spontaneously produce gestures to help them, and gestures can indeed improve performance. As they solve more problems, the spatial computation supported by gestures becomes internalized, and the gesture frequency decreases. The benefit of gestures persists even in subsequent spatial visualization problems in which gesture is prohibited. Moreover, the beneficial effect of gesturing can be generalized to a different spatial visualization task when two tasks require similar spatial transformation processes. We concluded that gestures enhance performance on spatial visualization tasks by improving the internal computation of spatial transformations.

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Consumption of cocoa flavanols results in an acute improvement in visual and cognitive function

David Field, Claire Williams & Laurie Butler
Physiology & Behavior, forthcoming

Abstract:
Cocoa flavanols (CF) influence physiological processes in ways that suggest their consumption may improve aspects of neural function, and previous studies have found positive influences of CF on cognitive performance. In this preliminary study we investigated whether visual, as well as cognitive, function is influenced by an acute dose of CF in young adults. We employed a randomized, single-blinded, order counterbalanced, crossover design in which 30 healthy adults consumed both dark chocolate containing 720 mg CF and a matched quantity of white chocolate, with a one week interval between testing sessions. Visual contrast sensitivity was assessed by reading numbers that became progressively more similar in luminance to their background. Motion sensitivity was assessed firstly by measuring the threshold proportion of coherently moving signal dots that could be detected against a background of random motion, and secondly by determining the minimum time required to detect motion direction in a display containing a high proportion of coherent motion. Cognitive performance was assessed using a visual spatial working memory for location task and a choice reaction time task designed to engage processes of sustained attention and inhibition. Relative to the control condition, CF improved visual contrast sensitivity and reduced the time required to detect motion direction, but had no statistically reliable effect on the minimum proportion of coherent motion that could be detected. In terms of cognitive performance, CF improved spatial memory and performance on some aspects of the choice reaction time task. As well as extending the range of cognitive tasks that are known to be influenced by CF consumption, this is the first report of acute effects of CF on the efficiency of visual function. These acute effects can be explained by increased cerebral blood flow caused by CF, although in the case of contrast sensitivity there may be an additional contribution from CF induced retinal blood flow changes.

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Responses to the Assurance game in monkeys, apes, and humans using equivalent procedures

Sarah Brosnan et al.
Proceedings of the National Academy of Sciences, forthcoming

Abstract:
There is great interest in the evolution of economic behavior. In typical studies, species are asked to play one of a series of economic games, derived from game theory, and their responses are compared. The advantage of this approach is the relative level of consistency and control that emerges from the games themselves; however, in the typical experiment, procedures and conditions differ widely, particularly between humans and other species. Thus, in the current study, we investigated how three primate species, capuchin monkeys, chimpanzees, and humans, played the Assurance (or Stag Hunt) game using procedures that were, to the best of our ability, the same across species, particularly with respect to training and pretesting. Our goal was to determine what, if any, differences existed in the ways in which these species made decisions in this game. We hypothesized differences along phylogenetic lines, which we found. However, the species were more similar than might be expected. In particular, humans who played using "nonhuman primate-friendly" rules did not behave as is typical. Thus, we find evidence for similarity in decision-making processes across the order Primates. These results indicate that such comparative studies are possible and, moreover, that in any comparison rating species' relative abilities, extreme care must be taken in ensuring that one species does not have an advantage over the others due to methodological procedures.

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The Effect of Incidental Hints When Problems Are Suspended Before, During, or After an Impasse

Jarrod Moss, Kenneth Kotovsky & Jonathan Cagan
Journal of Experimental Psychology: Learning, Memory, and Cognition, January 2011, Pages 140-148

Abstract:
Two studies examine how the time at which problem solving is suspended relative to an impasse affects the impact of incidental hints. An impasse is a point in problem solving at which a problem solver is not making progress and does not know how to proceed. In both studies, work on remote associates problems was suspended before an impasse was reached, at the time an impasse was reached, or after a period of continued work during an impasse. After problem solving was suspended on a set of problems, participants completed a lexical decision task before resuming work on the set of unsolved problems. For half of the problems suspended during each impasse state, solution words were presented as incidental hints in the lexical decision task. The proportion of initially unsolved problems that were solved after the intervening lexical decision task was greater when problem solving was suspended at the point an impasse was reached than when problem solving was suspended before an impasse or after a period of continued work during an impasse. These results suggest that suspending problem solving at the point of impasse may increase susceptibility to incidentally presented hints. The point of impasse may be an opportune time for hints because the problem has been explored but there has not been a large increase in fixation on failed solution attempts.

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Money enhances memory consolidation - But only for boring material

Kou Murayama & Christof Kuhbandner
Cognition, forthcoming

Abstract:
Money's ability to enhance memory has received increased attention in recent research. However, previous studies have not directly addressed the time-dependent nature of monetary effects on memory, which are suggested to exist by research in cognitive neuroscience, and the possible detrimental effects of monetary rewards on learning interesting material, as indicated by studies in motivational psychology. By utilizing a trivia question paradigm, the current study incorporated these perspectives and examined the effect of monetary rewards on immediate and delayed memory performance for answers to uninteresting and interesting questions. Results showed that monetary rewards promote memory performance only after a delay. In addition, the memory enhancement effect of monetary rewards was only observed for uninteresting questions. These results are consistent with both the hippocampus-dependent memory consolidation model of reward learning and previous findings documenting the ineffectiveness of monetary rewards on tasks that have intrinsic value.

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Click trains and the rate of information processing: Does "speeding up" subjective time make other psychological processes run faster?

Luke Jones, Clare Allely & John Wearden
Quarterly Journal of Experimental Psychology, February 2011, Pages 363-380

Abstract:
A series of experiments demonstrated that a 5-s train of clicks that have been shown in previous studies to increase the subjective duration of tones they precede (in a manner consistent with "speeding up" timing processes) could also have an effect on information-processing rate. Experiments used studies of simple and choice reaction time (Experiment 1), or mental arithmetic (Experiment 2). In general, preceding trials by clicks made response times significantly shorter than those for trials without clicks, but white noise had no effects on response times. Experiments 3 and 4 investigated the effects of clicks on performance on memory tasks, using variants of two classic experiments of cognitive psychology: Sperling's (1960) iconic memory task and Loftus, Johnson, and Shimamura's (1985) iconic masking task. In both experiments participants were able to recall or recognize significantly more information from stimuli preceded by clicks than those preceded by silence.

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Are intelligence and creativity really so different?: Fluid intelligence, executive processes, and strategy use in divergent thinking

Emily Nusbaum & Paul Silvia
Intelligence, January-February 2011, Pages 36-45

Abstract:
Contemporary creativity research views intelligence and creativity as essentially unrelated abilities, and many studies have found only modest correlations between them. The present research, based on improved approaches to creativity assessment and latent variable modeling, proposes that fluid and executive cognition is in fact central to creative thought. In Study 1, the substantial effect of fluid intelligence (Gf) on creativity was mediated by executive switching, the number of times people switched idea categories during the divergent thinking tasks. In Study 2, half the sample was given an effective strategy for an unusual uses task. The strategy condition interacted with Gf: people high in Gf did better when given the strategy, consistent with their higher ability to maintain access to it and use it despite interference. Taken together, the findings suggest that divergent thinking is more convergent than modern creativity theories presume.

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Height as a Proxy for Cognitive and Non-Cognitive Ability

Andreas Schick & Richard Steckel
NBER Working Paper, December 2010

Abstract:
Taller workers receive a substantial wage premium. Studies extending back to the middle of the last century attribute the premium to non-cognitive abilities, which are associated with stature and rewarded in the labor market. More recent research argues that cognitive abilities explain the stature-wage relationship. This paper reconciles the competing views by recognizing that net nutrition, a major determinant of adult height, is integral to our cognitive and non-cognitive development. Using data from Britain's National Childhood Development Study (NCDS), we show that taller children have higher average cognitive and non-cognitive test scores, and that each aptitude accounts for a substantial and roughly equal portion of the stature premium. Together these abilities explain why taller people have higher wages.

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Gene-Environment Interaction in the Etiology of Mathematical Ability Using SNP Sets

Sophia Docherty, Yulia Kovas & Robert Plomin
Behavior Genetics, January 2011, Pages 141-154

Abstract:
Mathematics ability and disability is as heritable as other cognitive abilities and disabilities, however its genetic etiology has received relatively little attention. In our recent genome-wide association study of mathematical ability in 10-year-old children, 10 SNP associations were nominated from scans of pooled DNA and validated in an individually genotyped sample. In this paper, we use a ‘SNP set' composite of these 10 SNPs to investigate gene-environment (GE) interaction, examining whether the association between the 10-SNP set and mathematical ability differs as a function of ten environmental measures in the home and school in a sample of 1888 children with complete data. We found two significant GE interactions for environmental measures in the home and the school both in the direction of the diathesis-stress type of GE interaction: The 10-SNP set was more strongly associated with mathematical ability in chaotic homes and when parents are negative.

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Does incorrect guessing impair fact learning?

Sean Kang et al.
Journal of Educational Psychology, February 2011, Pages 48-59

Abstract:
Taking a test has been shown to produce enhanced retention of the retrieved information. On tests, however, students often encounter questions the answers for which they are unsure. Should they guess anyway, even if they are likely to answer incorrectly? Or are errors engrained, impairing subsequent learning of the correct answer? We sought to answer this question in 3 experiments. In Experiments 1 and 2, subjects read 80 obscure facts (e.g., "Where is Disko Island? Greenland") and then took a cued recall test. When a subject reported being unable to answer a question, on a randomly chosen half of those questions the computer program insisted upon a guess. Corrective feedback was provided either immediately (Experiment 1) or after a delay (Experiment 2). Forced guessing did not affect subjects' performance on a final test given 1 day later. We extended the investigation to more complex material in Experiment 3. Subjects saw a question (e.g., "Why do ice cubes often pop as they melt in your drink?") and its answer, but for half of the questions, subjects did not see the answer until they first provided a plausible explanation. On a test administered either on the same day or 1 week later, recall performance was again unaffected by a prior wrong guess.

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Investigating the links between the subcomponents of executive function and academic achievement: A cross-cultural analysis of Chinese and American preschoolers

Xuezhao Lan et al.
Journal of Experimental Child Psychology, March 2011, Pages 677-692

Abstract:
Little is known about how components of executive function (EF) jointly and uniquely predict different aspects of academic achievement and how this may vary across cultural contexts. In the current study, 119 Chinese and 139 American preschoolers were tested on a battery of EF tasks (i.e., inhibition, working memory, and attentional control) as well as academic achievement tasks (i.e., reading and mathematics). Results demonstrate that although working memory performance in both cultures was comparable, Chinese children outperformed American children on inhibition and attentional control tasks. In addition, the relation between components of EF and achievement was similar in the two countries. Working memory uniquely predicted academic achievement, with some intriguing patterns in regard to tasks requiring complex processing. Inhibition uniquely predicted counting but did not uniquely predict calculation. Attentional control predicted most aspects of achievement uniformly and was the most robust predictor for reading in both countries. In sum, the data provide insight into both cultural variability and consistency in the development of EF during early childhood.

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Antecedents and consequences of peer-rated intelligence

Jaap Denissen et al.
European Journal of Personality, forthcoming

Abstract:
The current study investigated the antecedents and consequences of peer-rated intelligence in a longitudinal round robin design, following previously unacquainted members of small student work groups. Results indicated that peer-reputations of intelligence were reliable, stable and weakly correlated with objective intelligence. Bias was shown by correlations with interpersonal liking (decreasing across time) and idiosyncratic rating tendencies (increasing across time). Agreement between self-ratings and peer-reputations increased over time but was not based on increasing accuracy but on reciprocal associations between self-ratings and peer-reputations in the beginning of the acquaintanceship process, and on peer-reputations predicting changes in self-ratings later on. Finally, it was shown that peer-rated intelligence reputations predict academic achievement across two 4-month periods (even when tested intelligence was controlled) and dropout from university after 8 months. Overall, the pattern of results demonstrates the utility of a socioanalytic perspective in analysing personality and social processes.

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Learning by reviewing

Kwangsu Cho & Charles MacArthur
Journal of Educational Psychology, February 2011, Pages 73-84

Abstract:
Peer review of writing provides an alternative to the traditional approach of practicing writing with feedback from an instructor. Most of the limited research on peer review has examined the general effects or focused on the effects of receiving feedback from peers. The current study focused on the effects of giving feedback, that is, on whether students learn to write better by reviewing peer writing. Sixty-one undergraduate students were randomly assigned to reviewing, reading, or no-treatment control conditions. Reviewers rated and commented on papers written by peers. Readers read the same papers without commenting. All students then wrote a paper in the same genre but on a different topic. Students in the reviewing condition significantly outperformed those in both other conditions on the quality of the report. Follow-up analysis indicated that comments coded as "problem detection" and "solution suggestion" were positively correlated with writing outcomes for students in the reviewing condition. This research provides support for the use of peer review of writing as a learning activity.

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Torrance Tests of Creative Thinking as Predictors of Personal and Public Achievement: A Fifty-Year Follow-Up

Mark Runco et al.
Creativity Research Journal, October 2010, Pages 361-368

Abstract:
This article presents the results of the 50-year follow-up of the longitudinal study E. Paul Torrance initiated 5 decades ago. The Torrance Test of Creative Thinking (TTCT) was administered in the late 1950s and personal and public achievement data were obtained 50 years later and used as criteria in analyses reported here. These showed that TTCT scores were moderately correlated with personal, but not with public, achievement. However, an interaction of intelligence and creativity was significantly related to public achievement but not to personal achievement. When a composite was formed from the 4 TTCT indexes (fluency, originality, flexibility, and elaboration), a significant quadratic trend was found with the personal achievement criterion. Three of the indicators ("Love of work," Tolerance of mistakes, and Minority of one) from the Beyonder instrument developed by Torrance (2003) were related to public achievement. Only one other indicator from the Beyonder measure ("Well-roundedness") was associated with personal achievement. Men were significantly higher in public achievement than women, but there was no significant gender difference in personal achievement.

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Cognitive adaptations for gathering-related navigation in humans

Max Krasnow et al.
Evolution and Human Behavior, January 2011, Pages 1-12

Abstract:
Current research increasingly suggests that spatial cognition in humans is accomplished by many specialized mechanisms, each designed to solve a particular adaptive problem. A major adaptive problem for our hominin ancestors, particularly females, was the need to efficiently gather immobile foods which could vary greatly in quality, quantity, spatial location and temporal availability. We propose a cognitive model of a navigational gathering adaptation in humans and test its predictions in samples from the US and Japan. Our results are uniformly supportive: the human mind appears equipped with a navigational gathering adaptation that encodes the location of gatherable foods into spatial memory. This mechanism appears to be chronically active in women and activated under explicit motivation in men.

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The world is not flat: Can people reorient using slope?

Daniele Nardi, Nora Newcombe & Thomas Shipley
Journal of Experimental Psychology: Learning, Memory, and Cognition, forthcoming

Abstract:
Studies of spatial representation generally focus on flat environments and visual input. However, the world is not flat, and slopes are part of most natural environments. In a series of 4 experiments, we examined whether humans can use a slope as a source of allocentric, directional information for reorientation. A target was hidden in a corner of a square, featureless enclosure tilted at a 5° angle. Finding it required using the vestibular, kinesthetic, and visual cues associated with the slope gradient. In Experiment 1, the overall sample performed above chance, showing that slope is sufficient for reorientation in a real environment. However, a sex difference emerged; men outperformed women by 1.4 SDs because they were more likely to use a slope-based strategy. In Experiment 2, attention was drawn to the slope, and participants were prompted to rely on it to solve the task; however, men still outperformed women, indicating a greater ability to use slope. In Experiment 3, we excluded the possibility that women's disadvantage was due to wearing heeled footwear. In Experiment 4, women required more time than men to identify the uphill direction of the slope gradient; this suggests that, in a bottom-up fashion, a perceptual or attentional difficulty underlies women's disadvantage in the ability to use slope and their decreased reliance on this cue. Overall, a bi-coordinate representation was used to find the goal: The target was encoded primarily with respect to the vertical axis and secondarily with respect to the orthogonal axis of the slope.


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