Experimental evidence for route integration and strategic planning in wild capuchin monkeys

Both in captivity and the wild, primates are found to travel mostly to the nearest available resource, but they may skip over the closest resource and travel to more distant resources, which are often found to be more productive. This study examines the tradeoff between distance and reward in the foraging choices of one group of wild capuchin monkeys (Cebus apella nigritus) using feeding platforms in large-scale foraging experiments conducted over four years. Three feeding sites were arrayed in an oblique triangle, such that once the monkey group had chosen one site to feed, they had a choice between two remaining sites, a close one with less food and the other up to 2.3 times as far away but with more food. Sites were provisioned once per day. The capuchins generally chose the closer feeding site, even when the more distant site offered up to 12 times as much food. The distances to, rewards of, or various profitability measures applied to each alternative site individually did not explain the group’s choices in ways consistent with foraging theory or principles of operant psychology. The group’s site choices were predicted only by comparing efficiency measures of entire foraging pathways: (1) direct travel to the more rewarding distant site, versus (2) the longer ‘detour’ through the closer site on the way to the more distant one. The group chose the detour more often when the reward was larger and the added detour distance shorter. They appeared to be more sensitive to the absolute increase in detour distance than to the relative increase compared to the straight route. The qualitative and quantitative results agree with a simple rule: do not use the detour unless the energy gain from extra food outweighs the energy cost of extra travel. These results suggest that members of this group integrate information on spatial location, reward, and perhaps potential food competition in their choice of multi-site foraging routes, with important implications for social foraging. This contribution is part of the special issue “ A Socioecological Perspective on Primate Cognition” (Cunningham and Janson 2007b).     

Childhood obesity and social stigma: What we know and what we don't know

Evidence for the development of social stigma associated with body build in childhood, specifically obesity, was critically reviewed. Although there is overwhelming evidence to suggest that children hold a positive stereotype toward a mesomorph (normal) build when compared to other builds, and that this preference increases with age, studies have not convincingly shown a negative stereotype toward the endomorph or obese body build. Furthermore, the belief that obese children are generally discriminated against is without empirical verification. Specifically, it is unclear from the various empirical studies that examine self-esteem and body image, that the psychological consequences of obesity are debilitating. Studies which have noted disturbances in self-concept and body image have sampled clinical populations (youngsters seeking medically supervised reduction); and those studies which have examined nonclinical populations have not found psychological difficulties. Finally, potential moderators such as facial attractiveness × body build interactions, situational contexts, and degree of obesity are examined and new research directions are discussed.     

Motor resources in peripersonal space are intrinsic to spatial encoding: Evidence from motor interference

The aim of this study was to explore the role of motor resources in peripersonal space encoding: are they intrinsic to spatial processes or due to action potentiality of objects? To answer this question, we disentangled the effects of motor resources on object manipulability and spatial processing in peripersonal and extrapersonal spaces. Participants had to localize manipulable and non-manipulable 3-D stimuli presented within peripersonal or extrapersonal spaces of an immersive virtual reality scenario. To assess the contribution of motor resources to the spatial task a motor interference paradigm was used. In Experiment 1, localization judgments were provided with the left hand while the right dominant arm could be free or blocked. Results showed that participants were faster and more accurate in localizing both manipulable and non-manipulable stimuli in peripersonal space with their arms free. On the other hand, in extrapersonal space there was no significant effect of motor interference. Experiment 2 replicated these results by using alternatively both hands to give the response and controlling the possible effect of the orientation of object handles. Overall, the pattern of results suggests that the encoding of peripersonal space involves motor processes per se, and not because of the presence of manipulable stimuli. It is argued that this motor grounding reflects the adaptive need of anticipating what may happen near the body and preparing to react in time.     

What we know about what we have never heard: evidence from perceptual illusions

Are speakers equipped with preferences concerning grammatical structures that are absent in their language? We examine this question by investigating the sensitivity of English speakers to the sonority of onset clusters. Linguistic research suggests that certain onset clusters are universally preferred (e.g., bd>lb). We demonstrate that such preferences modulate the perception of unattested onsets by English speakers: Monosyllabic auditory nonwords with onsets that are universally dispreferred (e.g., lbif) are more likely to be classified as disyllabic and misperceived as identical to their disyllabic counterparts (e.g., lebif) compared to onsets that are relatively preferred across languages (e.g., bdif). Consequently, dispreferred onsets benefit from priming by their epenthetic counterpart (e.g., lebif-lbif) as much as they benefit from identity priming (e.g., lbif-lbif). A similar pattern of misperception (e.g., lbif-->lebif) was observed among speakers of Russian, where clusters of this type occur. But unlike English speakers, Russian speakers perceived these clusters accurately on most trials, suggesting that the perceptual illusions of English speakers are partly due to their linguistic experience, rather than phonetic confusion alone. Further evidence against a purely phonetic explanation for our results is offered by the capacity of English speakers to perceive such onsets accurately under conditions that encourage precise phonetic encoding. The perceptual illusions of English speakers are also irreducible to several statistical properties of the English lexicon. The systematic misperception of universally dispreferred onsets might reflect their ill-formedness in the grammars of all speakers, irrespective of linguistic experience. Such universal grammatical preferences implicate constraints on language learning.     

What children know about the source of their knowledge without reporting it as the source

We tested the development of attentional functions within Syrian and German children of pre-school and school age (n = 562, 5–12 years), using the Test of Attentional Performance for Children (KITAP). After controlling the intelligence (IQ) and socioeconomic status (SES), age-related improvements were found in all the attentional functions, with rapid improvements between 8 and 10 years. Gender differences were also found in some attention performances. More importantly, cultural differences were also evident. The performance in the activation functions “Alertness” and “Vigilance” were independent from cultural background, whereas performances in Sustained Attention, in functions of visuospatial orienting (Visual Scanning) and executive systems (Divided Attention, Flexibility and Distractibility) revealed cultural differences. In general, the Syrian children showed slower performances, higher variability of responses and more errors compared with German children. The overall results of the study supports the universal development of attention functions during school age, and show that attention performances could be influenced by characteristics of the cultural background (Arabic-Syrian: collectivistic–dependent; and Western German: individualistic–independent).     

Performance evaluation: On choosing to know the related attributes of others when we know their performance

It was hypothesized that people will choose to find out about the performance attributes of others who perform similarly to themselves if they believe the attributes are related to performance. Subjects within a group of nine were supposedly given different amounts of practice prior to taking a test on which performance was said to be either related or unrelated to practice. After taking the test, each subject was given his score, his rank order in the group, and the score obtained by each of the other group members. The subject was then allowed to find out about the number of items practiced by one other person in the group. A second choice was also given. On both first and second choices, subjects in the related condition chose to learn about others who were adjacent to them in the rank order. Subjects in the unrelated condition chose to learn about others with extreme scores. First choices in both conditions were strongly biased upward, supporting the unidirectional drive hypothesis.     

Domestic violence and sexual assault services: Inside the black box

Research examining the efficacy of community-based domestic violence and sexual assault services is yielding promising findings; however, little is known about the structure, components, and content of these services. Although service guidelines exist, a critical gap persists because review, comparison, and synthesis of these recommendations have not been undertaken. This research addresses this knowledge gap through a review of the domestic violence and sexual assault services literature. We gathered relevant literature by conducting systematic searches of databases, and by soliciting the service guidelines and training manuals from all the Domestic Violence and Sexual Assault Coalitions in the United States. These efforts yielded 43 articles, books, or manuals for review. The findings show strong consensus on core services for survivors, including crisis services, legal and medical advocacy, support groups, individual counseling, and shelter. This article presents the review results in tables comparing the service goals, intervention strategies, and recommendations for service delivery. We also found areas of contention (e.g., whether to continuously staff domestic violence shelters, and whether combined agencies can effectively offer both domestic violence and sexual assault services). Building upon the review findings, we discuss the implications for domestic violence and sexual assault services and intervention research.     

Acquiring new word meaning: What does it tell us about development

R. J. Sternberg (1984, Developmental Review, 4, 113–138) offers a thoughtful and provocative essay on how individuals acquire meanings for novel or unfamiliar nouns. The Sternberg essay, however, is incomplete on a number of grounds. By stressing general processes and specific knowledge as critical components in the acquisition of verbal concepts, for example, it overlooks two logically complementary categories—specific processes and general knowledge—and the role these play in the acquisitions in question. A second concern is that the paper blurs distinctions among development, short-term learning, and the origin/acquisition of individual differences. Finally, Sternberg is encouraged to frame the specific phenomenon described here within the context of a larger theory of intellectual development and to indicate what else this specific model can be used to explain.     

What infants know about syntax but couldn't have learned: experimental evidence for syntactic structure at 18 months

Generative linguistic theory stands on the hypothesis that grammar cannot be acquired solely on the basis of an analysis of the input, but depends, in addition, on innate structure within the learner to guide the process of acquisition. This hypothesis derives from a logical argument, however, and its consequences have never been examined experimentally with infant learners. Challenges to this hypothesis, claiming that an analysis of the input is indeed sufficient to explain grammatical acquisition, have recently gained attention. We demonstrate with novel experimentation the insufficiency of this countervailing view. Focusing on the syntactic structures required to determine the antecedent for the pronoun one, we demonstrate that the input to children does not contain sufficient information to support unaided learning. Nonetheless, we show that 18-month-old infants do have command of the syntax of one. Because this syntactic knowledge could not have been gleaned exclusively from the input, infants' mastery of this aspect of syntax constitutes evidence for the contribution of innate structure within the learner in acquiring a grammar.     

A generalization of the representational change theory from insight to non-insight problems: the case of arithmetic word problems

This paper provides evidence for a possible generalization of Knoblich and colleagues’ representational change theory [Knoblich, G., Ohlsson, S., Haider, H., & Rhenius, D. (1999). Constraint relaxation and chunk decomposition in insight problem solving. Journal of Experimental Psychology: Learning, Memory, and Cognition, 25, 1534-1555; Knoblich, G., Ohlsson, S., & Raney, G. E. (2001). An eye movement study of insight problem. Memory and Cognition, 29, 1000-1009] outside its original scope of application. While this theory has been proposed to explain insight problem solving, we demonstrate here that its main concepts, namely, constraint relaxation and chunk decomposition, are applicable to incremental problem solving. In a first experiment, we confirm, as already shown by problem solving and reasoning researchers, that individuals avoid the construction of alternative representations of the problems when possible. In the second and third experiments, we show that alternative representations of arithmetic problems are easier to construct and maintain when they violate constraints of narrow rather than wide scope. The specificity of insight problem solving is discussed in the light of these new findings.     

What hands know about objects; taking perception of hills out of context: A response to Durgin (2013)

In a recent paper, we provided independent evidence on the accuracy of ‘haptically’ measured geographical slant perception (Taylor-Covill & Eves, 2013). Durgin (2013) argues that the devices used in our work, namely the palm-board, and palm-controlled inclinometer (PCI), are not measures of perception. In response, we outline four failures of replication in the laboratory work of Durgin and colleagues on which they base their model of slant perception. We also highlight fundamental differences between the perceptual tasks Durgin and colleagues ask of participants relative to those of Proffitt and colleagues' traditional measures. These subtle differences might help explain how the two groups have arrived at discrepant conclusions.     

What we know about what we have never heard before: Beyond phonetics : Reply to Peperkamp

Berent, Steriade, Lennertz, and Vaknin (2007) [Berent, I., Steriade, D., Lennertz, T., & Vaknin, V. (2007). What we know about what we have never heard: evidence from perceptual illusions. Cognition, 104, 591-630] demonstrate that English speakers’ perception of onsets that are unattested in their language mirrors their typological markedness. We suggest that these findings might reflect the presence of universal grammatical constraints, a proposal challenged by Peperkamp’s commentary. Our reply exposes mischaracterizations of our claims and presents additional empirical arguments in their support.     

On the border: perimeter patrolling as a transitional exploratory phase in a diurnal rodent,the fat sand rat (<Emphasis Type="Italic">Psammomys obesus</Emphasis>)

Exploration is an initial phase of constructing spatial representation. In an illuminated environment, exploration by nocturnal rodents takes the form of home-base behavior, with the rodents organizing their activity in relation to the base, repeatedly orienting and returning to it. In the dark, home base behavior in gerbils is preceded by looping exploration, in which travel paths tangle into loops that close at various locations so that the gerbils pilot from one loop to the next. In the present study we tested a diurnal gerbil, the fat sand rat, Psammomys obesus, in both a lit and a dark open field in order to compare its exploratory behavior with that of nocturnal rodents. We found that under lit conditions, fat sand rats used perimeter patrolling, traveling mainly along the walls of the open field. In perimeter patrolling the animal probably monitors its location in relation to the perimeter (arena walls), and not to a specific location as in home base. In the dark, fat sand rats first used looping, and gradually shifted to perimeter patrolling exploration. We suggest that perimeter patrolling is a transient phase in which the animal evaluates possible locations for a home base. Thus, perimeter patrolling is an intermediate phase between looping, which is based on piloting from one landmark to the next, and home base exploration, in which the animal continuously orients to a specific location. This spatial behavior of perimeter patrolling may shed light on phases of information processing and spatial representation during exploration and navigation.     

Cognitive control in number processing: evidence from the unit-decade compatibility effect

In this study we evaluated whether the reverse compatibility effect observed when participants compare two-digit Spanish number words might be modulated as a function of the percentage of filler trials (within-decade comparisons). The participants performed a comparison task with two-digit Spanish number words while the unit–decade compatibility in between decade comparison trials was manipulated. We biased the relevance of units by increasing the intra/inter decade comparison ratio (20%, 50%, and 70%). The compatibility effect shifted from reverse to regular depending on the unit relevance which indicates that the relative emphasis on the unit processing in two-digit number word can be modulated by the stimulus list. These results are discussed in terms of cognitive control in number processing.     

Playing the Simon game: Use of the Simon task for investigating human information processing

A little more than 40 years ago, J. R. Simon and colleagues introduced what is now called the Simon task, which yielded a correspondence effect known as the Simon effect. In this paper, I set Simon's contribution in the context of research on stimulus-response compatibility. The novel contribution of the Simon task is described, along with foundational findings using the task that Simon and colleagues reported. I acknowledge the significance of Simon's (1990) review chapter in generating my own interests in the Simon task and describe four selected lines of research from my lab that have been a result of those interests. The article concludes with a brief tribute to Simon and his contribution to experimental psychology.     

Human Nature: What We Need to Know about Ourselves in the Twenty-First Century

The Western worldview that now dominates the planet embodies beliefs about human nature that are inconsistent with our evolutionarily evolved natures. Its "logic" at best ignores and at worst creates the symptoms of the modern world, which if uncorrected predict severe crises in coming centuries: population growth, environmental destruction, economic collapse, and increasing social violence. In contrast, there are numerous communities today creating alternative solutions based on different understandings of human nature and human needs: cooperation rather than competition; meaningful social identity; and respect for and trust in the autonomous behavior of all persons. There exist optimistic future models.     

Misconceptions about the Fishbein model: Reflections on a study by Songer-Nocks

Songer-Nocks has questioned the generality and sufficiency of Fishbein's model of intentions. It is shown that her conclusions reflect a basic misunderstanding of the model and its implications. Several misconceptions are identified and an attempt is made to clarify some of the theoretical and methodological issues involved.