Chimpanzee problem-solving: contrasting the use of causal and arbitrary cues

Humans are able to benefit from a causally structured problem-solving context rather than arbitrarily structured situations. In order to better understand nonhuman causal cognition, it is therefore important to isolate crucial factors that might differentiate between events that follow a purely spatial and temporal contingency and those that hold a “true” causal relationship. In the first of two experiments, chimpanzee subjects were required to detect a bottle containing juice from five opaque bottles of equal shape and size. In the causal condition, the juice bottle looked identical to the other four bottles, only it was much heavier than the others. In the arbitrary condition, the weight of all five bottles was identical, but the juice bottle was color-marked differently. Since bottle opening was made difficult (and therefore costly), the question was whether subject’s manipulative behavior would be random or somehow influenced by the nature of the provided information. Our results show that subjects detected and opened the juice bottle significantly faster when weight was the discriminating feature (causal condition) compared to situations in which the discrimination was necessarily based on a color-cue (arbitrary condition). Experiment 2 ruled out the possibility of a general learning bias toward tactile rather than visual information in chimpanzees. When tested in a simple exchange paradigm that prevented any use of causal information, no predominance of a tactile cue (weight) over a visual cue (color) could be found. Furthermore—and in contrast to the causal condition in Experiment 1—no learning occurred during the course of Experiment 2, neither in the weight nor in the color condition. We therefore conclude that chimpanzees can more easily determine the content of an object based on its causal properties compared to situations in which the only available information is a pure arbitrary regularity. This supports the view that chimpanzees’ causal cognition does not rely on mere perceptual information but also on structural abstraction about their physical environment.     

Discrete quantity judgments in the great apes (Pan paniscus, Pan troglodytes, Gorilla gorilla, Pongo pygmaeus): the effect of presenting whole sets versus item-by-item

The authors examined quantity-based judgments for up to 10 items for simultaneous and sequential whole sets as well as for sequentially dropped items in chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla), bonobos (Pan paniscus), and orangutans (Pongo pygmaeus). In Experiment 1, subjects had to choose the larger of 2 quantities presented in 2 separate dishes either simultaneously or 1 dish after the other. Representatives of all species were capable of selecting the larger of 2 quantities in both conditions, even when the quantities were large and the numerical distance between them was small. In Experiment 2, subjects had to select between the same food quantities sequentially dropped into 2 opaque cups so that none of the quantities were ever viewed as a whole. The authors found some evidence (albeit weaker) that subjects were able to select the larger quantity of items. Furthermore, the authors found no performance breakdown with the inclusion of certain quantities. Instead, the ratio between quantities was the best performance predictor. The authors conclude that quantity-based judgments rely on an analogical system, not a discrete object file model or perceptual estimation mechanism, such as subitizing.     

Visual adaptation of the perception of “life”: Animacy is a basic perceptual dimension of faces

One critical component of understanding another’s mind is the perception of “life” in a face. However, little is known about the cognitive and neural mechanisms underlying this perception of animacy. Here, using a visual adaptation paradigm, we ask whether face animacy is (1) a basic dimension of face perception and (2) supported by a common neural mechanism across distinct face categories defined by age and species. Observers rated the perceived animacy of adult human faces before and after adaptation to (1) adult faces, (2) child faces, and (3) dog faces. When testing the perception of animacy in human faces, we found significant adaptation to both adult and child faces, but not dog faces. We did, however, find significant adaptation when morphed dog images and dog adaptors were used. Thus, animacy perception in faces appears to be a basic dimension of face perception that is species specific but not constrained by age categories.     

EEG correlates of behavioural laterality: right-handedness

Among right-handers, the magnitude of differences in proficiency between the left and right hands varies considerably. Yet significance of the extent of right-handedness is still a controversial issue. To examine whether individual differences in asymmetry of hand skill can partly be attributed to individual differences in asymmetrical hemispheric activation, handedness and electroencephalographic (EEG) laterality were correlated in two large samples (ns = 60 and 128). Analysis indicated that part of the variability in right-handedness may arise from activation asymmetries in the cortex, but whether this relation becomes apparent depends on the cortical area examined and on the experimental condition under which the EEG measures are taken.     

Psychometric evaluation and experimental validation of the statistics anxiety rating scale

The Statistics Anxiety Rating Scale (STARS) was adapted into German to examine its psychometric properties (n = 400). Two validation studies (n = 66, n = 96) were conducted to examine its criterion-related validity. The psychometric properties of the questionnaire were very similar to those previously reported for the original English version in various countries and other language versions. Confirmatory factor analysis indicated 2 second-order factors: One was more closely related to anxiety and the other was more closely related to negative attitudes toward statistics. Predictive validity of the STARS was shown both in an experimental exam-like situation in the laboratory and during a real examination situation. Taken together, the findings indicate that statistics anxiety as assessed by the STARS is a useful construct that is more than just an expression of a more general disposition to anxiety.     

A computer program for testing and analyzing random generation behavior in normal and clinical samples: The Mittenecker Pointing Test

Random sequence generation tests have proved to be a useful diagnostic tool for the identification of clinically relevant impairments of executive functions and for the study of cognitive functioning in healthy individuals. The most prevalent variety, random number generation, involves several limitations, however. In the original Mittenecker Pointing Test (MPT; Mittenecker, 1958), subjects were instructed to point successively and as randomly as possible at nine unlabeled circles irregularly arranged on a cardboard. With the computer program presented here, Mittenecker’s classical test has been transferred to a contemporary format. The MPT can be applied using a standard PC keyboard and computes a series of sophisticated measures of deviations from randomness on the basis of information theory analysis. Because of its easy and well-controlled administration and reduced demands on memory and attention, the automatized MPT offers a wide range of application possibilities in normal but also in severely impaired clinical samples.     

State-dependent changes of prefrontal–posterior coupling in the context of affective processing: Susceptibility to humor

The aim of the present study was to examine whether interindividual differences in the coupling or decoupling of prefrontal and posterior cortices during the exposure to social–emotional information may predict an individual’s positive emotional responsiveness. Susceptibility to humor was assessed in a behavioral paradigm several weeks after the EEG recordings. State-dependent changes of prefrontal–posterior EEG beta coherence were recorded during stimulation with other people’s auditory expressions of cheerfulness and sadness. Greater decreases of coherence during the stimulation with positive affect expressions prospectively predicted greater positive emotional responsiveness, indicated by higher amusement ratings in response to cartoons and higher scores in a questionnaire measure of exhilarability. Greater increases of coherence during the stimulation with negative affect expressions did not predict perceived funniness but were related to shorter response latencies to the amusement ratings. The results further support the notion that a more loose prefrontal–posterior coupling may be related to loosening of control of the prefrontal cortex over incoming emotional information and, thus, to a propensity to deeper emotional involvement and a greater impact of perceptual input, whereas increased prefrontal–posterior coupling may be related to strong control and the propensity to protect oneself from becoming emotionally affected.     

Creative ways to well-being: Reappraisal inventiveness in the context of anger-evoking situations

Neuroscientific studies in the field of creativity mainly focused on tasks drawing on basic verbal divergent thinking demands. This study took a step further by investigating brain mechanisms in response to other types of creative behavior, involving more “real-life” creativity demands in the context of emotion regulation and well-being. Specifically, functional patterns of EEG alpha activity were investigated while participants were required to generate as many and as different ways as possible to reappraise presented anger-eliciting situations in a manner that reduces their anger. Cognitive reappraisal involves some of the same cognitive processes as in conventional verbal creativity tasks, inasmuch as it requires an individual to inhibit or disengage from an emotional event, to shift attention between different perspectives, and to flexibly adopt new solutions. To examine whether alpha oscillations during cognitive reappraisal are different from those during conventional creative ideation, the EEG was also assessed during performance of the Alternative Uses task, requiring individuals to generate as many and as original uses of an object as possible. While cognitive reappraisal was associated with a similar pattern of alpha power as observed in conventional verbal creative ideation, the former yielded significantly stronger alpha power increases at prefrontal sites, along with lower alpha increases at more posterior cortical sites, indicating higher cognitive control and less spontaneous imaginative thought processes in the generation of effective strategies to regulate an ongoing negative emotional state.     

Creative Thinking in an Emotional Context: Specific Relevance of Executive Control of Emotion-Laden Representations in the Inventiveness in Generating Alternative Appraisals of Negative Events

Although divergent thinking ability in different domains may largely rely on the same basic executive functions, domain-specific functions may also be important, in particular when it comes to more real-life creativity demands. This study investigated if functional executive control of emotion-laden representations may be specifically relevant in cognitive reappraisal, which implies being creative in an affective context. In a sample of 88 healthy individuals, the relation between the participants’ inventiveness in generating positive reappraisals of adverse events (Reappraisal Inventiveness Test) and in generating novel ideas without emotional component (conventional divergent thinking test) to their executive functioning in tasks without (Mittenecker Pointing Test) and with emotional contribution (humor processing task) was studied. In line with hybrid models of creative thinking, poorer basic inhibition skills were found to be associated with poorer fluency performance in both divergent thinking tasks. Relations applied more specifically to reappraisal inventiveness when it came to executive processes with a more prominent emotional component. Creative performance in both tasks may have been hampered by time limits. The results support the notion that, in addition to basic executive functioning, more specific cognitive control functions are implicated in more real-life creative performance, according to related domain-specific demands.