Effects of pre-experimental knowledge on recognition memory

The influence of pre-experimental autobiographical knowledge on recognition memory was investigated using as memoranda faces that were either personally known or unknown to the participant. Under a dual process theory, such knowledge boosted both recollection- and familiarity-based recognition judgements. Under an unequal variance signal detection model, pre-experimental knowledge increased both the variance and the separation of the target and foil memory strength distributions, boosting hits and correct rejections. Thus, pre-experimental knowledge has profound effects on the multiple, interacting processes that subserve recognition memory, and likely in the neural systems that underpin them.     

Consciousness cannot be separated from function

Numerous theories of consciousness hold that there are separate neural correlates of conscious experience and cognitive function, aligning with the assumption that there are 'hard' and 'easy' problems of consciousness. Here, we argue that any neurobiological theory based on an experience/function division cannot be empirically confirmed or falsified and is thus outside the scope of science. A 'perfect experiment' illustrates this point, highlighting the unbreachable boundaries of the scientific study of consciousness. We describe a more nuanced notion of cognitive access that captures personal experience without positing the existence of inaccessible conscious states. Finally, we discuss the criteria necessary for forming and testing a falsifiable theory of consciousness.     

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.     

Friends with benefits: the evolved psychology of same- and opposite-sex friendship

During human evolution, men and women faced distinct adaptive problems, including pregnancy, hunting, childcare, and warfare. Due to these sex-linked adaptive problems, natural selection would have favored psychological mechanisms that oriented men and women toward forming friendships with individuals possessing characteristics valuable for solving these problems. The current study explored sex-differentiated friend preferences and the psychological design features of same- and opposite-sex friendship in two tasks. In Task 1, participants (N = 121) categorized their same-sex friends (SSFs) and opposite-sex friends (OSFs) according to the functions these friends serve in their lives. In Task 2, participants designed their ideal SSFs and OSFs using limited budgets that forced them to make trade-offs between the characteristics they desire in their friends. In Task 1, men, more than women, reported maintaining SSFs for functions related to athleticism and status enhancement and OSFs for mating opportunities. In Task 2, both sexes prioritized agreeableness and dependability in their ideal SSFs, but men prioritized physical attractiveness in their OSFs, whereas women prioritized economic resources and physical prowess. These findings suggest that friend preferences may have evolved to solve ancestrally sex-linked adaptive problems, and that opposite-sex friendship may directly or indirectly serve mating functions.     

Voice pitch influences perceptions of sexual infidelity

Sexual infidelity can be costly to members of both the extra-pair and the paired couple. Thus, detecting infidelity risk is potentially adaptive if it aids in avoiding cuckoldry or loss of parental and relationship investment. Among men, testosterone is inversely related to voice pitch, relationship and offspring investment, and is positively related to the pursuit of short-term relationships, including extra-pair sex. Among women, estrogen is positively related to voice pitch, attractiveness, and the likelihood of extra-pair involvement. Although prior work has demonstrated a positive relationship between men?s testosterone levels and infidelity, this study is the first to investigate attributions of infidelity as a function of sexual dimorphism in male and female voices. We found that men attributed high infidelity risk to feminized women?s voices, but not significantly more often than did women. Women attributed high infidelity risk to masculinized men?s voices at significantly higher rates than did men. These data suggest that voice pitch is used as an indicator of sexual strategy in addition to underlying mate value. The aforementioned attributions may be adaptive if they prevent cuckoldry and/or loss of parental and relationship investment via avoidance of partners who may be more likely to be unfaithful.     

Uncertainty is associated with biased expectancies and heightened responses to aversion

Uncertainty is an omnipresent force in peoples' lives that has been shown to amplify the negative impact of aversive events. This amplified aversiveness, together with the negative attitudes that individuals can have toward uncertainty, suggests that a cue indicating uncertainty about future events might be associated with biased expectancies of negative outcomes or biased contingency estimates, similar to biases that have been observed for traditional fear-relevant cues, such as snakes or spiders. Participants in this study saw three different cues: one that indicated with certainty that an aversive picture would follow, one that indicated with certainty that a neutral picture would follow, and one that indicated uncertainty about whether an aversive or neutral picture would follow. Online self-report data revealed negatively biased expectancies of aversion after uncertain cues. The degree of this online expectancy bias predicted participants' estimates, at the conclusion of the experiment, of the relationship between uncertain cues and aversive pictures. Aversive pictures after the uncertain cue (relative to those after the certain cue) were accompanied by increased skin conductance responses and self-reported negative mood. These findings that uncertainty is accompanied by biased expectancies of aversion and heightened responses to aversion warrant extensions of this research in anxiety disorders, given evidence for intolerance of uncertainty and anticipatory dysfunction in the pathology of such disorders.     

The effect of mathematics anxiety on the processing of numerical magnitude

In an effort to understand the origins of mathematics anxiety, we investigated the processing of symbolic magnitude by high mathematics-anxious (HMA) and low mathematics-anxious (LMA) individuals by examining their performance on two variants of the symbolic numerical comparison task. In two experiments, a numerical distance by mathematics anxiety (MA) interaction was obtained, demonstrating that the effect of numerical distance on response times was larger for HMA than for LMA individuals. These data support the claim that HMA individuals have less precise representations of numerical magnitude than their LMA peers, suggesting that MA is associated with low-level numerical deficits that compromise the development of higher level mathematical skills.