Why do animals differ in their susceptibility to geometrical illusions?

In humans, geometrical illusions are thought to reflect mechanisms that are usually helpful for seeing the world in a predictable manner. These mechanisms deceive us given the right set of circumstances, correcting visual input where a correction is not necessary. Investigations of non-human animals’ susceptibility to geometrical illusions have yielded contradictory results, suggesting that the underlying mechanisms with which animals see the world may differ across species. In this review, we first collate studies showing that different species are susceptible to specific illusions in the same or reverse direction as humans. Based on a careful assessment of these findings, we then propose several ecological and anatomical factors that may affect how a species perceives illusory stimuli. We also consider the usefulness of this information for determining whether sight in different species might be more similar to human sight, being influenced by contextual information, or to how machines process and transmit information as programmed. Future testing in animals could provide new theoretical insights by focusing on establishing dissociations between stimuli that may or may not alter perception in a particular species. This information could improve our understanding of the mechanisms behind illusions, but also provide insight into how sight is subjectively experienced by different animals, and the degree to which vision is innate versus acquired, which is difficult to examine in humans.     

Liberalism,Autonomy and Conjugal Love

Res Publica - This paper argues that a liberal state is justified in promoting relationships of conjugal love – the form of relationship that is the basis of the institution of marriage...     

Working memory load differentially affects tip-of-the-tongue states and feeling-of-knowing judgments

Tip-of-the-tongue states (TOTs) are judgments of the likelihood of imminent retrieval for items currently not recalled, whereas feeling-of-knowing judgments (FOKs) are predictions of successful recognition for items not recalled. The assumption has been that similar metacognitive processes dictate these similar judgments. In Experiment 1, TOTs and FOKs were compared for general information questions. Participants remembered four digits (working memory load) during target retrieval for half of the questions, and there was no memory load for the other questions. Working memory did not affect recall but decreased the number of TOTs and increased FOKs. In Experiment 2, participants maintained six digits during retrieval. TOTs decreased in the working memory condition, but FOKs remained constant. Experiment 3 replicated the results of Experiment 2 while asking for FOKs for recall. In each of the first three experiments, positive metacognitive judgments also affected working memory performance, supporting the idea that working memory and metamemory use similar monitoring processes. In Experiment 4, visual working memory did not affect TOTs or FOKs. The data support a view that TOTs and FOKs are separable metacognitive entities.     

Implicit learning of predictive relationships in three-element visual sequences by young and old adults

Knowledge of sequential relationships enables future events to be anticipated and processed efficiently. Research with the serial reaction time task (SRTT) has shown that sequence learning often occurs implicitly without effort or awareness. Here, the authors report 4 experiments that use a triplet-learning task (TLT) to investigate sequence learning in young and older adults. In the TLT, people respond only to the last target event in a series of discrete, 3-event sequences or triplets. Target predictability is manipulated by varying the triplet frequency (joint probability) and/or the statistical relationships (conditional probabilities) among events within the triplets. Results reveal that both groups learned, though older adults showed less learning of both joint and conditional probabilities. Young people used the statistical information in both cues, but older adults relied primarily on information in the 2nd cue alone. The authors conclude that the TLT complements and extends the SRTT and other tasks by offering flexibility in the kinds of sequential statistical regularities that may be studied as well as by controlling event timing and eliminating motor response sequencing.     

Psychological Factors Associated with Emotional Responses to Receiving Genetic Risk Information

This study identified levels of distress, and predictors of levels of distress, in women undergoing assessment for genetic risk of breast/ovarian cancer based on their family history. It comprised a cohort study following 154 women who completed questionnaires at entry into a cancer genetic assessment programme and following risk provision. Independent significant associates of anxiety following risk provision were age, neuroticism, feeling hopeless about developing cancer, a perceived lack of control over developing cancer, lack of a social confidant, and a coping response involving acceptance/resignation. Depression was associated with age, neuroticism, feeling hopeless about developing cancer, lack of social confidant, and a coping response involving acceptance/resignation. To avoid high levels of psychological morbidity in future cohorts undergoing cancer genetic risk assessment, information should be given that emphasises that some degree of control over health outcomes through behaviour change or increased surveillance is possible.     

Vital exhaustion and cardiovascular disease: are circulating fibrinogen and D-dimer levels a plausible link?

Vital exhaustion has been implicated in the development and progression of cardiovascular disease. In addition, elevated levels of fibrinogen and D-dimer have been associated with an increased risk of cardiovascular disease. Some studies have suggested that fibrinogen and D-dimer are associated with acute, chronic, and perceived stress. In this issue, Kudielka et al examine the relationship between circulating fibrinogen and D-dimer levels and vital exhaustion in a cross-sectional study of middle-aged teachers in Germany, to examine the plausible link between chronic stress and the development of cardiovascular disease. This commentary discusses the limited available evidence of the mechanisms responsible for the association between vital exhaustion and the development of cardiovascular disease and highlights the limitations of previous research and discusses future directions.     

Knowledge and Expectations of Women Undergoing Cancer Genetic Risk Assessment: A Qualitative Analysis of Free-Text Questionnaire Comments

Individuals undergoing cancer genetic risk assessment have been found to have a poor understanding of the process, which may affect how well they cope with learning their risk. This paper reports free-text data from questionnaires completed by women undergoing a randomised controlled trial of a psychological intervention. Of the 268 women undergoing genetic assessment for familial breast/ovarian cancer risk who were invited to take part in the trial, 157 women returned research questionnaires. Of these, 97 women provided free-text comments upon referral to a cancer genetics clinic, 62 provided comments whilst waiting for risk information (average, moderate or high), and 36 women provided comments following notification of risk. This paper reports a thematic analysis of the free-text data. Themes reflected individuals’ poor knowledge and uncertainty about genetic risk assessment. How well individuals responded to learning their risk depended upon whether expectations had been met. Regardless of risk, individuals undergoing cancer genetic risk assessment are likely to benefit from increased information about its process and timescales, and access to increased psychological support. Free-text comments can provide valuable data about individuals’ expectations and knowledge of genetics services.