Detection of bilateral symmetry in complex biological images

The recognition of bilateral symmetry in simple dot patterns is reliably influenced by orientation. Performance is best when the axis of symmetry is vertical. We conducted two experiments to determine whether stimulus orientation also affects detection of the low levels of naturally occurring asymmetry in complex biological images. University students judged whether colour images displayed on a computer monitor possessed perfect bilateral symmetry. Stimuli were generated from high-resolution plan-view images of crabs and insects. In experiment 1, the asymmetric stimuli were the original animals, displayed on a standard black background. Symmetrical versions of each natural image were generated by sectioning the shape at the midline, copying and reflecting one side and then fusing the two halves together. To facilitate comparison of results with those obtained in earlier studies, we also presented dot patterns based upon both the slightly asymmetric and perfectly symmetrical natural images. Experiment 2 was designed to assess whether symmetry detection was dependent upon the markings and patterns on the body and appendages of the animals. The natural images were converted to silhouettes and tested against matched dot patterns. In both studies, images were presented in a random sequence with the axis of symmetry vertical, horizontal, oblique left, and oblique right. Performance with the biological images was consistently better than with the dot patterns. Abolishing fine detail did not appreciably reduce this effect. A pronounced vertical advantage was apparent with all stimuli, demonstrating that this phenomenon is robust despite considerable variation in image complexity. The implications of orientation effects for perception of natural structures are discussed.     

A titration schedule on a treadmill

A technique is presented utilizing a titration schedule to measure performance decrement as a function of continuing heavy muscular exertion. A treadmill is equipped with a reversible motor controlling the velocity control of the treadmill itself. This provides a constant acceleration of the treadmill unless a subject-controlled, spring loaded switch is depressed. If this switch is depressed, the treadmill decelerates at a constant rate. A subject is instructed to walk at maximum rate at all times, controlling the velocity of the treadmill with the switch. A performance record is obtained from a tachometer-generator on the treadmill delivering current to a recorder.     

Conditional desirability: comments on Richard Bradley’s decision theory with a human face

Synthese - Richard Bradley’s landmark book Decision Theory with a Human Face makes seminal contributions to nearly every major area of decision theory, as well as most areas of formal...     

Callous-unemotional traits and empathy deficits: Mediating effects of affective perspective-taking and facial emotion recognition

Although empathy deficits are thought to be associated with callous-unemotional (CU) traits, findings remain equivocal and little is known about what specific abilities may underlie these purported deficits. Affective perspective-taking (APT) and facial emotion recognition may be implicated, given their independent associations with both empathy and CU traits. The current study examined how CU traits relate to cognitive and affective empathy and whether APT and facial emotion recognition mediate these relations. Participants were 103 adolescents (70 males) aged 16–18 attending a residential programme. CU traits were negatively associated with cognitive and affective empathy to a similar degree. The association between CU traits and affective empathy was partially mediated by APT. Results suggest that assessing mechanisms that may underlie empathic deficits, such as perspective-taking, may be important for youth with CU traits and may inform targets of intervention.     

Investigating Predictors of Superior Face Recognition Ability in Police Super‐recognisers

There are large individual differences in the ability to recognise faces. Super‐recognisers are exceptionally good at face memory tasks. In London, a small specialist pool of police officers (also labelled ‘super‐recognisers’ by the Metropolitan Police Service) annually makes 1000's of suspect identifications from closed‐circuit television footage. Some suspects are disguised, have not been encountered recently or are depicted in poor quality images. Across tests measuring familiar face recognition, unfamiliar face memory and unfamiliar face matching, the accuracy of members of this specialist police pool was approximately equal to a group of non‐police super‐recognisers. Both groups were more accurate than matched control members of the public. No reliable relationships were found between the face processing tests and object recognition. Within each group, however, there were large performance variations across tests, and this research has implications for the deployment of police worldwide in operations requiring officers with superior face processing ability. Copyright © 2016 John Wiley & Sons, Ltd.     

Culturally Imposed Trauma: The Sleeping Dog Has Awakened. Will Psychoanalysis Take Heed?

This paper considers the scant attention psychoanalysis gives to cultural trauma. Three contributions to this deficiency are considered: (a) the continuing identification with our psychoanalytic forefathers’ silence regarding cultural trauma, (b) the authoritarian practices in psychoanalytic institutions that keep us overly focused on standard intrapsychic formulations to the near exclusion of cultural trauma, and (c) the fact that work with cultural trauma is difficult. To do this work requires us to “buck the system.” If we do so, we expose ourselves to toxic phenomena in a world still rife with cultural trauma. This paper, which includes clinical vignettes, is an invitation to do so.