The suppression model remains unsound: A reply to Deutsch

In the present issue, we critically review the influentialsuppression model of the octave illusion (Chambers, Mattingley, & Moss, 2004). In a rejoinder to our article, Deutsch (2004b) defends the utility of the suppression model. Here, we respond to Deutsch’s arguments, many of which are based on criticisms of our recent experimental report (Chambers, Mattingley, & Moss, 2002). We argue that Deutsch’s criticisms of this previous investigation are unfounded and that her defense of the suppression model fails to account for the most important weaknesses of this theory. We conclude that the suppression model remains inadequate as an explanation of the octave illusion.     

The reduction of saccadic latency by prior offset of the fixation point: an analysis of the gap effect

The latency to initiate a saccade (saccadic reaction time) to an eccentric target is reduced by extinguishing the fixation stimulus prior to the target onset. Various accounts have attributed this latency reduction (referred to as the gap effect) to facilitated sensory processing, oculomotor readiness, or attentional processes. Two experiments were performed to explore the relative contributions of these factors to the gap effect. Experiment 1 demonstrates that the reduction in saccadic reaction time (RT) produced by fixation point offset is additive with the effect of target luminance. Experiment 2 indicates that the gap effect is specific for saccades directed toward a peripheral target and does not influence saccades directed away from the target (i.e., antisaccades) or choice-manual RT. The results are consistent with an interpretation of the gap effect in terms of facilitated premotor processing in the superior colliculus.     

CONSCIOUSNESS IN EXTREMITY: DISCOURSE ON MADNESS AMONG THE TABWA OF ZAIRE

The madman makes it possible for us to grasp the radical potential of consciousness at its limits. He contradicts the other person's discursive thinking towards the virtually inarticulable or unthought self. The Lakeside Tabwa of Shaba, Zaire, apprehend madness in three rather different, discursive domains. There is, firstly, wazimu, or its ‘mature’, incurable form, kizenzezia, considered as a fact of social life. It is seen as inverting the norms or functions of personhood and undoing those of mentality. It breaks down reciprocity, it is the negative function of ‘Death’. Secondly, it is in the prodromal illness, mubulibuli, and certain related emotion states, that madness appears as the artefact of another's malicious and intrusive ‘Desire’: the madman is said to have ‘closed anger’ in his heart alienating him from ongoing experience and interaction. Finally, in the diviner, the ‘otherness’ of gaze and speech is transformed into the normative power of clairvoyance bringing about its own logic and historicity. Here, the inversion of personhood becomes an emblem of insight and ‘Law’, but at the risk of insanity. The ethnographic encounter with the very otherness of the thinking of madness and of another culture toward the unthought itself is, in a sense, epistemogenic.     

Do you remember where sounds,pictures and words came from? The role of the stimulus format in object location memory

Contrasting results in visual and auditory spatial memory stimulate the debate over the role of sensory modality and attention in identity-to-location binding. We investigated the role of sensory modality in the incidental/deliberate encoding of the location of a sequence of items. In 4 separated blocks, 88 participants memorised sequences of environmental sounds, spoken words, pictures and written words, respectively. After memorisation, participants were asked to recognise old from new items in a new sequence of stimuli. They were also asked to indicate from which side of the screen (visual stimuli) or headphone channel (sounds) the old stimuli were presented in encoding. In the first block, participants were not aware of the spatial requirement while, in blocks 2, 3 and 4 they knew that their memory for item location was going to be tested. Results show significantly lower accuracy of object location memory for the auditory stimuli (environmental sounds and spoken words) than for images (pictures and written words). Awareness of spatial requirement did not influence localisation accuracy. We conclude that: (a) object location memory is more effective for visual objects; (b) object location is implicitly associated with item identity during encoding and (c) visual supremacy in spatial memory does not depend on the automaticity of object location binding.     

McMahan on Speciesism and Deprivation

Jeff McMahan has long shown himself to be a vigorous and incisive critic of speciesism, and in his essay “Our Fellow Creatures” he has been particularly critical of speciesist arguments that draw inspiration from Wittgenstein. In this essay I consider his arguments against speciesism generally and the species‐norm account of deprivation in particular. I argue that McMahan's ethical framework (as outlined in The Ethics of Killing) is more nuanced and more open to the incorporation of speciesist intuitions regarding deprivation than he himself suggests. Specifically, I argue that, given his willingness to include a comparative dimension in his “Intrinsic Potential Account” he ought to recognize species as a legitimate comparison class. I also argue that a sensible speciesism can be pluralist and flexible enough to accommodate many of McMahan's arguments in defense of “moral individualist” intuitions. In this way, I hope to make the case for at least a partial reconciliation between McMahan and the “Wittgensteinian speciesists”, e.g. Cora Diamond, Stephen Mulhall, and Raimond Gaita.     

Postdeployment Suicide Risk Increases Over a 6‐month Period: Predictors of Increased Risk among Midwestern Army National Guard Soldiers

National Guard (NG) soldiers returning from deployments in Iraq and Afghanistan were surveyed at 6 and 12 months following their return (N = 970). The overall prevalence of suicide risk at 6 and 12 months following their return was assessed, as were changes in suicide risk among soldiers initially at high or low risk. Factors associated with changes in risk were assessed. The percentage of NG soldiers with high suicide risk increased from 6.8% at 6 months to 9.2% at 12 months (odds ratio = 1.7, p = .02). In the 882 soldiers initially at low risk, 5.9% (52/882) became high risk at 12 months; in the 64 soldiers initially at high risk, 46.9% (30/64) became low risk at 12 months. Initial levels of depressive symptoms were predictive of changing to high risk; this association appeared to be partially explained by soldier reports of increased search in the meaning in life and higher levels of perceived stress. Because suicide risk increases over the first 12 months, continued risk assessments during this time period should be considered. Supporting soldiers to find meaning in their life after deployment and enhancing their capacity to cope with perceived stress may help prevent increases in suicide risk over time.     

Failures of cognitive control or attention? The case of stop-signal deficits in schizophrenia

We used Bayesian cognitive modelling to identify the underlying causes of apparent inhibitory deficits in the stop-signal paradigm. The analysis was applied to stop-signal data reported by Badcock et al. (Psychological Medicine 32: 87-297, 2002) and Hughes et al. (Biological Psychology 89: 220-231, 2012), where schizophrenia patients and control participants made rapid choice responses, but on some trials were signalled to stop their ongoing response. Previous research has assumed an inhibitory deficit in schizophrenia, because estimates of the mean time taken to react to the stop signal are longer in patients than controls. We showed that these longer estimates are partly due to failing to react to the stop signal (“trigger failures”) and partly due to a slower initiation of inhibition, implicating a failure of attention rather than a deficit in the inhibitory process itself. Correlations between the probability of trigger failures and event-related potentials reported by Hughes et al. are interpreted as supporting the attentional account of inhibitory deficits. Our results, and those of Matzke et al. (2016), who report that controls also display a substantial although lower trigger-failure rate, indicate that attentional factors need to be taken into account when interpreting results from the stop-signal paradigm.     

Religion,Altruism, and Helping Strangers: A Multilevel Analysis of 126 Countries

This article tests how religion relates to helping strangers, an important but rarely studied measure of social solidarity and informal social capital. It uses the Gallup World Poll, a survey with nationally representative samples of 179,961 respondents from 126 countries. It finds that religious people, members of minority religions, and people in religiously diverse countries were more likely to help a stranger. Individuals living in devout countries were more likely to help strangers even if they themselves were not religious. The results suggest that religion plays a particularly important role in promoting the prosocial norms and values that motivate helping strangers.     

A Semantics for Means-end Relations

There has been considerable work on practical reasoning in artificial intelligence and also in philosophy. Typically, such reasoning includes premises regarding means–end relations. A clear semantics for such relations is needed in order to evaluate proposed syllogisms. In this paper, we provide a formal semantics for means–end relations, in particular for necessary and sufficient means–end relations. Our semantics includes a non-monotonic conditional operator, so that related practical reasoning is naturally defeasible. This work is primarily an exercise in conceptual analysis, aimed at clarifying and eventually evaluating existing theories of practical reasoning (pending a similar analysis regarding desires, intentions and other relevant concepts). “They were in conversation without speaking. They didn’t need to speak. They just changed reality so that they had spoken.” Terry Pratchett, Reaper Man     

Beliefs about personality change and continuity

Lay conceptions of personality change and continuity were examined in a sample of 112 undergraduates. Participants rated their personal change over 5 years (past or future), the change they perceived to be normative over 10-year age spans between 15 and 65, their beliefs about whether personality is fixed or malleable (“lay theories”) and their beliefs about the causes of personality change and continuity. Beliefs about normative personality change generally corresponded to research evidence on adult trajectories of the Big Five factors, with some age bias, whereas recalled and anticipated personal change tended to be more positive than these norms. Participants tended to endorse environmental causes more for personality change than for continuity. Lay theories were not consistently associated with these causal beliefs, or with beliefs about personal and normative change.