Cells,circuits, and choices: Social influences on perceptual decision making

Making decisions is an integral part of everyday life. Social psychologists have demonstrated in many studies that humans’ decisions are frequently and strongly influenced by the opinions of others—even in simple perceptual decisions, where, for example, participants have to judge what an image looks like. However, because the effect of other people’s opinions on decision making has remained largely unaddressed by the neuroimaging and neurophysiology literature, we are only beginning to understand how social influence is integrated into the decision-making process. We put forward the thesis that by probing the neurophysiology of social influence with perceptual decisionmaking tasks similar to those used in the seminal work of Asch (1952, 1956), this gap could be remedied. Perceptual paradigms are already widely used to probe neuronal mechanisms of decision making in nonhuman primates. There is also increasing evidence about how nonhuman primates’ behavior is influenced by observing conspecifics. The high spatial and temporal resolution of neurophysiological recordings in awake monkeys could provide insight into where and how social influence modulates decision making, and thus should enable us to develop detailed functional models of the neural mechanisms that support the integration of social influence into the decision-making process.     

A logic of intention and attempt

We present a modal logic called (logic of intention and attempt) in which we can reason about intention dynamics and intentional action execution. By exploiting the expressive power of , we provide a formal analysis of the relation between intention and action and highlight the pivotal role of attempt in action execution. Besides, we deal with the problems of instrumental reasoning and intention persistence.     

Equality of Education and Citizenship: Challenges of European Integration

What kind of equality among Europeans does equal citizenship require, especially regarding education? In particular, is there good reason to insist of equality of education among Europeans—and if so, equality of what? To what extent should the same knowledge base and citizenship norms be taught across state borders and religious and other normative divides? At least three philosophical issues merit attention: (a) The requirements of multiple democratic citizenships beyond the nation state; (b) how to respect diversity while securing such equality and inculcating commitments to justice and norms of citizenship, and (c) The multiple reasons for equality of various kinds among political equals living in a Union as compared to a unitary state. The article responds on the basis of several arguments in favour of certain kinds of equality. All Union citizens must enjoy a high minimum level of education, and all pupils must be informed concerning the various ways of life prevalent in Europe. Furthermore, there must be standards for securing equality of opportunity across the EU, though it is difficult to measure under multiculturalism. Citizens must also be socialised to certain ‘citizenship norms’. This shared basis to be taught in schools should avoid contested religious or philosophical premises as far as possible. Yet the school system should socialise pupils to three commitments: to the just domestic and European institutions and hence the legislation they engender, to principles that justify these institutions; and to a political theory that grounds these principles in a conception of the proper role of individuals, of member states and of the Union. I also argue that equality of result is not a plausible normative requirement among Europeans, while equality of opportunity is. The paper concludes with some comments on the lessons to be drawn for ‘Global’ citizenship.     

Effects of race on responses and response latencies in the weapon identification task: a test of six models

The authors consider six models of underlying process in the weapon identification task: The first two are response-time extensions of signal detection models; the last four, of the process dissociation model. Predictions for accuracy data, correct response latencies, and false response latencies are used to discriminate between models. In the present study, racial bias in responses and correct response latency was replicated. New findings were that the direction of bias was reversed in error latency and that errors were faster than correct responses. These findings rule out four models, in particular, the idea that race biases early perception and interpretation of targets. Implications for reducing errors in the weapon identification task and possibilities of discriminating between the remaining two models are discussed.     

Predictive coding explains binocular rivalry: an epistemological review

Binocular rivalry occurs when the eyes are presented with different stimuli and subjective perception alternates between them. Though recent years have seen a number of models of this phenomenon, the mechanisms behind binocular rivalry are still debated and we still lack a principled understanding of why a cognitive system such as the brain should exhibit this striking kind of behaviour. Furthermore, psychophysical and neurophysiological (single cell and imaging) studies of rivalry are not unequivocal and have proven difficult to reconcile within one framework. This review takes an epistemological approach to rivalry that considers the brain as engaged in probabilistic unconscious perceptual inference about the causes of its sensory input. We describe a simple empirical Bayesian framework, implemented with predictive coding, which seems capable of explaining binocular rivalry and reconciling many findings. The core of the explanation is that selection of one stimulus, and subsequent alternation between stimuli in rivalry occur when: (i) there is no single model or hypothesis about the causes in the environment that enjoys both high likelihood and high prior probability and (ii) when one stimulus dominates, the bottom-up, driving signal for that stimulus is explained away while, crucially, the bottom-up signal for the suppressed stimulus is not, and remains as an unexplained but explainable prediction error signal. This induces instability in perceptual dynamics that can give rise to perceptual transitions or alternations during rivalry.     

Social presence effects on the stroop task: Boundary conditions and an alternative account

Two studies investigated boundary conditions of an effect of social presence on the Stroop task and its interpretation in terms of an attentional view (P. Huguet, M. P. Galvaing, J. M. Monteil, & F. Dumas, 1999). In this view, social presence leads to attentional focusing, enhancing participants’ ability to screen out the distracting features of Stroop stimuli. As predicted, Stroop interference was found to be reduced by social presence, but an alternative account in which social presence exerts an effect on task selection received more support.     

Selective exposure and decision framing: The impact of gain and loss framing on confirmatory information search after decisions

When people make decisions, they often prefer to receive information that supports rather than conflicts with their decision. To date, this effect has mainly been investigated in the context of decisions about gains, whereas decisions about losses have received less attention. Based on Prospect Theory, we expected information search to be differently affected by whether people previously have decided about gains or losses. Three studies have revealed that selectivity of information search is stronger after gain-framed rather than after loss-framed decision problems. An investigation of the underlying psychological processes revealed that gain decisions are made with increased subjective decision certainty (i.e. they are easier and less effortful to make), which in turn systematically increases confirmatory information search.     

Testing the race inequality: A simple correction procedure for fast guesses

In speeded response tasks with redundant signals, parallel processing of the redundant signals is generally tested using the so-called race inequality. The race inequality states that the distribution of fast responses for a redundant stimulus never exceeds the summed distributions of fast responses for the single stimuli. It has been pointed out that fast guesses (e.g. anticipatory responses) interfere with this test, and a correction procedure (‘kill-the-twin’ procedure) has been suggested. In this note we formally derive this procedure and extend it to the case in which redundant stimuli are presented with onset asynchrony. We demonstrate how the kill-the-twin procedure is used in a statistical test of the race model prediction.     

Great apes' (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) understanding of tool functional properties after limited experience

Primates' understanding of tool functionality has been investigated extensively using a paradigm in which subjects are presented with a tool that they must use to obtain an out-of-reach reward. After being given experience on an initial problem, monkeys can transfer their skill to tools of different shapes while ignoring irrelevant tool changes (e.g., color). In contrast, monkeys without initial training perform poorly on the same tasks. Compared to most monkeys, great apes show a clear propensity for tool using and may not require as much experience to succeed on tool functionality tasks. We investigated this question by presenting 171 apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, and Pongo pygmaeus) with several tool-use problems without giving them initial training or familiarizing them with the test materials. Apes succeeded without experience, but only on problems based on basic properties such as the reward being supported by an object. However, only minimal experience was sufficient to allow them to quickly improve their performance on more complex problems in which the reward was not in contact with the tool.