Impulsiveness and resource allocation: Testing Humphreys and Revelle’s (1984) explanation of impulsive personality

Humphreys and Revelle [Humphreys, M. S., Revelle, W. (1984). Personality, motivation and performance: A theory of the relationship between individual differences and information processing. Psychological Review, 91, 153–184] suggest that impulsive individuals have relatively greater capacity to improve performance through task-directed resource allocation. This implies that there will be a differential effect of increases in effort intensity on performance for high and low impulsive individuals. Two quasi-experiments tested this prediction using a relative-judgement task (total N = 108, 68 females), however neither revealed the predicted interaction. In light of these findings, we re-consider the Humphreys–Revelle model in relation to independent but potentially related theory and research.     

Pro Patria: An Essay on Patriotism

This essay focuses on what patriotism is, as opposed to the value of patriotism. It focuses further on the basic patriotic motive: one acts with this motive if one acts on behalf of one’s country as such. I first argue that pre-theoretically the basic patriotic motive is sufficient to make an act patriotic from a motivational point of view. In particular the agent need not ascribe virtues or achievements to his country nor need he feel towards it the emotions characteristic of love. Why should one ever act on behalf of one’s country as such, if one does not particularly admire it or feel a special affection for it? In answer to this question I offer a further articulation of the basic patriotic motive, invoking a particular understanding of what it is to be the member of a political society. Building on this articulation I then consider how one might characterize a patriotic act, a patriotic person, and the relationship of patriotism and pride.     

Neurocognitive Functioning in AD/HD,Predominantly Inattentive and Combined Subtypes

The Predominantly Inattentive (PI) and Combined (CB) subtypes of AD/HD differ in cognitive tempo, age of onset, gender ratio, and comorbidity, yet a differentiating endophenotype has not been identified. The aim of this study was to test rigorously diagnosed PI, CB, and typical children on measures selected for their potential to reveal hypothesized differences between the subtypes in specific neurocognitive systems (anterior vs. posterior attentional systems) and processes (arousal vs. activation). Thirty-four CB and 26 PI children meeting full DSM-IV criteria for subtype both in school and at home, without confounding reading disability or emotional disorder, were enrolled along with 20 typically developing children. Neurocognitive functions measured included attention, inhibitory control, working memory, learning, and executive functions. Tasks included the Stroop, Wisconsin Card Sorting Test, Continuous Performance Test (CPT). Buschke Selective Reminding Test, ad the Tower of London (TOL), as well as instruments developed by Posner and Sternberg, and tasks assessing the impact on reaction time of [corrected] varying preparatory intervals and stimulus/response complexity. After co-varying for IQ, subtypes differed primarily on measures of impulsivity during tests of vigilance (CPT) and executive function (TOL), with the CB group showing greater impulsivity than both other groups. In addition, the PI group showed worse performance than CB and control groups on the WISC-III Processing Speed Index. Whether analyzed with or without an IQ co-variate, there was no support in the data for hypothesized differences between subtypes in functioning of the anterior vs. posterior attentional systems, nor in involvement of arousal vs. activation processes. The results indicate that the PI and CB subtypes are best differentiated by ratings, observations and tests of cognitive tempo and behavioral impulsivity. Neuropsychological methods have yet to identify critical neuropsychological [corrected] substrates of these differences.     

The ontology of intentionality II: dependence ontology as prolegomenon to noetic modal semantics

This is the second in a sequence of three essays which axiomatize and apply Edmund Husserl's dependence ontology of parts and wholes as a non-Diodorean, non-Kantian temporal semantics for first-order predicate modal languages. The Ontology of Intentionality I introduced enough of Husserl's dependence-ontology of parts and wholes to formulate his account of order as effected by relating moments of unity, and The Ontology of Intentionality II extends that axiomatic dependence-ontology far enough to enable its semantic application. Formalizing the compatibility [Vereinbarkeit] relation implicated in Husserl's notorious doctrine of impossible meanings, the essay introduces a compatibility restriction on relations to formulate Husserl's distinction between singular [einheitliche] and plural [mehrheitliche] objects, using plural relating moments to define first-order versions of Husserl's notions of relation complexes (i.e. Sachverhalte), abstracta of n-ary relation complexes, categorial relations, abstract eide as unifications of categorial relations, semantic domains as completions of abstract eide, and material regions as semantic domains which are compatibility upper bounds of categorial relations. These concepts will enable the formal dependence-ontological noetic semantics for two-valued, first-order modal languages introduced in the sequel Two-Valued Logics of Intentionality, the third essay in the sequence.     

The gateway hypothesis of rostral prefrontal cortex (area 10) function

Rostral prefrontal cortex (PFC) is a large brain region, and is unusually large in humans. Therefore, it seems likely that it might support functions that are central to cognition. However, until recently, almost nothing was known about what these functions might be. The 'gateway hypothesis' places these abilities at the centre of human mental processing. It maintains that rostral PFC supports mechanisms that enable us to attend, to a novel degree, either to environmental stimuli, or by contrast, to self-generated or maintained representations (i.e. the 'thoughts in our head'). In this way, investigations into the functions of rostral PFC will reveal key new insights into how human and non-human mental abilities differ.     

Effort during visual search and counting: insights from pupillometry

We investigated the processing effort during visual search and counting tasks using a pupil dilation measure. Search difficulty was manipulated by varying the number of distractors as well as the heterogeneity of the distractors. More difficult visual search resulted in more pupil dilation than did less difficult search. These results confirm a link between effort and increased pupil dilation. The pupil dilated more during the counting task than during target-absent search, even though the displays were identical, and the two tasks were matched for reaction time. The moment-to-moment dilation pattern during search suggests little effort in the early stages, but increasingly more effort towards response, whereas the counting task involved an increased initial effort, which was sustained throughout the trial. These patterns can be interpreted in terms of the differential memory load for item locations in each task. In an additional experiment, increasing the spatial memory requirements of the search evoked a corresponding increase in pupil dilation.These results support the view that search tasks involve some, but limited, memory for item locations, and the effort associated with this memory load increases during the trials. In contrast, counting involves a heavy locational memory component from the start.     

Opposite aftereffects for Chinese and Caucasian faces are selective for social category information and not just physical face differences

Opposite changes in perception (aftereffects) can be simultaneously induced for faces from different social categories—for example, Chinese and Caucasian faces. We investigated whether these aftereffects are generated in high-level face coding that is sensitive to the social category information in faces, or in earlier visual coding sensitive to simple physical differences between faces. We caricatured the race of face stimuli and created face continua ranging from caricatured Caucasian faces (SuperCaucasian) to caricatured Chinese faces (SuperChinese). Participants were adapted to oppositely distorted faces that were a fixed physical distance apart on the morph continua. Larger opposite aftereffects were found following adaptation to faces from different race categories (e.g., contracted Chinese and expanded Caucasian faces), than for faces that were the same physical distance apart on the morph continua, but were within a race category (e.g., contracted SuperChinese and expanded Chinese faces). These results suggest that opposite aftereffects for Chinese and Caucasian faces reflect the recalibration of face neurons tuned to high-level social category information.     

You can do it if you really try: The effects of motivation on thinking for pleasure

People find it difficult to enjoy their own thoughts when asked to do so, but what happens when they are asked to think about whatever they want? Do they find thinking more or less enjoyable? In the present studies, we show that people are more successful in enjoying their thoughts when instructed to do so. We present evidence in support of four reasons why this is: without instructions people do not realize how enjoyable it will be to think for pleasure, they do not realize how personally meaningful it will be to do so, they believe that thinking for pleasure will be effortful, and they believe it would be more worthwhile to engage in planning than to try to enjoy their thoughts. We discuss the practical implications of thinking for pleasure for promoting alternatives to the use of technology.     

Just responses to problems associated with the brain drain: Identity,community, and obligation in an unjust world

In this essay, which forms part of a symposium on the brain drain, I respond to the arguments of several critics. I defend my proposals concerning how to address problems associated with high levels of skilled migration, especially in the face of concerns about identity, community and obligation in an unjust world.     

Visual feature vs. conjunction searches as a robust manipulation of perceptual load

It has previously been suggested that Lavie’s Perceptual Load Theory can be assessed using feature vs. conjunction search tasks. In this study we manipulated load using a novel paradigm which retains the key features of both classic Load Theory and Feature Integration Theory paradigms. This new paradigm has the advantage of an inbuilt manipulation check which is necessary for future research to translate Load Theory to applied contexts. Across five experiments, we demonstrate the robust nature of this paradigm, which functions with extended display times, large, complex stimuli and when conditions are intermixed on a trial-by-trial basis. We also rule out dilution as a possible cause of these results. The results of all five experiments provide evidence that the feature vs. conjunction search dichotomy is an effective means of imposing low and high perceptual load while controlling for working memory load.