Dissociable stages of problem solving (II): first evidence for process-contingent temporal order of activation in dorsolateral prefrontal cortex

In a companion study, eye-movement analyses in the Tower of London task (TOL) revealed independent indicators of functionally separable cognitive processes during problem solving, with processes of building up an internal representation of the problem preceding actual planning processes. These results imply that processes of internalization and planning should also be distinguishable in time and space with respect to concomitant brain activation patterns. To investigate this possibility, here we conducted analyses of fMRI data for left and right dorsolateral prefrontal cortex (dlPFC) during problem solving in the TOL task by accounting for the trial-by-trial variability of onsets and durations of the different cognitive processing stages. Comparisons between stimulus-locked and response-locked modeling approaches affirmed that activation in left dlPFC was elicited particularly during early processes of internalization, comprising the extraction of goal information and the generation of an internal problem representation, whereas activation in right dlPFC was predominantly attributable to later processes of mental transformations on this representation, that is planning proper. Thus, present data corroborate the proposal that often observed bilateral dlPFC activation patterns during complex cognitive tasks such as problem solving may reflect functionally and, to some extent, even temporally separable processes with opposing lateralizations.     

Dissociable stages of problem solving (I): temporal characteristics revealed by eye-movement analyses

Understanding the functional neuroanatomy of planning and problem solving may substantially benefit from better insight into the chronology of the cognitive processes involved. Based on the assumption that regularities in cognitive processing are reflected in overtly observable eye-movement patterns, here we recorded eye movements while participants worked on Tower of London (TOL) problems that comprised an experimental manipulation of different task demands. Single-trial saccade-locked analyses revealed that higher demands on forming an internal problem representation were associated with an increased number of gaze alternations between start state and goal state, but did not show any effect on the durations of these inspections of the states. In contrast, higher demands on actual planning in terms of mental manipulations of working memory contents coincided with a prolonged duration of the very last inspection of the start state (i.e., immediately preceding movement execution) but did not show any effect on the number of gaze alterations. Differential task demands on internalization and planning processes during problem solving hence selectively affect different eye-movement parameters. Moreover, these findings complement previous neuroimaging data on dissociable contributions of left and right dorsolateral prefrontal cortex in problem solving with novel evidence for a corresponding dissociation in the eye-movement patterns reflecting the associated cognitive processes.     

Gaze behaviour during space perception and spatial decision making

A series of four experiments investigating gaze behavior and decision making in the context of wayfinding is reported. Participants were presented with screenshots of choice points taken in large virtual environments. Each screenshot depicted alternative path options. In Experiment 1, participants had to decide between them to find an object hidden in the environment. In Experiment 2, participants were first informed about which path option to take as if following a guided route. Subsequently, they were presented with the same images in random order and had to indicate which path option they chose during initial exposure. In Experiment 1, we demonstrate (1) that participants have a tendency to choose the path option that featured the longer line of sight, and (2) a robust gaze bias towards the eventually chosen path option. In Experiment 2, systematic differences in gaze behavior towards the alternative path options between encoding and decoding were observed. Based on data from Experiments 1 and 2 and two control experiments ensuring that fixation patterns were specific to the spatial tasks, we develop a tentative model of gaze behavior during wayfinding decision making suggesting that particular attention was paid to image areas depicting changes in the local geometry of the environments such as corners, openings, and occlusions. Together, the results suggest that gaze during a wayfinding tasks is directed toward, and can be predicted by, a subset of environmental features and that gaze bias effects are a general phenomenon of visual decision making.     

Age and gender differences in morningness-eveningness during adolescence

Morningness-eveningness was assessed in a large sample of adolescents and young adults. Morningness decreased from 12 to 15 years, and then remained on a stable level until about 20 years, when a turn back to morningness occurred. Boys and men were on average more evening-oriented than were girls and women. In detail, significant differences existed at the ages of 16, 18, and 19 years. A quadratic function explained more variance than a linear regression. Composite Scale of Morningness scores are related to puberty scores in boys and girls, and when combining data (i.e., higher pubertal development was related to eveningness).     

Do procedures for verbal reporting of thinking have to be reactive? A meta-analysis and recommendations for best reporting methods

Since its establishment, psychology has struggled to find valid methods for studying thoughts and subjective experiences. Thirty years ago, Ericsson and Simon (1980) proposed that participants can give concurrent verbal expression to their thoughts (think aloud) while completing tasks without changing objectively measurable performance (accuracy). In contrast, directed requests for concurrent verbal reports, such as explanations or directions to describe particular kinds of information, were predicted to change thought processes as a consequence of the need to generate this information, thus altering performance. By comparing performance of concurrent verbal reporting conditions with their matching silent control condition, Ericsson and Simon found several studies demonstrating that directed verbalization was associated with changes in performance. In contrast, the lack of effects of thinking aloud was merely suggested by a handful of experimental studies. In this article, Ericsson and Simon's model is tested by a meta-analysis of 94 studies comparing performance while giving concurrent verbalizations to a matching condition without verbalization. Findings based on nearly 3,500 participants show that the "think-aloud" effect size is indistinguishable from zero (r = -.03) and that this procedure remains nonreactive even after statistically controlling additional factors such as task type (primarily visual or nonvisual). In contrast, procedures that entail describing or explaining thoughts and actions are significantly reactive, leading to higher performance than silent control conditions. All verbal reporting procedures tend to increase times to complete tasks. These results suggest that think-aloud should be distinguished from other methods in future studies. Theoretical and practical implications are discussed.     

A problem for contrastivist accounts of knowledge

This paper raises a problem for contrastivist accounts of knowledge. It is argued that contrastivism fails to succeed in providing a modest solution to the sceptical paradox—i.e. one according to which we have knowledge of a wide range of ordinary empirical propositions whilst failing to know the various anti-sceptical hypotheses entailed by them—whilst, at the same time, retaining a contrastivist version of the closure principle for knowledge.     

Violent, nonviolent, and substance-related offending over the life course in a cohort of males and females treated for substance misuse as youths

Most studies on adolescent offending heterogeneity are based on general population samples, and few include individuals with substance misuse or look specifically at substance-related offending. It is also unclear how offender subtypes develop after young adulthood or how offending heterogeneity varies between genders. This study aimed to identify subgroups of offending among adolescents with misuse problems and to examine associations with offending in adulthood. The study included 1,992 females and males that consulted a clinic for adolescents with misuse problems between 1968 and 1971. Latent Class Analyses were conducted to identify subgroups based on violent and nonviolent offending before age 20. Participants were then followed until age 50 and reexamined regarding violent, nonviolent, and substance-related crimes. Associations between subgroups before age 20 and subgroups age 21-50 were examined. Before age 20, three subgroups were identified among the females and six among the males. Males were more specialized in their offending and demonstrated higher levels of offending. Results pointed to both stability and decrease of violent and nonviolent offending, and to the emergence of substance-related offending in adulthood in both genders. The connection between substance-related crimes and general delinquency in adulthood among individuals treated for substance misuse suggests that interventions should also address substance misuse for reducing the overall volume of crime. This study also highlights the importance of including females in research on offending heterogeneity.     

Individuals differ in the attentional blink: Mental speed and intra-subject stability matter

The failure to correctly report two targets (“T₁”, “T₂”) that follow each other in close temporal proximity has been called the “attentional blink” (AB). The AB has, so far, mainly been studied using experimental approaches. The present studies investigated individual differences in AB performance, revealing (among further findings) a high positive correlation between the accuracies of detecting the two targets correctly (r = 0.69); and between T₂∣T₁ accuracy and psychometric intelligence (0.41 ≤ r ≤ 0.43) and RT variability in short-term and working memory (− 0.38 ≤ r ≤ − 0.45). Together, these results support important aspects of major theoretical accounts of the AB from an individual differences perspective and introduce intelligence and intra-subject stability as contributing factors in AB performance.     

Defeat and proficiencies

Virtue epistemology is the view that beliefs are attempts at truth (or perhaps knowledge) and, as a result, can be assessed as successful, competent, and apt. Moreover, virtue epistemology identifies central epistemic properties with normative properties of beliefs as attempts. In particular, knowledge is apt belief and justified belief is competent belief. This paper develops a systematic virtue epistemological account of defeat (of justification/competence). I provide reason to think that defeat occurs not only for beliefs but for attempts more general. The key constructive idea is that defeaters are evidence that attempting (in a certain way) isn't successful and that defeaters defeat the competence of an attempt when one stands in a certain normative relation to the defeater. I argue that while this account handles paradigm cases of defeat both within epistemology and beyond nicely, cases of external (sometimes also ‘normative’ or ‘propositional’) defeat continue to cause trouble. To handle these cases, I develop a distinctively functionalist version of virtue epistemology. This functionalist version of virtue epistemology allows me to countenance proficiencies, that is, roughly, abilities that have the function to produce successes under certain conditions. It is the normative import of proficiencies that delivers the normative relation that serves to explain defeat in cases of external defeat. In this way, the functionalist version of virtue epistemology ushers the way towards a satisfactory account even of external defeat.