Blur detection is unaffected by cognitive load

Blur detection is affected by retinal eccentricity, but is it also affected by attentional resources? Research showing effects of selective attention on acuity and contrast sensitivity suggests that allocating attention should increase blur detection. However, research showing that blur affects selection of saccade targets suggests that blur detection may be pre-attentive. To investigate this question, we carried out experiments in which viewers detected blur in real-world scenes under varying levels of cognitive load manipulated by the N-back task. We used adaptive threshold estimation to measure blur detection thresholds at 0°, 3°, 6°, and 9° eccentricity. Participants carried out blur detection as a single task, a single task with to-be-ignored letters, or an N-back task with four levels of cognitive load (0, 1, 2, or 3-back). In Experiment 1, blur was presented gaze-contingently for occasional single eye fixations while participants viewed scenes in preparation for an easy picture recognition memory task, and the N-back stimuli were presented auditorily. The results for three participants showed a large effect of retinal eccentricity on blur thresholds, significant effects of N-back level on N-back performance, scene recognition memory, and gaze dispersion, but no effect of N-back level on blur thresholds. In Experiment 2, we replicated Experiment 1 but presented the images tachistoscopically for 200 ms (half with, half without blur), to determine whether gaze-contingent blur presentation in Experiment 1 had produced attentional capture by blur onset during a fixation, thus eliminating any effect of cognitive load on blur detection. The results with three new participants replicated those of Experiment 1, indicating that the use of gaze-contingent blur presentation could not explain the lack of effect of cognitive load on blur detection. Thus, apparently blur detection in real-world scene images is unaffected by attentional resources, as manipulated by the cognitive load produced by the N-back task.     

Conflict detection,dual processes,and logical intuitions: Some clarifications

Recent studies on conflict detection during thinking suggest that reasoners are sensitive to possible conflict between their heuristic judgement and elementary logical or probabilistic principles. I have argued that this conflict sensitivity calls for the postulation of logical intuitions and has implications for the way we conceive the interaction between System-1 and System-2 in dual process theories. In this paper I clarify potential misconceptions about this work, discuss the link with other approaches, and sketch directions for further research.     

Metacognitive sensitivity of subjective reports of decisional confidence and visual experience

Previous studies provided contradicting results regarding metacognitive sensitivity estimated from subjective reports of confidence in comparison to subjective reports of visual experience. We investigated whether this effect of content of subjective reports is influenced by the statistical method to quantify metacognitive sensitivity. Comparing logistic regression and meta-d in a masked orientation task, a masked shape task, and a random-dot motion task, we observed metacognitive sensitivity of reports regarding decisional confidence was greater than of reports about visual experience irrespective of mathematical procedures. However, the relationship between subjective reports and the logistic transform of accuracy was often not linear, implying that logistic regression is not a consistent measure of metacognitive sensitivity. We argue that a science of consciousness would benefit from the assessment of both visual experience and decisional confidence, and recommend meta-d as measure of metacognitive sensitivity for future studies.     

Nonspatial attentional capture by previously rewarded scene semantics

Recent research has shown that reward influences visual perception and cognition in a way that is distinct from the well-documented goal-directed mechanisms. In the current study we explored how task-irrelevant stimulus-reward associations affect processing of stimuli when attention is constrained and reward no longer delivered. During a training phase, participants performed a choice game, exposing them to different reward schedules for different semantic categories of natural scene pictures. In a separate test session in which no additional reward was provided, the differentially rewarded scene categories were used as task-irrelevant non-targets in a rapid serial visual presentation (RSVP) task. Participants performed a detection task on a previously non-rewarded target category. Results show that participants' sensitivity index (d′) for target detection decreased as a function of whether the reward was coupled to the distractor category during training. The semantic category of natural scenes associated with high reward caused more interference in target detection than the semantic category associated with a low reward. The same was found when new, unseen distractor pictures of the same semantic categories were used. The present findings suggest that reward can be selectively associated with high level scene semantics. We argue that learned stimulus-reward associations persistently bias perceptual processing independently of spatial shifts in attention and the immediate prospect of reward.     

Invisible Stimuli,Implicit Thresholds: Why Invisibility Judgments Cannot be Interpreted in Isolation

Some studies of unconscious cognition rely on judgments of participants stating that they have “not seen” the critical stimulus (e.g., in a masked-priming experiment). Trials in which participants gave invisibility judgments are then treated as those where the critical stimulus was “subliminal” or “unconscious,” as opposed to trials with higher visibility ratings. Sometimes, only these trials are further analyzed, for instance, for unconscious priming effects. Here I argue that this practice requires implicit assumptions about subjective measures of awareness incompatible with basic models of categorization under uncertainty (e.g., modern signal-detection and threshold theories). Most importantly, it ignores the potential effects of response bias. Instead of taking invisibility judgments literally, they would better be employed in parametric experiments where stimulus visibility is manipulated systematically, not accidentally. This would allow studying qualitative and double dissociations between measures of awareness and of stimulus processing per se.     

Experience with dynamic reinforcement rates decreases resistance to extinction

The ability of organisms to detect reinforcer‐rate changes in choice preparations is positively related to two factors: the magnitude of the change in rate and the frequency with which rates change. Gallistel (2012) suggested similar rate‐detection processes are responsible for decreases in responding during operant extinction. Although effects of magnitude of change in reinforcer rate on resistance to extinction are well known (e.g., the partial‐reinforcement‐extinction effect), effects of frequency of changes in rate prior to extinction are unknown. Thus, the present experiments examined whether frequency of changes in baseline reinforcer rates impacts resistance to extinction. Pigeons pecked keys for variable‐interval food under conditions where reinforcer rates were stable and where they changed within and between sessions. Overall reinforcer rates between conditions were controlled. In Experiment 1, resistance to extinction was lower following exposure to dynamic reinforcement schedules than to static schedules. Experiment 2 showed that resistance to presession feeding, a disruptor that should not involve change‐detection processes, was unaffected by baseline‐schedule dynamics. These findings are consistent with the suggestion that change detection contributes to extinction. We discuss implications of change‐detection processes for extinction of simple and discriminated operant behavior and relate these processes to the behavioral‐momentum based approach to understanding extinction.     

Social-class indicators differentially predict engagement in prevention vs. detection behaviours

Objective: Few systematic studies have examined the contexts in which social-class variables will predict engagement in health-relevant behaviours. The current research examined whether the impact of social-class on health behaviours depends upon how social-class is assessed and the category of health behaviour under consideration.

Method: Our sample was drawn from the Health Information National Trends Survey in 2012 (N = 3959). Participants reported their income and education as well as their engagement in a variety of prevention and detection behaviours.

Results: Consistent with our hypothesised framework, we found that income predicted engagement in a variety of detection behaviours above and beyond education, whereas education predicted engagement in a variety of prevention behaviours above and beyond income.

Conclusions: Our findings suggest that income and education operate on health behaviours via different pathways and have implications for public health policy and intervention.     

Conflict detection during moral decision-making: evidence for deontic reasoners’ utilitarian sensitivity

Moral dilemmas often force us to decide between deontological (harming others is wrong) and utilitarian (harming others can be acceptable depending on the consequences) considerations. Cognitive scientists have shown that utilitarian responders typically engage demanding deliberate thinking to override a conflicting intuitive deontological response. A key question is whether deontic responders also take utilitarian considerations into account and detect that there are conflicting responses at play. The present study addressed this issue by contrasting people's processing of moral dilemmas in which utilitarian and deontological considerations cued conflicting or non-conflicting decisions. Results showed that deontic responders were slower and less confident about their decision when solving the conflict (vs. no-conflict) dilemmas. This suggests that they are considering both deontic and utilitarian aspects of their decision and indicates that a deontic decision is more informed and less oblivious than it might appear.     

The role of motivation to avoid detection in reaction time-based concealed information detection

Do motivated liars lie more successfully? The motivational effort hypothesis predicts that higher motivation effectively diminishes the chance of being detected, whereas the motivational impairment hypothesis predicts that the higher the motivation to go undetected, the greater the chance of being detected. We manipulated motivation in two online reaction time-based Concealed Information Test studies in which participants tried to hide their identity. Detection of concealed identity information in Experiment 1 (n = 259) was successful and a small financial incentive to avoid detection did not impact upon validity. Despite a greater financial incentive and a manipulation check showing that motivation was increased, Experiment 2 (n = 233) did not impact upon the test's validity either. A financial incentive to avoid detection did not decrease the validity of concealed information detection.     

Visual search for drowning swimmers: Investigating the impact of lifeguarding experience

How does domain expertise influence dynamic visual search? Previous studies of visual search often use abstract search arrays that are devoid of applied context, with comparatively few studies exploring applied naturalistic and dynamic settings. The current research adds to this literature by examining lifeguard drowning‐detection across two studies using naturalistic, dynamic search tasks. Behavioural responses and eye‐movement data were recorded as participants watched staged video clips and attempted to identify if a swimmer was drowning. The results demonstrate lifeguard superiority in response times to drowning events, compared to non‐lifeguards. No differences between lifeguard and non‐lifeguard eye‐movements were noted however. This suggests that the experiential benefit in response times results from other underlying processes, rather than any scanning benefits. This research highlights the complex nature of naturalistic and dynamic searches, while demonstrating the robust nature of simulated videos in producing experience effects in visual search.