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.     

Effects of an Internet-based intervention for subthreshold eating disorders: a randomized controlled trial

BackgroundWomen reporting initial eating disorder (ED) symptoms are at highest risk for the development of an eating disorder. Preventive interventions should, therefore, be specifically tailored for this subgroup.AimsTo adapt and evaluate the effects of the Internet-based prevention program “Student Bodies?” for women with symptoms of disordered eating and/or subthreshold eating disorder (ED) syndromes.Method126 women, reporting subthreshold ED symptoms (high weight and shape concerns and below threshold bingeing, purging, chronic dieting or several of these symptoms) were randomly assigned to a Student Bodies?+ (SB+) intervention or a wait-list control group and assessed at pre-intervention, post-intervention, and 6-month follow-up. “Student Bodies?” was adapted to be suitable for subthreshold EDs. Main outcome measures were attitudes and symptoms of disordered eating. Pre-follow-up data were analyzed by ANCOVAS with mixed effects.ResultsAt 6-month follow-up, compared to participants in the control group, participants in the intervention group showed significantly greater improvements on ED-related attitudes. Intervention participants also showed 67% (95% CI = 20–87%) greater reductions in combined rates of subjective and objective binges, and 86% (95% CI = 63–95%) greater reduction in purging episodes. Also, the rates of participants abstinent from all symptoms of disordered eating (restrictive eating, binge eating and any compensatory behavior) were significantly higher in the intervention group (45.1% vs. 26.9%). Post-hoc subgroup analyses revealed that for participants with binge eating the effect on EDE-Q scores was larger than in the pure restricting subgroup.ConclusionThe adapted “SB+” program represents an effective intervention for women with subthreshold EDs of the binge eating subtype.     

Randomized controlled trial on the effectiveness of metacognitive therapy and intolerance-of-uncertainty therapy for generalized anxiety disorder

This randomized controlled trial compared the effectiveness of metacognitive therapy (MCT) and intolerance-of-uncertainty therapy (IUT) for generalized anxiety disorder (GAD) in an outpatient context. Patients with GAD (N = 126) consecutively referred to an outpatient treatment center for anxiety disorder were randomly allocated to MCT, IUT, or a delayed treatment (DT) condition. Patients were treated individually for up to 14 sessions. Assessments were conducted before treatment (pretreatment), after the last treatment session (posttreatment), and six months after treatment had ended (follow-up). At posttreatment and follow-up assessments, substantial improvements were observed in both treatment conditions across all outcome variables. Both MCT and IUT, but not DT, produced significant reductions in GAD-specific symptoms with large effect sizes (ranging between 0.94 and 2.39) and high proportions of clinically significant change (ranging between 77% and 95%) on various outcome measures, and the vast majority of the patients (i.e., 91% in the MCT group, and 80% in the IUT group) no longer fulfilled the diagnostic criteria for GAD. Results further indicate that MCT produced better results than IUT. This was evident on most outcome measures, and also reflected in effect sizes and degree of clinical response and recovery.     

Nonsymbolic numerical magnitude comparison: reliability and validity of different task variants and outcome measures, and their relationship to arithmetic achievement in adults

The numerical ratio effect (NRE) and the Weber fraction (w) are common metrics of the precision of the approximate numbers sense (ANS), a cognitive mechanism suggested to play a role in the development of numerical and arithmetic skills. The task most commonly used to measure the precision of the ANS is the numerical comparison task. Multiple variants of this task have been employed yet it is currently unclear how these affect metrics of ANS acuity, and how these relate to arithmetic achievement. The present study investigates the reliability, validity and relationship to standardized measures of arithmetic fluency of the NRE and w elicited by three variants of the nonsymbolic number comparison task. Results reveal that the strengths of the NRE and w differ between task variants. Moreover, the reliability and validity of the reaction time NRE and the w were generally significant across task variants, although reliability was stronger for w. None of the task variants revealed a correlation between ANS metrics and arithmetic fluency in adults. These results reveal important consistencies across nonsymbolic number comparison tasks, indicating a shared cognitive foundation. However, the relationship between ANS acuity and arithmetic performance remains unclear.     

Recognizing prosody across modalities, face areas and speakers: examining perceivers' sensitivity to variable realizations of visual prosody

Prosody can be expressed not only by modification to the timing, stress and intonation of auditory speech but also by modifying visual speech. Studies have shown that the production of visual cues to prosody is highly variable (both within and across speakers), however behavioural studies have shown that perceivers can effectively use such visual cues. The latter result suggests that people are sensitive to the type of prosody expressed despite cue variability. The current study investigated the extent to which perceivers can match visual cues to prosody from different speakers and from different face regions. Participants were presented two pairs of sentences (consisting of the same segmental content) and were required to decide which pair had the same prosody. Experiment 1 tested visual and auditory cues from the same speaker and Experiment 2 from different speakers. Experiment 3 used visual cues from the upper and the lower face of the same talker and Experiment 4 from different speakers. The results showed that perceivers could accurately match prosody even when signals were produced by different speakers. Furthermore, perceivers were able to match the prosodic cues both within and across modalities regardless of the face area presented. This ability to match prosody from very different visual cues suggests that perceivers cope with variation in the production of visual prosody by flexibly mapping specific tokens to abstract prosodic types.     

Predicted errors in children's early sentence comprehension

Children use syntax to interpret sentences and learn verbs; this is syntactic bootstrapping. The structure-mapping account of early syntactic bootstrapping proposes that a partial representation of sentence structure, the set of nouns occurring with the verb, guides initial interpretation and provides an abstract format for new learning. This account predicts early successes, but also telltale errors: Toddlers should be unable to tell transitive sentences from other sentences containing two nouns. In testing this prediction, we capitalized on evidence that 21-month-olds use what they have learned about noun order in English sentences to understand new transitive verbs. In two experiments, 21-month-olds applied this noun-order knowledge to two-noun intransitive sentences, mistakenly assigning different interpretations to "The boy and the girl are gorping!" and "The girl and the boy are gorping!". This suggests that toddlers exploit partial representations of sentence structure to guide sentence interpretation; these sparse representations are useful, but error-prone.     

Can survival processing enhance story memory? Testing the generalizability of the adaptive memory framework

Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival encoding for a list of words (e.g., "Will this object enhance my survival if I were stranded in the grasslands of a foreign land?"), they produced better free recall on a surprise test than did participants who intentionally tried to remember those words (Experiment 1). We also found this survival processing advantage when the words were presented within the context of a survival or neutral story (Experiment 2). However, this advantage did not extent to memory for a story's factual content, regardless of whether the participants were tested by cued recall (Experiment 3) or free recall (Experiments 4-5). Listening to a story for understanding under intentional or incidental learning conditions was just as good as survival processing for remembering story content. The functionalist approach to thinking about memory as an evolutionary adaptation designed to solve reproductive fitness problems provides a different theoretical framework for research, but it is not yet clear if survival processing has general applicability or is effective only for processing discrete stimuli in terms of fitness-relevant scenarios from our past.     

The motor side of emotions: investigating the relationship between hemispheres, motor reactions and emotional stimuli

The aim of the present study was to analyze if the left hemisphere preferentially controls flexion responses toward positive stimuli, while the right hemisphere is specialized toward extensor responses to negative pictures. To this end, right-handed subjects had to pull or push a joystick subsequent to seeing a positive or a negative stimulus in their left or right hemifield. Flexion responses were faster for positive stimuli, while negative stimuli were associated with faster extensions responses. Overall, performance was fastest when emotional stimuli were presented to the left visual hemifield. This right hemisphere superiority was especially clear for negative stimuli, while reaction times toward positive pictures showed no hemispheric difference. We did not find any interaction between hemifield and response type. Neither was there a triple interaction between valence, hemifield and response type. We suppose that response dichotomies in humans are not as tightly linked to a hemisphere- and valence-bound reaction type as previously assumed.