Does interference between self and other perspectives in theory of mind tasks reflect a common underlying process? Evidence from individual differences in theory of mind and inhibitory control

Theory of mind (ToM), the ability to understand that other agents have different beliefs, desires, and knowledge than oneself, has been extensively researched. Theory of mind tasks involve participants dealing with interference between their self-perspective and another agent’s perspective, and this interference has been related to executive function, particularly to inhibitory control. This study assessed whether there are individual differences in self–other interference, and whether these effects are due to individual differences in executive function. A total of 142 participants completed two ToM (the director task and a Level 1 visual perspective-taking task), which both involve self–other interference, and a battery of inhibitory control tasks. The relationships between the tasks were examined using path analysis. Results showed that the self–other interference effects of the two ToM tasks were dissociable, with individual differences in performance on the ToM tasks being unrelated and performance in each predicted by different inhibitory control tasks. We suggest that self–other differences are part of the nature of ToM tasks, but self–other interference is not a unitary construct. Instead, self–other differences result in interference effects in various ways and at different stages of processing, and these effects may not be a major limiting step for adults’ performance on typical ToM tasks. Further work is needed to assess other factors that may limit adults’ ToM performance and hence explain individual differences in social ability.

     

Cerebral blood flow in 5‐ to 8‐month‐olds: Regional tissue maturity is associated with infant affect

Infancy is marked by rapid neural and emotional development. The relation between brain function and emotion in infancy, however, is not well understood. Methods for measuring brain function predominantly rely on the BOLD signal; however, interpretation of the BOLD signal in infancy is challenging because the neuronal‐hemodynamic relation is immature. Regional cerebral blood flow (rCBF) provides a context for the infant BOLD signal and can yield insight into the developmental maturity of brain regions that may support affective behaviors. This study aims to elucidate the relations among rCBF, age, and emotion in infancy. One hundred and seven mothers reported their infants' (infant age M ± SD = 6.14 ± 0.51 months) temperament. A subsample of infants completed MRI scans, 38 of whom produced usable perfusion MRI during natural sleep to quantify rCBF. Mother‐infant dyads completed the repeated Still‐Face Paradigm, from which infant affect reactivity and recovery to stress were quantified. We tested associations of infant age at scan, temperament factor scores, and observed affect reactivity and recovery with voxel‐wise rCBF. Infant age was positively associated with CBF in nearly all voxels, with peaks located in sensory cortices and the ventral prefrontal cortex, supporting the formulation that rCBF is an indicator of tissue maturity. Temperamental Negative Affect and recovery of positive affect following a stressor were positively associated with rCBF in several cortical and subcortical limbic regions, including the orbitofrontal cortex and inferior frontal gyrus. This finding yields insight into the nature of affective neurodevelopment during infancy. Specifically, infants with relatively increased prefrontal cortex maturity may evidence a disposition toward greater negative affect and negative reactivity in their daily lives yet show better recovery of positive affect following a social stressor.     

Crying threshold and intensity in major depressive disorder

Clinical lore suggests that depression is associated with frequent and intense crying. To test these postulations empirically, a standardized cry-evoking stimulus was presented to depressed and nondepressed participants, and their likelihood of crying and the magnitude of crying-related changes in their emotion experience, behavior, and autonomic physiology were compared. Unexpectedly, crying was no more likely in depressed than in nondepressed participants. Within the nondepressed group, participants who cried exhibited increases in the report and display of sadness and had greater cardiac and electrodermal activation than did participants who did not cry. There was less evidence of this crying-related emotional activation within the depressed group. The lack of emotional activation among clinically depressed participants who cried provides a tantalizing clue concerning how emotions are dysregulated in this disorder.     

Separating sensitivity from response bias: implications of comparisons of yes-no and forced-choice tests for models and measures of recognition memory

A fundamental challenge to psychological research is the measurement of cognitive processes uncontaminated by response strategies resulting from different testing procedures. Test-free estimates of ability are vital when comparing the performance of different groups or different conditions. The current study applied several sets of measurement models to both forced-choice and yes-no recognition memory tests and concluded that the traditional signal-detection model resulted in distorted estimates of accuracy. Two-factor models were necessary to separate memory sensitivity from response bias. These models indicated that (a) memory accuracy did not differ across the tests and (b) the tests relied on the same underlying memory processes. The results illustrate the pitfalls of using a single-component model to measure accuracy in tasks that reflect 2 or more underlying processes.     

Recognition memory for source and occurrence: The importance of recollection

Previous recognition memory studies indicate that when both recollection and familiarity are expected to contribute to recognition performance (e.g., discriminating studied items from nonstudied items) the dual-process and the unequal-variance signal detection models provide comparable accounts of performance. When familiarity is not expected to be useful (e.g., when items from two equally familiar sources are discriminated between), the dual-process model provides a significantly better account of performance. In the present study, source recognition was tested under conditions in which familiarity could have been used to perform a list-discrimination task; participants were required to discriminate between strong studied items, weak studied items, and new items. The dual-process model provided a better account of performance than did the unequal-variance model. Moreover, the results indicated that the unequal-variance assumption in a single-process signal detection model was not a valid substitution for recollection and that recollection was used to make recognition judgments even when assessments of familiarity were useful.     

Predicting individual false alarm rates and signal detection theory: A role for remembering

The relationships between hit, remember, and false alarm rates were examined across individual subjects in three remember-know experiments in order to determine whether signal detection theory would be consistent with the observed data. The experimental data differed from signal detection predictions in two critical ways. First, remember reports were unrelated, or slightly negatively related, to the commission of false alarms. Second, both response types (remembers and false alarms) were uniquely related to hit rates, which demonstrated that the hit rate cannot be viewed as the result of a single underlying strength process. These results are consistent with the dual-process signal detection model of Yonelinas (1994), in which performance is determined by two independent processes--retrieval of categorical context information (remembering) and discriminations based on continuous item strength. Remember and false alarm rates selectively tap these processes, whereas the hit rate is jointly determined. Monte Carlo simulations in which the dual-process model was used successfully reproduced the pattern in the experimental data, whereas simulations in which a signal detection model, with separate "old" and "remember" criteria, was used, did not. The results demonstrate the utility of examining individual differences in response types when one is evaluating memory models.     

Colour matching of isoluminant samples and backgrounds: a dimming effect

Sequential asymmetrical colour matching of forty Munsell samples simulated under illuminant C and one of eight test illuminants was carried out. The subjects matched the appearance of each sample under illuminant C with its appearance under the test illuminant. Samples and background (N7) were presented for 1 s under the test illuminant and were isoluminant with each other. Subjects adjusted hue, chroma, and value under illuminant C. The experiments distinguished two groups of subjects; some observers needed to reduce the luminance of the sample to make a match while others did not. This 'dimming' occurred when the matches were close to cardinal axes, especially the tritanopic confusion line. A model of luminance and cone-opponent mechanisms contributing to brightness can account for the dimming effect. Details of analysis in cone-opponent space (L - M, L + M - S, L + M) are presented in the companion paper (Stanikunas et al, 2005 Perception 34 this issue).     

Adults with dyslexia demonstrate space-based and object-based covert attention deficits: shifting attention to the periphery and shifting attention between objects in the left visual field

Performance on a covert visual attention task is compared between a group of adults with developmental dyslexia (specifically phonological difficulties) and a group of age and IQ matched controls. The group with dyslexia were generally slower to detect validly-cued targets. Costs of shifting attention toward the periphery when the target was invalidly cued were significantly higher for the group with dyslexia, while costs associated with shifts toward the fovea tended to be lower. Higher costs were also shown by the group with dyslexia for up-down shifts of attention in the periphery. A visual field processing difference was found, in that the group with dyslexia showed higher costs associated with shifting attention between objects in they LVF. These findings indicate that these adults with dyslexia have difficulty in both the space-based and the object-based components of covert visual attention, and more specifically to stimuli located in the periphery.     

Classification of Antisocial Behaviors Along Severity and Frequency Parameters

Antisocial behaviors were systematically classified along a hierarchy of seriousness or severity that also accounted for frequency of occurrence and heterogeneity of behaviors. Items from the CD and ODD schedules of the NIMH DISC-IV and from the Elliot Delinquency Scales were listed at specified frequencies. Nine mental health clinicians rated the level of seriousness of each alternative on a scale from 0 (trivial) to 5 (very serious). Reliability of the ratings was assessed. Over two thirds of the items showed excellent agreement among the raters, 8% showed poor agreement and 21% showed fair to moderate agreement. The overall reliability of a single rater’s score was 0.56 and the reliability of the average was 0.84. The classification meets high psychometric standards for reliability and has face validity. The final output provides a classification along a spectrum that takes into account severity, frequency of occurrence during the previous year, and presence of multiple behaviors. It is useful for classification purposes and for longitudinal tracking of antisocial behavior.