Age-related differences in brain electrical activity during extended continuous face recognition in younger children, older children and adults

To examine the development of recognition memory in primary-school children, 36 healthy younger children (8-9 years old) and 36 healthy older children (11-12 years old) participated in an ERP study with an extended continuous face recognition task (Study 1). Each face of a series of 30 faces was shown randomly six times interspersed with distracter faces. The children were required to make old vs. new decisions. Older children responded faster than younger children, but younger children exhibited a steeper decrease in latencies across the five repetitions. Older children exhibited better accuracy for new faces, but there were no age differences in recognition accuracy for repeated faces. For the N2, N400 and late positive complex (LPC), we analyzed the old/new effects (repetition 1 vs. new presentation) and the extended repetition effects (repetitions 1 through 5). Compared to older children, younger children exhibited larger frontocentral N2 and N400 old/new effects. For extended face repetitions, negativity of the N2 and N400 decreased in a linear fashion in both age groups. For the LPC, an ERP component thought to reflect recollection, no significant old/new or extended repetition effects were found. Employing the same face recognition paradigm in 20 adults (Study 2), we found a significant N400 old/new effect at lateral frontal sites and a significant LPC repetition effect at parietal sites, with LPC amplitudes increasing linearly with the number of repetitions. This study clearly demonstrates differential developmental courses for the N400 and LPC pertaining to recognition memory for faces. It is concluded that face recognition in children is mediated by early and probably more automatic than conscious recognition processes. In adults, the LPC extended repetition effect indicates that adult face recognition memory is related to a conscious and graded recollection process rather than to an automatic recognition process.     

“There Is a Lot of Junk on the Web!”: Using Web Site Evaluation in an Introductory Religion Course

This essay describes a web site evaluation project which served as the final assignment for an undergraduate “Introduction to Religion” course. The essay discusses lessons learned from the design and implementation of this web‐based research assignment over three consecutive semesters. It includes insights from an instructor and a reference librarian who collaborated on this project.     

Taking your place or matching your face: two paths to empathic embarrassment

Empathic responding may be elicited by different processes, depending on the available situational and affective cues. We investigated two such processes, perspective-taking and nonverbal mimicry. In Study 1, participants watched an embarrassed or unembarrassed confederate dancing to music while either remaining objective or engaging in perspective-taking. Both manipulations affected empathic embarrassment. Study 2 further examined the effects of targets' embarrassment displays and observers' prior experience with the situation upon spontaneous perspective-taking, expressive mimicry, and empathic embarrassment. Embarrassment displays increased mimicry, but also spontaneous perspective-taking and subsequent empathy. Prior experience moderated the effects of embarrassment displays on perspective-taking and empathy. Path analyses demonstrated that embarrassment displays exerted indirect effects on empathic embarrassment through both perspective-taking and mimicry. The results suggest that available affective and situational cues can activate different routes to empathy, and highlight the value of simultaneously investigating target- and observer-based sources of influence.     

Response-retrieval and negative priming

The existence of across-notation automatic numerical processing of two-digit (2D) numbers was explored using size comparisons tasks. Participants were Arabic speakers, who use two sets of numerical symbols—Arabic and Indian. They were presented with pairs of 2D numbers in the same or in mixed notations. Responses for a numerical comparison task were affected by decade difference and unit-decade compatibility and global distance in both conditions, extending previous findings with Arabic digits (Nuerk, Weger, & Willmes, 2001). Responses for a physical comparison task were affected by congruency with the numerical size, as indicated by the size congruency effect (SiCE). The SiCE was affected by unit-decade compatibility but not by global distance, thus suggesting that the units and decades digits of the 2D numbers, but not the whole number value were automatically translated into a common representation of magnitude. The presence of similar results for same- and mixed-notation pairs supports the idea of an abstract representation of magnitude.     

Mirror, mirror on my Facebook wall: effects of exposure to Facebook on self-esteem

Contrasting hypotheses were posed to test the effect of Facebook exposure on self-esteem. Objective Self-Awareness (OSA) from social psychology and the Hyperpersonal Model from computer-mediated communication were used to argue that Facebook would either diminish or enhance self-esteem respectively. The results revealed that, in contrast to previous work on OSA, becoming self-aware by viewing one's own Facebook profile enhances self-esteem rather than diminishes it. Participants that updated their profiles and viewed their own profiles during the experiment also reported greater self-esteem, which lends additional support to the Hyperpersonal Model. These findings suggest that selective self-presentation in digital media, which leads to intensified relationship formation, also influences impressions of the self.     

Motor excitability is reduced prior to voluntary movements in children and adolescents with Tourette syndrome

Tourette syndrome (TS) is a neuro‐developmental disorder characterized by the occurrence of motor and vocal tics: involuntary, repetitive, stereotyped behaviours that occur with a limited duration, often typically many times in a single day. Previous studies suggest that children and adolescents with TS may undergo compensatory, neuroplastic changes in brain structure and function that help them gain control over their tics. In the current study we used single‐pulse and dual‐site paired‐pulse transcranial magnetic stimulation (TMS), in conjunction with a manual choice reaction time task that induces high levels of inter‐manual conflict, to investigate this conjecture in a group of children and adolescents with TS, but without co‐morbid Attention Deficit Hyperactivity Disorder (ADHD). We found that performance on the behavioural response‐conflict task did not differ between the adolescents with TS and a group of age‐matched typically developing individuals. By contrast, our study demonstrated that cortical excitability, as measured by TMS‐induced motor‐evoked potentials (MEPs), was significantly reduced in the TS group in the period immediately preceding a finger movement. This effect is interpreted as consistent with previous suggestions that the cortical hyper‐excitability that may give rise to tics in TS is actively suppressed by cognitive control mechanisms. Finally, we found no reliable evidence for altered patterns of functional inter‐hemispheric connectivity in TS. These results provide evidence for compensatory brain reorganization that may underlie the increased self‐regulation mechanisms that have been hypothesized to bring about the control of tics during adolescence.     

Visual imagery and memory: Do retrieval strategies affect what the mind's eye sees?

A variety of visual mental imagery tasks have been shown to activate regions of visual cortex that subserve the perception of visual events. Here fMRI was used to examine whether imagery‐related visuocortical activity is modulated if imagery content is held constant but there is a change in the memory retrieval strategy used to invoke imagery. Participants were scanned while visualising common objects in two different conditions: (a) recalling recently encoded pictures and (b) based on their knowledge of concrete nouns. Results showed that retrieval‐related activations in frontal cortex were bilateral when pictures were visualised but left‐lateralised when nouns were visualised. In posterior brain regions, both imagery conditions led to activation in the same set of circumscribed areas in left temporal‐parietal cortex, including a region of the left fusiform gyrus that has previously been implicated in visual imagery. These findings suggest that the posterior network activated during imagery did not vary with strategic task‐related changes in the frontal network used to retrieve imagery content from memory.     

Wisconsin Card Sorting in adolescents: analysis of performance, response times and heart rate

Forty-nine adolescents performed the Wisconsin Card Sorting Test (WCST). A main PCA component of WCST performance was identified as 'efficiency of reasoning'. This factor was related to feedback processing. From the WCST, a perseveration score can be derived. Perseveration is the continued application of a rule, after it has been disconfirmed. We compared more and less perseverating subjects in relation to stimulus-response (SR) time, feedback inspection time and cardiac acceleration and deceleration. Less perseverating subjects responded faster, and had longer and more adaptive inspection times of error feedback. We examined the switch from rule application to rule search, and the difference between correct and error responses. A transient cardiac deceleration at the initiation of rule search was interpreted as a change in supervisory attention. An error-related deceleration to negative feedback was interpreted as a disturbance of higher control processing. Previous trial feedback influenced current processing time, feedback inspection time, and the cardiac acceleration and deceleration responses.