Emily Hembacher

Abnormalities of Visual Processing and Frontostriatal Systems in Body Dysmorphic Disorder

CONTEXT Body dysmorphic disorder (BDD) is a psychiatric disorder in which individuals are preoccupied with perceived defects in their appearance, often related to their face. Little is known about its pathophysiology, although early research provides evidence of abnormal visual processing. OBJECTIVE To determine whether patients with BDD have abnormal patterns of brain activation when visually processing their own face with high, low, or normal spatial resolution. DESIGN Case-control study. SETTING A university hospital. PARTICIPANTS Seventeen right-handed medication-free subjects with BDD and 16 matched healthy control subjects. Intervention Functional magnetic resonance imaging while viewing photographs of face stimuli. Stimuli were neutral-expression photographs of the patients own face and a familiar face (control stimuli) that were unaltered, altered to include only high spatial frequency (fine spatial resolution), or altered to include only low spatial frequency (low spatial resolution). MAIN OUTCOME MEASURE Blood oxygen level-dependent signal changes in the BDD and control groups during each stimulus type. RESULTS Subjects with BDD showed relative hyperactivity in the left orbitofrontal cortex and bilateral head of the caudate for the unaltered own-face vs familiar-face condition. They showed relative hypoactivity in the left occipital cortex for the low spatial frequency faces. Differences in activity in frontostriatal systems but not visual cortex covaried with aversiveness ratings of the faces. Severity of BDD symptoms correlated with activity in frontostriatal systems and visual cortex. CONCLUSIONS These results suggest abnormalities in visual processing and frontostriatal systems in BDD. Hypoactivation in the occipital cortex for low spatial frequency faces may indicate either primary visual system abnormalities for configural face elements or top-down modulation of visual processing. Frontostriatal hyperactivity may be associated both with aversion and with symptoms of obsessive thoughts and compulsive behaviors.

Abnormalities of object visual processing in body dysmorphic disorder.

BACKGROUND Individuals with body dysmorphic disorder (BDD) may have perceptual distortions for their appearance. Previous studies suggest imbalances in detailed relative to configural/holistic visual processing when viewing faces. No study has investigated the neural correlates of processing non-symptom-related stimuli. The objective of this study was to determine whether individuals with BDD have abnormal patterns of brain activation when viewing non-face/non-body object stimuli. METHOD Fourteen medication-free participants with DSM-IV BDD and 14 healthy controls participated. We performed functional magnetic resonance imaging (fMRI) while participants matched photographs of houses that were unaltered, contained only high spatial frequency (HSF, high detail) information or only low spatial frequency (LSF, low detail) information. The primary outcome was group differences in blood oxygen level-dependent (BOLD) signal changes. RESULTS The BDD group showed lower activity in the parahippocampal gyrus, lingual gyrus and precuneus for LSF images. There were greater activations in medial prefrontal regions for HSF images, although no significant differences when compared to a low-level baseline. Greater symptom severity was associated with lower activity in the dorsal occipital cortex and ventrolateral prefrontal cortex for normal spatial frequency (NSF) and HSF images. CONCLUSIONS Individuals with BDD have abnormal brain activation patterns when viewing objects. Hypoactivity in visual association areas for configural and holistic (low detail) elements and abnormal allocation of prefrontal systems for details are consistent with a model of imbalances in global versus local processing. This may occur not only for appearance but also for general stimuli unrelated to their symptoms.

Early metacognitive abilities: The interplay of monitoring and control processes in 5- to 7-year-old children

The goal of the current investigation was to compare two monitoring processes (judgments of learning [JOLs] and confidence judgments [CJs]) and their corresponding control processes (allocation of study time and selection of answers to maximize accuracy, respectively) in 5-, 6-, and 7-year-old children (N=101). Children learned the meanings of Japanese characters and provided JOLs after a study phase and CJs after a memory test. They were given the opportunity to control their learning in self-paced study phases and to control their accuracy by placing correct answers in a treasure chest and placing incorrect answers in a trash can. All three age groups gave significantly higher CJs for correct answers compared with incorrect answers, with no age-related differences in the magnitude of this difference, suggesting robust metacognitive monitoring skills in children as young as 5 years. Furthermore, a link between JOLs and study time was found in 6- and 7-year-olds, such that children spent more time studying items with low JOLs compared with items with high JOLs. In addition, 6- and 7-year-olds, but not 5-year-olds, spent more time studying difficult items compared with easier items. Moreover, age-related improvements were found in childrens use of CJs to guide their selection of answers; although children as young as 5 years placed their most confident answers in the treasure chest and placed their least confident answers in the trash can, this pattern was more robust in older children. Overall, results support the view that some metacognitive judgments may be acted on with greater ease than others among young children.

Don’t Look at My Answer Subjective Uncertainty Underlies Preschoolers’ Exclusion of Their Least Accurate Memories

Preschoolers’ ability to introspect and make decisions on the basis of these introspections has traditionally been questioned. The present research introduces a novel paradigm to examine the development of the connection between subjective uncertainty about memory and decision making in preschoolers. Three-, 4-, and 5-year-olds (N = 81) encoded items presented once or twice. They then completed a forced-choice test, provided confidence judgments for each response, and decided whether to select or exclude answers to be evaluated for the possibility of reward. Four- and 5-year-olds, but not 3-year-olds, reported lower certainty for incorrect and weaker memories than for correct and stronger memories, and they judiciously excluded their least confident memories, which resulted in accuracy gains for selected memories; these findings highlight age-related improvements in introspection on memory accuracy. Among accurate responses only, even 3-year-olds excluded their least confident answers, which suggests that the connection between uncertainty and decision making precedes the ability to monitor memory accuracy.

Effects of cranial electrotherapy stimulation on resting state brain activity

Cranial electrotherapy stimulation (CES) is a U.S. Food and Drug Administration (FDA)‐approved treatment for insomnia, depression, and anxiety consisting of pulsed, low‐intensity current applied to the earlobes or scalp. Despite empirical evidence of clinical efficacy, its mechanism of action is largely unknown. The goal was to characterize the acute effects of CES on resting state brain activity. Our primary hypothesis was that CES would result in deactivation in cortical and subcortical regions. Eleven healthy controls were administered CES applied to the earlobes at subsensory thresholds while being scanned with functional magnetic resonance imaging in the resting state. We tested 0.5‐ and 100‐Hz stimulation, using blocks of 22 sec “on” alternating with 22 sec of baseline (device was “off”). The primary outcome measure was differences in blood oxygen level dependent data associated with the device being on versus baseline. The secondary outcome measures were the effects of stimulation on connectivity within the default mode, sensorimotor, and fronto‐parietal networks. Both 0.5‐ and 100‐Hz stimulation resulted in significant deactivation in midline frontal and parietal regions. 100‐Hz stimulation was associated with both increases and decreases in connectivity within the default mode network (DMN). Results suggest that CES causes cortical brain deactivation, with a similar pattern for high‐ and low‐frequency stimulation, and alters connectivity in the DMN. These effects may result from interference from high‐ or low‐frequency noise. Small perturbations of brain oscillations may therefore have significant effects on normal resting state brain activity. These results provide insight into the mechanism of action of CES, and may assist in the future development of optimal parameters for effective treatment.

How to bet on a memory: developmental linkages between subjective recollection and decision making.

The current study investigated the development of subjective recollection and its role in supporting decisions in 6- and 7-year-olds, 9- and 10-year-olds, and adults (N=78). Participants encoded items and details about them. Later, they were asked to recognize the items, recall the details, and report on subjective feelings of recollection and familiarity for test items. Critically, they were required to select a subset of trials to be evaluated for the possibility of a reward. All age groups were more likely to report subjective recollection when they accurately recalled details, demonstrating an ability to introspect on subtle differences in subjective memory states, although 6- and 7-year-olds could do so reliably only for color details. However, only 9- and 10-year-olds and adults were more likely to select trials that were associated with subjective recollection, suggesting that a connection between this subjective experience and decision making emerges later during middle childhood.

Nonlinear relationships between anxiety and visual processing of own and others’ faces in body dysmorphic disorder

Individuals with body dysmorphic disorder (BDD) often experience anxiety, as well as perceptual distortions of appearance. Anxiety has previously been found to impact visual processing. This study therefore tested the relationship between anxiety and visual processing of faces in BDD. Medication-free participants with BDD (N=17) and healthy controls (N=16) viewed photographs of their face and a familiar face during functional magnetic resonance imaging. Blood-oxygen-level dependent signal changes in regions involved in anxiety (amygdala) and detailed visual processing (ventral visual stream-VVS) were regressed on anxiety scores. Significant linear relationships between activity in the amygdala and VVS were found in both healthy controls and individuals with BDD. There was a trend of a quadratic relationship between anxiety and activity in the right VVS and a linear relationship between anxiety and activity in the left VVS for the BDD sample, and this was stronger for own-face stimuli versus familiar-face. Results suggest that anxiety symptoms in BDD may be associated with activity in systems responsible for detailed visual processing. This may have clinical implications related to heightened perceptual distortions associated with anxiety.

Subjective experience guides betting decisions beyond accuracy: evidence from a metamemory illusion

ABSTRACT The goal of this research was to test whether subjective memory experiences drive accuracy regulation decisions above and beyond objective memory indices. In four experiments (n = 115) subjective recollection (i.e., reporting “Remember” in the Remember-Know task) was dissociated from memory accuracy by manipulating retrieval during a two-alternative forced-choice recognition task: in the Match condition the distracter was a novel exemplar of the target (e.g., a studied and an unstudied toaster) and in the Non-match condition the distracter was a novel exemplar of another studied but untested item (e.g., a studied toaster and an unstudied birdhouse). Participants were more accurate on Match trials, but reported subjective recollection more frequently on Non-match trials. Critically, participants also bet more often on Non-match trials to the detriment of their score (Experiment 1). This pattern persisted when participants were additionally required to retrieve details about items (Experiment 2) and when confidence assessments were collected (Experiment 3). Finally, participants bet more on Non-match trials even when subjective judgments were not elicited, suggesting that the decision process does not require reporting on subjective experience (Experiment 4). These results indicate that subjective memory experiences guide decision-making independent of objective accuracy and thus are critical to accuracy regulation.