11 results on '"Christensen BK"'
Search Results
2. The effect of social anxiety on top-down attentional orienting to emotional faces.
- Author
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Delchau HL, Christensen BK, Lipp OV, and Goodhew SC
- Subjects
- Anger, Anxiety psychology, Facial Expression, Fear, Humans, Reaction Time, Attentional Bias, Emotions
- Abstract
One of the fundamental factors maintaining social anxiety is biased attention toward threatening facial expressions. Typically, this bias has been conceptualized as driven by an overactive bottom-up attentional system; however, this potentially overlooks the role of top-down attention in being able to modulate this bottom-up bias. Here, the role of top-down mechanisms in directing attention toward emotional faces was assessed with a modified dot-probe task, in which participants were given a top-down cue ("happy" or "angry") to attend to a happy or angry face on each trial, and the cued face was either presented with a face of the other emotion (angry, happy) or a neutral face. This study found that social anxiety was not associated with differences in shifting attention toward cued angry faces. However, participants with higher levels of social anxiety were selectively impaired in attentional shifting toward a cued happy face when it was paired with an angry face, but not when paired with a neutral face. The results indicate that top-down attention can be used to orient attention to emotional faces, but that higher levels of social anxiety are associated with selective deficits in top-down control of attention in the presence of threat. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
- Published
- 2022
- Full Text
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3. The beneficial influence of inattention on visual interference in schizophrenia.
- Author
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Brodeur MB, Kiang M, and Christensen BK
- Subjects
- Adult, Cognitive Dysfunction etiology, Female, Humans, Male, Middle Aged, Schizophrenia complications, Attention physiology, Cognitive Dysfunction physiopathology, Evoked Potentials physiology, Schizophrenia physiopathology, Space Perception physiology, Visual Perception physiology
- Abstract
Objective: Schizophrenia is associated with poor spatial attention. However, although this deficit undermines the perception of target information, it may be helpful for ignoring irrelevant inputs. The present study examined whether event-related brain potential (ERP) indices of visual spatial attention predicted the magnitude of the brain response to interference in schizophrenia., Method: ERPs were recorded in 16 schizophrenia patients and 20 healthy control participants who had to indicate whether the target E was global or local in compound letter stimuli. The nontarget could be either highly similar to the target (i.e., a global E composed of local Ss and vice versa) and thus produce more interference, or it could be dissimilar (i.e., a global E composed of local Hs and vice versa) and generate less interference., Results: Both groups' responses were slowed by interference. Voltage amplitudes of the P1, and of ERP interference effects from 300-500 ms after stimulus onset, were significantly smaller in schizophrenia patients than in healthy participants when the target was global. In patients, larger P1 amplitudes were correlated with larger interference effects and with more severe symptoms of attentional deficits and conceptual disorganization. Schizophrenia participants thus exhibited abnormal ERPs to interference despite normal behavioral performance., Conclusions: Schizophrenia patients likely pay less attention to stimuli in general; however, the impact of this impairment on target detection is compensated by relatively greater inattention to irrelevant components of the stimuli, and this explains why they are not more influenced by interference than healthy participants at the behavioral level. (PsycINFO Database Record, ((c) 2016 APA, all rights reserved).)
- Published
- 2016
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4. Visual-spatial episodic memory in schizophrenia: A multiple systems framework.
- Author
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Girard TA, Christensen BK, DeGroote MG, and Rizvi S
- Subjects
- Adult, Data Interpretation, Statistical, Female, Hippocampus physiology, Humans, Male, Neuropsychological Tests, Psychiatric Status Rating Scales, Recognition, Psychology, Sex Characteristics, Mental Recall physiology, Schizophrenic Psychology, Space Perception physiology, Visual Perception physiology
- Abstract
Objective: Enhanced understanding of cognitive deficits, and the neurobiological abnormalities that mediate them, can be achieved through translational research that employs comparable experimental approaches across species. This study employed a multiple-systems framework derived from the rodent literature to investigate visual-spatial memory abilities associated with schizophrenia., Method: Using the bin task, a human analog of rodent maze tasks, everyday objects were hidden in visually identical bins. Following a 1-min filled delay, participants with schizophrenia-spectrum disorders (n = 30) and healthy community controls (n = 30) were asked to identify both the object hidden and bin used on the basis of its spatial location. Three dimensions of visual-spatial memory were contrasted: (a) memory for spatial locations versus memory for objects, (b) allocentric (viewpoint independent) versus egocentric (body-centered) spatial representations, and (c) event (working) memory versus reference memory., Results: Most pronounced was a differential deficit in memory for spatial locations under allocentric (p = .005, d = -0.77) but not egocentric viewing conditions (p = .298, d = -0.28) in the schizophrenia group relative to healthy controls. Similarly, schizophrenia-related spatial memory deficits were pronounced under demands for event memory (p = .004, d = -0.77) but not reference memory (p = .171, d = -0.33)., Conclusions: These results support a heuristic of preferential deficits in hippocampal-mediated forms of memory in schizophrenia. Moreover, the task provides a useful paradigm for translational research and the pattern of deficits suggests that persons with schizophrenia may benefit from mnemonic approaches favoring egocentric representations and consistency when interacting with our visual-spatial world.
- Published
- 2010
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5. Visual search performance among persons with schizophrenia as a function of target eccentricity.
- Author
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Elahipanah A, Christensen BK, and Reingold EM
- Subjects
- Adult, Analysis of Variance, Female, Fixation, Ocular physiology, Humans, Male, Middle Aged, Neuropsychological Tests, Photic Stimulation methods, Reaction Time physiology, Attention physiology, Psychotic Disorders physiopathology, Schizophrenia physiopathology, Visual Perception physiology
- Abstract
The current study investigated one possible mechanism of impaired visual attention among patients with schizophrenia: a reduced visual span. Visual span is the region of the visual field from which one can extract information during a single eye fixation. This study hypothesized that schizophrenia-related visual search impairment is mediated, in part, by a smaller visual span. To test this hypothesis, 23 patients with schizophrenia and 22 healthy controls completed a visual search task where the target was pseudorandomly presented at different distances from the center of the display. Response times were analyzed as a function of search condition (feature vs. conjunctive), display size, and target eccentricity. Consistent with previous reports, patient search times were more adversely affected as the number of search items increased in the conjunctive search condition. It was important however, that patients' conjunctive search times were also impacted to a greater degree by target eccentricity. Moreover, a significant impairment in patients' visual search performance was only evident when targets were more eccentric and their performance was more similar to healthy controls when the target was located closer to the center of the search display. These results support the hypothesis that a narrower visual span may underlie impaired visual search performance among patients with schizophrenia., (Copyright 2010 APA, all rights reserved)
- Published
- 2010
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6. Grasping behavior in schizophrenia suggests selective impairment in the dorsal visual pathway.
- Author
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King JP, Christensen BK, and Westwood DA
- Subjects
- Adult, Biomechanical Phenomena, Brain Mapping, Dominance, Cerebral physiology, Female, Humans, Male, Middle Aged, Optical Illusions physiology, Perceptual Disorders diagnosis, Perceptual Disorders psychology, Prefrontal Cortex physiopathology, Psychiatric Status Rating Scales, Reaction Time physiology, Schizophrenia diagnosis, Size Perception physiology, Somatosensory Cortex physiopathology, Temporal Lobe physiopathology, Visual Cortex physiopathology, Visual Fields physiology, Young Adult, Hand Strength physiology, Orientation physiology, Perceptual Disorders physiopathology, Psychomotor Performance physiology, Schizophrenia physiopathology, Schizophrenic Psychology, Visual Pathways physiology
- Abstract
This study frames anomalous functional brain organization in schizophrenia (SCZ) within an evolutionary model of brain development, the dual trends theory (DTT). The DTT argues that neural architecture develops along 2 separate pathways: the dorsal archicortical trend and the ventral paleocortical trend. The DTT dovetails with visual system organization, which is also composed of 2 independent pathways: a dorsal stream dedicated to visuomotor action and a ventral stream dedicated to perceptual processing. The present study examined the integrity of these pathways using a size-contrast visual illusion. Prior research has shown that, normally, perceptual estimations of object size are susceptible to visual illusions, whereas goal-directed actions are resistant. The authors hypothesized that, unlike control participants, SCZ patients' actions would be susceptible to the illusion, reflecting dorsal stream dysfunction. Here, 42 SCZ patients and 42 healthy controls grasped and estimated the size of target blocks in control and illusion conditions. During estimation, both groups were equally perturbed by the illusion; however, grasping movements of patients alone were influenced by the illusion. These results suggest disrupted dorsal brain circuitry in SCZ but relatively intact ventral circuitry., ((PsycINFO Database Record (c) 2008 APA, all rights reserved).)
- Published
- 2008
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7. Wechsler Adult Intelligence Scale-Third Edition short form for index and IQ scores in a psychiatric population.
- Author
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Christensen BK, Girard TA, and Bagby RM
- Subjects
- Adolescent, Adult, Aged, Anxiety Disorders diagnosis, Anxiety Disorders psychology, Bipolar Disorder diagnosis, Bipolar Disorder psychology, Depressive Disorder diagnosis, Depressive Disorder psychology, Female, Humans, Male, Mental Disorders diagnosis, Middle Aged, Referral and Consultation, Schizophrenia diagnosis, Schizophrenic Psychology, Intelligence, Mental Disorders psychology, Wechsler Scales statistics & numerical data
- Abstract
An eight-subtest short form (SF8) of the Wechsler Adult Intelligence Scale, Third Edition (WAIS-III), maintaining equal representation of each index factor, was developed for use with psychiatric populations. Data were collected from a mixed inpatient/outpatient sample (99 men and 101 women) referred for neuropsychological assessment. Psychometric analyses revealed an optimal SF8 comprising Vocabulary, Similarities, Arithmetic, Digit Span, Picture Completion, Matrix Reasoning, Digit Symbol Coding, and Symbol Search, scored by linear scaling. Expanding on previous short forms, the current SF8 maximizes the breadth of information and reduces administration time while maintaining the original WAIS-III factor structure., ((c) 2007 APA, all rights reserved)
- Published
- 2007
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8. Quantitative reanalysis of aggregate data on IQ in sexual offenders.
- Author
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Cantor JM, Blanchard R, Robichaud LK, and Christensen BK
- Subjects
- Adult, Cognition Disorders diagnosis, Humans, Neuropsychological Tests, Severity of Illness Index, Cognition Disorders epidemiology, Sex Offenses statistics & numerical data
- Abstract
General intelligence has been the most commonly studied neuropsychological characteristic of sexual offenders for over 70 years. Results, however, have been highly inconsistent. To assess whether sexual offenders score lower in IQ than nonsexual offenders and to explore which sexual offense characteristics relate to IQ, the authors reanalyzed all reports providing sufficient information. Data spanned 236 samples, comprising 25,146 sexual offenders and controls. The literature contained sufficient information to permit comparison of adult versus juvenile sexual offenders, offenders targeting children versus adults, offenders targeting their own versus unrelated children, and offenders targeting boys versus girls. Results confirm the association between IQ and sexual offending and suggest that previous discrepancies are attributable to how many pedophilic individuals were in each sample., (Copyright 2005 APA, all rights reserved.)
- Published
- 2005
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9. Intelligence, memory, and handedness in pedophilia.
- Author
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Cantor JM, Blanchard R, Christensen BK, Dickey R, Klassen PE, Beckstead AL, Blak T, and Kuban ME
- Subjects
- Adult, Humans, Male, Middle Aged, Neuropsychological Tests statistics & numerical data, Penile Erection physiology, Penile Erection psychology, Psychometrics, Psychomotor Performance, Repression, Psychology, Sex Offenses, Verbal Learning, Wechsler Scales statistics & numerical data, Functional Laterality physiology, Intelligence, Memory, Pedophilia physiopathology
- Abstract
A sample of 473 male patients with pedophilia (assessed by the patients' sexual history and penile response in the laboratory to standardized, erotic stimuli) or other problematic sexual interests or behaviors received brief neuropsychological assessments. Neuropsychological measures included a short form of the Wechsler Adult Intelligence Scale--Revised (D. Wechsler, 1981), the Hopkins Verbal Learning Test--Revised (R. H. B. Benedict, D. Schretlen. L. Groninger. & J. Brandt, 1998), the Brief Visuospatial Memory Test--Revised (R. H. B. Benedict, 1997), and the Edinburgh Handedness Inventory (S. M. Williams, 1986). Pedophilia showed significant negative correlations with IQ and immediate and delayed recall memory. Pedophilia was also related to non-right-handedness even after covarying age and IQ. These results suggest that pedophilia is linked to early neurodevelopmental perturbations., (((c) 2004 APA, all rights reserved))
- Published
- 2004
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10. Neurophysiological evidence for disturbances of conflict processing in patients with schizophrenia.
- Author
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McNeely HE, West R, Christensen BK, and Alain C
- Subjects
- Adult, Arousal physiology, Attention physiology, Brain Mapping, Evoked Potentials physiology, Female, Gyrus Cinguli physiopathology, Humans, Male, Prefrontal Cortex physiopathology, Reaction Time physiology, Schizophrenia diagnosis, Cerebral Cortex physiopathology, Color Perception, Conflict, Psychological, Neuropsychological Tests, Problem Solving physiology, Reading, Schizophrenia physiopathology, Schizophrenic Psychology, Semantics
- Abstract
Deficits in cognition are a hallmark of schizophrenia. In the present study, the authors investigated the effects of schizophrenia on the neural correlates of conflict processing in a single-trial version of the Stroop task by using event-related brain potentials. Relative to matched controls, patients with schizophrenia showed increased Stroop interference in response time, but this effect was eliminated when the effect of response slowing was controlled. In controls, conflict processing was associated with a negative wave peaking between 400 and 500 ms (N450) and conflict sustained potential (SP) peaking between 600 and 800 ms after stimulus onset. In patients with schizophrenia, the amplitude of the N450 was significantly attenuated and the conflict SP was absent. These results provide evidence for the existence of altered neural processes associated with conflict processing that may be associated with dysfunction of the anterior cingulate and prefrontal cortex in patients with schizophrenia., (((c) 2003 APA, all rights reserved))
- Published
- 2003
- Full Text
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11. Development of defensive burying in Rattus norvegicus: experience and defensive responses.
- Author
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Pinel JP, Symons LA, Christensen BK, and Tees RC
- Subjects
- Animals, Avoidance Learning, Electroshock, Female, Male, Mental Recall, Motor Activity, Rats, Arousal, Conditioning, Classical, Fear, Social Environment, Species Specificity
- Abstract
Rats (Rattus norvegicus) deprived of the opportunity to interact with particulate matter until they were young adults engaged in defensive burying after they were shocked by a wire-wrapped dowel in a test chamber that held bedding material. Interacting with a particulate substrate during development is not necessary for the expression of defensive burying in adulthood. However, interacting with a particulate substrate early in the rats' lives did have a substantial effect on the emergence and maintenance of burying behavior. Defensive burying developed at a later age and declined at an earlier age in rats maintained on wire mesh from birth until testing than it did in rats raised until weaning on bedding and housed on mesh thereafter. Because defensive burying is a complex, flexible, yet reliable response sequence that cannot be performed without the appropriate substrate, it has considerable potential as a model for the study of the development of species-specific defense responses.
- Published
- 1989
- Full Text
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