37 research outputs found
Temporal dynamics of amygdala response to emotion- and action-relevance
It has been proposed that the human amygdala may not only encode the emotional value of sensory events, but more generally mediate the appraisal of their relevance for the individual's goals, including relevance for action or task-based needs. However, emotional and non-emotional/action-relevance might drive amygdala activity through distinct neural signals, and the relative timing of both kinds of responses remains undetermined. Here, we recorded intracranial event-related potentials (iERPs) from nine amygdalae of patients undergoing epilepsy surgery, while they performed variants of a Go/NoGo task with faces and abstract shapes, where emotion- and action-relevance were orthogonally manipulated. Our results revealed early amygdala responses to emotion facial expressions starting ~130ms after stimulus-onset. Importantly, the amygdala responded to action-relevance not only with face stimuli but also with abstract shapes (squares), and these relevance effects consistently occurred in later time-windows (starting ~220ms) for both faces and squares. A similar dissociation was observed in gamma activity. Furthermore, whereas emotional responses habituated over time, the action-relevance effect increased during the course of the experiment, suggesting progressive learning based on the task needs. Our results support the hypothesis that the human amygdala mediates a broader relevance appraisal function, with the processing of emotion-relevance preceding temporally that of action-relevance
Neutralization Serotyping of BK Polyomavirus Infection in Kidney Transplant Recipients
BK polyomavirus (BKV or BKPyV) associated nephropathy affects up to 10% of kidney transplant recipients (KTRs). BKV isolates are categorized into four genotypes. It is currently unclear whether the four genotypes are also serotypes. To address this issue, we developed high-throughput serological assays based on antibody-mediated neutralization of BKV genotype I and IV reporter vectors (pseudoviruses). Neutralization-based testing of sera from mice immunized with BKV-I or BKV-IV virus-like particles (VLPs) or sera from naturally infected human subjects revealed that BKV-I specific serum antibodies are poorly neutralizing against BKV-IV and vice versa. The fact that BKV-I and BKV-IV are distinct serotypes was less evident in traditional VLP-based ELISAs. BKV-I and BKV-IV neutralization assays were used to examine BKV type-specific neutralizing antibody responses in KTRs at various time points after transplantation. At study entry, sera from 5% and 49% of KTRs showed no detectable neutralizing activity for BKV-I or BKV-IV neutralization, respectively. By one year after transplantation, all KTRs were neutralization seropositive for BKV-I, and 43% of the initially BKV-IV seronegative subjects showed evidence of acute seroconversion for BKV-IV neutralization. The results suggest a model in which BKV-IV-specific seroconversion reflects a de novo BKV-IV infection in KTRs who initially lack protective antibody responses capable of neutralizing genotype IV BKVs. If this model is correct, it suggests that pre-vaccinating prospective KTRs with a multivalent VLP-based vaccine against all BKV serotypes, or administration of BKV-neutralizing antibodies, might offer protection against graft loss or dysfunction due to BKV associated nephropathy
The Neural Basis of Decision-Making and Reward Processing in Adults with Euthymic Bipolar Disorder or Attention-Deficit/Hyperactivity Disorder (ADHD)
Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) share DSM-IV criteria in adults and cause problems in decision-making. Nevertheless, no previous report has assessed a decision-making task that includes the examination of the neural correlates of reward and gambling in adults with ADHD and those with BD
Does the PFC model of analogy account for decision making, problem solving, reasoning, flexibility, adaptability, and even creativity?
Abstract From everyday cognition to scientific discovery, analogical processes play an important role: bringing connection, integration, and interrelation of information. Recently, a PFC model of analogy has been proposed to explain many cognitive processes and integrate general functional properties of PFC. We argue here that analogical processes do not suffice to explain the cognitive processes and functions of PFC. Moreover the model does not satisfactorily integrate specific explanatory mechanisms required for the different processes involved. Its relevance would be improved if fewer cognitive phenomena were considered and more specific predictions and explanations about those processes were stated
Effect of attention and prime-target gender congruence.
<p>Effect of attention and prime-target gender congruence.</p
Influence of Temporal Expectations on Response Priming by Subliminal Faces - Fig 6
<p><b>Effect of temporal attention on prime-target gender congruence</b> (A) Group-level contrast showing the combined effects of gender incongruence and unexpected targets in (A) left anterior insula and (C) right IPS. (B-D) show corresponding mean group parameter estimates (same conventions as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164613#pone.0164613.g003" target="_blank">Fig 3</a>). Note that this effect was not present when incongruent primes were attended and that the pattern of activity mirrors the RT data.</p
Effect of fearful primes and of temporal attention.
<p>Effect of fearful primes and of temporal attention.</p
Effect of temporal attention on fearful primes.
<p>(A) Group-level contrast map (p<0.001 uncorrected) showing greater responses in left parahippocampal gyrus on trials with fearful prime (vs neutral). (B) Contrast map and (C) group parameter estimates illustrating the attention-by-emotion interaction in bilateral parahippocampal gyrus, indicating that temporal attention specifically enhanced the processing of fearful primes relative to neutral or unattended primes (same conventions as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164613#pone.0164613.g003" target="_blank">Fig 3</a>).</p
Protocol and behavioral data for the fMRI task.
<p>(A) In each trial, subjects saw a male of female target face preceded by a short or long series of noise masks (note that faces used were from the Karolinska database and were equated for luminance, they were not the example faces used in the figure). Subjects were asked to make a fast gender decision on the final target face. At the start of each trial, a word cue (the word <i>short</i> or <i>long</i>) indicated with 75% validity the time at which the target face would appear. 100 ms before the target face appeared, we presented a fearful or a neutral subliminal face (prime) or a noise mask (baseline) for 33 ms, which was both forward and backward masked by the noise masks. Gender of the subliminal face was either congruent or incongruent with the target face, while its expression was either fearful or neutral (orthogonally to other factors). (B) Response times (RTs) show that attention and gender congruence speeded correct responses. This effect did not occur on the unexpected incongruent trials (*p < .05). (C) Mean performance during target-gender decision demonstrated that more errors were made when prime gender was incongruent with target gender in expected trials (**p < .01). We have received informed consent according to Plos guidelines from the 4 individuals portrayed here.</p
Effect of temporal attention.
<p>(A-C) Group-level contrast map and (B-D) mean group parameter estimates showing the effect of attention reorienting (i.e. unexpected > expected trials) in right IFG and left TPJ (same conventions as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0164613#pone.0164613.g003" target="_blank">Fig 3</a>).</p