Temporal lobe epilepsy and the selective reminding test: the conventional 30-minute delay suffices

Conventional memory assessment may fail to identify memory dysfunction characterized by intact recall for a relatively brief period but rapid forgetting thereafter. This study assessed learning and retention after 30-min and 24-hr delays on auditory and visual selective reminding tests (SRTs) in right (n=20) and left (n=22) temporal lobe epilepsy (TLE) patients and controls (n=49). The left TLE group performed significantly worse than controls on all 3 trials of both tests. The right TLE group differed from the controls on all 3 visual SRT trials and on learning for the auditory SRT. There were no between-groups differences in rate of information lost at the 30-min versus the 24-hr delay. At the individual level, there was no difference in the percentage of patients versus controls who demonstrated isolated memory impairment at the 24-hr delay. Accelerated forgetting over 24 hr is uncommon in TLE patients.     

CB1 cannabinoid receptors modulate kinase and phosphatase activity during extinction of conditioned fear in mice

Cannabinoid receptors type 1 (CB1) play a central role in both short-term and long-term extinction of auditory-cued fear memory. The molecular mechanisms underlying this function remain to be clarified. Several studies indicated extracellular signal-regulated kinases (ERKs), the phosphatidylinositol 3-kinase with its downstream effector AKT, and the phosphatase calcineurin as potential molecular substrates of extinction behavior. To test the involvement of these kinase and phosphatase activities in CB1-dependent extinction of conditioned fear behavior, conditioned CB1-deficient mice (CB1(-/-)) and wild-type littermates (CB1(+/+)) were sacrificed 30 min after recall of fear memory, and activation of ERKs, AKT, and calcineurin was examined by Western blot analysis in different brain regions. As compared with CB1(+/+), the nonreinforced tone presentation 24 h after auditory-cued fear conditioning led to lower levels of phosphorylated ERKs and/or calcineurin in the basolateral amygdala complex, ventromedial prefrontal cortex, dorsal hippocampus, and ventral hippocampus of CB1(-/-). In contrast, higher levels of phosphorylated p44 ERK and calcineurin were observed in the central nucleus of the amygdala of CB1(-/-). Phosphorylation of AKT was more pronounced in the basolateral amygdala complex and the dorsal hippocampus of CB1(-/-). We propose that the endogenous cannabinoid system modulates extinction of aversive memories, at least in part via regulation of the activity of kinases and phosphatases in a brain structure-dependent manner.     

How the brain blinks: towards a neurocognitive model of the attentional blink

When people monitor a visual stream of rapidly presented stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset-the attentional blink (AB). We provide an overview of recent neuroscientific studies devoted to analyze the neural processes underlying the AB and their temporal dynamics. The available evidence points to an attentional network involving temporal, right-parietal and frontal cortex, and suggests that the components of this neural network interact by means of synchronization and stimulus-induced desynchronization in the beta frequency range. We set up a neurocognitive scenario describing how the AB might emerge and why it depends on the presence of masks and the other event(s) the targets are embedded in. The scenario supports the idea that the AB arises from "biased competition", with the top-down bias being generated by parietal-frontal interactions and the competition taking place between stimulus codes in temporal cortex.     

Neuropsychology and temporal lobe epilepsy

The purpose of this article is to review aspects of the neuropsychology of temporal lobe epilepsy. Evidence will be presented to demonstrate that the cognitive consequences of this focal seizure disorder can be more generalized in nature than expected. Consistent with the extratemporal neurocognitive findings, careful quantitative magnetic resonance imaging volumetrics have shown that structural brain changes may be detected outside the temporal lobes. Many factors can potentially affect cognition and brain structure. We focus on the potential neurodevelopmental impact of early-onset temporal lobe epilepsy on brain structure and cognition positing that this disorder can have both immediate and lifespan implications for cognition and psychosocial status.     

Emotional processing following cortical and subcortical brain damage: contribution of the fronto-striatal circuitry

The present study examined the differential contribution of cortical and subcortical brain structures in emotional processing by comparing patients with focal cortical lesions (n = 32) to those with primarily subcortical dysregulation of the basal ganglia (Parkinson's disease n = 14). A standardized measure of emotional perception (Tübingen Affect Battery) was used. Only patients in the more advanced stages of Parkinson's disease and patients with focal damage to the (right) frontal lobe differed significantly from controls in both facial expression and affective prosody recognition. The findings imply involvement of the fronto-striatal circuitry in emotional processing.     

The MMPI and Jesness Inventory as measures of effectiveness on an inpatient conduct disorders treatment unit

There is a paucity of research on the effectiveness of inpatient treatment of conduct disorders. The purpose of the present study was to determine what effect a locked behavioral/cognitive treatment setting would have upon the Minnesota Multiphasic Personality Inventory (MMPI) and Jesness Inventory scores of adolescent inpatients. Fifty consecutive admissions (30 males, 20 females) to a conduct disorders unit were administered the MMPI and Jesness Inventory pre- and posttreatment. Statistically significant changes were found on both inventories. Males responded to treatment more favorably than did females. Improvement on the test scores could not conclusively be linked to the treatment due to the absence of a control group; however, combined with previous research, the results indicate areas of improvement in the sample's pathology.     

Criminal defenses and pleas in mitigation based on amnesia

Criminal defendants often claim to suffer from amnesia in connection with the events that are the basis of the criminal charges made against them. These claims present difficult problems of proof. Moreover, there are various defenses and opportunities to make pleas in mitigation which present a number of contexts in which evidence of amnesia can be introduced into the criminal trial. This article will examine the significance of amnesia in relation to: (1) a defense based on lack of mens rea; (2) a defense based on diminished capacity; (3) the insanity defense; (4) lack of fitness to stand trial; and (5) sentencing and the death penalty.     

Attention modulates somatosensory influences in passive speech listening

Previous studies showed that manipulating the speech production system influenced speech perception. This influence was mediated by task difficulty, listening conditions, and attention. In the present study we investigated the specificity of a somatosensory manipulation – a spoon over the tongue – in passive listening. We measured the mismatch negativity (MMN) while participants listened to vowels that differ in their articulation – the tongue height – and familiarity – native and unknown vowels. The same participants heard the vowels in a spoon and no-spoon block. The order of the blocks was counterbalanced across participants. Results showed no effect of the spoon. Instead, starting with the spoon enhanced the MMN amplitude. A second experiment showed the same MMN enhancement for starting with a somatosensory manipulation applied to a non-articulator – the hand. This result suggests that starting a study with a somatosensory manipulation raises attention to the task.     

Attentional tracking and inhibition of return in dynamic displays

Seven experiments were conducted to replicate, and extend, a finding by Tipper, Driver, and Weaver (1991). They reported evidence for dynamic, object-centered inhibition of return (IOR)—that is, coding of inhibition following a peripheral cue in coordinates that move with the previously cued object, providing a dynamic bias against reattending to that object. The present experiments used a variation of Posner and Cohen’s (1984) spatial cuing paradigm. Subjects responded manually (simple reaction time) to a luminance increment in one of two peripheral boxes, one of which had previously been cued (brightened). Experiments 1, 2, and 5 replicated the standard (environmental) IOR effect when the display was stationary. IOR was more marked for right-side targets than for left-side targets and tended to be affected by the compatibility between response hand and (cued) target position. However, when the boxes moved around the display center (Experiments 1, 2, 3, 4, 6, and 7), contrary to Tipper et al., there was no evidence of dynamic, object-centered IOR. Rather, there was strong evidence of attentive tracking of whatever box happened to move from left to right, irrespective of the direction of its motion (clockwise or counterclockwise) and whether it was more likely to contain the target than the other (right-to-left moving) box. There was a tendency for left-to-right tracking to be more marked with right-hand responses, pointing to the existence of a dynamic stimulus-response compatibility effect. The implications of the present findings for the role of attentive tracking and IOR in dynamic scenes are discussed.