Cognitive and affective Theory of Mind in mild to moderate Alzheimer's disease

Theory of Mind (ToM) allows one's own and others' cognitive and emotional mental states to be inferred. Although many patients with Alzheimer's disease (AD) display impaired social functioning as their disease progresses, very few studies have investigated ToM in AD. Those that have done so suggest that patients' ToM deficits are the consequence of other cognitive impairments. The aim of this study was thus to investigate changes in both the cognitive and the affective dimensions of ToM in AD, using tasks designed to circumvent the patients' comprehension difficulties. Sixteen mild to moderate AD patients and 15 healthy controls matched on age, sex and education level underwent cognitive (preference judgment and first‐ and second‐order false belief) and affective (Reading the Mind in the Eyes) ToM assessments. Comprehension of false belief stories was verified and an additional neuropsychological examination was undergone. We observed impaired performances by AD patients on all the ToM tasks. While working memory and executive functioning impairments contributed to the deterioration in the more complex aspects of cognitive ToM abilities as highlighted by a correlation analysis, we failed to observe any comprehension difficulties in patients who performed poorly on simple cognitive ToM tasks, which suggests that AD truly affects cognitive ToM.     

Electrical stimulation of the brain for psychiatric disorders

Despite advances in therapies, there remain psychiatric patients who are extremely ill and cannot be helped by classic psychiatric treatments, including psychotherapy and drug therapy. Certain of these patients may be helped by use of bilateral brain lesioning. The complication rate of standard stereotactic psychosurgery techniques is very low. The main rationale for the continued experimental use of deep brain stimulation (DBS) in neurosurgery for mental disorders is its reversibility. This reversibility is not an advantage in terms of the benefits obtained, but rather if side effects emerge. In addition, electrical stimulation may provide patients with some autonomy for their treatment. The first, very preliminary results of electrical stimulation for obsessive-compulsive disorder and for a small heterogeneous group of patients with other psychiatric disorders have been published. Electrical stimulation of the brain for psychiatric disorders may become a new treatment option for certain intractable psychiatric disorders. Nevertheless, the mechanism of action of DBS in psychiatric disorders is unknown, and the experience with this modality is extremely limited. The first results look promising, but this treatment option may prove unusable for some time because of a lack of knowledge of appropriate brain stimulation targets and technical problems such as the availability of sufficient current supply.     

The cascaded nature of lexical selection and integration in auditory sentence processing

An event-related brain potential experiment was carried out to investigate the temporal relationship between lexical selection and the semantic integration in auditory sentence processing. Participants were presented with spoken sentences that ended with a word that was either semantically congruent or anomalous. Information about the moment in which a sentence-final word could uniquely be identified, its isolation point (IP), was compared with the onset of the elicited N400 congruity effect, reflecting semantic integration processing. The results revealed that the onset of the N400 effect occurred prior to the IP of the sentence-final words. Moreover, the factor early or late IP did not affect the onset of the N400. These findings indicate that lexical selection and semantic integration are cascading processes, in that semantic integration processing can start before the acoustic information allows the selection of a unique candidate and seems to be attempted in parallel for multiple candidates that are still compatible with the bottom-up acoustic input.     

Psychometric qualities of the German version of the Posttraumatic Diagnostic Scale (PTDS)

In the present study, the psychometric properties of the German version of the Posttraumatic Diagnostic Scale (PTDS; A. Ehlers, R. Steil, H. Winter, & E. B. Foa, 1996) were evaluated in a sample of 143 trauma survivors. To investigate convergent and discriminant validity of this questionnaire, the authors assessed posttraumatic stress disorder (PTSD), anxiety, depression symptoms, and social phobia. Internal consistencies of the PTDS and its subscales as well as their association with related measures show that the German PTDS is a reliable and valid instrument for the assessment of posttraumatic stress symptoms. A 3-factor structure was found that is, however, not exactly in concordance with the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; American Psychiatric Association, 2000) formulation (Reexperiencing, Avoidance, and Hyperarousal) but rather comprises a Reexperiencing/Avoidance factor; an Emotional Numbing/Hyperarousal factor; and a 3rd factor, consisting of Hypervigilance and an Exaggerated Startle Response. The findings are discussed with respect to their equivalency to the original PTDS, core symptoms of PTSD, and desirable future research.     

Does marriage protect older people from distress? The role of equity and recency of bereavement

The association between marital status and distress was examined in a largely neglected group, namely older people (65 and older; N = 1,649). In this 2-wave study, married persons were less distressed than single persons, but perceived equity within the marriage and recency of bereavement qualified these findings. Married persons who felt inequitably treated were more distressed than persons who had always been single. Married persons reported less distress than recently (= 2 years ago) widowed persons, but only equitably treated married persons reported less distress than persons widowed for more than 2 years. Increased distress between the 2 waves occurred in recently widowed persons, and there was a decrease in distress in persons who were widowed shortly before the 1st wave. No gender effects were found.     

Retrospective assessment of childhood sexual and physical abuse: a comparison of scaled and behaviorally specific approaches

This study compared retrospective reports of childhood sexual and physical abuse as assessed by two measures: the Childhood Trauma Questionnaire (CTQ), which uses a Likert-type scaling approach, and the Computer Assisted Maltreatment Inventory (CAMI), which employs a behaviorally specific means of assessment. Participants included 1,195 undergraduate students recruited from three geographically diverse universities. Agreement was high across the two measures in the classification of victim status (92% and 80% for sexual and physical abuse, respectively). However, the CTQ classified more participants as sexually abused than did the CAMI, whereas the opposite trend was found for physical abuse. For child physical abuse, many participants reporting abusive acts on the CAMI scored below the cut-point for physical abuse on the CTQ. Classification differences for both types of abuse were largely unrelated to demographic factors, socially desirable responding, or self-reported withholding of information. The implications of these results are discussed in light of future research using retrospective methods of assessing childhood abuse.     

Categorizing facial identities, emotions, and genders: attention to high- and low-spatial frequencies by children and adults

Three age groups of participants (5-6 years, 7-8 years, adults) matched faces on the basis of facial identity. The procedure involved either low- or high-pass filtered faces or hybrid faces composed from two faces associated with different spatial bandwidths. The comparison stimuli were unfiltered faces. In the three age groups, the data indicated a significant bias for processing of low-pass information in priority. In a second task, participants were asked to identify the emotion (smiling or grimacing) or gender (male or female) of hybrid high-pass/low-pass faces. Opposite results emerged in the two tasks irrespective of the age group; the gender discrimination task indicated a bias for low-pass information, and the emotion task indicated a bias for high-pass information. These differences suggest independent processing routes for functionally different types of information such as emotion, gender, and identity. These routes are already established by 5 years of age.     

Long-term plasticity of intrinsic excitability: learning rules and mechanisms

Spatio-temporal configurations of distributed activity in the brain is thought to contribute to the coding of neuronal information and synaptic contacts between nerve cells could play a central role in the formation of privileged pathways of activity. Synaptic plasticity is not the exclusive mode of regulation of information processing in the brain, and persistent regulations of ionic conductances in some specialized neuronal areas such as the dendrites, the cell body, and the axon could also modulate, in the long-term, the propagation of neuronal information. Persistent changes in intrinsic excitability have been reported in several brain areas in which activity is elevated during a classical conditioning. The role of synaptic activity seems to be a determinant in the induction, but the learning rules and the underlying mechanisms remain to be defined. We discuss here the role of synaptic activity in the induction of intrinsic plasticity in cortical, hippocampal, and cerebellar neurons. Activation of glutamate receptors initiates a long-term modification in neuronal excitability that may represent a parallel, synergistic substrate for learning and memory. Similar to synaptic plasticity, long-lasting intrinsic plasticity appears to be bidirectional and to express a certain level of input or cell specificity. These nonsynaptic forms of plasticity affect the signal propagation in the axon, the dendrites, and the soma. They not only share common learning rules and induction pathways with the better-known synaptic plasticity such as NMDA receptor dependent LTP and LTD, but also contribute in synergy with these synaptic changes to the formation of a coherent engram.     

Does men’s advantage in mental rotation persist when real three-dimensional objects are either felt or seen?

In several spatial tasks in which men outperform women in the processing of visual input, the sex difference has been eliminated in matching contexts limited to haptic input. The present experiment tested whether such contrasting results would be reproduced in a mental rotation task. A standard visual condition involved two-dimensional illustrations of three-dimensional stimuli; in a haptic condition, three-dimensional replicas of these stimuli were only felt; in an additional visual condition, these replicas were seen. The results indicated that, irrespective of condition, men's response times were shorter than women's, although accuracy did not significantly differ according to sex. For both men and women, response times were shorter and accuracy was higher in the standard condition than in the haptic one, the best performances being recorded when full replicas were shown. Self-reported solving strategies also varied as a function of sex and condition. The discussion emphasizes the robustness of men's faster speed in mental rotation. With respect to both speed and accuracy, the demanding sequential processing called for in the haptic setting, relative to the standard condition, is underscored, as is the benefit resulting from easier access to depth cues in the visual context with real three-dimensional objects.